#!/usr/bin/env perl

# This program is part of Percona Toolkit: http://www.percona.com/software/
# See "COPYRIGHT, LICENSE, AND WARRANTY" at the end of this file for legal
# notices and disclaimers.

use strict;
use warnings FATAL => 'all';
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

# ###########################################################################
# DSNParser package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/DSNParser.pm
#   t/lib/DSNParser.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package DSNParser;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use Data::Dumper;
$Data::Dumper::Indent    = 0;
$Data::Dumper::Quotekeys = 0;

eval {
   require DBI;
};
my $have_dbi = $EVAL_ERROR ? 0 : 1;

sub new {
   my ( $class, %args ) = @_;
   foreach my $arg ( qw(opts) ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my $self = {
      opts => {}  # h, P, u, etc.  Should come from DSN OPTIONS section in POD.
   };
   foreach my $opt ( @{$args{opts}} ) {
      if ( !$opt->{key} || !$opt->{desc} ) {
         die "Invalid DSN option: ", Dumper($opt);
      }
      MKDEBUG && _d('DSN option:',
         join(', ',
            map { "$_=" . (defined $opt->{$_} ? ($opt->{$_} || '') : 'undef') }
               keys %$opt
         )
      );
      $self->{opts}->{$opt->{key}} = {
         dsn  => $opt->{dsn},
         desc => $opt->{desc},
         copy => $opt->{copy} || 0,
      };
   }
   return bless $self, $class;
}

sub prop {
   my ( $self, $prop, $value ) = @_;
   if ( @_ > 2 ) {
      MKDEBUG && _d('Setting', $prop, 'property');
      $self->{$prop} = $value;
   }
   return $self->{$prop};
}

sub parse {
   my ( $self, $dsn, $prev, $defaults ) = @_;
   if ( !$dsn ) {
      MKDEBUG && _d('No DSN to parse');
      return;
   }
   MKDEBUG && _d('Parsing', $dsn);
   $prev     ||= {};
   $defaults ||= {};
   my %given_props;
   my %final_props;
   my $opts = $self->{opts};

   foreach my $dsn_part ( split(/,/, $dsn) ) {
      if ( my ($prop_key, $prop_val) = $dsn_part =~  m/^(.)=(.*)$/ ) {
         $given_props{$prop_key} = $prop_val;
      }
      else {
         MKDEBUG && _d('Interpreting', $dsn_part, 'as h=', $dsn_part);
         $given_props{h} = $dsn_part;
      }
   }

   foreach my $key ( keys %$opts ) {
      MKDEBUG && _d('Finding value for', $key);
      $final_props{$key} = $given_props{$key};
      if (   !defined $final_props{$key}
           && defined $prev->{$key} && $opts->{$key}->{copy} )
      {
         $final_props{$key} = $prev->{$key};
         MKDEBUG && _d('Copying value for', $key, 'from previous DSN');
      }
      if ( !defined $final_props{$key} ) {
         $final_props{$key} = $defaults->{$key};
         MKDEBUG && _d('Copying value for', $key, 'from defaults');
      }
   }

   foreach my $key ( keys %given_props ) {
      die "Unknown DSN option '$key' in '$dsn'.  For more details, "
            . "please use the --help option, or try 'perldoc $PROGRAM_NAME' "
            . "for complete documentation."
         unless exists $opts->{$key};
   }
   if ( (my $required = $self->prop('required')) ) {
      foreach my $key ( keys %$required ) {
         die "Missing required DSN option '$key' in '$dsn'.  For more details, "
               . "please use the --help option, or try 'perldoc $PROGRAM_NAME' "
               . "for complete documentation."
            unless $final_props{$key};
      }
   }

   if ( !$final_props{n} ) {  # name
      $final_props{n} = $self->as_string(\%final_props, [qw(h P S F)]);
   }

   return \%final_props;
}

sub parse_options {
   my ( $self, $o ) = @_;
   die 'I need an OptionParser object' unless ref $o eq 'OptionParser';
   my $dsn_string
      = join(',',
          map  { "$_=".$o->get($_); }
          grep { $o->has($_) && $o->get($_) }
          keys %{$self->{opts}}
        );
   MKDEBUG && _d('DSN string made from options:', $dsn_string);
   return $self->parse($dsn_string);
}

sub as_string {
   my ( $self, $dsn, $props ) = @_;
   return $dsn unless ref $dsn;
   my @keys = $props ? @$props : sort keys %$dsn;
   return join(',',
      map  { "$_=" . ($_ eq 'p' ? '...' : $dsn->{$_}) }
      grep {
         exists $self->{opts}->{$_}
         && exists $dsn->{$_}
         && defined $dsn->{$_}
      } @keys);
}

sub usage {
   my ( $self ) = @_;
   my $usage
      = "DSN syntax is key=value[,key=value...]  Allowable DSN keys:\n\n"
      . "  KEY  COPY  MEANING\n"
      . "  ===  ====  =============================================\n";
   my %opts = %{$self->{opts}};
   foreach my $key ( sort keys %opts ) {
      $usage .= "  $key    "
             .  ($opts{$key}->{copy} ? 'yes   ' : 'no    ')
             .  ($opts{$key}->{desc} || '[No description]')
             . "\n";
   }
   $usage .= "\n  If the DSN is a bareword, the word is treated as the 'h' key.\n";
   return $usage;
}

sub get_cxn_params {
   my ( $self, $info ) = @_;
   my $dsn;
   my %opts = %{$self->{opts}};
   my $driver = $self->prop('dbidriver') || '';
   if ( $driver eq 'Pg' ) {
      $dsn = 'DBI:Pg:dbname=' . ( $info->{D} || '' ) . ';'
         . join(';', map  { "$opts{$_}->{dsn}=$info->{$_}" }
                     grep { defined $info->{$_} }
                     qw(h P));
   }
   else {
      $dsn = 'DBI:mysql:' . ( $info->{D} || '' ) . ';'
         . join(';', map  { "$opts{$_}->{dsn}=$info->{$_}" }
                     grep { defined $info->{$_} }
                     qw(F h P S A))
         . ';mysql_read_default_group=client';
   }
   MKDEBUG && _d($dsn);
   return ($dsn, $info->{u}, $info->{p});
}

sub fill_in_dsn {
   my ( $self, $dbh, $dsn ) = @_;
   my $vars = $dbh->selectall_hashref('SHOW VARIABLES', 'Variable_name');
   my ($user, $db) = $dbh->selectrow_array('SELECT USER(), DATABASE()');
   $user =~ s/@.*//;
   $dsn->{h} ||= $vars->{hostname}->{Value};
   $dsn->{S} ||= $vars->{'socket'}->{Value};
   $dsn->{P} ||= $vars->{port}->{Value};
   $dsn->{u} ||= $user;
   $dsn->{D} ||= $db;
}

sub get_dbh {
   my ( $self, $cxn_string, $user, $pass, $opts ) = @_;
   $opts ||= {};
   my $defaults = {
      AutoCommit         => 0,
      RaiseError         => 1,
      PrintError         => 0,
      ShowErrorStatement => 1,
      mysql_enable_utf8 => ($cxn_string =~ m/charset=utf8/i ? 1 : 0),
   };
   @{$defaults}{ keys %$opts } = values %$opts;

   if ( $opts->{mysql_use_result} ) {
      $defaults->{mysql_use_result} = 1;
   }

   if ( !$have_dbi ) {
      die "Cannot connect to MySQL because the Perl DBI module is not "
         . "installed or not found.  Run 'perl -MDBI' to see the directories "
         . "that Perl searches for DBI.  If DBI is not installed, try:\n"
         . "  Debian/Ubuntu  apt-get install libdbi-perl\n"
         . "  RHEL/CentOS    yum install perl-DBI\n"
         . "  OpenSolaris    pgk install pkg:/SUNWpmdbi\n";

   }

   my $dbh;
   my $tries = 2;
   while ( !$dbh && $tries-- ) {
      MKDEBUG && _d($cxn_string, ' ', $user, ' ', $pass, 
         join(', ', map { "$_=>$defaults->{$_}" } keys %$defaults ));

      eval {
         $dbh = DBI->connect($cxn_string, $user, $pass, $defaults);

         if ( $cxn_string =~ m/mysql/i ) {
            my $sql;

            $sql = 'SELECT @@SQL_MODE';
            MKDEBUG && _d($dbh, $sql);
            my ($sql_mode) = $dbh->selectrow_array($sql);

            $sql = 'SET @@SQL_QUOTE_SHOW_CREATE = 1'
                 . '/*!40101, @@SQL_MODE=\'NO_AUTO_VALUE_ON_ZERO'
                 . ($sql_mode ? ",$sql_mode" : '')
                 . '\'*/';
            MKDEBUG && _d($dbh, $sql);
            $dbh->do($sql);

            if ( my ($charset) = $cxn_string =~ m/charset=(\w+)/ ) {
               $sql = "/*!40101 SET NAMES $charset*/";
               MKDEBUG && _d($dbh, ':', $sql);
               $dbh->do($sql);
               MKDEBUG && _d('Enabling charset for STDOUT');
               if ( $charset eq 'utf8' ) {
                  binmode(STDOUT, ':utf8')
                     or die "Can't binmode(STDOUT, ':utf8'): $OS_ERROR";
               }
               else {
                  binmode(STDOUT) or die "Can't binmode(STDOUT): $OS_ERROR";
               }
            }

            if ( $self->prop('set-vars') ) {
               $sql = "SET " . $self->prop('set-vars');
               MKDEBUG && _d($dbh, ':', $sql);
               $dbh->do($sql);
            }
         }
      };
      if ( !$dbh && $EVAL_ERROR ) {
         MKDEBUG && _d($EVAL_ERROR);
         if ( $EVAL_ERROR =~ m/not a compiled character set|character set utf8/ ) {
            MKDEBUG && _d('Going to try again without utf8 support');
            delete $defaults->{mysql_enable_utf8};
         }
         elsif ( $EVAL_ERROR =~ m/locate DBD\/mysql/i ) {
            die "Cannot connect to MySQL because the Perl DBD::mysql module is "
               . "not installed or not found.  Run 'perl -MDBD::mysql' to see "
               . "the directories that Perl searches for DBD::mysql.  If "
               . "DBD::mysql is not installed, try:\n"
               . "  Debian/Ubuntu  apt-get install libdbd-mysql-perl\n"
               . "  RHEL/CentOS    yum install perl-DBD-MySQL\n"
               . "  OpenSolaris    pgk install pkg:/SUNWapu13dbd-mysql\n";
         }
         if ( !$tries ) {
            die $EVAL_ERROR;
         }
      }
   }

   MKDEBUG && _d('DBH info: ',
      $dbh,
      Dumper($dbh->selectrow_hashref(
         'SELECT DATABASE(), CONNECTION_ID(), VERSION()/*!50038 , @@hostname*/')),
      'Connection info:',      $dbh->{mysql_hostinfo},
      'Character set info:',   Dumper($dbh->selectall_arrayref(
                     'SHOW VARIABLES LIKE "character_set%"', { Slice => {}})),
      '$DBD::mysql::VERSION:', $DBD::mysql::VERSION,
      '$DBI::VERSION:',        $DBI::VERSION,
   );

   return $dbh;
}

sub get_hostname {
   my ( $self, $dbh ) = @_;
   if ( my ($host) = ($dbh->{mysql_hostinfo} || '') =~ m/^(\w+) via/ ) {
      return $host;
   }
   my ( $hostname, $one ) = $dbh->selectrow_array(
      'SELECT /*!50038 @@hostname, */ 1');
   return $hostname;
}

sub disconnect {
   my ( $self, $dbh ) = @_;
   MKDEBUG && $self->print_active_handles($dbh);
   $dbh->disconnect;
}

sub print_active_handles {
   my ( $self, $thing, $level ) = @_;
   $level ||= 0;
   printf("# Active %sh: %s %s %s\n", ($thing->{Type} || 'undef'), "\t" x $level,
      $thing, (($thing->{Type} || '') eq 'st' ? $thing->{Statement} || '' : ''))
      or die "Cannot print: $OS_ERROR";
   foreach my $handle ( grep {defined} @{ $thing->{ChildHandles} } ) {
      $self->print_active_handles( $handle, $level + 1 );
   }
}

sub copy {
   my ( $self, $dsn_1, $dsn_2, %args ) = @_;
   die 'I need a dsn_1 argument' unless $dsn_1;
   die 'I need a dsn_2 argument' unless $dsn_2;
   my %new_dsn = map {
      my $key = $_;
      my $val;
      if ( $args{overwrite} ) {
         $val = defined $dsn_1->{$key} ? $dsn_1->{$key} : $dsn_2->{$key};
      }
      else {
         $val = defined $dsn_2->{$key} ? $dsn_2->{$key} : $dsn_1->{$key};
      }
      $key => $val;
   } keys %{$self->{opts}};
   return \%new_dsn;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End DSNParser package
# ###########################################################################

# ###########################################################################
# OptionParser package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/OptionParser.pm
#   t/lib/OptionParser.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package OptionParser;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use List::Util qw(max);
use Getopt::Long;

my $POD_link_re = '[LC]<"?([^">]+)"?>';

sub new {
   my ( $class, %args ) = @_;
   my @required_args = qw();
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }

   my ($program_name) = $PROGRAM_NAME =~ m/([.A-Za-z-]+)$/;
   $program_name ||= $PROGRAM_NAME;
   my $home = $ENV{HOME} || $ENV{HOMEPATH} || $ENV{USERPROFILE} || '.';

   my %attributes = (
      'type'       => 1,
      'short form' => 1,
      'group'      => 1,
      'default'    => 1,
      'cumulative' => 1,
      'negatable'  => 1,
   );

   my $self = {
      head1             => 'OPTIONS',        # These args are used internally
      skip_rules        => 0,                # to instantiate another Option-
      item              => '--(.*)',         # Parser obj that parses the
      attributes        => \%attributes,     # DSN OPTIONS section.  Tools
      parse_attributes  => \&_parse_attribs, # don't tinker with these args.

      %args,

      strict            => 1,  # disabled by a special rule
      program_name      => $program_name,
      opts              => {},
      got_opts          => 0,
      short_opts        => {},
      defaults          => {},
      groups            => {},
      allowed_groups    => {},
      errors            => [],
      rules             => [],  # desc of rules for --help
      mutex             => [],  # rule: opts are mutually exclusive
      atleast1          => [],  # rule: at least one opt is required
      disables          => {},  # rule: opt disables other opts 
      defaults_to       => {},  # rule: opt defaults to value of other opt
      DSNParser         => undef,
      default_files     => [
         "/etc/percona-toolkit/percona-toolkit.conf",
         "/etc/percona-toolkit/$program_name.conf",
         "$home/.percona-toolkit.conf",
         "$home/.$program_name.conf",
      ],
      types             => {
         string => 's', # standard Getopt type
         int    => 'i', # standard Getopt type
         float  => 'f', # standard Getopt type
         Hash   => 'H', # hash, formed from a comma-separated list
         hash   => 'h', # hash as above, but only if a value is given
         Array  => 'A', # array, similar to Hash
         array  => 'a', # array, similar to hash
         DSN    => 'd', # DSN
         size   => 'z', # size with kMG suffix (powers of 2^10)
         time   => 'm', # time, with an optional suffix of s/h/m/d
      },
   };

   return bless $self, $class;
}

sub get_specs {
   my ( $self, $file ) = @_;
   $file ||= $self->{file} || __FILE__;
   my @specs = $self->_pod_to_specs($file);
   $self->_parse_specs(@specs);

   open my $fh, "<", $file or die "Cannot open $file: $OS_ERROR";
   my $contents = do { local $/ = undef; <$fh> };
   close $fh;
   if ( $contents =~ m/^=head1 DSN OPTIONS/m ) {
      MKDEBUG && _d('Parsing DSN OPTIONS');
      my $dsn_attribs = {
         dsn  => 1,
         copy => 1,
      };
      my $parse_dsn_attribs = sub {
         my ( $self, $option, $attribs ) = @_;
         map {
            my $val = $attribs->{$_};
            if ( $val ) {
               $val    = $val eq 'yes' ? 1
                       : $val eq 'no'  ? 0
                       :                 $val;
               $attribs->{$_} = $val;
            }
         } keys %$attribs;
         return {
            key => $option,
            %$attribs,
         };
      };
      my $dsn_o = new OptionParser(
         description       => 'DSN OPTIONS',
         head1             => 'DSN OPTIONS',
         dsn               => 0,         # XXX don't infinitely recurse!
         item              => '\* (.)',  # key opts are a single character
         skip_rules        => 1,         # no rules before opts
         attributes        => $dsn_attribs,
         parse_attributes  => $parse_dsn_attribs,
      );
      my @dsn_opts = map {
         my $opts = {
            key  => $_->{spec}->{key},
            dsn  => $_->{spec}->{dsn},
            copy => $_->{spec}->{copy},
            desc => $_->{desc},
         };
         $opts;
      } $dsn_o->_pod_to_specs($file);
      $self->{DSNParser} = DSNParser->new(opts => \@dsn_opts);
   }

   if ( $contents =~ m/^=head1 VERSION\n\n^(.+)$/m ) {
      $self->{version} = $1;
      MKDEBUG && _d($self->{version});
   }

   return;
}

sub DSNParser {
   my ( $self ) = @_;
   return $self->{DSNParser};
};

sub get_defaults_files {
   my ( $self ) = @_;
   return @{$self->{default_files}};
}

sub _pod_to_specs {
   my ( $self, $file ) = @_;
   $file ||= $self->{file} || __FILE__;
   open my $fh, '<', $file or die "Cannot open $file: $OS_ERROR";

   my @specs = ();
   my @rules = ();
   my $para;

   local $INPUT_RECORD_SEPARATOR = '';
   while ( $para = <$fh> ) {
      next unless $para =~ m/^=head1 $self->{head1}/;
      last;
   }

   while ( $para = <$fh> ) {
      last if $para =~ m/^=over/;
      next if $self->{skip_rules};
      chomp $para;
      $para =~ s/\s+/ /g;
      $para =~ s/$POD_link_re/$1/go;
      MKDEBUG && _d('Option rule:', $para);
      push @rules, $para;
   }

   die "POD has no $self->{head1} section" unless $para;

   do {
      if ( my ($option) = $para =~ m/^=item $self->{item}/ ) {
         chomp $para;
         MKDEBUG && _d($para);
         my %attribs;

         $para = <$fh>; # read next paragraph, possibly attributes

         if ( $para =~ m/: / ) { # attributes
            $para =~ s/\s+\Z//g;
            %attribs = map {
                  my ( $attrib, $val) = split(/: /, $_);
                  die "Unrecognized attribute for --$option: $attrib"
                     unless $self->{attributes}->{$attrib};
                  ($attrib, $val);
               } split(/; /, $para);
            if ( $attribs{'short form'} ) {
               $attribs{'short form'} =~ s/-//;
            }
            $para = <$fh>; # read next paragraph, probably short help desc
         }
         else {
            MKDEBUG && _d('Option has no attributes');
         }

         $para =~ s/\s+\Z//g;
         $para =~ s/\s+/ /g;
         $para =~ s/$POD_link_re/$1/go;

         $para =~ s/\.(?:\n.*| [A-Z].*|\Z)//s;
         MKDEBUG && _d('Short help:', $para);

         die "No description after option spec $option" if $para =~ m/^=item/;

         if ( my ($base_option) =  $option =~ m/^\[no\](.*)/ ) {
            $option = $base_option;
            $attribs{'negatable'} = 1;
         }

         push @specs, {
            spec  => $self->{parse_attributes}->($self, $option, \%attribs), 
            desc  => $para
               . (defined $attribs{default} ? " (default $attribs{default})" : ''),
            group => ($attribs{'group'} ? $attribs{'group'} : 'default'),
         };
      }
      while ( $para = <$fh> ) {
         last unless $para;
         if ( $para =~ m/^=head1/ ) {
            $para = undef; # Can't 'last' out of a do {} block.
            last;
         }
         last if $para =~ m/^=item /;
      }
   } while ( $para );

   die "No valid specs in $self->{head1}" unless @specs;

   close $fh;
   return @specs, @rules;
}

sub _parse_specs {
   my ( $self, @specs ) = @_;
   my %disables; # special rule that requires deferred checking

   foreach my $opt ( @specs ) {
      if ( ref $opt ) { # It's an option spec, not a rule.
         MKDEBUG && _d('Parsing opt spec:',
            map { ($_, '=>', $opt->{$_}) } keys %$opt);

         my ( $long, $short ) = $opt->{spec} =~ m/^([\w-]+)(?:\|([^!+=]*))?/;
         if ( !$long ) {
            die "Cannot parse long option from spec $opt->{spec}";
         }
         $opt->{long} = $long;

         die "Duplicate long option --$long" if exists $self->{opts}->{$long};
         $self->{opts}->{$long} = $opt;

         if ( length $long == 1 ) {
            MKDEBUG && _d('Long opt', $long, 'looks like short opt');
            $self->{short_opts}->{$long} = $long;
         }

         if ( $short ) {
            die "Duplicate short option -$short"
               if exists $self->{short_opts}->{$short};
            $self->{short_opts}->{$short} = $long;
            $opt->{short} = $short;
         }
         else {
            $opt->{short} = undef;
         }

         $opt->{is_negatable}  = $opt->{spec} =~ m/!/        ? 1 : 0;
         $opt->{is_cumulative} = $opt->{spec} =~ m/\+/       ? 1 : 0;
         $opt->{is_required}   = $opt->{desc} =~ m/required/ ? 1 : 0;

         $opt->{group} ||= 'default';
         $self->{groups}->{ $opt->{group} }->{$long} = 1;

         $opt->{value} = undef;
         $opt->{got}   = 0;

         my ( $type ) = $opt->{spec} =~ m/=(.)/;
         $opt->{type} = $type;
         MKDEBUG && _d($long, 'type:', $type);


         $opt->{spec} =~ s/=./=s/ if ( $type && $type =~ m/[HhAadzm]/ );

         if ( (my ($def) = $opt->{desc} =~ m/default\b(?: ([^)]+))?/) ) {
            $self->{defaults}->{$long} = defined $def ? $def : 1;
            MKDEBUG && _d($long, 'default:', $def);
         }

         if ( $long eq 'config' ) {
            $self->{defaults}->{$long} = join(',', $self->get_defaults_files());
         }

         if ( (my ($dis) = $opt->{desc} =~ m/(disables .*)/) ) {
            $disables{$long} = $dis;
            MKDEBUG && _d('Deferring check of disables rule for', $opt, $dis);
         }

         $self->{opts}->{$long} = $opt;
      }
      else { # It's an option rule, not a spec.
         MKDEBUG && _d('Parsing rule:', $opt); 
         push @{$self->{rules}}, $opt;
         my @participants = $self->_get_participants($opt);
         my $rule_ok = 0;

         if ( $opt =~ m/mutually exclusive|one and only one/ ) {
            $rule_ok = 1;
            push @{$self->{mutex}}, \@participants;
            MKDEBUG && _d(@participants, 'are mutually exclusive');
         }
         if ( $opt =~ m/at least one|one and only one/ ) {
            $rule_ok = 1;
            push @{$self->{atleast1}}, \@participants;
            MKDEBUG && _d(@participants, 'require at least one');
         }
         if ( $opt =~ m/default to/ ) {
            $rule_ok = 1;
            $self->{defaults_to}->{$participants[0]} = $participants[1];
            MKDEBUG && _d($participants[0], 'defaults to', $participants[1]);
         }
         if ( $opt =~ m/restricted to option groups/ ) {
            $rule_ok = 1;
            my ($groups) = $opt =~ m/groups ([\w\s\,]+)/;
            my @groups = split(',', $groups);
            %{$self->{allowed_groups}->{$participants[0]}} = map {
               s/\s+//;
               $_ => 1;
            } @groups;
         }
         if( $opt =~ m/accepts additional command-line arguments/ ) {
            $rule_ok = 1;
            $self->{strict} = 0;
            MKDEBUG && _d("Strict mode disabled by rule");
         }

         die "Unrecognized option rule: $opt" unless $rule_ok;
      }
   }

   foreach my $long ( keys %disables ) {
      my @participants = $self->_get_participants($disables{$long});
      $self->{disables}->{$long} = \@participants;
      MKDEBUG && _d('Option', $long, 'disables', @participants);
   }

   return; 
}

sub _get_participants {
   my ( $self, $str ) = @_;
   my @participants;
   foreach my $long ( $str =~ m/--(?:\[no\])?([\w-]+)/g ) {
      die "Option --$long does not exist while processing rule $str"
         unless exists $self->{opts}->{$long};
      push @participants, $long;
   }
   MKDEBUG && _d('Participants for', $str, ':', @participants);
   return @participants;
}

sub opts {
   my ( $self ) = @_;
   my %opts = %{$self->{opts}};
   return %opts;
}

sub short_opts {
   my ( $self ) = @_;
   my %short_opts = %{$self->{short_opts}};
   return %short_opts;
}

sub set_defaults {
   my ( $self, %defaults ) = @_;
   $self->{defaults} = {};
   foreach my $long ( keys %defaults ) {
      die "Cannot set default for nonexistent option $long"
         unless exists $self->{opts}->{$long};
      $self->{defaults}->{$long} = $defaults{$long};
      MKDEBUG && _d('Default val for', $long, ':', $defaults{$long});
   }
   return;
}

sub get_defaults {
   my ( $self ) = @_;
   return $self->{defaults};
}

sub get_groups {
   my ( $self ) = @_;
   return $self->{groups};
}

sub _set_option {
   my ( $self, $opt, $val ) = @_;
   my $long = exists $self->{opts}->{$opt}       ? $opt
            : exists $self->{short_opts}->{$opt} ? $self->{short_opts}->{$opt}
            : die "Getopt::Long gave a nonexistent option: $opt";

   $opt = $self->{opts}->{$long};
   if ( $opt->{is_cumulative} ) {
      $opt->{value}++;
   }
   else {
      $opt->{value} = $val;
   }
   $opt->{got} = 1;
   MKDEBUG && _d('Got option', $long, '=', $val);
}

sub get_opts {
   my ( $self ) = @_; 

   foreach my $long ( keys %{$self->{opts}} ) {
      $self->{opts}->{$long}->{got} = 0;
      $self->{opts}->{$long}->{value}
         = exists $self->{defaults}->{$long}       ? $self->{defaults}->{$long}
         : $self->{opts}->{$long}->{is_cumulative} ? 0
         : undef;
   }
   $self->{got_opts} = 0;

   $self->{errors} = [];

   if ( @ARGV && $ARGV[0] eq "--config" ) {
      shift @ARGV;
      $self->_set_option('config', shift @ARGV);
   }
   if ( $self->has('config') ) {
      my @extra_args;
      foreach my $filename ( split(',', $self->get('config')) ) {
         eval {
            push @extra_args, $self->_read_config_file($filename);
         };
         if ( $EVAL_ERROR ) {
            if ( $self->got('config') ) {
               die $EVAL_ERROR;
            }
            elsif ( MKDEBUG ) {
               _d($EVAL_ERROR);
            }
         }
      }
      unshift @ARGV, @extra_args;
   }

   Getopt::Long::Configure('no_ignore_case', 'bundling');
   GetOptions(
      map    { $_->{spec} => sub { $self->_set_option(@_); } }
      grep   { $_->{long} ne 'config' } # --config is handled specially above.
      values %{$self->{opts}}
   ) or $self->save_error('Error parsing options');

   if ( exists $self->{opts}->{version} && $self->{opts}->{version}->{got} ) {
      if ( $self->{version} ) {
         print $self->{version}, "\n";
      }
      else {
         print "Error parsing version.  See the VERSION section of the tool's documentation.\n";
      }
      exit 0;
   }

   if ( @ARGV && $self->{strict} ) {
      $self->save_error("Unrecognized command-line options @ARGV");
   }

   foreach my $mutex ( @{$self->{mutex}} ) {
      my @set = grep { $self->{opts}->{$_}->{got} } @$mutex;
      if ( @set > 1 ) {
         my $err = join(', ', map { "--$self->{opts}->{$_}->{long}" }
                      @{$mutex}[ 0 .. scalar(@$mutex) - 2] )
                 . ' and --'.$self->{opts}->{$mutex->[-1]}->{long}
                 . ' are mutually exclusive.';
         $self->save_error($err);
      }
   }

   foreach my $required ( @{$self->{atleast1}} ) {
      my @set = grep { $self->{opts}->{$_}->{got} } @$required;
      if ( @set == 0 ) {
         my $err = join(', ', map { "--$self->{opts}->{$_}->{long}" }
                      @{$required}[ 0 .. scalar(@$required) - 2] )
                 .' or --'.$self->{opts}->{$required->[-1]}->{long};
         $self->save_error("Specify at least one of $err");
      }
   }

   $self->_check_opts( keys %{$self->{opts}} );
   $self->{got_opts} = 1;
   return;
}

sub _check_opts {
   my ( $self, @long ) = @_;
   my $long_last = scalar @long;
   while ( @long ) {
      foreach my $i ( 0..$#long ) {
         my $long = $long[$i];
         next unless $long;
         my $opt  = $self->{opts}->{$long};
         if ( $opt->{got} ) {
            if ( exists $self->{disables}->{$long} ) {
               my @disable_opts = @{$self->{disables}->{$long}};
               map { $self->{opts}->{$_}->{value} = undef; } @disable_opts;
               MKDEBUG && _d('Unset options', @disable_opts,
                  'because', $long,'disables them');
            }

            if ( exists $self->{allowed_groups}->{$long} ) {

               my @restricted_groups = grep {
                  !exists $self->{allowed_groups}->{$long}->{$_}
               } keys %{$self->{groups}};

               my @restricted_opts;
               foreach my $restricted_group ( @restricted_groups ) {
                  RESTRICTED_OPT:
                  foreach my $restricted_opt (
                     keys %{$self->{groups}->{$restricted_group}} )
                  {
                     next RESTRICTED_OPT if $restricted_opt eq $long;
                     push @restricted_opts, $restricted_opt
                        if $self->{opts}->{$restricted_opt}->{got};
                  }
               }

               if ( @restricted_opts ) {
                  my $err;
                  if ( @restricted_opts == 1 ) {
                     $err = "--$restricted_opts[0]";
                  }
                  else {
                     $err = join(', ',
                               map { "--$self->{opts}->{$_}->{long}" }
                               grep { $_ } 
                               @restricted_opts[0..scalar(@restricted_opts) - 2]
                            )
                          . ' or --'.$self->{opts}->{$restricted_opts[-1]}->{long};
                  }
                  $self->save_error("--$long is not allowed with $err");
               }
            }

         }
         elsif ( $opt->{is_required} ) { 
            $self->save_error("Required option --$long must be specified");
         }

         $self->_validate_type($opt);
         if ( $opt->{parsed} ) {
            delete $long[$i];
         }
         else {
            MKDEBUG && _d('Temporarily failed to parse', $long);
         }
      }

      die "Failed to parse options, possibly due to circular dependencies"
         if @long == $long_last;
      $long_last = @long;
   }

   return;
}

sub _validate_type {
   my ( $self, $opt ) = @_;
   return unless $opt;

   if ( !$opt->{type} ) {
      $opt->{parsed} = 1;
      return;
   }

   my $val = $opt->{value};

   if ( $val && $opt->{type} eq 'm' ) {  # type time
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a time value');
      my ( $prefix, $num, $suffix ) = $val =~ m/([+-]?)(\d+)([a-z])?$/;
      if ( !$suffix ) {
         my ( $s ) = $opt->{desc} =~ m/\(suffix (.)\)/;
         $suffix = $s || 's';
         MKDEBUG && _d('No suffix given; using', $suffix, 'for',
            $opt->{long}, '(value:', $val, ')');
      }
      if ( $suffix =~ m/[smhd]/ ) {
         $val = $suffix eq 's' ? $num            # Seconds
              : $suffix eq 'm' ? $num * 60       # Minutes
              : $suffix eq 'h' ? $num * 3600     # Hours
              :                  $num * 86400;   # Days
         $opt->{value} = ($prefix || '') . $val;
         MKDEBUG && _d('Setting option', $opt->{long}, 'to', $val);
      }
      else {
         $self->save_error("Invalid time suffix for --$opt->{long}");
      }
   }
   elsif ( $val && $opt->{type} eq 'd' ) {  # type DSN
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a DSN');
      my $prev = {};
      my $from_key = $self->{defaults_to}->{ $opt->{long} };
      if ( $from_key ) {
         MKDEBUG && _d($opt->{long}, 'DSN copies from', $from_key, 'DSN');
         if ( $self->{opts}->{$from_key}->{parsed} ) {
            $prev = $self->{opts}->{$from_key}->{value};
         }
         else {
            MKDEBUG && _d('Cannot parse', $opt->{long}, 'until',
               $from_key, 'parsed');
            return;
         }
      }
      my $defaults = $self->{DSNParser}->parse_options($self);
      $opt->{value} = $self->{DSNParser}->parse($val, $prev, $defaults);
   }
   elsif ( $val && $opt->{type} eq 'z' ) {  # type size
      MKDEBUG && _d('Parsing option', $opt->{long}, 'as a size value');
      $self->_parse_size($opt, $val);
   }
   elsif ( $opt->{type} eq 'H' || (defined $val && $opt->{type} eq 'h') ) {
      $opt->{value} = { map { $_ => 1 } split(/(?<!\\),\s*/, ($val || '')) };
   }
   elsif ( $opt->{type} eq 'A' || (defined $val && $opt->{type} eq 'a') ) {
      $opt->{value} = [ split(/(?<!\\),\s*/, ($val || '')) ];
   }
   else {
      MKDEBUG && _d('Nothing to validate for option',
         $opt->{long}, 'type', $opt->{type}, 'value', $val);
   }

   $opt->{parsed} = 1;
   return;
}

sub get {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   return $self->{opts}->{$long}->{value};
}

sub got {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   return $self->{opts}->{$long}->{got};
}

sub has {
   my ( $self, $opt ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   return defined $long ? exists $self->{opts}->{$long} : 0;
}

sub set {
   my ( $self, $opt, $val ) = @_;
   my $long = (length $opt == 1 ? $self->{short_opts}->{$opt} : $opt);
   die "Option $opt does not exist"
      unless $long && exists $self->{opts}->{$long};
   $self->{opts}->{$long}->{value} = $val;
   return;
}

sub save_error {
   my ( $self, $error ) = @_;
   push @{$self->{errors}}, $error;
   return;
}

sub errors {
   my ( $self ) = @_;
   return $self->{errors};
}

sub usage {
   my ( $self ) = @_;
   warn "No usage string is set" unless $self->{usage}; # XXX
   return "Usage: " . ($self->{usage} || '') . "\n";
}

sub descr {
   my ( $self ) = @_;
   warn "No description string is set" unless $self->{description}; # XXX
   my $descr  = ($self->{description} || $self->{program_name} || '')
              . "  For more details, please use the --help option, "
              . "or try 'perldoc $PROGRAM_NAME' "
              . "for complete documentation.";
   $descr = join("\n", $descr =~ m/(.{0,80})(?:\s+|$)/g)
      unless $ENV{DONT_BREAK_LINES};
   $descr =~ s/ +$//mg;
   return $descr;
}

sub usage_or_errors {
   my ( $self, $file, $return ) = @_;
   $file ||= $self->{file} || __FILE__;

   if ( !$self->{description} || !$self->{usage} ) {
      MKDEBUG && _d("Getting description and usage from SYNOPSIS in", $file);
      my %synop = $self->_parse_synopsis($file);
      $self->{description} ||= $synop{description};
      $self->{usage}       ||= $synop{usage};
      MKDEBUG && _d("Description:", $self->{description},
         "\nUsage:", $self->{usage});
   }

   if ( $self->{opts}->{help}->{got} ) {
      print $self->print_usage() or die "Cannot print usage: $OS_ERROR";
      exit 0 unless $return;
   }
   elsif ( scalar @{$self->{errors}} ) {
      print $self->print_errors() or die "Cannot print errors: $OS_ERROR";
      exit 0 unless $return;
   }

   return;
}

sub print_errors {
   my ( $self ) = @_;
   my $usage = $self->usage() . "\n";
   if ( (my @errors = @{$self->{errors}}) ) {
      $usage .= join("\n  * ", 'Errors in command-line arguments:', @errors)
              . "\n";
   }
   return $usage . "\n" . $self->descr();
}

sub print_usage {
   my ( $self ) = @_;
   die "Run get_opts() before print_usage()" unless $self->{got_opts};
   my @opts = values %{$self->{opts}};

   my $maxl = max(
      map {
         length($_->{long})               # option long name
         + ($_->{is_negatable} ? 4 : 0)   # "[no]" if opt is negatable
         + ($_->{type} ? 2 : 0)           # "=x" where x is the opt type
      }
      @opts);

   my $maxs = max(0,
      map {
         length($_)
         + ($self->{opts}->{$_}->{is_negatable} ? 4 : 0)
         + ($self->{opts}->{$_}->{type} ? 2 : 0)
      }
      values %{$self->{short_opts}});

   my $lcol = max($maxl, ($maxs + 3));
   my $rcol = 80 - $lcol - 6;
   my $rpad = ' ' x ( 80 - $rcol );

   $maxs = max($lcol - 3, $maxs);

   my $usage = $self->descr() . "\n" . $self->usage();

   my @groups = reverse sort grep { $_ ne 'default'; } keys %{$self->{groups}};
   push @groups, 'default';

   foreach my $group ( reverse @groups ) {
      $usage .= "\n".($group eq 'default' ? 'Options' : $group).":\n\n";
      foreach my $opt (
         sort { $a->{long} cmp $b->{long} }
         grep { $_->{group} eq $group }
         @opts )
      {
         my $long  = $opt->{is_negatable} ? "[no]$opt->{long}" : $opt->{long};
         my $short = $opt->{short};
         my $desc  = $opt->{desc};

         $long .= $opt->{type} ? "=$opt->{type}" : "";

         if ( $opt->{type} && $opt->{type} eq 'm' ) {
            my ($s) = $desc =~ m/\(suffix (.)\)/;
            $s    ||= 's';
            $desc =~ s/\s+\(suffix .\)//;
            $desc .= ".  Optional suffix s=seconds, m=minutes, h=hours, "
                   . "d=days; if no suffix, $s is used.";
         }
         $desc = join("\n$rpad", grep { $_ } $desc =~ m/(.{0,$rcol})(?:\s+|$)/g);
         $desc =~ s/ +$//mg;
         if ( $short ) {
            $usage .= sprintf("  --%-${maxs}s -%s  %s\n", $long, $short, $desc);
         }
         else {
            $usage .= sprintf("  --%-${lcol}s  %s\n", $long, $desc);
         }
      }
   }

   $usage .= "\nOption types: s=string, i=integer, f=float, h/H/a/A=comma-separated list, d=DSN, z=size, m=time\n";

   if ( (my @rules = @{$self->{rules}}) ) {
      $usage .= "\nRules:\n\n";
      $usage .= join("\n", map { "  $_" } @rules) . "\n";
   }
   if ( $self->{DSNParser} ) {
      $usage .= "\n" . $self->{DSNParser}->usage();
   }
   $usage .= "\nOptions and values after processing arguments:\n\n";
   foreach my $opt ( sort { $a->{long} cmp $b->{long} } @opts ) {
      my $val   = $opt->{value};
      my $type  = $opt->{type} || '';
      my $bool  = $opt->{spec} =~ m/^[\w-]+(?:\|[\w-])?!?$/;
      $val      = $bool              ? ( $val ? 'TRUE' : 'FALSE' )
                : !defined $val      ? '(No value)'
                : $type eq 'd'       ? $self->{DSNParser}->as_string($val)
                : $type =~ m/H|h/    ? join(',', sort keys %$val)
                : $type =~ m/A|a/    ? join(',', @$val)
                :                    $val;
      $usage .= sprintf("  --%-${lcol}s  %s\n", $opt->{long}, $val);
   }
   return $usage;
}

sub prompt_noecho {
   shift @_ if ref $_[0] eq __PACKAGE__;
   my ( $prompt ) = @_;
   local $OUTPUT_AUTOFLUSH = 1;
   print $prompt
      or die "Cannot print: $OS_ERROR";
   my $response;
   eval {
      require Term::ReadKey;
      Term::ReadKey::ReadMode('noecho');
      chomp($response = <STDIN>);
      Term::ReadKey::ReadMode('normal');
      print "\n"
         or die "Cannot print: $OS_ERROR";
   };
   if ( $EVAL_ERROR ) {
      die "Cannot read response; is Term::ReadKey installed? $EVAL_ERROR";
   }
   return $response;
}

sub _read_config_file {
   my ( $self, $filename ) = @_;
   open my $fh, "<", $filename or die "Cannot open $filename: $OS_ERROR\n";
   my @args;
   my $prefix = '--';
   my $parse  = 1;

   LINE:
   while ( my $line = <$fh> ) {
      chomp $line;
      next LINE if $line =~ m/^\s*(?:\#|\;|$)/;
      $line =~ s/\s+#.*$//g;
      $line =~ s/^\s+|\s+$//g;
      if ( $line eq '--' ) {
         $prefix = '';
         $parse  = 0;
         next LINE;
      }
      if ( $parse
         && (my($opt, $arg) = $line =~ m/^\s*([^=\s]+?)(?:\s*=\s*(.*?)\s*)?$/)
      ) {
         push @args, grep { defined $_ } ("$prefix$opt", $arg);
      }
      elsif ( $line =~ m/./ ) {
         push @args, $line;
      }
      else {
         die "Syntax error in file $filename at line $INPUT_LINE_NUMBER";
      }
   }
   close $fh;
   return @args;
}

sub read_para_after {
   my ( $self, $file, $regex ) = @_;
   open my $fh, "<", $file or die "Can't open $file: $OS_ERROR";
   local $INPUT_RECORD_SEPARATOR = '';
   my $para;
   while ( $para = <$fh> ) {
      next unless $para =~ m/^=pod$/m;
      last;
   }
   while ( $para = <$fh> ) {
      next unless $para =~ m/$regex/;
      last;
   }
   $para = <$fh>;
   chomp($para);
   close $fh or die "Can't close $file: $OS_ERROR";
   return $para;
}

sub clone {
   my ( $self ) = @_;

   my %clone = map {
      my $hashref  = $self->{$_};
      my $val_copy = {};
      foreach my $key ( keys %$hashref ) {
         my $ref = ref $hashref->{$key};
         $val_copy->{$key} = !$ref           ? $hashref->{$key}
                           : $ref eq 'HASH'  ? { %{$hashref->{$key}} }
                           : $ref eq 'ARRAY' ? [ @{$hashref->{$key}} ]
                           : $hashref->{$key};
      }
      $_ => $val_copy;
   } qw(opts short_opts defaults);

   foreach my $scalar ( qw(got_opts) ) {
      $clone{$scalar} = $self->{$scalar};
   }

   return bless \%clone;     
}

sub _parse_size {
   my ( $self, $opt, $val ) = @_;

   if ( lc($val || '') eq 'null' ) {
      MKDEBUG && _d('NULL size for', $opt->{long});
      $opt->{value} = 'null';
      return;
   }

   my %factor_for = (k => 1_024, M => 1_048_576, G => 1_073_741_824);
   my ($pre, $num, $factor) = $val =~ m/^([+-])?(\d+)([kMG])?$/;
   if ( defined $num ) {
      if ( $factor ) {
         $num *= $factor_for{$factor};
         MKDEBUG && _d('Setting option', $opt->{y},
            'to num', $num, '* factor', $factor);
      }
      $opt->{value} = ($pre || '') . $num;
   }
   else {
      $self->save_error("Invalid size for --$opt->{long}: $val");
   }
   return;
}

sub _parse_attribs {
   my ( $self, $option, $attribs ) = @_;
   my $types = $self->{types};
   return $option
      . ($attribs->{'short form'} ? '|' . $attribs->{'short form'}   : '' )
      . ($attribs->{'negatable'}  ? '!'                              : '' )
      . ($attribs->{'cumulative'} ? '+'                              : '' )
      . ($attribs->{'type'}       ? '=' . $types->{$attribs->{type}} : '' );
}

sub _parse_synopsis {
   my ( $self, $file ) = @_;
   $file ||= $self->{file} || __FILE__;
   MKDEBUG && _d("Parsing SYNOPSIS in", $file);

   local $INPUT_RECORD_SEPARATOR = '';  # read paragraphs
   open my $fh, "<", $file or die "Cannot open $file: $OS_ERROR";
   my $para;
   1 while defined($para = <$fh>) && $para !~ m/^=head1 SYNOPSIS/;
   die "$file does not contain a SYNOPSIS section" unless $para;
   my @synop;
   for ( 1..2 ) {  # 1 for the usage, 2 for the description
      my $para = <$fh>;
      push @synop, $para;
   }
   close $fh;
   MKDEBUG && _d("Raw SYNOPSIS text:", @synop);
   my ($usage, $desc) = @synop;
   die "The SYNOPSIS section in $file is not formatted properly"
      unless $usage && $desc;

   $usage =~ s/^\s*Usage:\s+(.+)/$1/;
   chomp $usage;

   $desc =~ s/\n/ /g;
   $desc =~ s/\s{2,}/ /g;
   $desc =~ s/\. ([A-Z][a-z])/.  $1/g;
   $desc =~ s/\s+$//;

   return (
      description => $desc,
      usage       => $usage,
   );
};

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

if ( MKDEBUG ) {
   print '# ', $^X, ' ', $], "\n";
   if ( my $uname = `uname -a` ) {
      $uname =~ s/\s+/ /g;
      print "# $uname\n";
   }
   print '# Arguments: ',
      join(' ', map { my $a = "_[$_]_"; $a =~ s/\n/\n# /g; $a; } @ARGV), "\n";
}

1;
}
# ###########################################################################
# End OptionParser package
# ###########################################################################

# ###########################################################################
# Quoter package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/Quoter.pm
#   t/lib/Quoter.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package Quoter;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, %args ) = @_;
   return bless {}, $class;
}

sub quote {
   my ( $self, @vals ) = @_;
   foreach my $val ( @vals ) {
      $val =~ s/`/``/g;
   }
   return join('.', map { '`' . $_ . '`' } @vals);
}

sub quote_val {
   my ( $self, $val ) = @_;

   return 'NULL' unless defined $val;          # undef = NULL
   return "''" if $val eq '';                  # blank string = ''
   return $val if $val =~ m/^0x[0-9a-fA-F]+$/;  # hex data

   $val =~ s/(['\\])/\\$1/g;
   return "'$val'";
}

sub split_unquote {
   my ( $self, $db_tbl, $default_db ) = @_;
   $db_tbl =~ s/`//g;
   my ( $db, $tbl ) = split(/[.]/, $db_tbl);
   if ( !$tbl ) {
      $tbl = $db;
      $db  = $default_db;
   }
   return ($db, $tbl);
}

sub literal_like {
   my ( $self, $like ) = @_;
   return unless $like;
   $like =~ s/([%_])/\\$1/g;
   return "'$like'";
}

sub join_quote {
   my ( $self, $default_db, $db_tbl ) = @_;
   return unless $db_tbl;
   my ($db, $tbl) = split(/[.]/, $db_tbl);
   if ( !$tbl ) {
      $tbl = $db;
      $db  = $default_db;
   }
   $db  = "`$db`"  if $db  && $db  !~ m/^`/;
   $tbl = "`$tbl`" if $tbl && $tbl !~ m/^`/;
   return $db ? "$db.$tbl" : $tbl;
}

1;
}
# ###########################################################################
# End Quoter package
# ###########################################################################

# ###########################################################################
# VersionParser package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/VersionParser.pm
#   t/lib/VersionParser.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package VersionParser;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class ) = @_;
   bless {}, $class;
}

sub parse {
   my ( $self, $str ) = @_;
   my $result = sprintf('%03d%03d%03d', $str =~ m/(\d+)/g);
   MKDEBUG && _d($str, 'parses to', $result);
   return $result;
}

sub version_ge {
   my ( $self, $dbh, $target ) = @_;
   if ( !$self->{$dbh} ) {
      $self->{$dbh} = $self->parse(
         $dbh->selectrow_array('SELECT VERSION()'));
   }
   my $result = $self->{$dbh} ge $self->parse($target) ? 1 : 0;
   MKDEBUG && _d($self->{$dbh}, 'ge', $target, ':', $result);
   return $result;
}

sub innodb_version {
   my ( $self, $dbh ) = @_;
   return unless $dbh;
   my $innodb_version = "NO";

   my ($innodb) =
      grep { $_->{engine} =~ m/InnoDB/i }
      map  {
         my %hash;
         @hash{ map { lc $_ } keys %$_ } = values %$_;
         \%hash;
      }
      @{ $dbh->selectall_arrayref("SHOW ENGINES", {Slice=>{}}) };
   if ( $innodb ) {
      MKDEBUG && _d("InnoDB support:", $innodb->{support});
      if ( $innodb->{support} =~ m/YES|DEFAULT/i ) {
         my $vars = $dbh->selectrow_hashref(
            "SHOW VARIABLES LIKE 'innodb_version'");
         $innodb_version = !$vars ? "BUILTIN"
                         :          ($vars->{Value} || $vars->{value});
      }
      else {
         $innodb_version = $innodb->{support};  # probably DISABLED or NO
      }
   }

   MKDEBUG && _d("InnoDB version:", $innodb_version);
   return $innodb_version;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End VersionParser package
# ###########################################################################

# ###########################################################################
# TableParser package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/TableParser.pm
#   t/lib/TableParser.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package TableParser;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use Data::Dumper;
$Data::Dumper::Indent    = 1;
$Data::Dumper::Sortkeys  = 1;
$Data::Dumper::Quotekeys = 0;

sub new {
   my ( $class, %args ) = @_;
   my @required_args = qw(Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my $self = { %args };
   return bless $self, $class;
}

sub get_create_table {
   my ( $self, $dbh, $db, $tbl ) = @_;
   die "I need a dbh parameter" unless $dbh;
   die "I need a db parameter"  unless $db;
   die "I need a tbl parameter" unless $tbl;
   my $q = $self->{Quoter};

   my $sql = '/*!40101 SET @OLD_SQL_MODE := @@SQL_MODE, '
           . q{@@SQL_MODE := REPLACE(REPLACE(@@SQL_MODE, 'ANSI_QUOTES', ''), ',,', ','), }
           . '@OLD_QUOTE := @@SQL_QUOTE_SHOW_CREATE, '
           . '@@SQL_QUOTE_SHOW_CREATE := 1 */';
   MKDEBUG && _d($sql);
   eval { $dbh->do($sql); };
   MKDEBUG && $EVAL_ERROR && _d($EVAL_ERROR);

   $sql = 'USE ' . $q->quote($db);
   MKDEBUG && _d($dbh, $sql);
   $dbh->do($sql);

   $sql = "SHOW CREATE TABLE " . $q->quote($db, $tbl);
   MKDEBUG && _d($sql);
   my $href;
   eval { $href = $dbh->selectrow_hashref($sql); };
   if ( $EVAL_ERROR ) {
      MKDEBUG && _d($EVAL_ERROR);
      return;
   }

   $sql = '/*!40101 SET @@SQL_MODE := @OLD_SQL_MODE, '
        . '@@SQL_QUOTE_SHOW_CREATE := @OLD_QUOTE */';
   MKDEBUG && _d($sql);
   $dbh->do($sql);

   my ($key) = grep { m/create table/i } keys %$href;
   if ( $key ) {
      MKDEBUG && _d('This table is a base table');
      $href->{$key}  =~ s/\b[ ]{2,}/ /g;
      $href->{$key} .= "\n";
   }
   else {
      MKDEBUG && _d('This table is a view');
      ($key) = grep { m/create view/i } keys %$href;
   }

   return $href->{$key};
}

sub parse {
   my ( $self, $ddl, $opts ) = @_;
   return unless $ddl;

   if ( $ddl !~ m/CREATE (?:TEMPORARY )?TABLE `/ ) {
      die "Cannot parse table definition; is ANSI quoting "
         . "enabled or SQL_QUOTE_SHOW_CREATE disabled?";
   }

   my ($name)     = $ddl =~ m/CREATE (?:TEMPORARY )?TABLE\s+(`.+?`)/;
   (undef, $name) = $self->{Quoter}->split_unquote($name) if $name;

   $ddl =~ s/(`[^`]+`)/\L$1/g;

   my $engine = $self->get_engine($ddl);

   my @defs   = $ddl =~ m/^(\s+`.*?),?$/gm;
   my @cols   = map { $_ =~ m/`([^`]+)`/ } @defs;
   MKDEBUG && _d('Table cols:', join(', ', map { "`$_`" } @cols));

   my %def_for;
   @def_for{@cols} = @defs;

   my (@nums, @null);
   my (%type_for, %is_nullable, %is_numeric, %is_autoinc);
   foreach my $col ( @cols ) {
      my $def = $def_for{$col};
      my ( $type ) = $def =~ m/`[^`]+`\s([a-z]+)/;
      die "Can't determine column type for $def" unless $type;
      $type_for{$col} = $type;
      if ( $type =~ m/(?:(?:tiny|big|medium|small)?int|float|double|decimal|year)/ ) {
         push @nums, $col;
         $is_numeric{$col} = 1;
      }
      if ( $def !~ m/NOT NULL/ ) {
         push @null, $col;
         $is_nullable{$col} = 1;
      }
      $is_autoinc{$col} = $def =~ m/AUTO_INCREMENT/i ? 1 : 0;
   }

   my ($keys, $clustered_key) = $self->get_keys($ddl, $opts, \%is_nullable);

   my ($charset) = $ddl =~ m/DEFAULT CHARSET=(\w+)/;

   return {
      name           => $name,
      cols           => \@cols,
      col_posn       => { map { $cols[$_] => $_ } 0..$#cols },
      is_col         => { map { $_ => 1 } @cols },
      null_cols      => \@null,
      is_nullable    => \%is_nullable,
      is_autoinc     => \%is_autoinc,
      clustered_key  => $clustered_key,
      keys           => $keys,
      defs           => \%def_for,
      numeric_cols   => \@nums,
      is_numeric     => \%is_numeric,
      engine         => $engine,
      type_for       => \%type_for,
      charset        => $charset,
   };
}

sub sort_indexes {
   my ( $self, $tbl ) = @_;

   my @indexes
      = sort {
         (($a ne 'PRIMARY') <=> ($b ne 'PRIMARY'))
         || ( !$tbl->{keys}->{$a}->{is_unique} <=> !$tbl->{keys}->{$b}->{is_unique} )
         || ( $tbl->{keys}->{$a}->{is_nullable} <=> $tbl->{keys}->{$b}->{is_nullable} )
         || ( scalar(@{$tbl->{keys}->{$a}->{cols}}) <=> scalar(@{$tbl->{keys}->{$b}->{cols}}) )
      }
      grep {
         $tbl->{keys}->{$_}->{type} eq 'BTREE'
      }
      sort keys %{$tbl->{keys}};

   MKDEBUG && _d('Indexes sorted best-first:', join(', ', @indexes));
   return @indexes;
}

sub find_best_index {
   my ( $self, $tbl, $index ) = @_;
   my $best;
   if ( $index ) {
      ($best) = grep { uc $_ eq uc $index } keys %{$tbl->{keys}};
   }
   if ( !$best ) {
      if ( $index ) {
         die "Index '$index' does not exist in table";
      }
      else {
         ($best) = $self->sort_indexes($tbl);
      }
   }
   MKDEBUG && _d('Best index found is', $best);
   return $best;
}

sub find_possible_keys {
   my ( $self, $dbh, $database, $table, $quoter, $where ) = @_;
   return () unless $where;
   my $sql = 'EXPLAIN SELECT * FROM ' . $quoter->quote($database, $table)
      . ' WHERE ' . $where;
   MKDEBUG && _d($sql);
   my $expl = $dbh->selectrow_hashref($sql);
   $expl = { map { lc($_) => $expl->{$_} } keys %$expl };
   if ( $expl->{possible_keys} ) {
      MKDEBUG && _d('possible_keys =', $expl->{possible_keys});
      my @candidates = split(',', $expl->{possible_keys});
      my %possible   = map { $_ => 1 } @candidates;
      if ( $expl->{key} ) {
         MKDEBUG && _d('MySQL chose', $expl->{key});
         unshift @candidates, grep { $possible{$_} } split(',', $expl->{key});
         MKDEBUG && _d('Before deduping:', join(', ', @candidates));
         my %seen;
         @candidates = grep { !$seen{$_}++ } @candidates;
      }
      MKDEBUG && _d('Final list:', join(', ', @candidates));
      return @candidates;
   }
   else {
      MKDEBUG && _d('No keys in possible_keys');
      return ();
   }
}

sub check_table {
   my ( $self, %args ) = @_;
   my @required_args = qw(dbh db tbl);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $db, $tbl) = @args{@required_args};
   my $q      = $self->{Quoter};
   my $db_tbl = $q->quote($db, $tbl);
   MKDEBUG && _d('Checking', $db_tbl);

   my $sql = "SHOW TABLES FROM " . $q->quote($db)
           . ' LIKE ' . $q->literal_like($tbl);
   MKDEBUG && _d($sql);
   my $row;
   eval {
      $row = $dbh->selectrow_arrayref($sql);
   };
   if ( $EVAL_ERROR ) {
      MKDEBUG && _d($EVAL_ERROR);
      return 0;
   }
   if ( !$row->[0] || $row->[0] ne $tbl ) {
      MKDEBUG && _d('Table does not exist');
      return 0;
   }

   MKDEBUG && _d('Table exists; no privs to check');
   return 1 unless $args{all_privs};

   $sql = "SHOW FULL COLUMNS FROM $db_tbl";
   MKDEBUG && _d($sql);
   eval {
      $row = $dbh->selectrow_hashref($sql);
   };
   if ( $EVAL_ERROR ) {
      MKDEBUG && _d($EVAL_ERROR);
      return 0;
   }
   if ( !scalar keys %$row ) {
      MKDEBUG && _d('Table has no columns:', Dumper($row));
      return 0;
   }
   my $privs = $row->{privileges} || $row->{Privileges};

   $sql = "DELETE FROM $db_tbl LIMIT 0";
   MKDEBUG && _d($sql);
   eval {
      $dbh->do($sql);
   };
   my $can_delete = $EVAL_ERROR ? 0 : 1;

   MKDEBUG && _d('User privs on', $db_tbl, ':', $privs,
      ($can_delete ? 'delete' : ''));

   if ( !($privs =~ m/select/ && $privs =~ m/insert/ && $privs =~ m/update/
          && $can_delete) ) {
      MKDEBUG && _d('User does not have all privs');
      return 0;
   }

   MKDEBUG && _d('User has all privs');
   return 1;
}

sub get_engine {
   my ( $self, $ddl, $opts ) = @_;
   my ( $engine ) = $ddl =~ m/\).*?(?:ENGINE|TYPE)=(\w+)/;
   MKDEBUG && _d('Storage engine:', $engine);
   return $engine || undef;
}

sub get_keys {
   my ( $self, $ddl, $opts, $is_nullable ) = @_;
   my $engine        = $self->get_engine($ddl);
   my $keys          = {};
   my $clustered_key = undef;

   KEY:
   foreach my $key ( $ddl =~ m/^  ((?:[A-Z]+ )?KEY .*)$/gm ) {

      next KEY if $key =~ m/FOREIGN/;

      my $key_ddl = $key;
      MKDEBUG && _d('Parsed key:', $key_ddl);

      if ( $engine !~ m/MEMORY|HEAP/ ) {
         $key =~ s/USING HASH/USING BTREE/;
      }

      my ( $type, $cols ) = $key =~ m/(?:USING (\w+))? \((.+)\)/;
      my ( $special ) = $key =~ m/(FULLTEXT|SPATIAL)/;
      $type = $type || $special || 'BTREE';
      if ( $opts->{mysql_version} && $opts->{mysql_version} lt '004001000'
         && $engine =~ m/HEAP|MEMORY/i )
      {
         $type = 'HASH'; # MySQL pre-4.1 supports only HASH indexes on HEAP
      }

      my ($name) = $key =~ m/(PRIMARY|`[^`]*`)/;
      my $unique = $key =~ m/PRIMARY|UNIQUE/ ? 1 : 0;
      my @cols;
      my @col_prefixes;
      foreach my $col_def ( $cols =~ m/`[^`]+`(?:\(\d+\))?/g ) {
         my ($name, $prefix) = $col_def =~ m/`([^`]+)`(?:\((\d+)\))?/;
         push @cols, $name;
         push @col_prefixes, $prefix;
      }
      $name =~ s/`//g;

      MKDEBUG && _d( $name, 'key cols:', join(', ', map { "`$_`" } @cols));

      $keys->{$name} = {
         name         => $name,
         type         => $type,
         colnames     => $cols,
         cols         => \@cols,
         col_prefixes => \@col_prefixes,
         is_unique    => $unique,
         is_nullable  => scalar(grep { $is_nullable->{$_} } @cols),
         is_col       => { map { $_ => 1 } @cols },
         ddl          => $key_ddl,
      };

      if ( $engine =~ m/InnoDB/i && !$clustered_key ) {
         my $this_key = $keys->{$name};
         if ( $this_key->{name} eq 'PRIMARY' ) {
            $clustered_key = 'PRIMARY';
         }
         elsif ( $this_key->{is_unique} && !$this_key->{is_nullable} ) {
            $clustered_key = $this_key->{name};
         }
         MKDEBUG && $clustered_key && _d('This key is the clustered key');
      }
   }

   return $keys, $clustered_key;
}

sub get_fks {
   my ( $self, $ddl, $opts ) = @_;
   my $q   = $self->{Quoter};
   my $fks = {};

   foreach my $fk (
      $ddl =~ m/CONSTRAINT .* FOREIGN KEY .* REFERENCES [^\)]*\)/mg )
   {
      my ( $name ) = $fk =~ m/CONSTRAINT `(.*?)`/;
      my ( $cols ) = $fk =~ m/FOREIGN KEY \(([^\)]+)\)/;
      my ( $parent, $parent_cols ) = $fk =~ m/REFERENCES (\S+) \(([^\)]+)\)/;

      my ($db, $tbl) = $q->split_unquote($parent, $opts->{database});
      my %parent_tbl = (tbl => $tbl);
      $parent_tbl{db} = $db if $db;

      if ( $parent !~ m/\./ && $opts->{database} ) {
         $parent = $q->quote($opts->{database}) . ".$parent";
      }

      $fks->{$name} = {
         name           => $name,
         colnames       => $cols,
         cols           => [ map { s/[ `]+//g; $_; } split(',', $cols) ],
         parent_tbl     => \%parent_tbl,
         parent_tblname => $parent,
         parent_cols    => [ map { s/[ `]+//g; $_; } split(',', $parent_cols) ],
         parent_colnames=> $parent_cols,
         ddl            => $fk,
      };
   }

   return $fks;
}

sub remove_auto_increment {
   my ( $self, $ddl ) = @_;
   $ddl =~ s/(^\).*?) AUTO_INCREMENT=\d+\b/$1/m;
   return $ddl;
}

sub get_table_status {
   my ( $self, $dbh, $db, $like ) = @_;
   my $q = $self->{Quoter};
   my $sql = "SHOW TABLE STATUS FROM " . $q->quote($db);
   my @params;
   if ( $like ) {
      $sql .= ' LIKE ?';
      push @params, $like;
   }
   MKDEBUG && _d($sql, @params);
   my $sth = $dbh->prepare($sql);
   eval { $sth->execute(@params); };
   if ($EVAL_ERROR) {
      MKDEBUG && _d($EVAL_ERROR);
      return;
   }
   my @tables = @{$sth->fetchall_arrayref({})};
   @tables = map {
      my %tbl; # Make a copy with lowercased keys
      @tbl{ map { lc $_ } keys %$_ } = values %$_;
      $tbl{engine} ||= $tbl{type} || $tbl{comment};
      delete $tbl{type};
      \%tbl;
   } @tables;
   return @tables;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End TableParser package
# ###########################################################################

# ###########################################################################
# TableNibbler package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/TableNibbler.pm
#   t/lib/TableNibbler.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package TableNibbler;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, %args ) = @_;
   my @required_args = qw(TableParser Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my $self = { %args };
   return bless $self, $class;
}

sub generate_asc_stmt {
   my ( $self, %args ) = @_;
   my @required_args = qw(tbl_struct index);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless defined $args{$arg};
   }
   my ($tbl_struct, $index) = @args{@required_args};
   my @cols = $args{cols} ? @{$args{cols}} : @{$tbl_struct->{cols}};
   my $q    = $self->{Quoter};

   die "Index '$index' does not exist in table"
      unless exists $tbl_struct->{keys}->{$index};
   MKDEBUG && _d('Will ascend index', $index);  

   my @asc_cols = @{$tbl_struct->{keys}->{$index}->{cols}};
   if ( $args{asc_first} ) {
      @asc_cols = $asc_cols[0];
      MKDEBUG && _d('Ascending only first column');
   }
   MKDEBUG && _d('Will ascend columns', join(', ', @asc_cols));

   my @asc_slice;
   my %col_posn = do { my $i = 0; map { $_ => $i++ } @cols };
   foreach my $col ( @asc_cols ) {
      if ( !exists $col_posn{$col} ) {
         push @cols, $col;
         $col_posn{$col} = $#cols;
      }
      push @asc_slice, $col_posn{$col};
   }
   MKDEBUG && _d('Will ascend, in ordinal position:', join(', ', @asc_slice));

   my $asc_stmt = {
      cols  => \@cols,
      index => $index,
      where => '',
      slice => [],
      scols => [],
   };

   if ( @asc_slice ) {
      my $cmp_where;
      foreach my $cmp ( qw(< <= >= >) ) {
         $cmp_where = $self->generate_cmp_where(
            type        => $cmp,
            slice       => \@asc_slice,
            cols        => \@cols,
            quoter      => $q,
            is_nullable => $tbl_struct->{is_nullable},
         );
         $asc_stmt->{boundaries}->{$cmp} = $cmp_where->{where};
      }
      my $cmp = $args{asc_only} ? '>' : '>=';
      $asc_stmt->{where} = $asc_stmt->{boundaries}->{$cmp};
      $asc_stmt->{slice} = $cmp_where->{slice};
      $asc_stmt->{scols} = $cmp_where->{scols};
   }

   return $asc_stmt;
}

sub generate_cmp_where {
   my ( $self, %args ) = @_;
   foreach my $arg ( qw(type slice cols is_nullable) ) {
      die "I need a $arg arg" unless defined $args{$arg};
   }
   my @slice       = @{$args{slice}};
   my @cols        = @{$args{cols}};
   my $is_nullable = $args{is_nullable};
   my $type        = $args{type};
   my $q           = $self->{Quoter};

   (my $cmp = $type) =~ s/=//;

   my @r_slice;    # Resulting slice columns, by ordinal
   my @r_scols;    # Ditto, by name

   my @clauses;
   foreach my $i ( 0 .. $#slice ) {
      my @clause;

      foreach my $j ( 0 .. $i - 1 ) {
         my $ord = $slice[$j];
         my $col = $cols[$ord];
         my $quo = $q->quote($col);
         if ( $is_nullable->{$col} ) {
            push @clause, "((? IS NULL AND $quo IS NULL) OR ($quo = ?))";
            push @r_slice, $ord, $ord;
            push @r_scols, $col, $col;
         }
         else {
            push @clause, "$quo = ?";
            push @r_slice, $ord;
            push @r_scols, $col;
         }
      }

      my $ord = $slice[$i];
      my $col = $cols[$ord];
      my $quo = $q->quote($col);
      my $end = $i == $#slice; # Last clause of the whole group.
      if ( $is_nullable->{$col} ) {
         if ( $type =~ m/=/ && $end ) {
            push @clause, "(? IS NULL OR $quo $type ?)";
         }
         elsif ( $type =~ m/>/ ) {
            push @clause, "((? IS NULL AND $quo IS NOT NULL) OR ($quo $cmp ?))";
         }
         else { # If $type =~ m/</ ) {
            push @clause, "((? IS NOT NULL AND $quo IS NULL) OR ($quo $cmp ?))";
         }
         push @r_slice, $ord, $ord;
         push @r_scols, $col, $col;
      }
      else {
         push @r_slice, $ord;
         push @r_scols, $col;
         push @clause, ($type =~ m/=/ && $end ? "$quo $type ?" : "$quo $cmp ?");
      }

      push @clauses, '(' . join(' AND ', @clause) . ')';
   }
   my $result = '(' . join(' OR ', @clauses) . ')';
   my $where = {
      slice => \@r_slice,
      scols => \@r_scols,
      where => $result,
   };
   return $where;
}

sub generate_del_stmt {
   my ( $self, %args ) = @_;

   my $tbl  = $args{tbl_struct};
   my @cols = $args{cols} ? @{$args{cols}} : ();
   my $tp   = $self->{TableParser};
   my $q    = $self->{Quoter};

   my @del_cols;
   my @del_slice;

   my $index = $tp->find_best_index($tbl, $args{index});
   die "Cannot find an ascendable index in table" unless $index;

   if ( $index ) {
      @del_cols = @{$tbl->{keys}->{$index}->{cols}};
   }
   else {
      @del_cols = @{$tbl->{cols}};
   }
   MKDEBUG && _d('Columns needed for DELETE:', join(', ', @del_cols));

   my %col_posn = do { my $i = 0; map { $_ => $i++ } @cols };
   foreach my $col ( @del_cols ) {
      if ( !exists $col_posn{$col} ) {
         push @cols, $col;
         $col_posn{$col} = $#cols;
      }
      push @del_slice, $col_posn{$col};
   }
   MKDEBUG && _d('Ordinals needed for DELETE:', join(', ', @del_slice));

   my $del_stmt = {
      cols  => \@cols,
      index => $index,
      where => '',
      slice => [],
      scols => [],
   };

   my @clauses;
   foreach my $i ( 0 .. $#del_slice ) {
      my $ord = $del_slice[$i];
      my $col = $cols[$ord];
      my $quo = $q->quote($col);
      if ( $tbl->{is_nullable}->{$col} ) {
         push @clauses, "((? IS NULL AND $quo IS NULL) OR ($quo = ?))";
         push @{$del_stmt->{slice}}, $ord, $ord;
         push @{$del_stmt->{scols}}, $col, $col;
      }
      else {
         push @clauses, "$quo = ?";
         push @{$del_stmt->{slice}}, $ord;
         push @{$del_stmt->{scols}}, $col;
      }
   }

   $del_stmt->{where} = '(' . join(' AND ', @clauses) . ')';

   return $del_stmt;
}

sub generate_ins_stmt {
   my ( $self, %args ) = @_;
   foreach my $arg ( qw(ins_tbl sel_cols) ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my $ins_tbl  = $args{ins_tbl};
   my @sel_cols = @{$args{sel_cols}};

   die "You didn't specify any SELECT columns" unless @sel_cols;

   my @ins_cols;
   my @ins_slice;
   for my $i ( 0..$#sel_cols ) {
      next unless $ins_tbl->{is_col}->{$sel_cols[$i]};
      push @ins_cols, $sel_cols[$i];
      push @ins_slice, $i;
   }

   return {
      cols  => \@ins_cols,
      slice => \@ins_slice,
   };
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End TableNibbler package
# ###########################################################################

# ###########################################################################
# MasterSlave package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/MasterSlave.pm
#   t/lib/MasterSlave.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package MasterSlave;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, %args ) = @_;
   my $self = {
      %args,
      replication_thread => {},
   };
   return bless $self, $class;
}

sub get_slaves {
   my ($self, %args) = @_;
   my @required_args = qw(OptionParser DSNParser Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($o, $dp) = @args{@required_args};

   my $slaves = [];
   my $method = $o->get('recursion-method');
   MKDEBUG && _d('Slave recursion method:', $method);
   if ( !$method || $method =~ m/proocesslist|hosts/i ) {
      my @required_args = qw(dbh dsn);
      foreach my $arg ( @required_args ) {
         die "I need a $arg argument" unless $args{$arg};
      }
      my ($dbh, $dsn) = @args{@required_args};
      $self->recurse_to_slaves(
         {  dbh        => $dbh,
            dsn        => $dsn,
            dsn_parser => $dp,
            recurse    => $o->get('recurse'),
            method     => $o->get('recursion-method'),
            callback   => sub {
               my ( $dsn, $dbh, $level, $parent ) = @_;
               return unless $level;
               MKDEBUG && _d('Found slave:', $dp->as_string($dsn));
               $dbh->{InactiveDestroy}  = 1; # Prevent destroying on fork.
               $dbh->{FetchHashKeyName} = 'NAME_lc';
               push @$slaves, { dsn=>$dsn, dbh=>$dbh };
               return;
            },
         }
      );
   }
   elsif ( $method =~ m/^dsn=/i ) {
      my ($dsn_table_dsn) = $method =~ m/^dsn=(.+)/i;
      $slaves = $self->get_cxn_from_dsn_table(
         %args,
         dsn_table_dsn => $dsn_table_dsn,
      );
   }
   else {
      die "Invalid --recusion-method: $method.  Valid values are: "
        . "dsn=DSN, hosts, or processlist.\n";
   }

   return $slaves;
}

sub recurse_to_slaves {
   my ( $self, $args, $level ) = @_;
   $level ||= 0;
   my $dp   = $args->{dsn_parser};
   my $dsn  = $args->{dsn};

   my $dbh;
   eval {
      $dbh = $args->{dbh} || $dp->get_dbh(
         $dp->get_cxn_params($dsn), { AutoCommit => 1 });
      MKDEBUG && _d('Connected to', $dp->as_string($dsn));
   };
   if ( $EVAL_ERROR ) {
      print STDERR "Cannot connect to ", $dp->as_string($dsn), "\n"
         or die "Cannot print: $OS_ERROR";
      return;
   }

   my $sql  = 'SELECT @@SERVER_ID';
   MKDEBUG && _d($sql);
   my ($id) = $dbh->selectrow_array($sql);
   MKDEBUG && _d('Working on server ID', $id);
   my $master_thinks_i_am = $dsn->{server_id};
   if ( !defined $id
       || ( defined $master_thinks_i_am && $master_thinks_i_am != $id )
       || $args->{server_ids_seen}->{$id}++
   ) {
      MKDEBUG && _d('Server ID seen, or not what master said');
      if ( $args->{skip_callback} ) {
         $args->{skip_callback}->($dsn, $dbh, $level, $args->{parent});
      }
      return;
   }

   $args->{callback}->($dsn, $dbh, $level, $args->{parent});

   if ( !defined $args->{recurse} || $level < $args->{recurse} ) {

      my @slaves =
         grep { !$_->{master_id} || $_->{master_id} == $id } # Only my slaves.
         $self->find_slave_hosts($dp, $dbh, $dsn, $args->{method});

      foreach my $slave ( @slaves ) {
         MKDEBUG && _d('Recursing from',
            $dp->as_string($dsn), 'to', $dp->as_string($slave));
         $self->recurse_to_slaves(
            { %$args, dsn => $slave, dbh => undef, parent => $dsn }, $level + 1 );
      }
   }
}

sub find_slave_hosts {
   my ( $self, $dsn_parser, $dbh, $dsn, $method ) = @_;

   my @methods = qw(processlist hosts);
   if ( $method ) {
      @methods = grep { $_ ne $method } @methods;
      unshift @methods, $method;
   }
   else {
      if ( ($dsn->{P} || 3306) != 3306 ) {
         MKDEBUG && _d('Port number is non-standard; using only hosts method');
         @methods = qw(hosts);
      }
   }
   MKDEBUG && _d('Looking for slaves on', $dsn_parser->as_string($dsn),
      'using methods', @methods);

   my @slaves;
   METHOD:
   foreach my $method ( @methods ) {
      my $find_slaves = "_find_slaves_by_$method";
      MKDEBUG && _d('Finding slaves with', $find_slaves);
      @slaves = $self->$find_slaves($dsn_parser, $dbh, $dsn);
      last METHOD if @slaves;
   }

   MKDEBUG && _d('Found', scalar(@slaves), 'slaves');
   return @slaves;
}

sub _find_slaves_by_processlist {
   my ( $self, $dsn_parser, $dbh, $dsn ) = @_;

   my @slaves = map  {
      my $slave        = $dsn_parser->parse("h=$_", $dsn);
      $slave->{source} = 'processlist';
      $slave;
   }
   grep { $_ }
   map  {
      my ( $host ) = $_->{host} =~ m/^([^:]+):/;
      if ( $host eq 'localhost' ) {
         $host = '127.0.0.1'; # Replication never uses sockets.
      }
      $host;
   } $self->get_connected_slaves($dbh);

   return @slaves;
}

sub _find_slaves_by_hosts {
   my ( $self, $dsn_parser, $dbh, $dsn ) = @_;

   my @slaves;
   my $sql = 'SHOW SLAVE HOSTS';
   MKDEBUG && _d($dbh, $sql);
   @slaves = @{$dbh->selectall_arrayref($sql, { Slice => {} })};

   if ( @slaves ) {
      MKDEBUG && _d('Found some SHOW SLAVE HOSTS info');
      @slaves = map {
         my %hash;
         @hash{ map { lc $_ } keys %$_ } = values %$_;
         my $spec = "h=$hash{host},P=$hash{port}"
            . ( $hash{user} ? ",u=$hash{user}" : '')
            . ( $hash{password} ? ",p=$hash{password}" : '');
         my $dsn           = $dsn_parser->parse($spec, $dsn);
         $dsn->{server_id} = $hash{server_id};
         $dsn->{master_id} = $hash{master_id};
         $dsn->{source}    = 'hosts';
         $dsn;
      } @slaves;
   }

   return @slaves;
}

sub get_connected_slaves {
   my ( $self, $dbh ) = @_;

   my $show = "SHOW GRANTS FOR ";
   my $user = 'CURRENT_USER()';
   my $vp   = $self->{VersionParser};
   if ( $vp && !$vp->version_ge($dbh, '4.1.2') ) {
      $user = $dbh->selectrow_arrayref('SELECT USER()')->[0];
      $user =~ s/([^@]+)@(.+)/'$1'\@'$2'/;
   }
   my $sql = $show . $user;
   MKDEBUG && _d($dbh, $sql);

   my $proc;
   eval {
      $proc = grep {
         m/ALL PRIVILEGES.*?\*\.\*|PROCESS/
      } @{$dbh->selectcol_arrayref($sql)};
   };
   if ( $EVAL_ERROR ) {

      if ( $EVAL_ERROR =~ m/no such grant defined for user/ ) {
         MKDEBUG && _d('Retrying SHOW GRANTS without host; error:',
            $EVAL_ERROR);
         ($user) = split('@', $user);
         $sql    = $show . $user;
         MKDEBUG && _d($sql);
         eval {
            $proc = grep {
               m/ALL PRIVILEGES.*?\*\.\*|PROCESS/
            } @{$dbh->selectcol_arrayref($sql)};
         };
      }

      die "Failed to $sql: $EVAL_ERROR" if $EVAL_ERROR;
   }
   if ( !$proc ) {
      die "You do not have the PROCESS privilege";
   }

   $sql = 'SHOW PROCESSLIST';
   MKDEBUG && _d($dbh, $sql);
   grep { $_->{command} =~ m/Binlog Dump/i }
   map  { # Lowercase the column names
      my %hash;
      @hash{ map { lc $_ } keys %$_ } = values %$_;
      \%hash;
   }
   @{$dbh->selectall_arrayref($sql, { Slice => {} })};
}

sub is_master_of {
   my ( $self, $master, $slave ) = @_;
   my $master_status = $self->get_master_status($master)
      or die "The server specified as a master is not a master";
   my $slave_status  = $self->get_slave_status($slave)
      or die "The server specified as a slave is not a slave";
   my @connected     = $self->get_connected_slaves($master)
      or die "The server specified as a master has no connected slaves";
   my (undef, $port) = $master->selectrow_array('SHOW VARIABLES LIKE "port"');

   if ( $port != $slave_status->{master_port} ) {
      die "The slave is connected to $slave_status->{master_port} "
         . "but the master's port is $port";
   }

   if ( !grep { $slave_status->{master_user} eq $_->{user} } @connected ) {
      die "I don't see any slave I/O thread connected with user "
         . $slave_status->{master_user};
   }

   if ( ($slave_status->{slave_io_state} || '')
      eq 'Waiting for master to send event' )
   {
      my ( $master_log_name, $master_log_num )
         = $master_status->{file} =~ m/^(.*?)\.0*([1-9][0-9]*)$/;
      my ( $slave_log_name, $slave_log_num )
         = $slave_status->{master_log_file} =~ m/^(.*?)\.0*([1-9][0-9]*)$/;
      if ( $master_log_name ne $slave_log_name
         || abs($master_log_num - $slave_log_num) > 1 )
      {
         die "The slave thinks it is reading from "
            . "$slave_status->{master_log_file},  but the "
            . "master is writing to $master_status->{file}";
      }
   }
   return 1;
}

sub get_master_dsn {
   my ( $self, $dbh, $dsn, $dsn_parser ) = @_;
   my $master = $self->get_slave_status($dbh) or return undef;
   my $spec   = "h=$master->{master_host},P=$master->{master_port}";
   return       $dsn_parser->parse($spec, $dsn);
}

sub get_slave_status {
   my ( $self, $dbh ) = @_;
   if ( !$self->{not_a_slave}->{$dbh} ) {
      my $sth = $self->{sths}->{$dbh}->{SLAVE_STATUS}
            ||= $dbh->prepare('SHOW SLAVE STATUS');
      MKDEBUG && _d($dbh, 'SHOW SLAVE STATUS');
      $sth->execute();
      my ($ss) = @{$sth->fetchall_arrayref({})};

      if ( $ss && %$ss ) {
         $ss = { map { lc($_) => $ss->{$_} } keys %$ss }; # lowercase the keys
         return $ss;
      }

      MKDEBUG && _d('This server returns nothing for SHOW SLAVE STATUS');
      $self->{not_a_slave}->{$dbh}++;
   }
}

sub get_master_status {
   my ( $self, $dbh ) = @_;

   if ( $self->{not_a_master}->{$dbh} ) {
      MKDEBUG && _d('Server on dbh', $dbh, 'is not a master');
      return;
   }

   my $sth = $self->{sths}->{$dbh}->{MASTER_STATUS}
         ||= $dbh->prepare('SHOW MASTER STATUS');
   MKDEBUG && _d($dbh, 'SHOW MASTER STATUS');
   $sth->execute();
   my ($ms) = @{$sth->fetchall_arrayref({})};
   MKDEBUG && _d(
      $ms ? map { "$_=" . (defined $ms->{$_} ? $ms->{$_} : '') } keys %$ms
          : '');

   if ( !$ms || scalar keys %$ms < 2 ) {
      MKDEBUG && _d('Server on dbh', $dbh, 'does not seem to be a master');
      $self->{not_a_master}->{$dbh}++;
   }

  return { map { lc($_) => $ms->{$_} } keys %$ms }; # lowercase the keys
}

sub wait_for_master {
   my ( $self, %args ) = @_;
   my @required_args = qw(master_status slave_dbh);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($master_status, $slave_dbh) = @args{@required_args};
   my $timeout       = $args{timeout} || 60;

   my $result;
   my $waited;
   if ( $master_status ) {
      my $sql = "SELECT MASTER_POS_WAIT('$master_status->{file}', "
              . "$master_status->{position}, $timeout)";
      MKDEBUG && _d($slave_dbh, $sql);
      my $start = time;
      ($result) = $slave_dbh->selectrow_array($sql);

      $waited = time - $start;

      MKDEBUG && _d('Result of waiting:', $result);
      MKDEBUG && _d("Waited", $waited, "seconds");
   }
   else {
      MKDEBUG && _d('Not waiting: this server is not a master');
   }

   return {
      result => $result,
      waited => $waited,
   };
}

sub stop_slave {
   my ( $self, $dbh ) = @_;
   my $sth = $self->{sths}->{$dbh}->{STOP_SLAVE}
         ||= $dbh->prepare('STOP SLAVE');
   MKDEBUG && _d($dbh, $sth->{Statement});
   $sth->execute();
}

sub start_slave {
   my ( $self, $dbh, $pos ) = @_;
   if ( $pos ) {
      my $sql = "START SLAVE UNTIL MASTER_LOG_FILE='$pos->{file}', "
              . "MASTER_LOG_POS=$pos->{position}";
      MKDEBUG && _d($dbh, $sql);
      $dbh->do($sql);
   }
   else {
      my $sth = $self->{sths}->{$dbh}->{START_SLAVE}
            ||= $dbh->prepare('START SLAVE');
      MKDEBUG && _d($dbh, $sth->{Statement});
      $sth->execute();
   }
}

sub catchup_to_master {
   my ( $self, $slave, $master, $timeout ) = @_;
   $self->stop_slave($master);
   $self->stop_slave($slave);
   my $slave_status  = $self->get_slave_status($slave);
   my $slave_pos     = $self->repl_posn($slave_status);
   my $master_status = $self->get_master_status($master);
   my $master_pos    = $self->repl_posn($master_status);
   MKDEBUG && _d('Master position:', $self->pos_to_string($master_pos),
      'Slave position:', $self->pos_to_string($slave_pos));

   my $result;
   if ( $self->pos_cmp($slave_pos, $master_pos) < 0 ) {
      MKDEBUG && _d('Waiting for slave to catch up to master');
      $self->start_slave($slave, $master_pos);

      $result = $self->wait_for_master(
            master_status => $master_status,
            slave_dbh     => $slave,
            timeout       => $timeout,
            master_status => $master_status
      );
      if ( !defined $result->{result} ) {
         $slave_status = $self->get_slave_status($slave);
         if ( !$self->slave_is_running($slave_status) ) {
            MKDEBUG && _d('Master position:',
               $self->pos_to_string($master_pos),
               'Slave position:', $self->pos_to_string($slave_pos));
            $slave_pos = $self->repl_posn($slave_status);
            if ( $self->pos_cmp($slave_pos, $master_pos) != 0 ) {
               die "MASTER_POS_WAIT() returned NULL but slave has not "
                  . "caught up to master";
            }
            MKDEBUG && _d('Slave is caught up to master and stopped');
         }
         else {
            die "Slave has not caught up to master and it is still running";
         }
      }
   }
   else {
      MKDEBUG && _d("Slave is already caught up to master");
   }

   return $result;
}

sub catchup_to_same_pos {
   my ( $self, $s1_dbh, $s2_dbh ) = @_;
   $self->stop_slave($s1_dbh);
   $self->stop_slave($s2_dbh);
   my $s1_status = $self->get_slave_status($s1_dbh);
   my $s2_status = $self->get_slave_status($s2_dbh);
   my $s1_pos    = $self->repl_posn($s1_status);
   my $s2_pos    = $self->repl_posn($s2_status);
   if ( $self->pos_cmp($s1_pos, $s2_pos) < 0 ) {
      $self->start_slave($s1_dbh, $s2_pos);
   }
   elsif ( $self->pos_cmp($s2_pos, $s1_pos) < 0 ) {
      $self->start_slave($s2_dbh, $s1_pos);
   }

   $s1_status = $self->get_slave_status($s1_dbh);
   $s2_status = $self->get_slave_status($s2_dbh);
   $s1_pos    = $self->repl_posn($s1_status);
   $s2_pos    = $self->repl_posn($s2_status);

   if ( $self->slave_is_running($s1_status)
     || $self->slave_is_running($s2_status)
     || $self->pos_cmp($s1_pos, $s2_pos) != 0)
   {
      die "The servers aren't both stopped at the same position";
   }

}

sub slave_is_running {
   my ( $self, $slave_status ) = @_;
   return ($slave_status->{slave_sql_running} || 'No') eq 'Yes';
}

sub has_slave_updates {
   my ( $self, $dbh ) = @_;
   my $sql = q{SHOW VARIABLES LIKE 'log_slave_updates'};
   MKDEBUG && _d($dbh, $sql);
   my ($name, $value) = $dbh->selectrow_array($sql);
   return $value && $value =~ m/^(1|ON)$/;
}

sub repl_posn {
   my ( $self, $status ) = @_;
   if ( exists $status->{file} && exists $status->{position} ) {
      return {
         file     => $status->{file},
         position => $status->{position},
      };
   }
   else {
      return {
         file     => $status->{relay_master_log_file},
         position => $status->{exec_master_log_pos},
      };
   }
}

sub get_slave_lag {
   my ( $self, $dbh ) = @_;
   my $stat = $self->get_slave_status($dbh);
   return unless $stat;  # server is not a slave
   return $stat->{seconds_behind_master};
}

sub pos_cmp {
   my ( $self, $a, $b ) = @_;
   return $self->pos_to_string($a) cmp $self->pos_to_string($b);
}

sub short_host {
   my ( $self, $dsn ) = @_;
   my ($host, $port);
   if ( $dsn->{master_host} ) {
      $host = $dsn->{master_host};
      $port = $dsn->{master_port};
   }
   else {
      $host = $dsn->{h};
      $port = $dsn->{P};
   }
   return ($host || '[default]') . ( ($port || 3306) == 3306 ? '' : ":$port" );
}

sub is_replication_thread {
   my ( $self, $query, %args ) = @_; 
   return unless $query;

   my $type = lc($args{type} || 'all');
   die "Invalid type: $type"
      unless $type =~ m/^binlog_dump|slave_io|slave_sql|all$/i;

   my $match = 0;
   if ( $type =~ m/binlog_dump|all/i ) {
      $match = 1
         if ($query->{Command} || $query->{command} || '') eq "Binlog Dump";
   }
   if ( !$match ) {
      if ( ($query->{User} || $query->{user} || '') eq "system user" ) {
         MKDEBUG && _d("Slave replication thread");
         if ( $type ne 'all' ) { 
            my $state = $query->{State} || $query->{state} || '';

            if ( $state =~ m/^init|end$/ ) {
               MKDEBUG && _d("Special state:", $state);
               $match = 1;
            }
            else {
               my ($slave_sql) = $state =~ m/
                  ^(Waiting\sfor\sthe\snext\sevent
                   |Reading\sevent\sfrom\sthe\srelay\slog
                   |Has\sread\sall\srelay\slog;\swaiting
                   |Making\stemp\sfile
                   |Waiting\sfor\sslave\smutex\son\sexit)/xi; 

               $match = $type eq 'slave_sql' &&  $slave_sql ? 1
                      : $type eq 'slave_io'  && !$slave_sql ? 1
                      :                                       0;
            }
         }
         else {
            $match = 1;
         }
      }
      else {
         MKDEBUG && _d('Not system user');
      }

      if ( !defined $args{check_known_ids} || $args{check_known_ids} ) {
         my $id = $query->{Id} || $query->{id};
         if ( $match ) {
            $self->{replication_thread}->{$id} = 1;
         }
         else {
            if ( $self->{replication_thread}->{$id} ) {
               MKDEBUG && _d("Thread ID is a known replication thread ID");
               $match = 1;
            }
         }
      }
   }

   MKDEBUG && _d('Matches', $type, 'replication thread:',
      ($match ? 'yes' : 'no'), '; match:', $match);

   return $match;
}


sub get_replication_filters {
   my ( $self, %args ) = @_;
   my @required_args = qw(dbh);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh) = @args{@required_args};

   my %filters = ();

   my $status = $self->get_master_status($dbh);
   if ( $status ) {
      map { $filters{$_} = $status->{$_} }
      grep { defined $status->{$_} && $status->{$_} ne '' }
      qw(
         binlog_do_db
         binlog_ignore_db
      );
   }

   $status = $self->get_slave_status($dbh);
   if ( $status ) {
      map { $filters{$_} = $status->{$_} }
      grep { defined $status->{$_} && $status->{$_} ne '' }
      qw(
         replicate_do_db
         replicate_ignore_db
         replicate_do_table
         replicate_ignore_table 
         replicate_wild_do_table
         replicate_wild_ignore_table
      );

      my $sql = "SHOW VARIABLES LIKE 'slave_skip_errors'";
      MKDEBUG && _d($dbh, $sql);
      my $row = $dbh->selectrow_arrayref($sql);
      $filters{slave_skip_errors} = $row->[1] if $row->[1] && $row->[1] ne 'OFF';
   }

   return \%filters; 
}


sub pos_to_string {
   my ( $self, $pos ) = @_;
   my $fmt  = '%s/%020d';
   return sprintf($fmt, @{$pos}{qw(file position)});
}

sub reset_known_replication_threads {
   my ( $self ) = @_;
   $self->{replication_thread} = {};
   return;
}

sub get_cxn_from_dsn_table {
   my ($self, %args) = @_;
   my @required_args = qw(dsn_table_dsn DSNParser Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dsn_table_dsn, $dp, $q) = @args{@required_args};
   MKDEBUG && _d('DSN table DSN:', $dsn_table_dsn);

   my $dsn = $dp->parse($dsn_table_dsn);
   my $dsn_table;
   if ( $dsn->{D} && $dsn->{t} ) {
      $dsn_table = $q->quote($dsn->{D}, $dsn->{t});
   }
   elsif ( $dsn->{t} && $dsn->{t} =~ m/\./ ) {
      $dsn_table = $q->quote($q->split_unquote($dsn->{t}));
   }
   else {
      die "DSN table DSN does not specify a database (D) "
        . "or a database-qualified table (t)";
   }

   my @cxn;
   my $dbh = $dp->get_dbh($dp->get_cxn_params($dsn));
   my $sql = "SELECT dsn FROM $dsn_table ORDER BY id";
   MKDEBUG && _d($sql);
   my $dsns = $dbh->selectcol_arrayref($sql);
   if ( $dsns ) {
      foreach my $dsn ( @$dsns ) {
         MKDEBUG && _d('DSN from DSN table:', $dsn);
         my $dsn = $dp->parse($dsn);
         my $dbh = $dp->get_dbh($dp->get_cxn_params($dsn));
         push @cxn, {dsn=>$dsn, dbh=>$dbh};
      }
   }
   $dbh->disconnect();
   return \@cxn;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End MasterSlave package
# ###########################################################################

# ###########################################################################
# RowChecksum package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/RowChecksum.pm
#   t/lib/RowChecksum.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package RowChecksum;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use List::Util qw(max);
use Data::Dumper;
$Data::Dumper::Indent    = 1;
$Data::Dumper::Sortkeys  = 1;
$Data::Dumper::Quotekeys = 0;

sub new {
   my ( $class, %args ) = @_;
   foreach my $arg ( qw(OptionParser Quoter) ) {
      die "I need a $arg argument" unless defined $args{$arg};
   }
   my $self = { %args };
   return bless $self, $class;
}

sub make_row_checksum {
   my ( $self, %args ) = @_;
   my @required_args = qw(tbl);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($tbl) = @args{@required_args};

   my $o          = $self->{OptionParser};
   my $q          = $self->{Quoter};
   my $tbl_struct = $tbl->{tbl_struct};
   my $func       = $args{func} || uc($o->get('function'));
   my $cols       = $self->get_checksum_columns(%args);

   my $query;
   if ( !$args{no_cols} ) {
      $query = join(', ',
                  map { 
                     my $col = $_;
                     if ( $col =~ m/\+ 0/ ) {
                        my ($real_col) = /^(\S+)/;
                        $col .= " AS $real_col";
                     }
                     elsif ( $col =~ m/TRIM/ ) {
                        my ($real_col) = m/TRIM\(([^\)]+)\)/;
                        $col .= " AS $real_col";
                     }
                     $col;
                  } @{$cols->{select}})
             . ', ';
   }

   if ( uc $func ne 'FNV_64' && uc $func ne 'FNV1A_64' ) {
      my $sep = $o->get('separator') || '#';
      $sep    =~ s/'//g;
      $sep  ||= '#';

      my @nulls = grep { $cols->{allowed}->{$_} } @{$tbl_struct->{null_cols}};
      if ( @nulls ) {
         my $bitmap = "CONCAT("
            . join(', ', map { 'ISNULL(' . $q->quote($_) . ')' } @nulls)
            . ")";
         push @{$cols->{select}}, $bitmap;
      }

      $query .= @{$cols->{select}} > 1
              ? "$func(CONCAT_WS('$sep', " . join(', ', @{$cols->{select}}) . '))'
              : "$func($cols->{select}->[0])";
   }
   else {
      my $fnv_func = uc $func;
      $query .= "$fnv_func(" . join(', ', @{$cols->{select}}) . ')';
   }

   MKDEBUG && _d('Row checksum:', $query);
   return $query;
}

sub make_chunk_checksum {
   my ( $self, %args ) = @_;
   my @required_args = qw(tbl);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   if ( !$args{dbh} && !($args{func} && $args{crc_width} && $args{crc_type}) ) {
      die "I need a dbh argument"
   }
   my ($tbl) = @args{@required_args};
   my $o     = $self->{OptionParser};
   my $q     = $self->{Quoter};

   my %crc_args = $self->get_crc_args(%args);
   MKDEBUG && _d("Checksum strat:", Dumper(\%crc_args));

   my $row_checksum = $self->make_row_checksum(
      %args,
      %crc_args,
      no_cols => 1
   );
   my $crc;
   if ( $crc_args{crc_type} =~ m/int$/ ) {
      $crc = "COALESCE(LOWER(CONV(BIT_XOR(CAST($row_checksum AS UNSIGNED)), "
           . "10, 16)), 0)";
   }
   else {
      my $slices = $self->_make_xor_slices(
         row_checksum => $row_checksum,
         %crc_args,
      );
      $crc = "COALESCE(LOWER(CONCAT($slices)), 0)";
   }

   my $select = "COUNT(*) AS cnt, $crc AS crc";
   MKDEBUG && _d('Chunk checksum:', $select);
   return $select;
}

sub get_checksum_columns {
   my ($self, %args) = @_;
   my @required_args = qw(tbl);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($tbl) = @args{@required_args};
   my $o     = $self->{OptionParser};
   my $q     = $self->{Quoter};

   my $trim            = $o->get('trim');
   my $float_precision = $o->get('float-precision');

   my $tbl_struct = $tbl->{tbl_struct};
   my $ignore_col = $o->get('ignore-columns') || {};
   my $all_cols   = $o->get('columns') || $tbl_struct->{cols};
   my %cols       = map { lc($_) => 1 } grep { !$ignore_col->{$_} } @$all_cols;
   my %seen;
   my @cols =
      map {
         my $type   = $tbl_struct->{type_for}->{$_};
         my $result = $q->quote($_);
         if ( $type eq 'timestamp' ) {
            $result .= ' + 0';
         }
         elsif ( $float_precision && $type =~ m/float|double/ ) {
            $result = "ROUND($result, $float_precision)";
         }
         elsif ( $trim && $type =~ m/varchar/ ) {
            $result = "TRIM($result)";
         }
         $result;
      }
      grep {
         $cols{$_} && !$seen{$_}++
      }
      @{$tbl_struct->{cols}};

   return {
      select  => \@cols,
      allowed => \%cols,
   };
}

sub get_crc_args {
   my ($self, %args) = @_;
   my $func      = $args{func}     || $self->_get_hash_func(%args);
   my $crc_width = $args{crc_width}|| $self->_get_crc_width(%args, func=>$func);
   my $crc_type  = $args{crc_type} || $self->_get_crc_type(%args, func=>$func);
   my $opt_slice; 
   if ( $args{dbh} && $crc_type !~ m/int$/ ) {
      $opt_slice = $self->_optimize_xor(%args, func=>$func);
   }

   return (
      func      => $func,
      crc_width => $crc_width,
      crc_type  => $crc_type,
      opt_slice => $opt_slice,
   );
}

sub _get_hash_func {
   my ( $self, %args ) = @_;
   my @required_args = qw(dbh);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh) = @args{@required_args};
   my $o     = $self->{OptionParser};
   my @funcs = qw(CRC32 FNV1A_64 FNV_64 MD5 SHA1);

   if ( my $func = $o->get('function') ) {
      unshift @funcs, $func;
   }

   my ($result, $error);
   foreach my $func ( @funcs ) {
      eval {
         my $sql = "SELECT $func('test-string')";
         MKDEBUG && _d($sql);
         $args{dbh}->do($sql);
      };
      if ( $EVAL_ERROR && $EVAL_ERROR =~ m/failed: (.*?) at \S+ line/ ) {
         $error .= qq{$func cannot be used because "$1"\n};
         MKDEBUG && _d($func, 'cannot be used because', $1);
      }
      MKDEBUG && _d('Chosen hash func:', $result);
      return $func;
   }
   die $error || 'No hash functions (CRC32, MD5, etc.) are available';
}

sub _get_crc_width {
   my ( $self, %args ) = @_;
   my @required_args = qw(dbh func);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $func) = @args{@required_args};

   my $crc_width = 16;
   if ( uc $func ne 'FNV_64' && uc $func ne 'FNV1A_64' ) {
      eval {
         my ($val) = $dbh->selectrow_array("SELECT $func('a')");
         $crc_width = max(16, length($val));
      };
   }
   return $crc_width;
}

sub _get_crc_type {
   my ( $self, %args ) = @_;
   my @required_args = qw(dbh func);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $func) = @args{@required_args};

   my $type   = '';
   my $length = 0;
   my $sql    = "SELECT $func('a')";
   my $sth    = $dbh->prepare($sql);
   eval {
      $sth->execute();
      $type   = $sth->{mysql_type_name}->[0];
      $length = $sth->{mysql_length}->[0];
      MKDEBUG && _d($sql, $type, $length);
      if ( $type eq 'bigint' && $length < 20 ) {
         $type = 'int';
      }
   };
   $sth->finish;
   MKDEBUG && _d('crc_type:', $type, 'length:', $length);
   return $type;
}

sub _optimize_xor {
   my ( $self, %args ) = @_;
   my @required_args = qw(dbh func);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $func) = @args{@required_args};

   die "$func never needs BIT_XOR optimization"
      if $func =~ m/^(?:FNV1A_64|FNV_64|CRC32)$/i;

   my $opt_slice = 0;
   my $unsliced  = uc $dbh->selectall_arrayref("SELECT $func('a')")->[0]->[0];
   my $sliced    = '';
   my $start     = 1;
   my $crc_width = length($unsliced) < 16 ? 16 : length($unsliced);

   do { # Try different positions till sliced result equals non-sliced.
      MKDEBUG && _d('Trying slice', $opt_slice);
      $dbh->do('SET @crc := "", @cnt := 0');
      my $slices = $self->_make_xor_slices(
         row_checksum => "\@crc := $func('a')",
         crc_width    => $crc_width,
         opt_slice    => $opt_slice,
      );

      my $sql = "SELECT CONCAT($slices) AS TEST FROM (SELECT NULL) AS x";
      $sliced = ($dbh->selectrow_array($sql))[0];
      if ( $sliced ne $unsliced ) {
         MKDEBUG && _d('Slice', $opt_slice, 'does not work');
         $start += 16;
         ++$opt_slice;
      }
   } while ( $start < $crc_width && $sliced ne $unsliced );

   if ( $sliced eq $unsliced ) {
      MKDEBUG && _d('Slice', $opt_slice, 'works');
      return $opt_slice;
   }
   else {
      MKDEBUG && _d('No slice works');
      return undef;
   }
}

sub _make_xor_slices {
   my ( $self, %args ) = @_;
   my @required_args = qw(row_checksum crc_width);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($row_checksum, $crc_width) = @args{@required_args};
   my ($opt_slice) = $args{opt_slice};

   my @slices;
   for ( my $start = 1; $start <= $crc_width; $start += 16 ) {
      my $len = $crc_width - $start + 1;
      if ( $len > 16 ) {
         $len = 16;
      }
      push @slices,
         "LPAD(CONV(BIT_XOR("
         . "CAST(CONV(SUBSTRING(\@crc, $start, $len), 16, 10) AS UNSIGNED))"
         . ", 10, 16), $len, '0')";
   }

   if ( defined $opt_slice && $opt_slice < @slices ) {
      $slices[$opt_slice] =~ s/\@crc/\@crc := $row_checksum/;
   }
   else {
      map { s/\@crc/$row_checksum/ } @slices;
   }

   return join(', ', @slices);
}

sub find_replication_differences {
   my ($self, %args) = @_;
   my @required_args = qw(dbh repl_table);
   foreach my $arg( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $repl_table) = @args{@required_args};

   my $sql
      = "SELECT CONCAT(db, '.', tbl) AS `table`, "
      . "chunk, chunk_index, lower_boundary, upper_boundary, "
      . "COALESCE(this_cnt-master_cnt, 0) AS cnt_diff, "
      . "COALESCE("
      .   "this_crc <> master_crc OR ISNULL(master_crc) <> ISNULL(this_crc), 0"
      . ") AS crc_diff, this_cnt, master_cnt, this_crc, master_crc "
      . "FROM $repl_table "
      . "WHERE (master_cnt <> this_cnt OR master_crc <> this_crc "
      .        "OR ISNULL(master_crc) <> ISNULL(this_crc))"
      . ($args{where} ? " AND ($args{where})" : "");
   MKDEBUG && _d($sql);
   my $diffs = $dbh->selectall_arrayref($sql, { Slice => {} });
   return $diffs;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End RowChecksum package
# ###########################################################################

# ###########################################################################
# NibbleIterator package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/NibbleIterator.pm
#   t/lib/NibbleIterator.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package NibbleIterator;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use Data::Dumper;
$Data::Dumper::Indent    = 1;
$Data::Dumper::Sortkeys  = 1;
$Data::Dumper::Quotekeys = 0;

sub new {
   my ( $class, %args ) = @_;
   my @required_args = qw(dbh tbl chunk_size OptionParser Quoter TableNibbler TableParser);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $tbl, $chunk_size, $o, $q) = @args{@required_args};

   my $one_nibble = !defined $args{one_nibble} || $args{one_nibble}
                  ?  _can_nibble_once(%args)
                  : 0;

   my $index = _find_best_index(%args);
   if ( !$index && !$one_nibble ) {
      die "There is no good index and the table is oversized.";
   }

   my $self;
   if ( $one_nibble ) {
      my $tbl_struct = $tbl->{tbl_struct};
      my $ignore_col = $o->get('ignore-columns') || {};
      my $all_cols   = $o->get('columns') || $tbl_struct->{cols};
      my @cols       = grep { !$ignore_col->{$_} } @$all_cols;

      my $nibble_sql
         = ($args{dms} ? "$args{dms} " : "SELECT ")
         . ($args{select} ? $args{select}
                          : join(', ', map { $q->quote($_) } @cols))
         . " FROM " . $q->quote(@{$tbl}{qw(db tbl)})
         . ($args{where} ? " AND ($args{where})" : '')
         . " /*one nibble*/";
      MKDEBUG && _d('One nibble statement:', $nibble_sql);

      my $explain_nibble_sql
         = "EXPLAIN SELECT "
         . ($args{select} ? $args{select}
                          : join(', ', map { $q->quote($_) } @cols))
         . " FROM " . $q->quote(@{$tbl}{qw(db tbl)})
         . ($args{where} ? " AND ($args{where})" : '')
         . " /*explain one nibble*/";
      MKDEBUG && _d('Explain one nibble statement:', $explain_nibble_sql);

      $self = {
         %args,
         one_nibble         => 1,
         limit              => 0,
         nibble_sql         => $nibble_sql,
         explain_nibble_sql => $explain_nibble_sql,
      };
   }
   else {
      my $index_cols = $tbl->{tbl_struct}->{keys}->{$index}->{cols};

      my $asc = $args{TableNibbler}->generate_asc_stmt(
         %args,
         tbl_struct => $tbl->{tbl_struct},
         index      => $index,
         asc_only   => 1,
      );
      MKDEBUG && _d('Ascend params:', Dumper($asc));

      my $from     = $q->quote(@{$tbl}{qw(db tbl)}) . " FORCE INDEX(`$index`)";
      my $order_by = join(', ', map {$q->quote($_)} @{$index_cols});

      my $first_lb_sql
         = "SELECT /*!40001 SQL_NO_CACHE */ "
         . join(', ', map { $q->quote($_) } @{$asc->{scols}})
         . " FROM $from"
         . ($args{where} ? " WHERE $args{where}" : '')
         . " ORDER BY $order_by"
         . " LIMIT 1"
         . " /*first lower boundary*/";
      MKDEBUG && _d('First lower boundary statement:', $first_lb_sql);

      my $last_ub_sql
         = "SELECT /*!40001 SQL_NO_CACHE */ "
         . join(', ', map { $q->quote($_) } @{$asc->{scols}})
         . " FROM $from"
         . ($args{where} ? " WHERE $args{where}" : '')
         . " ORDER BY "
         . join(' DESC, ', map {$q->quote($_)} @{$index_cols}) . ' DESC'
         . " LIMIT 1"
         . " /*last upper boundary*/";
      MKDEBUG && _d('Last upper boundary statement:', $last_ub_sql);

      my $ub_sql
         = "SELECT /*!40001 SQL_NO_CACHE */ "
         . join(', ', map { $q->quote($_) } @{$asc->{scols}})
         . " FROM $from"
         . " WHERE " . $asc->{boundaries}->{'>='}
                     . ($args{where} ? " AND ($args{where})" : '')
         . " ORDER BY $order_by"
         . " LIMIT ?, 2"
         . " /*upper boundary*/";
      MKDEBUG && _d('Upper boundary statement:', $ub_sql);

      my $nibble_sql
         = ($args{dms} ? "$args{dms} " : "SELECT ")
         . ($args{select} ? $args{select}
                          : join(', ', map { $q->quote($_) } @{$asc->{cols}}))
         . " FROM $from"
         . " WHERE " . $asc->{boundaries}->{'>='}  # lower boundary
         . " AND "   . $asc->{boundaries}->{'<='}  # upper boundary
         . ($args{where} ? " AND ($args{where})" : '')
         . " ORDER BY $order_by"
         . " /*nibble*/";
      MKDEBUG && _d('Nibble statement:', $nibble_sql);

      my $explain_nibble_sql 
         = "EXPLAIN SELECT "
         . ($args{select} ? $args{select}
                          : join(', ', map { $q->quote($_) } @{$asc->{cols}}))
         . " FROM $from"
         . " WHERE " . $asc->{boundaries}->{'>='}  # lower boundary
         . " AND "   . $asc->{boundaries}->{'<='}  # upper boundary
         . ($args{where} ? " AND ($args{where})" : '')
         . " ORDER BY $order_by"
         . " /*explain nibble*/";
      MKDEBUG && _d('Explain nibble statement:', $explain_nibble_sql);

      my $limit = $chunk_size - 1;
      MKDEBUG && _d('Initial chunk size (LIMIT):', $limit);

      $self = {
         %args,
         index              => $index,
         limit              => $limit,
         first_lb_sql       => $first_lb_sql,
         last_ub_sql        => $last_ub_sql,
         ub_sql             => $ub_sql,
         nibble_sql         => $nibble_sql,
         explain_ub_sql     => "EXPLAIN $ub_sql",
         explain_nibble_sql => $explain_nibble_sql,
         sql                => {
            columns    => $asc->{scols},
            from       => $from,
            where      => $args{where},
            boundaries => $asc->{boundaries},
            order_by   => $order_by,
         },
      };
   }

   $self->{nibbleno}  = 0;
   $self->{have_rows} = 0;
   $self->{rowno}     = 0;

   return bless $self, $class;
}

sub next {
   my ($self) = @_;

   my %callback_args = (
      dbh            => $self->{dbh},
      tbl            => $self->{tbl},
      NibbleIterator => $self,
   );

   if ($self->{nibbleno} == 0) {
      $self->_prepare_sths();
      $self->_get_bounds();
      if ( my $callback = $self->{callbacks}->{init} ) {
         my $oktonibble = $callback->(%callback_args);
         MKDEBUG && _d('init callback returned', $oktonibble);
         if ( !$oktonibble ) {
            $self->{no_more_boundaries} = 1;
            return;
         }
      }
   }

   NIBBLE:
   while ( $self->{have_rows} || $self->_next_boundaries() ) {
      if ( !$self->{have_rows} ) {
         $self->{nibbleno}++;
         MKDEBUG && _d($self->{nibble_sth}->{Statement}, 'params:',
            join(', ', (@{$self->{lower}}, @{$self->{upper}})));
         if ( my $callback = $self->{callbacks}->{exec_nibble} ) {
            $self->{have_rows} = $callback->(%callback_args);
         }
         else {
            $self->{nibble_sth}->execute(@{$self->{lower}}, @{$self->{upper}});
            $self->{have_rows} = $self->{nibble_sth}->rows();
         }
         MKDEBUG && _d($self->{have_rows}, 'rows in nibble', $self->{nibbleno});
      }

      if ( $self->{have_rows} ) {
         my $row = $self->{nibble_sth}->fetchrow_arrayref();
         if ( $row ) {
            $self->{rowno}++;
            MKDEBUG && _d('Row', $self->{rowno}, 'in nibble',$self->{nibbleno});
            return [ @$row ];
         }
      }

      MKDEBUG && _d('No rows in nibble or nibble skipped');
      if ( my $callback = $self->{callbacks}->{after_nibble} ) {
         $callback->(%callback_args);
      }
      $self->{rowno}     = 0;
      $self->{have_rows} = 0;
   }

   MKDEBUG && _d('Done nibbling');
   if ( my $callback = $self->{callbacks}->{done} ) {
      $callback->(%callback_args);
   }

   return;
}

sub nibble_number {
   my ($self) = @_;
   return $self->{nibbleno};
}

sub set_nibble_number {
   my ($self, $n) = @_;
   die "I need a number" unless $n;
   $self->{nibbleno} = $n;
   MKDEBUG && _d('Set new nibble number:', $n);
   return;
}

sub nibble_index {
   my ($self) = @_;
   return $self->{index};
}

sub statements {
   my ($self) = @_;
   return {
      nibble                 => $self->{nibble_sth},
      explain_nibble         => $self->{explain_nibble_sth},
      upper_boundary         => $self->{ub_sth},
      explain_upper_boundary => $self->{explain_ub_sth},
   }
}

sub boundaries {
   my ($self) = @_;
   return {
      lower       => $self->{lower},
      upper       => $self->{upper},
      next_lower  => $self->{next_lower},
      last_upper  => $self->{last_upper},
   };
}

sub set_boundary {
   my ($self, $boundary, $values) = @_;
   die "I need a boundary parameter"
      unless $boundary;
   die "Invalid boundary: $boundary"
      unless $boundary =~ m/^(?:lower|upper|next_lower|last_upper)$/;
   die "I need a values arrayref parameter"
      unless $values && ref $values eq 'ARRAY';
   $self->{$boundary} = $values;
   MKDEBUG && _d('Set new', $boundary, 'boundary:', Dumper($values));
   return;
}

sub one_nibble {
   my ($self) = @_;
   return $self->{one_nibble};
}

sub chunk_size {
   my ($self) = @_;
   return $self->{limit};
}

sub set_chunk_size {
   my ($self, $limit) = @_;
   return if $self->{one_nibble};
   die "Chunk size must be > 0" unless $limit;
   $self->{limit} = $limit - 1;
   MKDEBUG && _d('Set new chunk size (LIMIT):', $limit);
   return;
}

sub sql {
   my ($self) = @_;
   return $self->{sql};
}

sub _find_best_index {
   my (%args) = @_;
   my @required_args = qw(tbl TableParser dbh Quoter);
   my ($tbl, $tp) = @args{@required_args};

   my $tbl_struct = $tbl->{tbl_struct};
   my $indexes    = $tbl_struct->{keys};

   my $best_index;
   my @possible_indexes;
   if ( my $want_index = $args{chunk_index} ) {
      MKDEBUG && _d('Want to use nibble index', $want_index);
      if ( $want_index eq 'PRIMARY' || $indexes->{$want_index}->{is_unique} ) {
         $best_index = $want_index;
      }
      else {
         push @possible_indexes, $want_index;
      }
   }
   else {
      foreach my $index ( $tp->sort_indexes($tbl_struct) ) {
         if ( $index eq 'PRIMARY' || $indexes->{$index}->{is_unique} ) {
            $best_index = $index;
            last;
         }
         else {
            push @possible_indexes, $index;
         }
      }
   }

   if ( !$best_index && @possible_indexes ) {
      MKDEBUG && _d('No PRIMARY or unique indexes;',
         'will use index with highest cardinality');
      foreach my $index ( @possible_indexes ) {
         $indexes->{$index}->{cardinality} = _get_index_cardinality(
            %args,
            index => $index,
         );
      }
      @possible_indexes = sort {
         my $cmp
            = $indexes->{$b}->{cardinality} <=> $indexes->{$b}->{cardinality};
         if ( $cmp == 0 ) {
            $cmp = scalar @{$indexes->{$b}->{cols}}
               <=> scalar @{$indexes->{$a}->{cols}};
         }
         $cmp;
      } @possible_indexes;
      $best_index = $possible_indexes[0];
   }

   MKDEBUG && _d('Best index:', $best_index);
   return $best_index;
}

sub _get_index_cardinality {
   my (%args) = @_;
   my @required_args = qw(dbh tbl index Quoter);
   my ($dbh, $tbl, $index, $q) = @args{@required_args};

   my $sql = "SHOW INDEXES FROM " . $q->quote(@{$tbl}{qw(db tbl)})
           . " WHERE Key_name = '$index'";
   MKDEBUG && _d($sql);
   my $cardinality = 1;
   my $rows = $dbh->selectall_hashref($sql, 'key_name');
   foreach my $row ( values %$rows ) {
      $cardinality *= $row->{cardinality} if $row->{cardinality};
   }
   MKDEBUG && _d('Index', $index, 'cardinality:', $cardinality);
   return $cardinality;
}

sub _can_nibble_once {
   my (%args) = @_;
   my @required_args = qw(dbh tbl chunk_size OptionParser TableParser);
   my ($dbh, $tbl, $chunk_size, $o, $tp) = @args{@required_args};
   my ($table_status)   = $tp->get_table_status($dbh, $tbl->{db}, $tbl->{tbl});
   MKDEBUG && _d('TABLE STATUS', Dumper($table_status));
   my $n_rows           = $table_status->{rows} || 0;
   my $limit            = $o->get('chunk-size-limit');
   my $one_nibble       = $n_rows < $chunk_size * $limit ? 1 : 0;
   MKDEBUG && _d('One nibble:', $one_nibble ? 'yes' : 'no');
   return $one_nibble;
}

sub _prepare_sths {
   my ($self) = @_;
   MKDEBUG && _d('Preparing statement handles');
   $self->{nibble_sth}
      = $self->{dbh}->prepare($self->{nibble_sql});
   $self->{explain_nibble_sth}
      = $self->{dbh}->prepare($self->{explain_nibble_sql});
   if ( !$self->{one_nibble} ) {
      $self->{ub_sth} = $self->{dbh}->prepare($self->{ub_sql});
      $self->{explain_ub_sth} = $self->{dbh}->prepare($self->{explain_ub_sql});
   }
   return;
}

sub _get_bounds { 
   my ($self) = @_;
   return if $self->{one_nibble};

   $self->{next_lower} = $self->{dbh}->selectrow_arrayref($self->{first_lb_sql});
   MKDEBUG && _d('First lower boundary:', Dumper($self->{next_lower}));

   $self->{last_upper} = $self->{dbh}->selectrow_arrayref($self->{last_ub_sql});
   MKDEBUG && _d('Last upper boundary:', Dumper($self->{last_upper}));

   return;
}

sub _next_boundaries {
   my ($self) = @_;

   if ( $self->{no_more_boundaries} ) {
      MKDEBUG && _d('No more boundaries');
      return; # stop nibbling
   }

   if ( $self->{one_nibble} ) {
      $self->{lower} = $self->{upper} = [];
      $self->{no_more_boundaries} = 1;  # for next call
      return 1; # continue nibbling
   }

   if ( $self->identical_boundaries($self->{lower}, $self->{next_lower}) ) {
      MKDEBUG && _d('Infinite loop detected');
      my $tbl     = $self->{tbl};
      my $index   = $tbl->{tbl_struct}->{keys}->{$self->{index}};
      my $n_cols  = scalar @{$index->{cols}};
      my $chunkno = $self->{nibbleno};
      die "Possible infinite loop detected!  "
         . "The lower boundary for chunk $chunkno is "
         . "<" . join(', ', @{$self->{lower}}) . "> and the lower "
         . "boundary for chunk " . ($chunkno + 1) . " is also "
         . "<" . join(', ', @{$self->{next_lower}}) . ">.  "
         . "This usually happens when using a non-unique single "
         . "column index.  The current chunk index for table "
         . "$tbl->{db}.$tbl->{tbl} is $self->{index} which is"
         . ($index->{is_unique} ? '' : ' not') . " unique and covers "
         . ($n_cols > 1 ? "$n_cols columns" : "1 column") . ".\n";
   }
   $self->{lower} = $self->{next_lower};

   if ( my $callback = $self->{callbacks}->{next_boundaries} ) {
      my $oktonibble = $callback->(
         dbh            => $self->{dbh},
         tbl            => $self->{tbl},
         NibbleIterator => $self,
      );
      MKDEBUG && _d('next_boundaries callback returned', $oktonibble);
      if ( !$oktonibble ) {
         $self->{no_more_boundaries} = 1;
         return; # stop nibbling
      }
   }

   MKDEBUG && _d($self->{ub_sth}->{Statement}, 'params:',
      join(', ', @{$self->{lower}}), $self->{limit});
   $self->{ub_sth}->execute(@{$self->{lower}}, $self->{limit});
   my $boundary = $self->{ub_sth}->fetchall_arrayref();
   MKDEBUG && _d('Next boundary:', Dumper($boundary));
   if ( $boundary && @$boundary ) {
      $self->{upper} = $boundary->[0]; # this nibble
      if ( $boundary->[1] ) {
         $self->{next_lower} = $boundary->[1]; # next nibble
      }
      else {
         $self->{no_more_boundaries} = 1;  # for next call
         MKDEBUG && _d('Last upper boundary:', Dumper($boundary->[0]));
      }
   }
   else {
      $self->{no_more_boundaries} = 1;  # for next call
      $self->{upper} = $self->{last_upper};
      MKDEBUG && _d('Last upper boundary:', Dumper($self->{upper}));
   }
   $self->{ub_sth}->finish();

   return 1; # continue nibbling
}

sub identical_boundaries {
   my ($self, $b1, $b2) = @_;

   return 0 if ($b1 && !$b2) || (!$b1 && $b2);

   return 1 if !$b1 && !$b2;

   die "Boundaries have different numbers of values"
      if scalar @$b1 != scalar @$b2;  # shouldn't happen
   my $n_vals = scalar @$b1;
   for my $i ( 0..($n_vals-1) ) {
      return 0 if $b1->[$i] ne $b2->[$i]; # diff
   }
   return 1;
}

sub DESTROY {
   my ( $self ) = @_;
   foreach my $key ( keys %$self ) {
      if ( $key =~ m/_sth$/ ) {
         $self->{$key}->finish();
      }
   }
   return;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End NibbleIterator package
# ###########################################################################

# ###########################################################################
# Daemon package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/Daemon.pm
#   t/lib/Daemon.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package Daemon;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use POSIX qw(setsid);

sub new {
   my ( $class, %args ) = @_;
   foreach my $arg ( qw(o) ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my $o = $args{o};
   my $self = {
      o        => $o,
      log_file => $o->has('log') ? $o->get('log') : undef,
      PID_file => $o->has('pid') ? $o->get('pid') : undef,
   };

   check_PID_file(undef, $self->{PID_file});

   MKDEBUG && _d('Daemonized child will log to', $self->{log_file});
   return bless $self, $class;
}

sub daemonize {
   my ( $self ) = @_;

   MKDEBUG && _d('About to fork and daemonize');
   defined (my $pid = fork()) or die "Cannot fork: $OS_ERROR";
   if ( $pid ) {
      MKDEBUG && _d('I am the parent and now I die');
      exit;
   }

   $self->{PID_owner} = $PID;
   $self->{child}     = 1;

   POSIX::setsid() or die "Cannot start a new session: $OS_ERROR";
   chdir '/'       or die "Cannot chdir to /: $OS_ERROR";

   $self->_make_PID_file();

   $OUTPUT_AUTOFLUSH = 1;

   if ( -t STDIN ) {
      close STDIN;
      open  STDIN, '/dev/null'
         or die "Cannot reopen STDIN to /dev/null: $OS_ERROR";
   }

   if ( $self->{log_file} ) {
      close STDOUT;
      open  STDOUT, '>>', $self->{log_file}
         or die "Cannot open log file $self->{log_file}: $OS_ERROR";

      close STDERR;
      open  STDERR, ">&STDOUT"
         or die "Cannot dupe STDERR to STDOUT: $OS_ERROR"; 
   }
   else {
      if ( -t STDOUT ) {
         close STDOUT;
         open  STDOUT, '>', '/dev/null'
            or die "Cannot reopen STDOUT to /dev/null: $OS_ERROR";
      }
      if ( -t STDERR ) {
         close STDERR;
         open  STDERR, '>', '/dev/null'
            or die "Cannot reopen STDERR to /dev/null: $OS_ERROR";
      }
   }

   MKDEBUG && _d('I am the child and now I live daemonized');
   return;
}

sub check_PID_file {
   my ( $self, $file ) = @_;
   my $PID_file = $self ? $self->{PID_file} : $file;
   MKDEBUG && _d('Checking PID file', $PID_file);
   if ( $PID_file && -f $PID_file ) {
      my $pid;
      eval { chomp($pid = `cat $PID_file`); };
      die "Cannot cat $PID_file: $OS_ERROR" if $EVAL_ERROR;
      MKDEBUG && _d('PID file exists; it contains PID', $pid);
      if ( $pid ) {
         my $pid_is_alive = kill 0, $pid;
         if ( $pid_is_alive ) {
            die "The PID file $PID_file already exists "
               . " and the PID that it contains, $pid, is running";
         }
         else {
            warn "Overwriting PID file $PID_file because the PID that it "
               . "contains, $pid, is not running";
         }
      }
      else {
         die "The PID file $PID_file already exists but it does not "
            . "contain a PID";
      }
   }
   else {
      MKDEBUG && _d('No PID file');
   }
   return;
}

sub make_PID_file {
   my ( $self ) = @_;
   if ( exists $self->{child} ) {
      die "Do not call Daemon::make_PID_file() for daemonized scripts";
   }
   $self->_make_PID_file();
   $self->{PID_owner} = $PID;
   return;
}

sub _make_PID_file {
   my ( $self ) = @_;

   my $PID_file = $self->{PID_file};
   if ( !$PID_file ) {
      MKDEBUG && _d('No PID file to create');
      return;
   }

   $self->check_PID_file();

   open my $PID_FH, '>', $PID_file
      or die "Cannot open PID file $PID_file: $OS_ERROR";
   print $PID_FH $PID
      or die "Cannot print to PID file $PID_file: $OS_ERROR";
   close $PID_FH
      or die "Cannot close PID file $PID_file: $OS_ERROR";

   MKDEBUG && _d('Created PID file:', $self->{PID_file});
   return;
}

sub _remove_PID_file {
   my ( $self ) = @_;
   if ( $self->{PID_file} && -f $self->{PID_file} ) {
      unlink $self->{PID_file}
         or warn "Cannot remove PID file $self->{PID_file}: $OS_ERROR";
      MKDEBUG && _d('Removed PID file');
   }
   else {
      MKDEBUG && _d('No PID to remove');
   }
   return;
}

sub DESTROY {
   my ( $self ) = @_;

   $self->_remove_PID_file() if ($self->{PID_owner} || 0) == $PID;

   return;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End Daemon package
# ###########################################################################

# ###########################################################################
# SchemaIterator package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/SchemaIterator.pm
#   t/lib/SchemaIterator.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package SchemaIterator;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use Data::Dumper;
$Data::Dumper::Indent    = 1;
$Data::Dumper::Sortkeys  = 1;
$Data::Dumper::Quotekeys = 0;

my $open_comment = qr{/\*!\d{5} };
my $tbl_name     = qr{
   CREATE\s+
   (?:TEMPORARY\s+)?
   TABLE\s+
   (?:IF NOT EXISTS\s+)?
   ([^\(]+)
}x;


sub new {
   my ( $class, %args ) = @_;
   my @required_args = qw(OptionParser Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }

   my ($file_itr, $dbh) = @args{qw(file_itr dbh)};
   die "I need either a dbh or file_itr argument"
      if (!$dbh && !$file_itr) || ($dbh && $file_itr);

   my %resume;
   if ( my $table = $args{resume} ) {
      MKDEBUG && _d('Will resume from', $table);
      my ($db, $tbl) = $args{Quoter}->split_unquote($table);
      $resume{db}  = $db;
      $resume{tbl} = $tbl;
   }

   my $self = {
      %args,
      resume  => \%resume,
      filters => _make_filters(%args),
   };

   return bless $self, $class;
}

sub _make_filters {
   my ( %args ) = @_;
   my @required_args = qw(OptionParser Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($o, $q) = @args{@required_args};

   my %filters;


   my @simple_filters = qw(
      databases         tables         engines
      ignore-databases  ignore-tables  ignore-engines);
   FILTER:
   foreach my $filter ( @simple_filters ) {
      if ( $o->has($filter) ) {
         my $objs = $o->get($filter);
         next FILTER unless $objs && scalar keys %$objs;
         my $is_table = $filter =~ m/table/ ? 1 : 0;
         foreach my $obj ( keys %$objs ) {
            die "Undefined value for --$filter" unless $obj;
            $obj = lc $obj;
            if ( $is_table ) {
               my ($db, $tbl) = $q->split_unquote($obj);
               $db ||= '*';
               MKDEBUG && _d('Filter', $filter, 'value:', $db, $tbl);
               $filters{$filter}->{$tbl} = $db;
            }
            else { # database
               MKDEBUG && _d('Filter', $filter, 'value:', $obj);
               $filters{$filter}->{$obj} = 1;
            }
         }
      }
   }

   my @regex_filters = qw(
      databases-regex         tables-regex
      ignore-databases-regex  ignore-tables-regex);
   REGEX_FILTER:
   foreach my $filter ( @regex_filters ) {
      if ( $o->has($filter) ) {
         my $pat = $o->get($filter);
         next REGEX_FILTER unless $pat;
         $filters{$filter} = qr/$pat/;
         MKDEBUG && _d('Filter', $filter, 'value:', $filters{$filter});
      }
   }

   MKDEBUG && _d('Schema object filters:', Dumper(\%filters));
   return \%filters;
}

sub next {
   my ( $self ) = @_;

   my $schema_obj;
   if ( $self->{file_itr} ) {
      $schema_obj= $self->_iterate_files();
   }
   else { # dbh
      $schema_obj= $self->_iterate_dbh();
   }

   if ( $schema_obj ) {
      if ( $schema_obj->{ddl} && $self->{TableParser} ) {
         $schema_obj->{tbl_struct}
            = $self->{TableParser}->parse($schema_obj->{ddl});
      }

      delete $schema_obj->{ddl} unless $self->{keep_ddl};

      if ( my $schema = $self->{Schema} ) {
         $schema->add_schema_object($schema_obj);
      }
      MKDEBUG && _d('Next schema object:', $schema_obj->{db}, $schema_obj->{tbl});
   }

   return $schema_obj;
}

sub _iterate_files {
   my ( $self ) = @_;

   if ( !$self->{fh} ) {
      my ($fh, $file) = $self->{file_itr}->();
      if ( !$fh ) {
         MKDEBUG && _d('No more files to iterate');
         return;
      }
      $self->{fh}   = $fh;
      $self->{file} = $file;
   }
   my $fh = $self->{fh};
   MKDEBUG && _d('Getting next schema object from', $self->{file});

   local $INPUT_RECORD_SEPARATOR = '';
   CHUNK:
   while (defined(my $chunk = <$fh>)) {
      if ($chunk =~ m/Database: (\S+)/) {
         my $db = $1; # XXX
         $db =~ s/^`//;  # strip leading `
         $db =~ s/`$//;  # and trailing `
         if ( $self->database_is_allowed($db)
              && $self->_resume_from_database($db) ) {
            $self->{db} = $db;
         }
      }
      elsif ($self->{db} && $chunk =~ m/CREATE TABLE/) {
         if ($chunk =~ m/DROP VIEW IF EXISTS/) {
            MKDEBUG && _d('Table is a VIEW, skipping');
            next CHUNK;
         }

         my ($tbl) = $chunk =~ m/$tbl_name/;
         $tbl      =~ s/^\s*`//;
         $tbl      =~ s/`\s*$//;
         if ( $self->table_is_allowed($self->{db}, $tbl)
              && $self->_resume_from_table($tbl) ) {
            my ($ddl) = $chunk =~ m/^(?:$open_comment)?(CREATE TABLE.+?;)$/ms;
            if ( !$ddl ) {
               warn "Failed to parse CREATE TABLE from\n" . $chunk;
               next CHUNK;
            }
            $ddl =~ s/ \*\/;\Z/;/;  # remove end of version comment

            my ($engine) = $ddl =~ m/\).*?(?:ENGINE|TYPE)=(\w+)/;   

            if ( !$engine || $self->engine_is_allowed($engine) ) {
               return {
                  db  => $self->{db},
                  tbl => $tbl,
                  ddl => $ddl,
               };
            }
         }
      }
   }  # CHUNK

   MKDEBUG && _d('No more schema objects in', $self->{file});
   close $self->{fh};
   $self->{fh} = undef;

   return $self->_iterate_files();
}

sub _iterate_dbh {
   my ( $self ) = @_;
   my $q   = $self->{Quoter};
   my $dbh = $self->{dbh};
   MKDEBUG && _d('Getting next schema object from dbh', $dbh);

   if ( !defined $self->{dbs} ) {
      my $sql = 'SHOW DATABASES';
      MKDEBUG && _d($sql);
      my @dbs = grep { $self->database_is_allowed($_) }
                @{$dbh->selectcol_arrayref($sql)};
      MKDEBUG && _d('Found', scalar @dbs, 'databases');
      $self->{dbs} = \@dbs;
   }

   if ( !$self->{db} ) {
      do {
         $self->{db} = shift @{$self->{dbs}};
      } until $self->_resume_from_database($self->{db});
      MKDEBUG && _d('Next database:', $self->{db});
      return unless $self->{db};
   }

   if ( !defined $self->{tbls} ) {
      my $sql = 'SHOW /*!50002 FULL*/ TABLES FROM ' . $q->quote($self->{db});
      MKDEBUG && _d($sql);
      my @tbls = map {
         $_->[0];  # (tbl, type)
      }
      grep {
         my ($tbl, $type) = @$_;
         $self->table_is_allowed($self->{db}, $tbl)
            && (!$type || ($type ne 'VIEW'));
      }
      @{$dbh->selectall_arrayref($sql)};
      MKDEBUG && _d('Found', scalar @tbls, 'tables in database', $self->{db});
      $self->{tbls} = \@tbls;
   }

   while ( my $tbl = shift @{$self->{tbls}} ) {
      next unless $self->_resume_from_table($tbl);
      my $engine;
      if ( $self->{filters}->{'engines'}
           || $self->{filters}->{'ignore-engines'} ) {
         my $sql = "SHOW TABLE STATUS FROM " . $q->quote($self->{db})
                 . " LIKE \'$tbl\'";
         MKDEBUG && _d($sql);
         $engine = $dbh->selectrow_hashref($sql)->{engine};
         MKDEBUG && _d($tbl, 'uses', $engine, 'engine');
      }


      if ( !$engine || $self->engine_is_allowed($engine) ) {
         my $ddl;
         if ( my $tp = $self->{TableParser} ) {
            $ddl = $tp->get_create_table($dbh, $self->{db}, $tbl);
         }

         return {
            db  => $self->{db},
            tbl => $tbl,
            ddl => $ddl,
         };
      }
   }

   MKDEBUG && _d('No more tables in database', $self->{db});
   $self->{db}   = undef;
   $self->{tbls} = undef;

   return $self->_iterate_dbh();
}

sub database_is_allowed {
   my ( $self, $db ) = @_;
   die "I need a db argument" unless $db;

   $db = lc $db;

   my $filter = $self->{filters};

   if ( $db =~ m/information_schema|performance_schema|lost\+found/ ) {
      MKDEBUG && _d('Database', $db, 'is a system database, ignoring');
      return 0;
   }

   if ( $self->{filters}->{'ignore-databases'}->{$db} ) {
      MKDEBUG && _d('Database', $db, 'is in --ignore-databases list');
      return 0;
   }

   if ( $filter->{'ignore-databases-regex'}
        && $db =~ $filter->{'ignore-databases-regex'} ) {
      MKDEBUG && _d('Database', $db, 'matches --ignore-databases-regex');
      return 0;
   }

   if ( $filter->{'databases'}
        && !$filter->{'databases'}->{$db} ) {
      MKDEBUG && _d('Database', $db, 'is not in --databases list, ignoring');
      return 0;
   }

   if ( $filter->{'databases-regex'}
        && $db !~ $filter->{'databases-regex'} ) {
      MKDEBUG && _d('Database', $db, 'does not match --databases-regex, ignoring');
      return 0;
   }

   return 1;
}

sub table_is_allowed {
   my ( $self, $db, $tbl ) = @_;
   die "I need a db argument"  unless $db;
   die "I need a tbl argument" unless $tbl;

   $db  = lc $db;
   $tbl = lc $tbl;

   my $filter = $self->{filters};

   if ( $db eq 'mysql' && ($tbl eq 'general_log' || $tbl eq 'slow_log') ) {
      return 0;
   }

   if ( $filter->{'ignore-tables'}->{$tbl}
        && ($filter->{'ignore-tables'}->{$tbl} eq '*'
            || $filter->{'ignore-tables'}->{$tbl} eq $db) ) {
      MKDEBUG && _d('Table', $tbl, 'is in --ignore-tables list');
      return 0;
   }

   if ( $filter->{'ignore-tables-regex'}
        && $tbl =~ $filter->{'ignore-tables-regex'} ) {
      MKDEBUG && _d('Table', $tbl, 'matches --ignore-tables-regex');
      return 0;
   }

   if ( $filter->{'tables'}
        && !$filter->{'tables'}->{$tbl} ) { 
      MKDEBUG && _d('Table', $tbl, 'is not in --tables list, ignoring');
      return 0;
   }

   if ( $filter->{'tables-regex'}
        && $tbl !~ $filter->{'tables-regex'} ) {
      MKDEBUG && _d('Table', $tbl, 'does not match --tables-regex, ignoring');
      return 0;
   }

   if ( $filter->{'tables'}
        && $filter->{'tables'}->{$tbl}
        && $filter->{'tables'}->{$tbl} ne '*'
        && $filter->{'tables'}->{$tbl} ne $db ) {
      MKDEBUG && _d('Table', $tbl, 'is only allowed in database',
         $filter->{'tables'}->{$tbl});
      return 0;
   }

   return 1;
}

sub engine_is_allowed {
   my ( $self, $engine ) = @_;
   die "I need an engine argument" unless $engine;

   $engine = lc $engine;

   my $filter = $self->{filters};

   if ( $filter->{'ignore-engines'}->{$engine} ) {
      MKDEBUG && _d('Engine', $engine, 'is in --ignore-databases list');
      return 0;
   }

   if ( $filter->{'engines'}
        && !$filter->{'engines'}->{$engine} ) {
      MKDEBUG && _d('Engine', $engine, 'is not in --engines list, ignoring');
      return 0;
   }

   return 1;
}

sub _resume_from_database {
   my ($self, $db) = @_;

   return 1 unless $self->{resume}->{db};

   if ( $db eq $self->{resume}->{db} ) {
      MKDEBUG && _d('At resume db', $db);
      delete $self->{resume}->{db};
      return 1;
   }

   return 0;
}

sub _resume_from_table {
   my ($self, $tbl) = @_;

   return 1 unless $self->{resume}->{tbl};

   if ( $tbl eq $self->{resume}->{tbl} ) {
      MKDEBUG && _d('At resume table', $tbl);
      delete $self->{resume}->{tbl};
      return 1;
   }

   return 0;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End SchemaIterator package
# ###########################################################################

# ###########################################################################
# Retry package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/Retry.pm
#   t/lib/Retry.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package Retry;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, %args ) = @_;
   my $self = {
      %args,
   };
   return bless $self, $class;
}

sub retry {
   my ( $self, %args ) = @_;
   my @required_args = qw(try wait);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   };
   my ($try, $wait) = @args{@required_args};
   my $tries = $args{tries} || 3;

   my $tryno = 0;
   while ( ++$tryno <= $tries ) {
      MKDEBUG && _d("Retry", $tryno, "of", $tries);
      my $result;
      eval {
         $result = $try->(tryno=>$tryno);
      };

      if ( defined $result ) {
         MKDEBUG && _d("Try code succeeded");
         if ( my $on_success = $args{on_success} ) {
            MKDEBUG && _d("Calling on_success code");
            $on_success->(tryno=>$tryno, result=>$result);
         }
         return $result;
      }

      if ( $EVAL_ERROR ) {
         MKDEBUG && _d("Try code died:", $EVAL_ERROR);
         die $EVAL_ERROR unless $args{retry_on_die};
      }

      if ( $tryno < $tries ) {
         MKDEBUG && _d("Try code failed, calling wait code");
         $wait->(tryno=>$tryno);
      }
   }

   MKDEBUG && _d("Try code did not succeed");
   if ( my $on_failure = $args{on_failure} ) {
      MKDEBUG && _d("Calling on_failure code");
      $on_failure->();
   }

   return;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End Retry package
# ###########################################################################

# ###########################################################################
# Transformers package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/Transformers.pm
#   t/lib/Transformers.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package Transformers;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use Time::Local qw(timegm timelocal);
use Digest::MD5 qw(md5_hex);

require Exporter;
our @ISA         = qw(Exporter);
our %EXPORT_TAGS = ();
our @EXPORT      = ();
our @EXPORT_OK   = qw(
   micro_t
   percentage_of
   secs_to_time
   time_to_secs
   shorten
   ts
   parse_timestamp
   unix_timestamp
   any_unix_timestamp
   make_checksum
   crc32
);

our $mysql_ts  = qr/(\d\d)(\d\d)(\d\d) +(\d+):(\d+):(\d+)(\.\d+)?/;
our $proper_ts = qr/(\d\d\d\d)-(\d\d)-(\d\d)[T ](\d\d):(\d\d):(\d\d)(\.\d+)?/;
our $n_ts      = qr/(\d{1,5})([shmd]?)/; # Limit \d{1,5} because \d{6} looks

sub micro_t {
   my ( $t, %args ) = @_;
   my $p_ms = defined $args{p_ms} ? $args{p_ms} : 0;  # precision for ms vals
   my $p_s  = defined $args{p_s}  ? $args{p_s}  : 0;  # precision for s vals
   my $f;

   $t = 0 if $t < 0;

   $t = sprintf('%.17f', $t) if $t =~ /e/;

   $t =~ s/\.(\d{1,6})\d*/\.$1/;

   if ($t > 0 && $t <= 0.000999) {
      $f = ($t * 1000000) . 'us';
   }
   elsif ($t >= 0.001000 && $t <= 0.999999) {
      $f = sprintf("%.${p_ms}f", $t * 1000);
      $f = ($f * 1) . 'ms'; # * 1 to remove insignificant zeros
   }
   elsif ($t >= 1) {
      $f = sprintf("%.${p_s}f", $t);
      $f = ($f * 1) . 's'; # * 1 to remove insignificant zeros
   }
   else {
      $f = 0;  # $t should = 0 at this point
   }

   return $f;
}

sub percentage_of {
   my ( $is, $of, %args ) = @_;
   my $p   = $args{p} || 0; # float precision
   my $fmt = $p ? "%.${p}f" : "%d";
   return sprintf $fmt, ($is * 100) / ($of ||= 1);
}

sub secs_to_time {
   my ( $secs, $fmt ) = @_;
   $secs ||= 0;
   return '00:00' unless $secs;

   $fmt ||= $secs >= 86_400 ? 'd'
          : $secs >= 3_600  ? 'h'
          :                   'm';

   return
      $fmt eq 'd' ? sprintf(
         "%d+%02d:%02d:%02d",
         int($secs / 86_400),
         int(($secs % 86_400) / 3_600),
         int(($secs % 3_600) / 60),
         $secs % 60)
      : $fmt eq 'h' ? sprintf(
         "%02d:%02d:%02d",
         int(($secs % 86_400) / 3_600),
         int(($secs % 3_600) / 60),
         $secs % 60)
      : sprintf(
         "%02d:%02d",
         int(($secs % 3_600) / 60),
         $secs % 60);
}

sub time_to_secs {
   my ( $val, $default_suffix ) = @_;
   die "I need a val argument" unless defined $val;
   my $t = 0;
   my ( $prefix, $num, $suffix ) = $val =~ m/([+-]?)(\d+)([a-z])?$/;
   $suffix = $suffix || $default_suffix || 's';
   if ( $suffix =~ m/[smhd]/ ) {
      $t = $suffix eq 's' ? $num * 1        # Seconds
         : $suffix eq 'm' ? $num * 60       # Minutes
         : $suffix eq 'h' ? $num * 3600     # Hours
         :                  $num * 86400;   # Days

      $t *= -1 if $prefix && $prefix eq '-';
   }
   else {
      die "Invalid suffix for $val: $suffix";
   }
   return $t;
}

sub shorten {
   my ( $num, %args ) = @_;
   my $p = defined $args{p} ? $args{p} : 2;     # float precision
   my $d = defined $args{d} ? $args{d} : 1_024; # divisor
   my $n = 0;
   my @units = ('', qw(k M G T P E Z Y));
   while ( $num >= $d && $n < @units - 1 ) {
      $num /= $d;
      ++$n;
   }
   return sprintf(
      $num =~ m/\./ || $n
         ? "%.${p}f%s"
         : '%d',
      $num, $units[$n]);
}

sub ts {
   my ( $time, $gmt ) = @_;
   my ( $sec, $min, $hour, $mday, $mon, $year )
      = $gmt ? gmtime($time) : localtime($time);
   $mon  += 1;
   $year += 1900;
   my $val = sprintf("%d-%02d-%02dT%02d:%02d:%02d",
      $year, $mon, $mday, $hour, $min, $sec);
   if ( my ($us) = $time =~ m/(\.\d+)$/ ) {
      $us = sprintf("%.6f", $us);
      $us =~ s/^0\././;
      $val .= $us;
   }
   return $val;
}

sub parse_timestamp {
   my ( $val ) = @_;
   if ( my($y, $m, $d, $h, $i, $s, $f)
         = $val =~ m/^$mysql_ts$/ )
   {
      return sprintf "%d-%02d-%02d %02d:%02d:"
                     . (defined $f ? '%09.6f' : '%02d'),
                     $y + 2000, $m, $d, $h, $i, (defined $f ? $s + $f : $s);
   }
   return $val;
}

sub unix_timestamp {
   my ( $val, $gmt ) = @_;
   if ( my($y, $m, $d, $h, $i, $s, $us) = $val =~ m/^$proper_ts$/ ) {
      $val = $gmt
         ? timegm($s, $i, $h, $d, $m - 1, $y)
         : timelocal($s, $i, $h, $d, $m - 1, $y);
      if ( defined $us ) {
         $us = sprintf('%.6f', $us);
         $us =~ s/^0\././;
         $val .= $us;
      }
   }
   return $val;
}

sub any_unix_timestamp {
   my ( $val, $callback ) = @_;

   if ( my ($n, $suffix) = $val =~ m/^$n_ts$/ ) {
      $n = $suffix eq 's' ? $n            # Seconds
         : $suffix eq 'm' ? $n * 60       # Minutes
         : $suffix eq 'h' ? $n * 3600     # Hours
         : $suffix eq 'd' ? $n * 86400    # Days
         :                  $n;           # default: Seconds
      MKDEBUG && _d('ts is now - N[shmd]:', $n);
      return time - $n;
   }
   elsif ( $val =~ m/^\d{9,}/ ) {
      MKDEBUG && _d('ts is already a unix timestamp');
      return $val;
   }
   elsif ( my ($ymd, $hms) = $val =~ m/^(\d{6})(?:\s+(\d+:\d+:\d+))?/ ) {
      MKDEBUG && _d('ts is MySQL slow log timestamp');
      $val .= ' 00:00:00' unless $hms;
      return unix_timestamp(parse_timestamp($val));
   }
   elsif ( ($ymd, $hms) = $val =~ m/^(\d{4}-\d\d-\d\d)(?:[T ](\d+:\d+:\d+))?/) {
      MKDEBUG && _d('ts is properly formatted timestamp');
      $val .= ' 00:00:00' unless $hms;
      return unix_timestamp($val);
   }
   else {
      MKDEBUG && _d('ts is MySQL expression');
      return $callback->($val) if $callback && ref $callback eq 'CODE';
   }

   MKDEBUG && _d('Unknown ts type:', $val);
   return;
}

sub make_checksum {
   my ( $val ) = @_;
   my $checksum = uc substr(md5_hex($val), -16);
   MKDEBUG && _d($checksum, 'checksum for', $val);
   return $checksum;
}

sub crc32 {
   my ( $string ) = @_;
   return unless $string;
   my $poly = 0xEDB88320;
   my $crc  = 0xFFFFFFFF;
   foreach my $char ( split(//, $string) ) {
      my $comp = ($crc ^ ord($char)) & 0xFF;
      for ( 1 .. 8 ) {
         $comp = $comp & 1 ? $poly ^ ($comp >> 1) : $comp >> 1;
      }
      $crc = (($crc >> 8) & 0x00FFFFFF) ^ $comp;
   }
   return $crc ^ 0xFFFFFFFF;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End Transformers package
# ###########################################################################

# ###########################################################################
# Progress package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/Progress.pm
#   t/lib/Progress.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package Progress;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, %args ) = @_;
   foreach my $arg (qw(jobsize)) {
      die "I need a $arg argument" unless defined $args{$arg};
   }
   if ( (!$args{report} || !$args{interval}) ) {
      if ( $args{spec} && @{$args{spec}} == 2 ) {
         @args{qw(report interval)} = @{$args{spec}};
      }
      else {
         die "I need either report and interval arguments, or a spec";
      }
   }

   my $name  = $args{name} || "Progress";
   $args{start} ||= time();
   my $self;
   $self = {
      last_reported => $args{start},
      fraction      => 0,       # How complete the job is
      callback      => sub {
         my ($fraction, $elapsed, $remaining, $eta) = @_;
         printf STDERR "$name: %3d%% %s remain\n",
            $fraction * 100,
            Transformers::secs_to_time($remaining),
            Transformers::ts($eta);
      },
      %args,
   };
   return bless $self, $class;
}

sub validate_spec {
   shift @_ if $_[0] eq 'Progress'; # Permit calling as Progress-> or Progress::
   my ( $spec ) = @_;
   if ( @$spec != 2 ) {
      die "spec array requires a two-part argument\n";
   }
   if ( $spec->[0] !~ m/^(?:percentage|time|iterations)$/ ) {
      die "spec array's first element must be one of "
        . "percentage,time,iterations\n";
   }
   if ( $spec->[1] !~ m/^\d+$/ ) {
      die "spec array's second element must be an integer\n";
   }
}

sub set_callback {
   my ( $self, $callback ) = @_;
   $self->{callback} = $callback;
}

sub start {
   my ( $self, $start ) = @_;
   $self->{start} = $self->{last_reported} = $start || time();
}

sub update {
   my ( $self, $callback, $now ) = @_;
   my $jobsize   = $self->{jobsize};
   $now        ||= time();
   $self->{iterations}++; # How many updates have happened;

   if ( $self->{report} eq 'time'
         && $self->{interval} > $now - $self->{last_reported}
   ) {
      return;
   }
   elsif ( $self->{report} eq 'iterations'
         && ($self->{iterations} - 1) % $self->{interval} > 0
   ) {
      return;
   }
   $self->{last_reported} = $now;

   my $completed = $callback->();
   $self->{updates}++; # How many times we have run the update callback

   return if $completed > $jobsize;

   my $fraction = $completed > 0 ? $completed / $jobsize : 0;

   if ( $self->{report} eq 'percentage'
         && $self->fraction_modulo($self->{fraction})
            >= $self->fraction_modulo($fraction)
   ) {
      $self->{fraction} = $fraction;
      return;
   }
   $self->{fraction} = $fraction;

   my $elapsed   = $now - $self->{start};
   my $remaining = 0;
   my $eta       = $now;
   if ( $completed > 0 && $completed <= $jobsize && $elapsed > 0 ) {
      my $rate = $completed / $elapsed;
      if ( $rate > 0 ) {
         $remaining = ($jobsize - $completed) / $rate;
         $eta       = $now + int($remaining);
      }
   }
   $self->{callback}->($fraction, $elapsed, $remaining, $eta, $completed);
}

sub fraction_modulo {
   my ( $self, $num ) = @_;
   $num *= 100; # Convert from fraction to percentage
   return sprintf('%d',
      sprintf('%d', $num / $self->{interval}) * $self->{interval});
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End Progress package
# ###########################################################################

# ###########################################################################
# ReplicaLagWaiter package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/ReplicaLagWaiter.pm
#   t/lib/ReplicaLagWaiter.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package ReplicaLagWaiter;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use Time::HiRes qw(sleep time);
use Data::Dumper;

sub new {
   my ( $class, %args ) = @_;
   my @required_args = qw(oktorun get_lag sleep max_lag slaves);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless defined $args{$arg};
   }

   my $self = {
      %args,
   };

   return bless $self, $class;
}

sub wait {
   my ( $self, %args ) = @_;
   my @required_args = qw();
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my $pr = $args{Progress};

   my $oktorun = $self->{oktorun};
   my $get_lag = $self->{get_lag};
   my $sleep   = $self->{sleep};
   my $slaves  = $self->{slaves};
   my $max_lag = $self->{max_lag};

   my $worst;  # most lagging slave
   my $pr_callback;
   if ( $pr ) {
      $pr_callback = sub {
         my ($fraction, $elapsed, $remaining, $eta, $completed) = @_;
         if ( defined $worst->{lag} ) {
            print STDERR "Replica lag is $worst->{lag} seconds on "
               . "$worst->{dsn}->{n}.  Waiting.\n";
         }
         else {
            print STDERR "Replica $worst->{dsn}->{n} is stopped.  Waiting.\n";
         }
         return;
      };
      $pr->set_callback($pr_callback);
   }

   my @lagged_slaves = @$slaves;  # first check all slaves
   while ( $oktorun->() && @lagged_slaves ) {
      MKDEBUG && _d('Checking slave lag');
      for my $i ( 0..$#lagged_slaves ) {
         my $slave = $lagged_slaves[$i];
         my $lag   = $get_lag->($slave->{dbh});
         MKDEBUG && _d($slave->{dsn}->{n}, 'slave lag:', $lag);
         if ( !defined $lag || $lag > $max_lag ) {
            $slave->{lag} = $lag;
         }
         else {
            delete $lagged_slaves[$i];
         }
      }

      @lagged_slaves = grep { defined $_ } @lagged_slaves;
      if ( @lagged_slaves ) {
         @lagged_slaves = reverse sort {
              defined $a && defined $b ? $a <=> $b
            : defined $a               ? -1
            :                             1;
         } @lagged_slaves;
         $worst = $lagged_slaves[0];
         MKDEBUG && _d(scalar @lagged_slaves, 'slaves are lagging, worst:',
            Dumper($worst));

         if ( $pr ) {
            $pr->update(sub { return 0; });
         }

         MKDEBUG && _d('Calling sleep callback');
         $sleep->();
      }
   }

   MKDEBUG && _d('All slaves caught up');
   return;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End ReplicaLagWaiter package
# ###########################################################################

# ###########################################################################
# WeightedAvgRate package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/WeightedAvgRate.pm
#   t/lib/WeightedAvgRate.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package WeightedAvgRate;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, %args ) = @_;
   my @required_args = qw(target_t);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless defined $args{$arg};
   }

   my $self = {
      %args,
      avg_n  => 0,
      avg_t  => 0,
      weight => $args{weight} || 0.75,
   };

   return bless $self, $class;
}

sub update {
   my ($self, $n, $t) = @_;
   MKDEBUG && _d('Master op time:', $n, 'n /', $t, 's');

   if ( $self->{avg_n} && $self->{avg_t} ) {
      $self->{avg_n}    = ($self->{avg_n} * $self->{weight}) + $n;
      $self->{avg_t}    = ($self->{avg_t} * $self->{weight}) + $t;
      $self->{avg_rate} = $self->{avg_n}  / $self->{avg_t};
      MKDEBUG && _d('Weighted avg rate:', $self->{avg_rate}, 'n/s');
   }
   else {
      $self->{avg_n}    = $n;
      $self->{avg_t}    = $t;
      $self->{avg_rate} = $self->{avg_n}  / $self->{avg_t};
      MKDEBUG && _d('Initial avg rate:', $self->{avg_rate}, 'n/s');
   }

   my $new_n = int($self->{avg_rate} * $self->{target_t});
   MKDEBUG && _d('Adjust n to', $new_n);
   return $new_n;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End WeightedAvgRate package
# ###########################################################################

# ###########################################################################
# CleanupTask package
# This package is a copy without comments from the original.  The original
# with comments and its test file can be found in the Bazaar repository at,
#   lib/CleanupTask.pm
#   t/lib/CleanupTask.t
# See https://launchpad.net/percona-toolkit for more information.
# ###########################################################################
{
package CleanupTask;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

sub new {
   my ( $class, $task ) = @_;
   die "I need a task parameter" unless $task;
   die "The task parameter must be a coderef" unless ref $task eq 'CODE';
   my $self = {
      task => $task,
   };
   MKDEBUG && _d('Created cleanup task', $task);
   return bless $self, $class;
}

sub DESTROY {
   my ($self) = @_;
   my $task = $self->{task};
   MKDEBUG && _d('Calling cleanup task', $task);
   $task->();
   return;
}

sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

1;
}
# ###########################################################################
# End CleanupTask package
# ###########################################################################

# ###########################################################################
# This is a combination of modules and programs in one -- a runnable module.
# http://www.perl.com/pub/a/2006/07/13/lightning-articles.html?page=last
# Or, look it up in the Camel book on pages 642 and 643 in the 3rd edition.
#
# Check at the end of this package for the call to main() which actually runs
# the program.
# ###########################################################################
package pt_table_checksum;

use strict;
use warnings FATAL => 'all';
use English qw(-no_match_vars);
use constant MKDEBUG => $ENV{MKDEBUG} || 0;

use POSIX qw(signal_h);
use List::Util qw(max);
use Time::HiRes qw(sleep time);
use Data::Dumper;
$Data::Dumper::Indent    = 1;
$Data::Dumper::Sortkeys  = 1;
$Data::Dumper::Quotekeys = 0;

use sigtrap 'handler', \&sig_int, 'normal-signals';
my $oktorun = 1;
my $print_header = 1; # print headers once

sub main {
   # Reset global vars else tests will fail in strange ways.
   @ARGV         = @_;
   $oktorun      = 1;  
   $print_header = 1;

   my $exit_status = 0;

   # ########################################################################
   # Get configuration information.
   # ########################################################################
   # Because of --arg-table, $final_o is the OptionParser obj used to get
   # most options (see my $final_o below).
   my $o = new OptionParser();
   $o->get_specs();
   $o->get_opts();

   my $dp = $o->DSNParser();
   $dp->prop('set-vars', $o->get('set-vars'));

   # Add the --replicate table to --ignore-tables.
   my %ignore_tables = (
      %{$o->get('ignore-tables')},
      $o->get('replicate') => 1,
   );
   $o->set('ignore-tables', \%ignore_tables);

   if ( !$o->get('help') ) {
      if ( @ARGV > 1 ) {
         $o->save_error("More than one host specified; only one allowed");
      }

      if ( ($o->get('replicate') || '') !~ m/[\w`]\.[\w`]/ ) {
         $o->save_error('The --replicate table must be database-qualified');
      }

      if ( my $limit = $o->get('chunk-size-limit') ) {
         if ( $limit < 0 || ($limit > 0 && $limit < 1) ) {
            $o->save_error('--chunk-size-limit must be >= 1 or 0 to disable');
         }
      }

      if ( $o->get('progress') ) {
         eval { Progress->validate_spec($o->get('progress')) };
         if ( $EVAL_ERROR ) {
            chomp $EVAL_ERROR;
            $o->save_error("--progress $EVAL_ERROR");
         }
      }
   }

   $o->usage_or_errors();

   # ########################################################################
   # If --pid, check it first since we'll die if it already exits.
   # ########################################################################
   my $daemon;
   if ( $o->get('pid') ) {
      # We're not daemoninzing, it just handles PID stuff.  Keep $daemon
      # in the the scope of main() because when it's destroyed it automatically
      # removes the PID file.
      $daemon = new Daemon(o=>$o);
      $daemon->make_PID_file();
   }

   # ########################################################################
   # Connect to the master.
   # ########################################################################
   my $dsn_defaults = $dp->parse_options($o);
   my $dsn          = $dp->parse(shift @ARGV, undef, $dsn_defaults);
   my $dbh = get_cxn(
      dsn          => $dsn,
      DSNParser    => $dp,
      OptionParser => $o,
   );

   # ########################################################################
   # Find and connect to slaves.
   # ########################################################################
   my $q      = new Quoter();
   my $vp     = new VersionParser();
   my $ms     = new MasterSlave(VersionParser => $vp);
   my $slaves = $ms->get_slaves(
      dbh          => $dbh,
      dsn          => $dsn,
      OptionParser => $o,
      DSNParser    => $dp,
      Quoter       => $q,
   );
   MKDEBUG && _d(scalar @$slaves, 'slaves found');

   my $slave_lag_cxn;
   if ( $o->get('check-slave-lag') ) {
      MKDEBUG && _d('Will use --check-slave-lag to check for slave lag');
      # OptionParser can't auto-copy DSN vals from a cmd line DSN
      # to an opt DSN, so we copy them manually.
      my $dsn = $dp->copy($dsn, $o->get('check-slave-lag'));
      my $dbh = get_cxn(
         dsn          => $dsn,
         DSNParser    => $dp,
         OptionParser => $o,
      );
      $slave_lag_cxn = [ {dsn=>$dsn, dbh=>$dbh} ];
   }
   else {
      MKDEBUG && _d('Will check slave lag on all slaves');
      $slave_lag_cxn = $slaves;
   }

   # When we exit main(), either nicely or via death, this object will
   # be destoryed and its deconstructor will call this callback.
   my $close_all_dbh = new CleanupTask(
      sub { 
         $dbh->disconnect() if $dbh;
         foreach my $slave ( @$slaves ) {
            $slave->{dbh}->disconnect() if $slave->{dbh};
         }
         if ( $o->get('check-slave-lag') ) {
            $slave_lag_cxn->[0]->{dbh}->disconnect()
               if $slave_lag_cxn->[0]->{dbh};
         }
      }
   );

   # ########################################################################
   # Create modules needed from here forward.
   # ########################################################################
   my $tp    = new TableParser(Quoter => $q);
   my $tn    = new TableNibbler(TableParser => $tp, Quoter => $q);
   my $rc    = new RowChecksum(Quoter=> $q, OptionParser => $o);
   my $retry = new Retry();

   # ########################################################################
   # Check replication slaves.
   # ########################################################################
   my $repl_table = $q->quote($q->split_unquote($o->get('replicate')));

   if ( $o->get('replicate-check') && !$o->get('recheck') ) {
      MKDEBUG && _d('Will --replicate-check and exit');

      foreach my $slave ( @$slaves ) {
         my $diffs = $rc->find_replication_differences(
            dbh        => $slave->{dbh},
            repl_table => $repl_table,
         );
         MKDEBUG && _d(scalar @$diffs, 'checksum diffs on', $slave->{dsn}->{n});
         if ( @$diffs ) {
            $exit_status |= 1;
            next if $o->get('quiet');
            print_checksum_diffs(
               cxn   => $slave,
               diffs => $diffs,
            );
         }
      }

      MKDEBUG && _d('Exit status', $exit_status, 'oktorun', $oktorun);
      return $exit_status;
   }

   # ########################################################################
   # Check that the replication table exists, or possibly create it.
   # ########################################################################
   check_repl_table(
      dbh          => $dbh,
      repl_table   => $repl_table,
      OptionParser => $o,
      TableParser  => $tp,
      Quoter       => $q,
   );

   # ########################################################################
   # Check for replication filters.
   # ########################################################################
   if ( $o->get('check-replication-filters') ) {
      MKDEBUG && _d("Checking slave replication filters");
      my @all_repl_filters;
      foreach my $host ( @$slaves ) {
         my $repl_filters = $ms->get_replication_filters(dbh=>$host->{dbh});
         if ( keys %$repl_filters ) {
            my $host = $dp->as_string($host->{dsn});
            push @all_repl_filters,
               { name    => $host,
                 filters => $repl_filters,
               };
         }
      }
      if ( @all_repl_filters ) {
         my $msg = "Replication filters are set on these hosts:\n";
         foreach my $host ( @all_repl_filters ) {
            my $filters = $host->{filters};
            $msg .= "  $host->{name}\n"
                  . join("\n", map { "    $_ = $host->{filters}->{$_}" }
                         keys %{$host->{filters}})
                  . "\n";
         }
         $msg .= "Please read the --check-replication-filters documentation "
               . "to learn how to solve this problem.";
         die $msg;
      }
   }

   # ########################################################################
   # Set transaction isolation level.
   # http://code.google.com/p/maatkit/issues/detail?id=720
   # ########################################################################
   my $sql = "SET SESSION TRANSACTION ISOLATION LEVEL REPEATABLE READ";
   eval {
      MKDEBUG && _d($dbh, $sql);
      $dbh->do($sql);
   };
   if ( $EVAL_ERROR ) {
      $dbh->disconnect();
      die "Failed to $sql: $EVAL_ERROR\n"
         . "If the --replicate table is InnoDB and the default server "
         . "transaction isolation level is not REPEATABLE-READ then "
         . "checksumming may fail with errors like \"Binary logging not "
         . "possible. Message: Transaction level 'READ-COMMITTED' in "
         . "InnoDB is not safe for binlog mode 'STATEMENT'\".  In that "
         . "case you will need to manually set the transaction isolation "
         . "level to REPEATABLE-READ.\n";
   }

   # ########################################################################
   # Checksum query statementn and sths to update the checksum table.
   # ########################################################################
   my %crc_args = $rc->get_crc_args(dbh => $dbh);
   my $checksum_dms = "REPLACE INTO $repl_table "
                   . "(db, tbl, chunk, chunk_index,"
                   . " lower_boundary, upper_boundary, this_cnt, this_crc) "
                   . "SELECT ?, ?, ?, ?, ?, ?,";
   my $fetch_sth = $dbh->prepare(
      "SELECT this_crc, this_cnt FROM $repl_table "
      . "WHERE db = ? AND tbl = ? AND chunk = ?");
   my $update_sth = $dbh->prepare(
      "UPDATE $repl_table SET chunk_time = ?, master_crc = ?, master_cnt = ? "
      . "WHERE db = ? AND tbl = ? AND chunk = ?");
   my $delete_sth = $dbh->prepare(
      "DELETE FROM $repl_table WHERE db = ? AND tbl = ?");

   # ########################################################################
   # Make a ReplicaLagWaiter to help wait for slaves after each chunk.
   # ########################################################################
   my $sleep = sub {
      # Don't let the master dbh die while waiting for slaves because we
      # may wait a very long time for slaves.
      $dbh->do("SELECT 'pt-table-checksum keepalive'");
      sleep $o->get('check-interval');
      return;
   };

   my $replica_lag = new ReplicaLagWaiter(
      oktorun  => sub { return $oktorun },
      get_lag  => sub { return $ms->get_slave_lag(@_) },
      sleep    => $sleep,
      max_lag  => $o->get('max-lag'),
      slaves   => $slave_lag_cxn,
   );

   # ########################################################################
   # Variables for adjusting chunk size for each table and chunk.
   # ########################################################################
   my $total_rows = 0;
   my $total_time = 0;
   my $total_rate = 0;
   my $limit      = $o->get('chunk-size-limit');

   # ########################################################################
   # Get last chunk for --resume.
   # ########################################################################
   my $last_chunk;
   if ( $o->get('resume') ) {
      $last_chunk = last_chunk(
         dbh        => $dbh,
         repl_table => $repl_table,
      );
   }

   # ########################################################################
   # Callbacks for each table's nibble iterator.  All checksum work is done
   # in these callbacks and the subs that they call.
   # ########################################################################
   my $callbacks = {
      init => sub {
         my (%args) = @_;
         my $tbl = $args{tbl};

         my $oktonibble = 1;

         if ( $o->get('empty-replicate-table') ) {
            MKDEBUG && _d($delete_sth->{Statement});
            $delete_sth->execute($tbl->{db}, $tbl->{tbl});
         }
         elsif ( $last_chunk ) {
            my $nibble_iter = $args{NibbleIterator};
            my $next_lb     = next_lower_boundary(
               %args,
               last_chunk => $last_chunk,
               Quoter     => $q,
            );
            if ( !$next_lb ) {
               # This can happen if the tool stops after the last checksum
               # of a table.  So we just start with the next table.
               MKDEBUG && _d('Resuming from last chunk in table;',
                  'getting next table');
               $oktonibble = 0;
            }
            else {
               $nibble_iter->set_nibble_number($last_chunk->{chunk});
               $nibble_iter->set_boundary('next_lower', $next_lb);
               print "Resuming from $tbl->{db}.$tbl->{tbl} at chunk "
                  . "$last_chunk->{chunk}, timestamp $last_chunk->{ts}\n";
            }

            # Just need to call us once to kick-start the resume process.
            $last_chunk = undef;
         }

         return $oktonibble; # continue nibbling?
      },
      next_boundaries => sub {
         my (%args) = @_;
         my $tbl         = $args{tbl};
         my $nibble_iter = $args{NibbleIterator};
         my $sth         = $nibble_iter->statements();
         my $boundary    = $nibble_iter->boundaries();

         return 1 if $nibble_iter->one_nibble();

         # Check that MySQL will use the nibble index for the next upper
         # boundary sql.  This check applies to the next nibble.  So if
         # the current nibble number is 5, then nibble 5 is already done
         # and we're checking nibble number 6.
         my $expl = explain_statement(
            tbl  => $tbl,
            sth  => $sth->{explain_upper_boundary},
            vals => [ @{$boundary->{lower}}, $nibble_iter->chunk_size() ],
         );
         if ( ($expl->{key} || '') ne $nibble_iter->nibble_index() ) {
            warn "Aborting $tbl->{db}.$tbl->{tbl} because "
               . ($nibble_iter->nibble_number() + 1)
               . " cannot be nibbled safely.\n";
            $tbl->{checksum_results}->{errors}++;
            return 0; # stop nibbling table
         }

         # Once nibbling begins for a table, control does not return to this
         # tool until nibbling is done because, as noted above, all work is
         # done in these callbacks.  This callback is the only place where we
         # can prematurely stop nibbling by returning false.  This allows
         # Ctrl-C to stop the tool between nibbles instead of between tables.
         return $oktorun; # continue nibbling table?
      },
      exec_nibble => sub {
         my (%args) = @_;
         my $tbl         = $args{tbl};
         my $nibble_iter = $args{NibbleIterator};
         my $sth         = $nibble_iter->statements();
         my $boundary    = $nibble_iter->boundaries();

         # Count every chunk, even if it's ultimately skipped, etc.
         $tbl->{checksum_results}->{n_chunks}++;

         # If the table is being chunk (i.e., it's not small enough to be
         # consumed by one nibble), then check index usage and chunk size.
         if ( !$nibble_iter->one_nibble() ) {
            my $expl = explain_statement(
               tbl  => $tbl,
               sth  => $sth->{explain_nibble},
               vals => [ @{$boundary->{lower}}, @{$boundary->{upper}} ],
            );
            my $oversize_chunk
               = $limit ? ($expl->{rows} || 0) >= $tbl->{chunk_size} * $limit
               :          0;

            # Ensure that MySQL is using the chunk index.
            if ( ($expl->{key} || '') ne $nibble_iter->nibble_index() ) {
               MKDEBUG && _d('Chunk', $args{nibbleno}, 'of table',
                  "$tbl->{db}.$tbl->{tbl} not using chunk index, skipping");
               $tbl->{checksum_results}->{skipped}++;
               $tbl->{nibble_time} = 0;
               return 0;  # next boundary
            }

            # Check chunk size limit if the upper boundary and next lower
            # boundary are identical.
            if ( $limit ) {
               my $boundary = $nibble_iter->boundaries(); 
               if ( $nibble_iter->identical_boundaries(
                       $boundary->{upper}, $boundary->{next_lower})
                    && $oversize_chunk ) {
                  MKDEBUG && _d('Chunk', $args{nibbleno}, 'of table',
                     "$tbl->{db}.$tbl->{tbl} is too large, skipping");
                  $tbl->{checksum_results}->{skipped}++;
                  $tbl->{nibble_time} = 0;
                  return 0;  # next boundary
               }
            }
         }

         # Exec and time the chunk checksum query.
         $tbl->{nibble_time} = exec_nibble(
            %args,
            Retry  => $retry,
            Quoter => $q
         );
         MKDEBUG && _d('Nibble time:', $tbl->{nibble_time});

         # We're executing REPLACE queries which don't return rows.
         # Returning 0 from this callback causes the nibble iter to
         # get the next boundaries/nibble.
         return 0;
      },
      after_nibble => sub {
         my (%args) = @_;
         my $tbl         = $args{tbl};
         my $nibble_iter = $args{NibbleIterator};

         # Nibble time will be zero if the chunk was skipped.
         return unless $tbl->{nibble_time};

         # Chunk/nibble number that we just inserted.
         my $chunk = $nibble_iter->nibble_number();

         # Fetch the checksum that we just executed from the replicate table.
         $fetch_sth->execute(@{$tbl}{qw(db tbl)}, $chunk);
         my ($crc, $cnt) = $fetch_sth->fetchrow_array();

         $tbl->{checksum_results}->{n_rows} += $cnt || 0;

         # We're working on the master, so update the checksum's master_cnt
         # and master_crc.
         $update_sth->execute(
            # UPDATE repl_table SET
            sprintf('%.3f', $tbl->{nibble_time}), # chunk_time
            $crc,                                 # master_crc
            $cnt,                                 # master_cnt
            # WHERE
            $tbl->{db},
            $tbl->{tbl},
            $chunk,
         );

         # Should be done automatically, but I like to be explicit.
         $fetch_sth->finish();
         $update_sth->finish();

         # Update rate, chunk size, and progress if the nibble actually
         # selected some rows.
         if ( ($cnt || 0) > 0 ) {
            # Update the rate of rows per second for the entire server.
            # This is used for the initial chunk size of the next table.
            $total_rows += $cnt;
            $total_time += $tbl->{nibble_time};
            $total_rate  = int($total_rows / $total_time);
            MKDEBUG && _d('Total avg rate:', $total_rate);

            # Adjust chunk size.  This affects the next chunk.
            if ( $o->get('chunk-time') ) {
               $tbl->{chunk_size}
                  = $tbl->{rate}->update($cnt, $tbl->{nibble_time});
               if ( $tbl->{chunk_size} < 1 ) {
                  # This shouldn't happen.  WeightedAvgRate::update() may return
                  # a value < 1, but minimum chunk size is 1.
                  warn "Checksums are executing very slowly.  --chunk-size "
                     . "has been automatically reduced to 1.  Check that the "
                     . "server is not being overloaded, or increase "
                     . "--chunk-time.  The last chunk, number $args{nibbleno} "
                     . "of table $tbl->{db}.$tbl->{tbl}, selected $cnt rows "
                     . "and took "
                     . sprintf('%.3f', $tbl->{nibble_time})
                     . " seconds to execute.\n";
                  $tbl->{chunk_size} = 1;
               }
               $args{NibbleIterator}->set_chunk_size($tbl->{chunk_size});
            }

            # Every table should have a Progress obj; update it.
            if ( my $tbl_pr = $tbl->{progress} ) {
               $tbl_pr->update(sub {return $tbl->{checksum_results}->{n_rows}});
            }
         }

         # Wait forever for slaves to catch up.
         my $lag_pr;
         if ( $o->get('progress') ) {
            $lag_pr = new Progress(
               jobsize => scalar @$slaves,
               spec    => $o->get('progress'),
               name    => "Waiting for replicas to catch up",
            );
         }
         $replica_lag->wait(Progress => $lag_pr);

         return;
      },
      done => sub { # done nibbling table
         my (%args) = @_;
         my $tbl         = $args{tbl};
         my $nibble_iter = $args{NibbleIterator};
         my $max_chunk   = $nibble_iter->nibble_number();

         # Wait for all slaves to run all checksum chunks,
         # then check for differences.
         if ( $o->get('replicate-check') && scalar @$slaves ) {
            MKDEBUG && _d('Checking slave diffs');

            my $check_pr;
            if ( $o->get('progress') ) {
               $check_pr = new Progress(
                  jobsize => $max_chunk,
                  spec    => $o->get('progress'),
                  name    => "Waiting to check replicas for differences",
               );
            }

            my $sql = "SELECT MAX(chunk) FROM $repl_table "
                    . "WHERE db='$tbl->{db}' AND tbl='$tbl->{tbl}'";
            MKDEBUG && _d($sql);

            my $n_slaves = scalar @$slaves - 1;
            my @chunks   = (0);
            while ( $chunks[0] < $max_chunk ) {
               for my $i ( 0..$n_slaves ) {
                  my $slave = $slaves->[$i];
                  my ($chunk) = $slave->{dbh}->selectrow_array($sql);
                  MKDEBUG && _d($slave->{dsn}->{n}, 'max chunk:', $chunk);
                  $chunks[$i] = $chunk || 0;
               }
               @chunks = sort { $a <=> $b } @chunks;
               if ( $chunks[0] < $max_chunk ) {
                  $check_pr->update(sub { return $chunks[0]; });
                  sleep 1;
               }
            }

            foreach my $slave ( @$slaves ) {
               my $diffs = $rc->find_replication_differences(
                  dbh        => $slave->{dbh},
                  repl_table => $repl_table,
                  where      => "db='$tbl->{db}' AND tbl='$tbl->{tbl}'",
               );
               MKDEBUG && _d(scalar @$diffs, 'checksum diffs on',
                  $slave->{dsn}->{n});
               if ( @$diffs ) {
                  $tbl->{checksum_results}->{diffs} = scalar @$diffs;
               }
            }
         }

         print_checksum_results(tbl => $tbl);

         return;
      },
   };

   # ########################################################################
   # Checksum each table.
   # ########################################################################
   my $schema_iter = new SchemaIterator(
      dbh          => $dbh,
      resume       => $last_chunk ? $q->quote(@{$last_chunk}{qw(db tbl)}) : "",
      OptionParser => $o,
      TableParser  => $tp,
      Quoter       => $q,
   );

   TABLE:
   while ( $oktorun &&  (my $tbl = $schema_iter->next()) ) {
      eval {
         # Results, stats, and info related to checksuming this table can
         # be saved here.  print_checksum_results() uses this info.
         $tbl->{checksum_results} = {};

         # USE the correct db while checksumming this table.  The "correct"
         # db is a complicated subject; see sub for comments.
         use_repl_db(
            dbh          => $dbh,
            tbl          => $tbl,
            repl_table   => $repl_table,
            OptionParser => $o,
            Quoter       => $q,
         );

         # Set table's initial chunk size.  If this is the first table,
         # then total rate will be zero, so use --chunk-size.  Or, if
         # --chunk-time=0, then only use --chunk-size for every table.
         # Else, the initial chunk size is based on the total rates of
         # rows/s from all previous tables.
         my $chunk_time = $o->get('chunk-time');
         my $chunk_size = $chunk_time && $total_rate
                        ? int($total_rate * $chunk_time)
                        : $o->get('chunk-size');
         $tbl->{chunk_size} = $chunk_size;

         # Init a new weighted avg rate calculator for the table.
         $tbl->{rate} = new WeightedAvgRate(target_t => $chunk_time);

         # Make a Progress obj for this table.  It may not be used;
         # depends on how many rows, chunk size, how fast the server
         # is, etc.  But just in case, all tables have a Progress obj.
         if ( $o->get('progress') ) {
            $tbl->{progress} = table_progress(
               dbh          => $dbh,
               tbl          => $tbl,
               OptionParser => $o,
               Quoter       => $q,
            );
         }

         # Make a nibble iterator for this table.
         my $checksum_cols = $rc->make_chunk_checksum(
            dbh => $dbh,
            tbl => $tbl,
            %crc_args
         );
         my $nibble_iter = new NibbleIterator(
            dbh          => $dbh,
            tbl          => $tbl,
            chunk_size   => $tbl->{chunk_size},
            chunk_index  => $o->get('chunk-index'),
            dms          => $checksum_dms,
            select       => $checksum_cols,
            callbacks    => $callbacks,
            OptionParser => $o,
            Quoter       => $q,
            TableNibbler => $tn,
            TableParser  => $tp,
            RowChecksum  => $rc,
         );

         # Finally, checksum the table.
         # The "1 while" loop is necessary because we're executing REPLACE
         # statements which don't return rows and NibbleIterator only
         # returns if it has rows to return.  So all the work is done via
         # the callbacks. -- print_checksum_results(), which is called
         # from the done callback, uses this start time.
         $tbl->{checksum_results}->{start_time} = time;
         1 while $nibble_iter->next();
      };
      if ($EVAL_ERROR) {
         warn "Error checksumming $tbl->{db}.$tbl->{tbl}: $EVAL_ERROR\n";
         $tbl->{checksum_results}->{errors}++;
         print_checksum_results(tbl => $tbl);
      }

      # Update the tool's exit status.
      if ( $tbl->{checksum_results}->{errors}
           || $tbl->{checksum_results}->{diffs} ) {
         $exit_status |= 1;
      }
   }

   MKDEBUG && _d('Exit status', $exit_status, 'oktorun', $oktorun);
   return $exit_status;
}

# ############################################################################
# Subroutines
# ############################################################################
sub get_cxn {
   my ( %args ) = @_;
   my ($dsn, $dp, $o) = @args{qw(dsn DSNParser OptionParser)};

   if ( $o->get('ask-pass') ) {
      $dsn->{p} = OptionParser::prompt_noecho("Enter password: "); 
   }
   my $dbh = $dp->get_dbh($dp->get_cxn_params($dsn),  { AutoCommit => 1 });
   $dbh->{FetchHashKeyName} = 'NAME_lc';
   return $dbh;
}

sub exec_nibble {
   my (%args) = @_;
   my @required_args = qw(dbh tbl NibbleIterator Retry Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $tbl, $nibble_iter, $retry, $q)= @args{@required_args};
   
   my $sth         = $nibble_iter->statements();
   my $boundary    = $nibble_iter->boundaries();
   my $lb_quoted   = join(',', @{$boundary->{lower}});
   my $ub_quoted   = join(',', @{$boundary->{upper}});
   my $chunk       = $nibble_iter->nibble_number();
   my $chunk_index = $nibble_iter->nibble_index();

   return $retry->retry(
      tries        => 2,
      wait         => sub { return; },
      retry_on_die => 1,
      try          => sub {
         # ###################################################################
         # Start timing the checksum query.
         # ###################################################################
         my $t_start = time;        

         # Reset the BIT_XOR user vars.
         my $sql = 'SET @crc := "", @cnt := 0 /*!50108 , '
                 . '@@binlog_format := "STATEMENT"*/';
         MKDEBUG && _d($sql);
         $dbh->do($sql);

         # Execute the REPLACE...SELECT checksum query.
         MKDEBUG && _d($sth->{nibble}->{Statement},
            'lower boundary:', @{$boundary->{lower}},
            'upper boundary:', @{$boundary->{upper}});
         $sth->{nibble}->execute(
            # REPLACE INTO repl_table SELECT
            $tbl->{db},             # db
            $tbl->{tbl},            # tbl
            $chunk,                 # chunk (number)
            $chunk_index,           # chunk_index
            $lb_quoted,             # lower_boundary
            $ub_quoted,             # upper_boundary
            # this_cnt, this_crc WHERE
            @{$boundary->{lower}},  # upper boundary values
            @{$boundary->{upper}},  # lower boundary values
         );

         my $t_end = time;
         # ###################################################################
         # End timing the checksum query.
         # ###################################################################

         # Check if checksum query caused any warnings.
         my $sql_warn = 'SHOW WARNINGS';
         MKDEBUG && _d($sql_warn);
         my $warnings = $dbh->selectall_arrayref($sql_warn, { Slice => {} } );
         foreach my $warning ( @$warnings ) {
            if ( $warning->{message}
                     =~ m/Data truncated for column 'boundaries'/ ) {
               _d('Warning: WHERE clause too large for boundaries column;',
                  'pt-table-sync may fail');
            }
            elsif ( ($warning->{code} || 0) == 1592 ) {
               # Error: 1592 SQLSTATE: HY000  (ER_BINLOG_UNSAFE_STATEMENT)
               # Message: Statement may not be safe to log in statement format. 
               # Ignore this warning because we have purposely set
               # statement-based replication.
               MKDEBUG && _d('Ignoring warning:', $warning->{message});
            }
            else {
               die "Checksum query caused a warning:\n"
                  . "    Level: " . ($warning->{level} || '')   . "\n"
                  . "     Code: " . ($warning->{code} || '')    . "\n"
                  . "  Message: " . ($warning->{message} || '') . "\n"
                  . "    Query: " . $sth->{Statement}           . "\n";
            }
         }

         return $t_end - $t_start; # success, return nibble time
      },
      on_failure => sub {
         # Checksum query caused an error,
         # or something in the try sub died.
         $tbl->{checksum_results}->{errors}++;
         warn $EVAL_ERROR;
      },
   );
}

{
my $line_fmt     = "%14s %6s %6s %7s %7s %7s %7s %-s\n";
my @headers      =  qw(TS ERRORS DIFFS ROWS CHUNKS SKIPPED TIME TABLE);

sub print_checksum_results {
   my (%args) = @_;
   my @required_args = qw(tbl);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($tbl) = @args{@required_args};

   if ($print_header) {
      printf $line_fmt, @headers;
      $print_header = 0;
   }

   my ($s, $m, $h, $d, $M) = localtime;

   my $res = $tbl->{checksum_results};
   printf $line_fmt,
      sprintf('%02d-%02dT%02d:%02d:%02d', $d, $M+1, $h, $m, $s),
      $res->{errors}   || 0,
      $res->{diffs}    || 0,
      $res->{n_rows}   || 0,
      $res->{n_chunks} || 0,
      $res->{skipped}  || 0,
      sprintf('%.3f', $res->{start_time} ? time - $res->{start_time} : 0),
      "$tbl->{db}.$tbl->{tbl}";

   return;
}
}

{
my @headers = qw(table chunk cnt_diff crc_diff chunk_index lower_boundary upper_boundary);

sub print_checksum_diffs {
   my ( %args ) = @_;
   my @required_args = qw(cxn diffs);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($cxn, $diffs) = @args{@required_args};

   print "Differences on $cxn->{dsn}->{n}\n";
   print join(' ', map { uc $_ } @headers), "\n";
   foreach my $diff ( @$diffs ) {
      print join(' ', map { defined $_ ? $_ : '' } @{$diff}{@headers}), "\n";
   }
   print "\n";

   return;
}
}

# Check for existence and privileges on the replication table before
# starting, and prepare the statements that will be used to update it.
# Also clean out the checksum table.  And create it if needed.
# Returns fetch and update statement handles.
sub check_repl_table {
   my ( %args ) = @_;
   my @required_args = qw(dbh repl_table OptionParser TableParser Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $repl_table, $o, $tp, $q) = @args{@required_args};
   MKDEBUG && _d('Checking --replicate table', $repl_table);
   use_repl_db(%args);

   my ($db, $tbl) = $q->split_unquote($repl_table);
   my $tbl_exists = $tp->check_table(
      dbh => $dbh,
      db  => $db,
      tbl => $tbl,
   );
   if ( !$tbl_exists ) {
      if ( $o->get('create-replicate-table') ) {
         create_repl_table(%args)
      }
      else {
         die  "--replicate table $repl_table does not exist; "
            . "read the documentation or use --create-replicate-table "
            . "to create it.\n";
      }
   }
   else {
      MKDEBUG && _d('--replicate table', $repl_table, 'already exists');
      # Check it again but this time check the privs.
      my $have_tbl_privs = $tp->check_table(
         dbh       => $dbh,
         db        => $db,
         tbl       => $tbl,
         all_privs => 1,
      );
      die "User does not have all privileges on --replicate table $repl_table"
         unless $have_tbl_privs;
   }

   return;
}

# Sub: use_repl_db
#   USE the correct database for the --replicate table.
#   This sub must be called before any work is done with the --replicatte
#   table because replication filters can really complicate replicating the
#   checksums.  The originally issue is,
#   http://code.google.com/p/maatkit/issues/detail?id=982,
#   but here's what you need to know:
#   - If there is no active DB, then if there's any do-db or ignore-db
#     settings, the checksums will get filtered out of replication. So we
#     have to have some DB be the current one.
#   - Other places in the code may change the DB and we might not know it.
#     Opportunity for bugs.  The SHOW CREATE TABLE, for example. In the
#     end, a bunch of USE statements isn't a big deal, it just looks noisy
#     when you analyze the logs this tool creates. But it's better to just
#     have them even if they're no-op.
#   - We need to always let the user specify, because there are so many
#     possibilities that the tool can't guess the right thing in all of
#     them.
#   - The right default behavior, which the user can override, is:
#       * When running queries on the --replicate table itself, such as
#         emptying it, USE that table's database.
#       * When running checksum queries, USE the database of the table that's
#         being checksummed.
#       * When the user specifies --replicate-database, in contrast, always
#         USE that database.
#   - This behavior is the best compromise by default, because users who
#     explicitly replicate some databases and filter out others will be
#     very likely to run pt-table-checksum and limit its checksumming to
#     only the databases that are replicated. I've seen people do this,
#     including Peter. In this case, the tool will work okay even without
#     an explicit --replicate-database setting.
#
# Required Arguments:
#   dbh          - dbh
#   repl_table   - Full quoted --replicate table name
#   OptionParser - <OptionParser>
#   Quoter       - <Quoter>
#
# Optional Arguments:
#   tbl - Standard tbl hashref of table being checksummed
#
# Returns:
#   Nothing or dies on error
{
my $current_db;

sub use_repl_db {
   my ( %args ) = @_;
   my @required_args = qw(dbh repl_table OptionParser Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $repl_table, $o, $q) = @args{@required_args};

   my ($db, $tbl) = $q->split_unquote($repl_table);
   if ( my $tbl = $args{tbl} ) {
      # If there's a tbl arg then its db will be used unless
      # --replicate-database was specified.  A tbl arg means
      # we're checksumming that table.  Other callers won't
      # pass a tbl arg when they're just doing something to
      # the --replicate table.
      $db = $o->get('replicate-database') ? $o->get('replicate-database')
          :                                 $tbl->{db};
   }
   else {
      # Caller is doing something just to the --replicate table.
      # Use the db from --replicate db.tbl (gotten earlier) unless
      # --replicate-database is in effect.
      $db = $o->get('replicate-database') if $o->get('replicate-database');
   }

   if ( !$current_db || $current_db ne $db ) {
      eval {
         my $sql = "USE " . $q->quote($db);
         MKDEBUG && _d($sql);
         $dbh->do($sql);
      };
      if ( $EVAL_ERROR ) {
         # Report which option db really came from.
         my $opt = $o->get('replicate-database') ? "--replicate-database"
                 :                                 "--replicate database";
         if ( $EVAL_ERROR =~ m/unknown database/i ) {
            die "$opt `$db` does not exist.  You need to create the "
               . "database or specify a database for $opt that exists.\n";
         }
         else {
            die "Error using $opt `$db`: $EVAL_ERROR\n";
         }
      }
      $current_db = $db;
   }

   return;
}
}

sub create_repl_table {
   my ( %args ) = @_;
   my @required_args = qw(dbh repl_table OptionParser);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $repl_table, $o) = @args{@required_args};
   MKDEBUG && _d('Creating --replicate table', $repl_table); 
   my $sql = $o->read_para_after(__FILE__, qr/MAGIC_create_replicate/);
   $sql =~ s/CREATE TABLE checksum/CREATE TABLE $repl_table/;
   $sql =~ s/;$//;
   MKDEBUG && _d($dbh, $sql);
   eval {
      $dbh->do($sql);
   };
   if ( $EVAL_ERROR ) {
      die "--create-replicate-table failed: $EVAL_ERROR";
   }

   return;
}

# Sub: explain_statement
#   EXPLAIN a statement.
#
# Required Arguments:
#   * tbl  - Standard tbl hashref
#   * sth  - Sth with EXLAIN <statement>
#   * vals - Values for sth, if any
#
# Returns:
#   Hashref with EXPLAIN plan
sub explain_statement {
   my ( %args ) = @_;
   my @required_args = qw(tbl sth vals);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless defined $args{$arg};
   }
   my ($tbl, $sth, $vals) = @args{@required_args};

   my $expl;
   eval {
      MKDEBUG && _d($sth->{Statement}, 'params:', @$vals);
      $sth->execute(@$vals);
      $expl = $sth->fetchrow_hashref();
      $sth->finish();
   };
   if ( $EVAL_ERROR ) {
      # This shouldn't happen.
      warn "Failed to " . $sth->{Statement} . ": $EVAL_ERROR\n";
      $tbl->{checksum_results}->{errors}++;
   }
   MKDEBUG && _d('EXPLAIN plan:', Dumper($expl));
   return $expl;
}

sub table_progress {
   my (%args) = @_;
   my @required_args = qw(dbh tbl OptionParser Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $tbl, $o, $q) = @args{@required_args};

   my $table = $q->quote(@{$tbl}{qw(db tbl)});
   my $sql   = "EXPLAIN SELECT COUNT(*) FROM $table"
             . ($args{where} ? " WHERE $args{where}" : '');
   MKDEBUG && _d($sql);
   my $expl = $dbh->selectrow_hashref($sql);
   my $rows = $expl->{rows} || 0;
   my $pr;
   if ( $rows ) {
      $pr = new Progress(
         jobsize => $rows,
         spec    => $o->get('progress'),
         name    => "Checksumming $tbl->{db}.$tbl->{tbl}",
      );
   }
   return $pr;
}

sub last_chunk {
   my (%args) = @_;
   my @required_args = qw(dbh repl_table);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $repl_table, $q) = @args{@required_args};

   my $sql = "SELECT MAX(ts) FROM $repl_table";
   MKDEBUG && _d($sql);
   my ($max_ts) = $dbh->selectrow_array($sql);
   if ( !$max_ts ) {
      MKDEBUG && _d('Replicate table is empty; will not resume');
      return;
   }

   $sql = "SELECT * FROM $repl_table "
        . "WHERE ts='$max_ts' "
        . "ORDER BY db DESC, tbl DESC, chunk DESC LIMIT 1";
   MKDEBUG && _d($sql);
   my $last_chunk = $dbh->selectrow_hashref($sql);
   MKDEBUG && _d('Last chunk:', Dumper($last_chunk));

   $sql = "SELECT MAX(chunk) FROM $repl_table "
        . "WHERE db='$last_chunk->{db}' AND tbl='$last_chunk->{tbl}'";
   MKDEBUG && _d($sql);
   my ($max_chunk) = $dbh->selectrow_array($sql);
   if ( ($last_chunk->{chunk} || 0) ne ($max_chunk || 0) ) {
      warn "Not resuming from max chunk (" . ($last_chunk->{chunk} || 0)
         . " != " . ($max_chunk || 0) > "); resuming may not work correctly.\n";
   }

   return $last_chunk;
}

sub next_lower_boundary {
   my (%args) = @_;
   my @required_args = qw(dbh tbl last_chunk NibbleIterator Quoter);
   foreach my $arg ( @required_args ) {
      die "I need a $arg argument" unless $args{$arg};
   }
   my ($dbh, $tbl, $last_chunk, $nibble_iter, $q) = @args{@required_args};

   if ( $nibble_iter->nibble_index() ne ($last_chunk->{chunk_index} || '') ) {
      warn "Cannot resume from table $tbl->{db}.$tbl->{tbl} chunk "
         . "$last_chunk->{chunk} because the chunk index are different: "
         . "$last_chunk->{chunk_index} was used originally but "
         . $nibble_iter->nibble_index() . " is used now.\n";
      $tbl->{checksum_results}->{skipped}++;
      return;
   }

   my $sql = $nibble_iter->sql();
   my $next_lb_sql
      = "SELECT /*!40001 SQL_NO_CACHE */ "
      . join(', ', map { $q->quote($_) } @{$sql->{columns}})
      . " FROM $sql->{from}"
      . " WHERE " . $sql->{boundaries}->{'>'}
                  . ($sql->{where} ? " AND ($sql->{where})" : '')
      . " ORDER BY $sql->{order_by}"
      . " LIMIT 1"
      . " /*resume next lower boundary*/";
   MKDEBUG && _d($next_lb_sql);
   my $sth = $dbh->prepare($next_lb_sql);
   
   my @ub = split ',', $last_chunk->{upper_boundary};
   MKDEBUG && _d($sth->{Statement}, 'params:', @ub);
   $sth->execute(@ub);
   my $next_lb = $sth->fetchrow_arrayref();
   $sth->finish();
   return $next_lb;
}

# Catches signals so we can exit gracefully.
sub sig_int {
   my ( $signal ) = @_;
   if ( $oktorun ) {
      print STDERR "# Caught SIG$signal.\n";
      $oktorun = 0;
   }
   else {
      print STDERR "# Exiting on SIG$signal.\n";
      exit 1;
   }
}


sub _d {
   my ($package, undef, $line) = caller 0;
   @_ = map { (my $temp = $_) =~ s/\n/\n# /g; $temp; }
        map { defined $_ ? $_ : 'undef' }
        @_;
   print STDERR "# $package:$line $PID ", join(' ', @_), "\n";
}

# ############################################################################
# Run the program.
# ############################################################################
if ( !caller ) { exit main(@ARGV); }

1; # Because this is a module as well as a script.

# ############################################################################
# Documentation
# ############################################################################
=pod

=head1 NAME

pt-table-checksum - Perform an online replication consistency check.

=head1 SYNOPSIS

Usage: pt-table-checksum [OPTION...] [DSN]

pt-table-checksum performs an online replication consistency check by
replicating checksum queries.  By default, all tables on all replicas
are checked.  The C<DSN>, if specified, must be the master host.  The
tool exists non-zero if any differences are found, or if any warnings
or error occur.

First create a C<percona> database on the master:

   CREATE DATABASE percona;

Then run the tool on the master to check that all data on all replicas
is consistent:

   pt-table-checksum --create-replicate-table

The L<"--create-replicate-table"> option can be dropped once the
L<"--replicate"> table has been created.

=head1 RISKS

The following section is included to inform users about the potential risks,
whether known or unknown, of using this tool.  The two main categories of risks
are those created by the nature of the tool (e.g. read-only tools vs. read-write
tools) and those created by bugs.

pt-table-checksum executes queries that cause the MySQL server to checksum its
data.  This can cause significant server load.  The tool also inserts a small
amount of data into the L<"--replicate"> table.

At the time of this release, we know of no bugs that could cause serious harm to
users.

The authoritative source for updated information is always the online issue
tracking system.  Issues that affect this tool will be marked as such.  You can
see a list of such issues at the following URL:
L<http://www.percona.com/bugs/pt-table-checksum>.

See also L<"BUGS"> for more information on filing bugs and getting help.

=head1 DESCRIPTION

pt-table-checksum generates table checksums for MySQL tables, typically
useful for verifying your slaves are in sync with the master.  The checksums
are generated by a query on the server, and there is very little network
traffic as a result.

Checksums typically take about twice as long as COUNT(*) on very large InnoDB
tables in my tests.  For smaller tables, COUNT(*) is a good bit faster than
the checksums.

TODO

=head1 HOW FAST IS IT?

Speed and efficiency are important, because the typical use case is checksumming
large amounts of data.

C<pt-table-checksum> is designed to do very little work itself, and generates
very little network traffic aside from inspecting table structures with C<SHOW
CREATE TABLE>.  The results of checksum queries are typically 40-character or
shorter strings.

The MySQL server does the bulk of the work, in the form of the checksum queries.
The following benchmarks show the checksum query times for various checksum
algorithms.  The first two results are simply running C<COUNT(col8)> and
C<CHECKSUM TABLE> on the table.  C<CHECKSUM TABLE> is just C<CRC32> under the
hood, but it's implemented inside the storage engine layer instead of at the
MySQL layer.

 ALGORITHM       HASH FUNCTION  EXTRA           TIME
 ==============  =============  ==============  =====
 COUNT(col8)                                    2.3
 CHECKSUM TABLE                                 5.3
 BIT_XOR         FNV_64                         12.7
 ACCUM           FNV_64                         42.4
 BIT_XOR         MD5            --optimize-xor  80.0
 ACCUM           MD5                            87.4
 BIT_XOR         SHA1           --optimize-xor  90.1
 ACCUM           SHA1                           101.3
 BIT_XOR         MD5                            172.0
 BIT_XOR         SHA1                           197.3

The tests are entirely CPU-bound.  The sample data is an InnoDB table with the
following structure:

 CREATE TABLE test (
   col1 int NOT NULL,
   col2 date NOT NULL,
   col3 int NOT NULL,
   col4 int NOT NULL,
   col5 int,
   col6 decimal(3,1),
   col7 smallint unsigned NOT NULL,
   col8 timestamp NOT NULL,
   PRIMARY KEY  (col2, col1),
   KEY (col7),
   KEY (col1)
 ) ENGINE=InnoDB

The table has 4303585 rows, 365969408 bytes of data and 173457408 bytes of
indexes.  The server is a Dell PowerEdge 1800 with dual 32-bit Xeon 2.8GHz
processors and 2GB of RAM.  The tests are fully CPU-bound, and the server is
otherwise idle.  The results are generally consistent to within a tenth of a
second on repeated runs.

C<CRC32> is the default checksum function to use, and should be enough for most
cases.  If you need stronger guarantees that your data is identical, you should
use one of the other functions.

=head1 OUTPUT

TODO

=head1 EXIT STATUS

An exit status of 0 (sometimes also called a return value or return code)
indicates success.  If there is an error checksumming any table, the exit status
is 1.

When running L<"--replicate-check">, if any slave has chunks that differ from
the master, the exit status is 1.

=head1 QUERIES

If you are using innotop (see L<http://code.google.com/p/innotop>),
mytop, or another tool to watch currently running MySQL queries, you may see
the checksum queries.  They look similar to this:

  TODO

Since pt-table-checksum's queries run for a long time and tend to be
textually very long, and thus won't fit on one screen of these monitoring
tools, I've been careful to place a comment at the beginning of the query so
you can see what it is and what it's doing.  The comment contains the name of
the table that's being checksummed, the chunk it is currently checksumming,
and how many chunks will be checksummed.  In the case above, it is
checksumming chunk 2 of 5 in table test.test_tbl.

=head1 OPTIONS

This tool accepts additional command-line arguments.  Refer to the
L<"SYNOPSIS"> and usage information for details.

=over

=item --ask-pass

group: Connection

Prompt for a password when connecting to MySQL.

=item --check-interval

type: time; default: 1; group: Throttle

Sleep time between checks for L<"--max-lag">.

=item --[no]check-replication-filters

default: yes; group: Safety

Do not L<"--replicate"> if any replication filters are set.  When
--replicate is specified, pt-table-checksum tries to detect slaves and look
for options that filter replication, such as binlog_ignore_db and
replicate_do_db.  If it finds any such filters, it aborts with an error.
Replication filtering makes it impossible to be sure that the checksum
queries won't break replication or simply fail to replicate.  If you are sure
that it's OK to run the checksum queries, you can negate this option to
disable the checks.  See also L<"--replicate-database">.

=item --check-slave-lag

type: DSN; group: Throttle

Pause checksumming until the specified slave's lag is less than L<"--max-lag">.

=item --chunk-index

type: string

Prefer this index for chunking tables.  By default, pt-table-checksum chooses
an appropriate index for chunking.  This option lets you specify the index
that you prefer.  If the index doesn't exist, then pt-table-checksum will fall
back to its default behavior.  pt-table-checksum adds the index to the checksum
SQL statements in a C<FORCE INDEX> clause.  Be careful when using this option;
a poor choice of index could cause bad performance.  This is probably best to
use when you are checksumming only a single table, not an entire server.

=item --chunk-size

type: size; default: 1000

Approximate number of rows or size of data to checksum at a time.  Allowable
suffixes are k, M, G.

If you specify a chunk size, pt-table-checksum will try to find an index that
will let it split the table into ranges of approximately L<"--chunk-size">
rows, based on the table's index statistics.  Currently only numeric and date
types can be chunked.

If the table is chunkable, pt-table-checksum will checksum each range separately
with parameters in the checksum query's WHERE clause.  If pt-table-checksum
cannot find a suitable index, it will do the entire table in one chunk as though
you had not specified L<"--chunk-size"> at all.  Each table is handled
individually, so some tables may be chunked and others not.

The chunks will be approximately sized, and depending on the distribution of
values in the indexed column, some chunks may be larger than the value you
specify.

If you specify a suffix (one of k, M or G), the parameter is treated as a data
size rather than a number of rows.  The output of SHOW TABLE STATUS is then used
to estimate the amount of data the table contains, and convert that to a number
of rows.

=item --chunk-size-limit

type: float; default: 2.0; group: Safety

Do not checksum chunks with this many times more rows than L<"--chunk-size">.

When L<"--chunk-size"> is given it specifies an ideal size for each chunk
of a chunkable table (in rows; size values are converted to rows).  Before
checksumming each chunk, pt-table-checksum checks how many rows are in the
chunk with EXPLAIN.  If the number of rows reported by EXPLAIN is this many
times greater than L<"--chunk-size">, then the chunk is skipped and C<OVERSIZE>
is printed for the C<COUNT> column of the L<"OUTPUT">.

For example, if you specify L<"--chunk-size"> 100 and a chunk has 150 rows,
then it is checksummed with the default L<"--chunk-size-limit"> value 2.0
because 150 is less than 100 * 2.0.  But if the chunk has 205 rows, then it
is not checksummed because 205 is greater than 100 * 2.0.

The minimum value for this option is 1 which means that no chunk can be any
larger than L<"--chunk-size">.  You probably don't want to specify 1 because
rows reported by EXPLAIN are estimates which can be greater than or less than
the real number of rows in the chunk.  If too many chunks are skipped because
they are oversize, you might want to specify a value larger than 2.

You can disable oversize chunk checking by specifying L<"--chunk-size-limit"> 0.

=item --chunk-time

type: float; default: 0.5

Taget time for each chunk.  Set to 0 to disable.

=item --columns

short form: -c; type: array; group: Filter

Checksum only this comma-separated list of columns.

=item --config

type: Array; group: Config

Read this comma-separated list of config files; if specified, this must be the
first option on the command line.

=item --create-replicate-table

Create the replicate table given by L<"--replicate"> if it does not exist.

Normally, if the replicate table given by L<"--replicate"> does not exist,
C<pt-table-checksum> will die. With this option, however, C<pt-table-checksum>
will create the replicate table for you, using the database.table name given to
L<"--replicate">.

The structure of the replicate table is the same as the suggested table
mentioned in L<"--replicate">. Note that since ENGINE is not specified, the
replicate table will use the server's default storage engine.  If you want to
use a different engine, you need to create the table yourself.

=item --databases

short form: -d; type: hash; group: Filter

Only checksum this comma-separated list of databases.

=item --databases-regex

type: string; group: Filter

Only checksum databases whose names match this Perl regex.

=item --defaults-file

short form: -F; type: string; group: Connection

Only read mysql options from the given file.  You must give an absolute
pathname.

=item --[no]empty-replicate-table

default: yes

Delete previous checksums for each table before checksumming the table.
This option does not truncate the entire L<"--replicate"> table, it
only deletes rows (checksums) for each table right before checksumming
the table.  Therefore, if checksumming stops prematurely, the L<"--replicate">
table will still contain rows for tables that were not checksumed before
the tool was stopped.

L<"--resume"> disables this option because if previous checksums are
deleted then there is nothing to resume.

=item --engines

short form: -e; type: hash; group: Filter

Do only this comma-separated list of storage engines.

=item --float-precision

type: int

Precision for C<FLOAT> and C<DOUBLE> number-to-string conversion.  Causes FLOAT
and DOUBLE values to be rounded to the specified number of digits after the
decimal point, with the ROUND() function in MySQL.  This can help avoid
checksum mismatches due to different floating-point representations of the same
values on different MySQL versions and hardware.  The default is no rounding;
the values are converted to strings by the CONCAT() function, and MySQL chooses
the string representation.  If you specify a value of 2, for example, then the
values 1.008 and 1.009 will be rounded to 1.01, and will checksum as equal.

=item --function

type: string

Hash function for checksums (FNV1A_64, MURMUR_HASH, SHA1, MD5, CRC32, etc).

The default is to use
C<CRC32>, but C<MD5> and C<SHA1> also work, and you can use your own function,
such as a compiled UDF, if you wish.  Whatever function you specify is run in
SQL, not in Perl, so it must be available to MySQL.

The C<FNV1A_64> UDF mentioned in the benchmarks is much faster than C<MD5>.  The
C++ source code is distributed with Maatkit.  It is very simple to compile and
install; look at the header in the source code for instructions.  If it is
installed, it is preferred over C<MD5>.  You can also use the MURMUR_HASH
function if you compile and install that as a UDF; the source is also
distributed with Maatkit, and it is faster and has better distribution
than FNV1A_64.

=item --help

group: Help

Show help and exit.

=item --ignore-columns

type: Hash; group: Filter

Ignore this comma-separated list of columns when calculating the checksum.

=item --ignore-databases

type: Hash; group: Filter

Ignore this comma-separated list of databases.

=item --ignore-databases-regex

type: string; group: Filter

Ignore databases whose names match this Perl regex.

=item --ignore-engines

type: Hash; default: FEDERATED,MRG_MyISAM; group: Filter

Ignore this comma-separated list of storage engines.

=item --ignore-tables

type: Hash; group: Filter

Ignore this comma-separated list of tables.

Table names may be qualified with the database name.

=item --ignore-tables-regex

type: string; group: Filter

Ignore tables whose names match the Perl regex.

=item --max-lag

type: time; default: 1s; group: Throttle

Suspend checksumming if the slave given by L<"--check-slave-lag"> lags.

This option causes pt-table-checksum to look at slave lag after each checksum.
If the any slave's lag is greater than the option's value, or if the slave
isn't running (so its lag is NULL), pt-table-checksum sleeps for
L<"--check-interval"> seconds and then looks at the lag again.  It repeats
until all slaves are caught up, then continues checksumming.

This option is useful to let you checksum data as fast as the slaves can handle
it, assuming the slave you directed pt-table-checksum to monitor is
representative of all the slaves that may be replicating from this server.

=item --password

short form: -p; type: string; group: Connection

Password to use when connecting.

=item --pid

type: string

Create the given PID file.  The file contains the process ID of the script.
The PID file is removed when the script exits.  Before starting, the script
checks if the PID file already exists.  If it does not, then the script creates
and writes its own PID to it.  If it does, then the script checks the following:
if the file contains a PID and a process is running with that PID, then
the script dies; or, if there is no process running with that PID, then the
script overwrites the file with its own PID and starts; else, if the file
contains no PID, then the script dies.

=item --port

short form: -P; type: int; group: Connection

Port number to use for connection.

=item --progress

type: array; default: time,30

Print progress reports to STDERR.

The value is a comma-separated list with two parts.  The first part can be
percentage, time, or iterations; the second part specifies how often an update
should be printed, in percentage, seconds, or number of iterations.

=item --quiet

Don't print anything to STDOUT.

=item --[no]recheck

default: yes

Re-checksum chunks that L<"--replicate-check"> found to be different.

=item --recurse

type: int

Number of levels to recurse in the hierarchy when discovering slaves.
Default is infinite.

See L<"--recursion-method">.

=item --recursion-method

type: string

Preferred recursion method for discovering slaves.

Possible methods are:

  METHOD       USES
  ===========  ==================
  processlist  SHOW PROCESSLIST
  hosts        SHOW SLAVE HOSTS
  dsn=DSN      DSNs from a table

The C<processlist> method is preferred because SHOW SLAVE HOSTS is not reliable.
However, the C<hosts> method is required if the server uses a non-standard
port (not 3306).  Usually the tool does the right thing and finds all slaves,
but you may give a preferred method and it will be used first.

The C<dsn> method is special: it specifies a DSN from which other DSN strings
are read.  The specified DSN must specify a D and t, or a database-qualified
t.  The DSN table should have the following structure:

  CREATE TABLE `dsns` (
    `id` int(11) NOT NULL AUTO_INCREMENT,
    `parent_id` int(11) DEFAULT NULL,
    `dsn` varchar(255) NOT NULL,
    PRIMARY KEY (`id`)
  );

One row specifies one DSN in the C<dsn> column.  Currently, the DSNs are
ordered by C<id>, but C<id> and C<parent_id> are otherwise ignored.

=item --replicate

type: string; default: percona.checksums

Replicate checksums to slaves.

This option enables a completely different checksum strategy for a consistent,
lock-free checksum across a master and its slaves.  Instead of running the
checksum queries on each server, you run them only on the master.  You specify a
table, fully qualified in db.table format, to insert the results into.  The
checksum queries will insert directly into the table, so they will be replicated
through the binlog to the slaves.

When the queries are finished replicating, you can run a simple query on each
slave to see which tables have differences from the master.  With the
L<"--replicate-check"> option, pt-table-checksum can run the query for you to
make it even easier.  See L<"CONSISTENT CHECKSUMS"> for details.  

If you find tables that have differences, you can use the chunk boundaries in a
WHERE clause with L<pt-table-sync> to help repair them more efficiently.  See
L<pt-table-sync> for details.

The table must have at least these columns: db, tbl, chunk, boundaries,
this_crc, master_crc, this_cnt, master_cnt.  The table may be named anything you
wish.  Here is a suggested table structure, which is automatically used for
L<"--create-replicate-table"> (MAGIC_create_replicate):

  CREATE TABLE checksum (
     db             char(64)     NOT NULL,
     tbl            char(64)     NOT NULL,
     chunk          int          NOT NULL,
     chunk_time     float            NULL,
     chunk_index    varchar(200)     NULL,
     lower_boundary text         NOT NULL,
     upper_boundary text         NOT NULL,
     this_crc       char(40)     NOT NULL,
     this_cnt       int          NOT NULL,
     master_crc     char(40)         NULL,
     master_cnt     int              NULL,
     ts             timestamp    NOT NULL,
     PRIMARY KEY (db, tbl, chunk)
  ) ENGINE=InnoDB;

Be sure to choose an appropriate storage engine for the checksum table.  If you
are checksumming InnoDB tables, for instance, a deadlock will break replication
if the checksum table is non-transactional, because the transaction will still
be written to the binlog.  It will then replay without a deadlock on the
slave and break replication with "different error on master and slave."  This
is not a problem with pt-table-checksum, it's a problem with MySQL
replication, and you can read more about it in the MySQL manual.

This works only with statement-based replication (pt-table-checksum will switch
the binlog format to STATEMENT for the duration of the session if your server
uses row-based replication).  

In contrast to running the tool against multiple servers at once, using this
option eliminates the complexities of synchronizing checksum queries across
multiple servers, which normally requires locking and unlocking, waiting for
master binlog positions, and so on.

The checksum queries actually do a REPLACE into this table, so existing rows
need not be removed before running.  However, you may wish to do this anyway to
remove rows related to tables that don't exist anymore.  The
L<"--[no]empty-replicate-table"> option does this for you.

Since the table must be qualified with a database (e.g. C<db.checksums>),
pt-table-checksum will only USE this database.  This may be important if any
replication options are set because it could affect whether or not changes
to the table are replicated.

If the slaves have any --replicate-do-X or --replicate-ignore-X options, you
should be careful not to checksum any databases or tables that exist on the
master and not the slaves.  Changes to such tables may not normally be executed
on the slaves because of the --replicate options, but the checksum queries
modify the contents of the table that stores the checksums, not the tables whose
data you are checksumming.  Therefore, these queries will be executed on the
slave, and if the table or database you're checksumming does not exist, the
queries will cause replication to fail.  For more information on replication
rules, see L<http://dev.mysql.com/doc/en/replication-rules.html>.

The table specified by L<"--replicate"> will never be checksummed itself.

=item --[no]replicate-check

default: yes

Check results in L<"--replicate"> table, to the specified depth.  You must use
this after you run the tool normally; it skips the checksum step and only checks
results.

It recursively finds differences recorded in the table given by
L<"--replicate">.  It recurses to the depth you specify: 0 is no recursion
(check only the server you specify), 1 is check the server and its slaves, 2 is
check the slaves of its slaves, and so on.

It finds differences by running the query shown in L<"CONSISTENT CHECKSUMS">,
and prints results, then exits after printing.  This is just a convenient way of
running the query so you don't have to do it manually.

The output is one informational line per slave host, followed by the results
of the query, if any.  If
there are no differences between the master and any slave, there is no output.
If any slave has chunks that differ from the master, pt-table-checksum's
exit status is 1; otherwise it is 0.

This option makes C<pt-table-checksum> look for slaves by running C<SHOW
PROCESSLIST>.  If it finds connections that appear to be from slaves, it derives
connection information for each slave with the same default-and-override method
described in L<"SPECIFYING HOSTS">.

If C<SHOW PROCESSLIST> doesn't return any rows, C<pt-table-checksum> looks at
C<SHOW SLAVE HOSTS> instead.  The host and port, and user and password if
available, from C<SHOW SLAVE HOSTS> are combined into a DSN and used as the
argument.  This requires slaves to be configured with C<report-host>,
C<report-port> and so on.

This requires the @@SERVER_ID system variable, so it works only on MySQL
3.23.26 or newer.

=item --replicate-database

type: string

C<USE> only this database with L<"--replicate">.  By default, pt-table-checksum
executes USE to set its default database to the database that contains the table
it's currently working on.  It changes its default database as it works on
different tables.  This is is a best effort to avoid problems with replication
filters such as binlog_ignore_db and replicate_ignore_db.  However, replication
filters can create a situation where there simply is no one right way to do
things.  Some statements might not be replicated, and others might cause
replication to fail on the slaves.  In such cases, it is up to the user to
specify a safe default database.  This option specifies a default database that
pt-table-checksum selects with USE, and never changes afterwards.  See also
<L"--[no]check-replication-filters">.

=item --resume

Resume checksumming (disables L<"--[no]empty-replicate-table">).
If the tool is stopped prematurely, checksumming can
be resumed from the last successful checksum by specifying this option.

This option disables L<"--[no]empty-replicate-table"> because if previous
checksums are deleted then there is nothing to resume.

=item --separator

type: string; default: #

The separator character used for CONCAT_WS().

This character is used to join the values of columns when checksumming.

=item --set-vars

type: string; default: wait_timeout=10000; group: Connection

Set these MySQL variables.  Immediately after connecting to MySQL, this
string will be appended to SET and executed.

=item --socket

short form: -S; type: string; group: Connection

Socket file to use for connection.

=item --tables

short form: -t; type: hash; group: Filter

Do only this comma-separated list of tables.

Table names may be qualified with the database name.

=item --tables-regex

type: string; group: Filter

Only checksum tables whose names match this Perl regex.

=item --trim

Trim C<VARCHAR> columns (helps when comparing 4.1 to >= 5.0).

This option adds a C<TRIM()> to C<VARCHAR> columns in C<BIT_XOR> and C<ACCUM>
modes.

This is useful when you don't care about the trailing space differences between
MySQL versions which vary in their handling of trailing spaces. MySQL 5.0 and 
later all retain trailing spaces in C<VARCHAR>, while previous versions would 
remove them.

=item --user

short form: -u; type: string; group: Connection

User for login if not current user.

=item --version

group: Help

Show version and exit.

=item --where

type: string

Do only rows matching this C<WHERE> clause.

You can use this option to limit the checksum to only part of the table.  This
is particularly useful if you have append-only tables and don't want to
constantly re-check all rows; you could run a daily job to just check
yesterday's rows, for instance.

This option is much like the -w option to mysqldump.  Do not specify the WHERE
keyword.  You may need to quote the value.  Here is an example:

  pt-table-checksum --where "foo=bar"

=back

=head1 DSN OPTIONS

These DSN options are used to create a DSN.  Each option is given like
C<option=value>.  The options are case-sensitive, so P and p are not the
same option.  There cannot be whitespace before or after the C<=> and
if the value contains whitespace it must be quoted.  DSN options are
comma-separated.  See the L<percona-toolkit> manpage for full details.

=over

=item * A

dsn: charset; copy: yes

Default character set.

=item * D

dsn: database; copy: yes

Default database.

=item * F

dsn: mysql_read_default_file; copy: yes

Only read default options from the given file

=item * h

dsn: host; copy: yes

Connect to host.

=item * p

dsn: password; copy: yes

Password to use when connecting.

=item * P

dsn: port; copy: yes

Port number to use for connection.

=item * S

dsn: mysql_socket; copy: yes

Socket file to use for connection.

=item * t

dsn: table; copy: no

Table for DSN L<"--recursion-method">.

=item * u

dsn: user; copy: yes

User for login if not current user.

=back

=head1 ENVIRONMENT

The environment variable C<PTDEBUG> enables verbose debugging output to STDERR.
To enable debugging and capture all output to a file, run the tool like:

   PTDEBUG=1 pt-table-checksum ... > FILE 2>&1

Be careful: debugging output is voluminous and can generate several megabytes
of output.

=head1 SYSTEM REQUIREMENTS

You need Perl, DBI, DBD::mysql, and some core packages that ought to be
installed in any reasonably new version of Perl.

=head1 BUGS

For a list of known bugs, see L<http://www.percona.com/bugs/pt-table-checksum>.

Please report bugs at L<https://bugs.launchpad.net/percona-toolkit>.
Include the following information in your bug report:

=over

=item * Complete command-line used to run the tool

=item * Tool L<"--version">

=item * MySQL version of all servers involved

=item * Output from the tool including STDERR

=item * Input files (log/dump/config files, etc.)

=back

If possible, include debugging output by running the tool with C<PTDEBUG>;
see L<"ENVIRONMENT">.

=head1 DOWNLOADING

Visit L<http://www.percona.com/software/percona-toolkit/> to download the
latest release of Percona Toolkit.  Or, get the latest release from the
command line:

   wget percona.com/get/percona-toolkit.tar.gz

   wget percona.com/get/percona-toolkit.rpm

   wget percona.com/get/percona-toolkit.deb

You can also get individual tools from the latest release:

   wget percona.com/get/TOOL

Replace C<TOOL> with the name of any tool.

=head1 AUTHORS

Baron Schwartz and Daniel Nichter

=head1 ACKNOWLEDGMENTS

Claus Jeppesen, Francois Saint-Jacques, Giuseppe Maxia, Heikki Tuuri,
James Briggs, Martin Friebe, and Sergey Zhuravlev

=head1 ABOUT PERCONA TOOLKIT

This tool is part of Percona Toolkit, a collection of advanced command-line
tools developed by Percona for MySQL support and consulting.  Percona Toolkit
was forked from two projects in June, 2011: Maatkit and Aspersa.  Those
projects were created by Baron Schwartz and developed primarily by him and
Daniel Nichter, both of whom are employed by Percona.  Visit
L<http://www.percona.com/software/> for more software developed by Percona.

=head1 COPYRIGHT, LICENSE, AND WARRANTY

This program is copyright 2007-2011 Baron Schwartz, 2011 Percona Inc.
Feedback and improvements are welcome.

THIS PROGRAM IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED
WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

This program is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation, version 2; OR the Perl Artistic License.  On UNIX and similar
systems, you can issue `man perlgpl' or `man perlartistic' to read these
licenses.

You should have received a copy of the GNU General Public License along with
this program; if not, write to the Free Software Foundation, Inc., 59 Temple
Place, Suite 330, Boston, MA  02111-1307  USA.

=head1 VERSION

pt-table-checksum 1.0.1

=cut