flush table change updates on trailing edge. Prevents race conditions…

… in watched queries
powersync-ja · Jan 26, 2024 · 63887f4 · 63887f4
1 parent 7d4c6fe
commit 63887f4
Show file tree

Hide file tree

Showing 4 changed files with 20 additions and 11 deletions.
diff --git a/.changeset/warm-foxes-act.md b/.changeset/warm-foxes-act.md
@@ -0,0 +1,5 @@
+---
+'@journeyapps/powersync-sdk-common': patch
+---
+
+Fixed table change updates to be throttled and flushed on the trailing edge to avoid race conditions in watched queries.
diff --git a/apps/supabase-todolist b/apps/supabase-todolist
diff --git a/packages/powersync-sdk-common/src/client/AbstractPowerSyncDatabase.ts b/packages/powersync-sdk-common/src/client/AbstractPowerSyncDatabase.ts
@@ -499,15 +499,19 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
     const throttleMs = options.throttleMs ?? DEFAULT_WATCH_THROTTLE_MS;
 
     return new EventIterator<WatchOnChangeEvent>((eventOptions) => {
-      const flushTableUpdates = _.throttle(async () => {
-        const intersection = _.intersection(watchedTables, throttledTableUpdates);
-        if (intersection.length) {
-          eventOptions.push({
-            changedTables: intersection
-          });
-        }
-        throttledTableUpdates = [];
-      }, throttleMs);
+      const flushTableUpdates = _.throttle(
+        async () => {
+          const intersection = _.intersection(watchedTables, throttledTableUpdates);
+          if (intersection.length) {
+            eventOptions.push({
+              changedTables: intersection
+            });
+          }
+          throttledTableUpdates = [];
+        },
+        throttleMs,
+        { leading: false, trailing: true }
+      );
 
       const dispose = this.database.registerListener({
         tablesUpdated: async (update) => {

diff --git a/yarn.lock b/yarn.lock
@@ -2220,7 +2220,7 @@
     "@types/yargs" "^17.0.8"
     chalk "^4.0.0"
 
-"@journeyapps/react-native-quick-sqlite@^1.0.0", "@journeyapps/react-native-quick-sqlite@^1.1.0":
+"@journeyapps/react-native-quick-sqlite@^1.1.0":
   version "1.1.0"
   resolved "https://registry.npmjs.org/@journeyapps/react-native-quick-sqlite/-/react-native-quick-sqlite-1.1.0.tgz#cf4aa6694b7232d0f86e565fdba4e41ef15d80cc"
   integrity sha512-Pg6VA6ABC7N5FrNB5eqTgNsKdzzmDSp5aBtnQh1BlcZu7ISPZdCcKo+ZJtKyzTAWpc17LIttvJwxez6zBxUdOw==
+22 −22		README.md
+1 −1		android/gradle.properties
+2 −2		app.json
+2 −1		app/index.tsx
+11 −11		ios/Podfile.lock
+2 −2		library/supabase/AppConfig.template.ts
+13 −10		library/widgets/TodoItemWidget.tsx
+3 −3		package.json
+24 −24		yarn.lock