perf: buffer;fix: back up split (#4913)

* perf: buffer

* fix: back up split

* fix: app limit

* doc

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

@@ -6,13 +6,13 @@ import { type DatasetFileSchema } from '@fastgpt/global/core/dataset/type';
 import { MongoChatFileSchema, MongoDatasetFileSchema } from './schema';
 import { detectFileEncoding, detectFileEncodingByPath } from '@fastgpt/global/common/file/tools';
 import { CommonErrEnum } from '@fastgpt/global/common/error/code/common';
-import { MongoRawTextBuffer } from '../../buffer/rawText/schema';
 import { readRawContentByFileBuffer } from '../read/utils';
 import { gridFsStream2Buffer, stream2Encoding } from './utils';
 import { addLog } from '../../system/log';
-import { readFromSecondary } from '../../mongo/utils';
 import { parseFileExtensionFromUrl } from '@fastgpt/global/common/string/tools';
 import { Readable } from 'stream';
+import { addRawTextBuffer, getRawTextBuffer } from '../../buffer/rawText/controller';
+import { addMinutes } from 'date-fns';
 
 export function getGFSCollection(bucket: `${BucketNameEnum}`) {
   MongoDatasetFileSchema;
@@ -225,13 +225,11 @@ export const readFileContentFromMongo = async ({
 }> => {
   const bufferId = `${fileId}-${customPdfParse}`;
   // read buffer
-  const fileBuffer = await MongoRawTextBuffer.findOne({ sourceId: bufferId }, undefined, {
-    ...readFromSecondary
-  }).lean();
+  const fileBuffer = await getRawTextBuffer(bufferId);
   if (fileBuffer) {
     return {
-      rawText: fileBuffer.rawText,
-      filename: fileBuffer.metadata?.filename || ''
+      rawText: fileBuffer.text,
+      filename: fileBuffer?.sourceName
     };
   }
 
@@ -265,16 +263,13 @@ export const readFileContentFromMongo = async ({
     }
   });
 
-  // < 14M
-  if (fileBuffers.length < 14 * 1024 * 1024 && rawText.trim()) {
-    MongoRawTextBuffer.create({
-      sourceId: bufferId,
-      rawText,
-      metadata: {
-        filename: file.filename
-      }
-    });
-  }
+  // Add buffer
+  addRawTextBuffer({
+    sourceId: bufferId,
+    sourceName: file.filename,
+    text: rawText,
+    expiredTime: addMinutes(new Date(), 20)
+  });
 
   return {
     rawText,