Add mongo forward read. Fix markdown code block. (#2174)

* perf: read from mongo forward node

* fix: code block ui

* perf: markdown code css

packages/service/common/file/image/controller.ts

@@ -3,6 +3,7 @@ import { imageBaseUrl } from '@fastgpt/global/common/file/image/constants';
 import { MongoImage } from './schema';
 import { ClientSession } from '../../../common/mongo';
 import { guessBase64ImageType } from '../utils';
+import { readFromSecondary } from '../../mongo/utils';
 
 export function getMongoImgUrl(id: string, extension: string) {
   return `${imageBaseUrl}${id}.${extension}`;
@@ -44,10 +45,13 @@ export async function uploadMongoImg({
 export async function readMongoImg({ id }: { id: string }) {
   const formatId = id.replace(/\.[^/.]+$/, '');
 
-  const data = await MongoImage.findById(formatId);
+  const data = await MongoImage.findById(formatId, undefined, {
+    ...readFromSecondary
+  });
   if (!data) {
     return Promise.reject('Image not found');
   }
+
   return {
     binary: data.binary,
     mime: data.metadata?.mime ?? guessBase64ImageType(data.binary.toString('base64'))

packages/service/common/mongo/utils.ts

@@ -1,4 +1,6 @@
+import { ReadPreference } from './index';
+
 export const readFromSecondary = {
-  readPreference: 'secondaryPreferred',
-  readConcern: 'local'
+  readPreference: ReadPreference.SECONDARY_PREFERRED, // primary | primaryPreferred | secondary | secondaryPreferred | nearest
+  readConcern: 'local' as any // local | majority | linearizable | available
 };