improves discarding tabs on startup

Author: Richard Neomy

v3/worker/core/prefs.mjs

@@ -16,7 +16,8 @@ const prefs = {
   'pinned': false, // pinned = true => do not discard if tab is pinned
   'startup-unpinned': false,
   'startup-pinned': false,
-  'startup-release-pinned': false
+  'startup-release-pinned': false,
+  'startup-discarding-period': 10 // in seconds
 };
 
 const storage = (prefs, type = 'managed') => new Promise(resolve => {

v3/worker/modes/number.mjs

@@ -11,7 +11,8 @@ const number = {
     'online': false,
     'number': 0,
     'period': 0,
-    'max.single.discard': Infinity
+    'max.single.discard': Infinity,
+    'ignore.meta.data': true
   }
 };
 const pluginFilters = {}; // this object adds custom filters to the number-based discarding
@@ -158,8 +159,9 @@ number.check = async (filterTabsFrom, ops = {}) => {
       }
     });
   }
-  if (filterTabsFrom) {
-    tbs = tbs.filter(tb => filterTabsFrom.some(t => t.id === tb.id));
+  if (filterTabsFrom && filterTabsFrom.length) {
+    const ids = filterTabsFrom.map(t => t.id);
+    tbs = tbs.filter(tb => ids.includes(tb.id));
   }
 
   // do not discard if number of tabs is smaller than required
@@ -176,14 +178,15 @@ number.check = async (filterTabsFrom, ops = {}) => {
         allFrames: true
       },
       files: ['/data/inject/meta.js']
-    }).then(r => r.map(o => o.result), () => undefined);
+    }).then(r => r.map(o => o.result), () => []);
     // remove protected tabs (e.g. addons.mozilla.org)
-    if (!ms) {
-      log('discarding aborted', 'metadata fetch error');
-      icon(tb, 'metadata fetch error');
-      continue;
+    if (ms.length === 0) {
+      if (ops['ignore.meta.data'] === true && tb.url.startsWith('http') !== true) {
+        log('discarding aborted', 'metadata fetch error', tb.url);
+        icon(tb, 'metadata fetch error');
+        continue;
+      }
     }
-
     const meta = Object.assign({}, ...ms);
     log('number check', 'got meta data of tab');
     meta.forms = ms.some(o => o.forms);
@@ -201,7 +204,7 @@ number.check = async (filterTabsFrom, ops = {}) => {
       continue;
     }
     // is this tab loaded
-    if (meta.ready !== true) {
+    if (meta.ready !== true && ops['ignore.ready.state'] !== true) {
       log('discarding aborted', 'tab is not ready');
       continue;
     }

v3/worker/plugins/startup/core.mjs

@@ -23,17 +23,25 @@ const observe = () => {
       number.check(tbs.filter(t => t.status !== 'unloaded'), number.IGNORE);
       const rst = tbs.filter(t => t.status === 'unloaded');
       if (rst.length) {
-        const observe = (id, info) => {
+        const observe = (id, info, tab) => {
           if (info.status === 'complete') {
-            const tbs = rst.filter(t => t.id === id);
-            if (tbs.length) {
-              number.check(tbs, number.IGNORE);
+            if (rst.some(t => t.id === id)) {
+              number.check([tab], number.IGNORE);
             }
           }
         };
+        const remove = alarm => {
+          if (alarm.name === 'remove.startup.discarding.observer') {
+            chrome.tabs.onUpdated.removeListener(observe);
+            chrome.alarms.onAlarm.removeListener(remove);
+          }
+        };
         chrome.tabs.onUpdated.addListener(observe);
-        // we do discard for the next 10 seconds
-        setTimeout(() => chrome.tabs.onUpdated.removeListener(observe), 10000);
+        // we keep discarding for the next 10 seconds
+        chrome.alarms.create('remove.startup.discarding.observer', {
+          when: Date.now() + prefs['startup-discarding-period'] * 1000
+        });
+        chrome.alarms.onAlarm.addListener(remove);
       }
     });
   }