[bug] Fix bug: disconnect after uploading oversized changes (#131)

Common/config/default.json

@@ -195,7 +195,8 @@
 				"reconnection":{
 					"attempts": 50,
 					"delay": "2s"
-				}
+				},
+				"websocketMaxPayloadSize": "1.5MB"
 			},
 			"sockjs": {
 				"sockjs_url": "",

DocService/npm-shrinkwrap.json

@@ -43,6 +43,13 @@
         "qs": "6.5.2",
         "raw-body": "2.3.3",
         "type-is": "~1.6.16"
+      },
+      "dependencies": {
+        "bytes": {
+          "version": "3.0.0",
+          "resolved": "https://registry.npmjs.org/bytes/-/bytes-3.0.0.tgz",
+          "integrity": "sha1-0ygVQE1olpn4Wk6k+odV3ROpYEg="
+        }
       }
     },
     "buffer-equal-constant-time": {
@@ -636,6 +643,13 @@
         "http-errors": "1.6.3",
         "iconv-lite": "0.4.23",
         "unpipe": "1.0.0"
+      },
+      "dependencies": {
+        "bytes": {
+          "version": "3.0.0",
+          "resolved": "https://registry.npmjs.org/bytes/-/bytes-3.0.0.tgz",
+          "integrity": "sha1-0ygVQE1olpn4Wk6k+odV3ROpYEg="
+        }
       }
     },
     "readable-stream": {

DocService/package.json

@@ -11,6 +11,7 @@
   "dependencies": {
     "base64-stream": "^1.0.0",
     "body-parser": "^1.18.3",
+    "bytes": "^3.0.0",
     "co": "^4.6.0",
     "config": "^2.0.1",
     "cron": "^1.5.0",

DocService/sources/DocsCoServer.js

@@ -83,6 +83,7 @@ const jwt = require('jsonwebtoken');
 const jwa = require('jwa');
 const ms = require('ms');
 const deepEqual  = require('deep-equal');
+const bytes = require('bytes');
 const storage = require('./../../Common/sources/storage-base');
 const logger = require('./../../Common/sources/logger');
 const constants = require('./../../Common/sources/constants');
@@ -103,6 +104,11 @@ const rabbitMQCore = require('./../../Common/sources/rabbitMQCore');
 const activeMQCore = require('./../../Common/sources/activeMQCore');
 let cfgEditor = JSON.parse(JSON.stringify(config.get('editor')));
 cfgEditor['reconnection']['delay'] = ms(cfgEditor['reconnection']['delay']);
+cfgEditor['websocketMaxPayloadSize'] = bytes.parse(cfgEditor['websocketMaxPayloadSize']);
+//websocket payload size is limited by https://github.com/faye/faye-websocket-node#initialization-options (64 MiB)
+//xhr payload size is limited by nginx param client_max_body_size (current 100MB)
+//"1.5MB" is choosen to avoid disconnect(after 25s) while downloading/uploading oversized changes with 0.5Mbps connection
+const cfgWebsocketMaxPayloadSize = cfgEditor['websocketMaxPayloadSize'];
 const cfgCallbackRequestTimeout = config.get('server.callbackRequestTimeout');
 //The waiting time to document assembly when all out(not 0 in case of F5 in the browser)
 const cfgAscSaveTimeOutDelay = config.get('server.savetimeoutdelay');
@@ -2280,19 +2286,32 @@ exports.install = function(server, callbackFunction) {
     } while (changes && cfgMaxRequestChanges === changes.length);
   }
 
+  function sendAuthChangesByChunks(changes, connections) {
+    let startIndex = 0;
+    let endIndex = 0;
+    while (endIndex < changes.length) {
+      startIndex = endIndex;
+      let curBytes = 0;
+      for (; endIndex < changes.length && curBytes < cfgWebsocketMaxPayloadSize; ++endIndex) {
+        curBytes += JSON.stringify(changes[endIndex]).length + 24;//24 - for JSON overhead
+      }
+      //todo simplify 'authChanges' format to reduce message size and JSON overhead
+      const sendObject = {
+        type: 'authChanges',
+        changes: changes.slice(startIndex, endIndex)
+      };
+      for (let i = 0; i < connections.length; ++i) {
+        sendData(connections[i], sendObject);//Or 0 if fails
+      }
+    }
+  }
   function* sendAuthChanges(docId, connections) {
     let index = 0;
     let changes;
     do {
       let objChangesDocument = yield getDocumentChanges(docId, index, index + cfgMaxRequestChanges);
       changes = objChangesDocument.arrChanges;
-      const sendObject = {
-        type: 'authChanges',
-        changes: changes
-      };
-      for (let i = 0; i < connections.length; ++i) {
-        sendData(connections[i], sendObject);//Or 0 if fails
-      }
+      sendAuthChangesByChunks(changes, connections);
       index += cfgMaxRequestChanges;
     } while (changes && cfgMaxRequestChanges === changes.length);
   }