Make asset updater compatible with non-persistent background page

Related issue:
https://github.com/uBlockOrigin/uBlock-issues/issues/2969

Additionally, modified default timing values for asset updater and
selfie creation.

src/js/assets.js

@@ -1325,6 +1325,8 @@ async function diffUpdater() {
             terminate();
         };
         const worker = new Worker('js/diff-updater.js');
+    }).catch(reason => {
+        ubolog(`Diff updater: ${reason}`);
     });
 }
 

src/js/background.js

@@ -49,8 +49,8 @@ const hiddenSettingsDefault = {
     allowGenericProceduralFilters: false,
     assetFetchTimeout: 30,
     autoCommentFilterTemplate: '{{date}} {{origin}}',
-    autoUpdateAssetFetchPeriod: 15,
-    autoUpdateDelayAfterLaunch: 105,
+    autoUpdateAssetFetchPeriod: 5,
+    autoUpdateDelayAfterLaunch: 37,
     autoUpdatePeriod: 1,
     benchmarkDatasetURL: 'unset',
     blockingProfiles: '11111/#F00 11010/#C0F 11001/#00F 00001',
@@ -84,7 +84,7 @@ const hiddenSettingsDefault = {
     popupPanelHeightMode: 0,
     requestJournalProcessPeriod: 1000,
     requestStatsDisabled: false,
-    selfieAfter: 2,
+    selfieDelayInSeconds: 53,
     strictBlockingBypassDuration: 120,
     toolbarWarningTimeout: 60,
     trustedListPrefixes: 'ublock-',

src/js/start.js

@@ -476,15 +476,6 @@ webRequest.start();
 // as possible ensure minimal memory usage baseline.
 lz4Codec.relinquish();
 
-// https://github.com/chrisaljoudi/uBlock/issues/184
-//   Check for updates not too far in the future.
-io.addObserver(µb.assetObserver.bind(µb));
-µb.scheduleAssetUpdater({
-    updateDelay: µb.userSettings.autoUpdate
-        ? µb.hiddenSettings.autoUpdateDelayAfterLaunch * 1000
-        : 0
-});
-
 // Force an update of the context menu according to the currently
 // active tab.
 contextMenu.update();
@@ -509,11 +500,39 @@ ubolog(`All ready ${µb.supportStats.allReadyAfter} after launch`);
 
 µb.isReadyResolve();
 
+
+// https://github.com/chrisaljoudi/uBlock/issues/184
+//   Check for updates not too far in the future.
+io.addObserver(µb.assetObserver.bind(µb));
+if ( µb.userSettings.autoUpdate ) {
+    let needEmergencyUpdate = false;
+    const entries = await io.getUpdateAges({
+        filters: µb.selectedFilterLists,
+        internal: [ '*' ],
+    });
+    for ( const entry of entries ) {
+        if ( entry.ageNormalized < 2 ) { continue; }
+        needEmergencyUpdate = true;
+        break;
+    }
+    const updateDelay = needEmergencyUpdate
+        ? 2000
+        : µb.hiddenSettings.autoUpdateDelayAfterLaunch * 1000;
+    µb.scheduleAssetUpdater({
+        auto: true,
+        updateDelay,
+        fetchDelay: needEmergencyUpdate ? 1000 : undefined
+    });
+}
+
 // Process alarm queue
 while ( µb.alarmQueue.length !== 0 ) {
     const what = µb.alarmQueue.shift();
     ubolog(`Processing alarm event from suspended state: '${what}'`);
     switch ( what ) {
+    case 'assetUpdater':
+        µb.scheduleAssetUpdater({ auto: true, updateDelay: 2000, fetchDelay : 1000 });
+        break;
     case 'createSelfie':
         µb.selfieManager.create();
         break;

src/js/storage.js

@@ -1376,9 +1376,9 @@ onBroadcast(msg => {
             ubolog('Filtering engine selfie marked for invalidation');
         }
         vAPI.alarms.create('createSelfie', {
-            delayInMinutes: µb.hiddenSettings.selfieAfter + 0.5
+            delayInMinutes: (µb.hiddenSettings.selfieDelayInSeconds + 17) / 60,
         });
-        createTimer.offon({ min: µb.hiddenSettings.selfieAfter });
+        createTimer.offon({ sec: µb.hiddenSettings.selfieDelayInSeconds });
     };
 
     const createTimer = vAPI.defer.create(create);
@@ -1543,7 +1543,6 @@ onBroadcast(msg => {
 
 {
     let next = 0;
-    let lastEmergencyUpdate = 0;
 
     const launchTimer = vAPI.defer.create(fetchDelay => {
         next = 0;
@@ -1552,6 +1551,7 @@ onBroadcast(msg => {
 
     µb.scheduleAssetUpdater = async function(details = {}) {
         launchTimer.off();
+        vAPI.alarms.clear('assetUpdater');
 
         if ( details.now ) {
             next = 0;
@@ -1570,40 +1570,23 @@ onBroadcast(msg => {
             this.hiddenSettings.autoUpdatePeriod * 3600000;
 
         const now = Date.now();
-        let needEmergencyUpdate = false;
-
-        // Respect cooldown period before launching an emergency update.
-        const timeSinceLastEmergencyUpdate = (now - lastEmergencyUpdate) / 3600000;
-        if ( timeSinceLastEmergencyUpdate > 1 ) {
-            const entries = await io.getUpdateAges({
-                filters: µb.selectedFilterLists,
-                internal: [ '*' ],
-            });
-            for ( const entry of entries ) {
-                if ( entry.ageNormalized < 2 ) { continue; }
-                needEmergencyUpdate = true;
-                lastEmergencyUpdate = now;
-                break;
-            }
-        }
 
         // Use the new schedule if and only if it is earlier than the previous
         // one.
         if ( next !== 0 ) {
-            updateDelay = Math.min(updateDelay, Math.max(next - now, 0));
-        }
-
-        if ( needEmergencyUpdate ) {
-            updateDelay = Math.min(updateDelay, 15000);
+            updateDelay = Math.min(updateDelay, Math.max(next - now, 1));
         }
 
         next = now + updateDelay;
 
-        const fetchDelay = needEmergencyUpdate
-            ? 2000
-            : this.hiddenSettings.autoUpdateAssetFetchPeriod * 1000 || 60000;
+        const fetchDelay = details.fetchDelay ||
+            this.hiddenSettings.autoUpdateAssetFetchPeriod * 1000 ||
+            60000;
 
         launchTimer.on(updateDelay, fetchDelay);
+        vAPI.alarms.create('assetUpdater', {
+            delayInMinutes: Math.ceil(updateDelay / 60000) + 0.25
+        });
     };
 }