From f117ae491574fb820e37cd00d6f72aec82341346 Mon Sep 17 00:00:00 2001
From: zadam <adam.zivner@gmail.com>
Date: Sun, 21 Jun 2020 13:44:47 +0200
Subject: [PATCH] fix sending sync rows via WebSocket after transaction is
 committed

---
 src/services/cls.js | 10 +++++++---
 src/services/sql.js | 20 +++-----------------
 src/services/ws.js  | 17 ++++++-----------
 3 files changed, 16 insertions(+), 31 deletions(-)

diff --git a/src/services/cls.js b/src/services/cls.js
index ba026dfae..32af8ff6c 100644
--- a/src/services/cls.js
+++ b/src/services/cls.js
@@ -33,8 +33,12 @@ function isEntityEventsDisabled() {
     return !!namespace.get('disableEntityEvents');
 }
 
-function getSyncRows() {
-    return namespace.get('syncRows') || [];
+function getAndClearSyncRows() {
+    const syncRows = namespace.get('syncRows') || [];
+
+    namespace.set('syncRows', []);
+
+    return syncRows;
 }
 
 function addSyncRow(syncRow) {
@@ -68,7 +72,7 @@ module.exports = {
     disableEntityEvents,
     isEntityEventsDisabled,
     reset,
-    getSyncRows,
+    getAndClearSyncRows,
     addSyncRow,
     getEntityFromCache,
     setEntityToCache
diff --git a/src/services/sql.js b/src/services/sql.js
index 1b997ab7c..7529890f0 100644
--- a/src/services/sql.js
+++ b/src/services/sql.js
@@ -1,7 +1,6 @@
 "use strict";
 
 const log = require('./log');
-const cls = require('./cls');
 const Database = require('better-sqlite3');
 const dataDir = require('./data_dir');
 
@@ -74,21 +73,6 @@ function stmt(sql) {
     return statementCache[sql];
 }
 
-function beginTransaction() {
-    // DEFERRED means that the transaction does not actually start until the database is first accessed.
-    // Internally, the BEGIN DEFERRED statement merely sets a flag on the database connection that turns off
-    // the automatic commit that would normally occur when the last statement finishes.
-    return stmt("BEGIN DEFERRED").run();
-}
-
-function commit() {
-    return stmt("COMMIT").run();
-}
-
-function rollback() {
-    return stmt("ROLLBACK").run();
-}
-
 function getRow(query, params = []) {
     return wrap(query, s => s.get(params));
 }
@@ -213,7 +197,9 @@ function wrap(query, func) {
 function transactional(func) {
     const ret = dbConnection.transaction(func).deferred();
 
-    require('./ws.js').sendPingToAllClients();
+    if (!dbConnection.inTransaction) { // i.e. transaction was really committed (and not just savepoint released)
+        require('./ws.js').sendTransactionSyncsToAllClients();
+    }
 
     return ret;
 }
diff --git a/src/services/ws.js b/src/services/ws.js
index 1e1d5a446..83a22a319 100644
--- a/src/services/ws.js
+++ b/src/services/ws.js
@@ -7,7 +7,6 @@ const syncMutexService = require('./sync_mutex');
 const protectedSessionService = require('./protected_session');
 
 let webSocketServer;
-let lastAcceptedSyncIds = {};
 
 function init(httpServer, sessionParser) {
     webSocketServer = new WebSocket.Server({
@@ -28,8 +27,6 @@ function init(httpServer, sessionParser) {
     webSocketServer.on('connection', (ws, req) => {
         ws.id = utils.randomString(10);
 
-        lastAcceptedSyncIds[ws.id] = 0;
-
         console.log(`websocket client connected`);
 
         ws.on('message', async messageJson => {
@@ -39,8 +36,6 @@ function init(httpServer, sessionParser) {
                 log.info('JS Error: ' + message.error + '\r\nStack: ' + message.stack);
             }
             else if (message.type === 'ping') {
-                lastAcceptedSyncIds[ws.id] = message.lastSyncId;
-
                 await syncMutexService.doExclusively(() => sendPing(ws));
             }
             else {
@@ -97,9 +92,7 @@ function fillInAdditionalProperties(sync) {
     }
 }
 
-function sendPing(client) {
-    const syncRows = cls.getSyncRows();
-
+function sendPing(client, syncRows = []) {
     for (const sync of syncRows) {
         try {
             fillInAdditionalProperties(sync);
@@ -119,10 +112,12 @@ function sendPing(client) {
     });
 }
 
-function sendPingToAllClients() {
+function sendTransactionSyncsToAllClients() {
     if (webSocketServer) {
+        const syncRows = cls.getAndClearSyncRows();
+
         webSocketServer.clients.forEach(function each(client) {
-           sendPing(client);
+           sendPing(client, syncRows);
         });
     }
 }
@@ -140,5 +135,5 @@ module.exports = {
     sendMessageToAllClients,
     syncPullInProgress,
     syncPullFinished,
-    sendPingToAllClients
+    sendTransactionSyncsToAllClients
 };