Add ETags that won't work

extensions/chromium/runet-censorship-bypass/src/extension-common/13-http-lib.js

@@ -11,30 +11,38 @@
 
     ifModifiedSince(
       url,
-      lastModified,
-      cb = mandatory()
+      cacheImprints,
+      cb = mandatory(),
     ) {
 
+      if (!cacheImprints.eTag && !cacheImprints.lastModifiedStr) {
+        throw new TypeError('No cacheImprints provided!');
+      }
       if (url.startsWith('data:')) {
         return cb(null, false);
       }
-      const wasModifiedIn1970 = new Date(0).toUTCString();
       const notModifiedCode = 304;
       fetch(url, {
         method: 'HEAD',
-        headers: new Headers({
-          'If-Modified-Since': lastModified,
-        }),
+        headers: new Headers(
+          cacheImprints.eTag
+            ? {'If-None-Match': cacheImprints.eTag}
+            : {'If-Modified-Since': cacheImprints.lastModifiedStr},
+        ),
       }).then(
         (res) => {
+
+          const eTag = res.headers.get('ETag');
+          const lastModifiedStr = res.headers.get('Last-Modified');
+          const newCacheImprints = (eTag || lastModifiedStr) ? { eTag, lastModifiedStr } : undefined;
           cb(
             null,
-            res.status === notModifiedCode ?
-              false :
-              (res.headers.get('Last-Modified') || wasModifiedIn1970)
+            res.status === notModifiedCode
+              ? undefined
+              : newCacheImprints,
           );
         },
-        errorsLib.clarifyThen(checkCon, (err) => cb(err, wasModifiedIn1970))
+        errorsLib.clarifyThen(checkCon, (err) => cb(err)),
       );
 
     },
@@ -42,6 +50,7 @@
     get(url, cb = mandatory()) {
 
       const start = Date.now();
+      // 'no-store' disables cache completely, we handle caching manually instead.
       fetch(url, {cache: 'no-store'}).then(
         (res) => {
 
@@ -54,7 +63,7 @@
                   console.log('Calling CB...');
                   cb(err, text);
                 },
-                cb
+                cb,
               );
 
             };
@@ -64,8 +73,8 @@
             return textCb(
               errorsLib.clarify(
                 res,
-                'Получен ответ с неудачным HTTP-кодом ' + status + '.'
-              )
+                'Получен ответ с неудачным HTTP-кодом ' + status + '.',
+              ),
             );
           }
 
@@ -73,7 +82,7 @@
           textCb();
 
         },
-        errorsLib.clarifyThen(checkCon, cb)
+        errorsLib.clarifyThen(checkCon, cb),
       );
 
     },
@@ -98,7 +107,7 @@
           cb();
 
         },
-        errorsLib.clarifyThen(checkCon, cb)
+        errorsLib.clarifyThen(checkCon, cb),
       );
 
     },

extensions/chromium/runet-censorship-bypass/src/extension-common/37-sync-pac-script-with-pac-provider-api.tmpl.js

@@ -94,7 +94,7 @@
   };
 
   const updatePacProxyIps = function updatePacProxyIps(
-    cb = throwIfError
+    cb = throwIfError,
   ) {
 
     cb = asyncLogGroup(
@@ -106,7 +106,7 @@
   };
 
   const setPacScriptFromProviderAsync = function setPacScriptFromProviderAsync(
-    provider, lastModifiedStr = mandatory(), cb = throwIfError,
+    provider, cacheImprints = mandatory(), cb = throwIfError,
   ) {
 
     const pacUrl = provider.pacUrls[0];
@@ -135,18 +135,19 @@
 
     }
 
-    httpLib.ifModifiedSince(pacUrl, lastModifiedStr, (err, newLastModifiedStr) => {
+    httpLib.ifModifiedSince(pacUrl, cacheImprints, (err, newCacheImprints) => {
 
-      if (!newLastModifiedStr) {
-        const ifWasEverModified = lastModifiedStr !== new Date(0).toUTCString();
-        if (ifWasEverModified) {
+      // Always empty or non-empty object:
+      const cacheImprintsForCb = newCacheImprints || cacheImprints;
+      if (!err && !newCacheImprints) {
+        const { eTag, lastModifiedStr } = cacheImprints;
+        if (eTag || lastModifiedStr) {
 
           addWarning(
-            'Ваш PAC-скрипт не нуждается в обновлении. Его дата: ' +
-              lastModifiedStr,
+            'Ваш PAC-скрипт не нуждается в обновлении. Его ' +
+             (lastModifiedStr ? 'дата (на сервере): ' + lastModifiedStr : 'ETag: ' + eTag),
           );
-          const res = {lastModified: lastModifiedStr};
-          return cb(null, res);
+          return cb(null, cacheImprintsForCb);
         }
       }
 
@@ -169,9 +170,9 @@
 
           setPacAsync(
             pacData,
-            (err, res) => cb(
+            (err) => cb(
               err,
-              Object.assign(res || {}, {lastModified: newLastModifiedStr}),
+              cacheImprintsForCb,
             ),
           );
 
@@ -263,20 +264,22 @@
 
     },
 
-    _currentPacProviderLastModified: 0,
+    _currentPacProviderLastModified: 0, // Milliseconds or as a string.
+    _currentPacProviderETag: '',
 
-    getLastModifiedForKey(key = mandatory()) {
+    getCacheImprintsForKey(key = mandatory()) {
 
       if (this._currentPacProviderKey === key) {
-        return new Date(this._currentPacProviderLastModified).toUTCString();
+        return {
+          lastModifiedStr: new Date(this._currentPacProviderLastModified).toUTCString(),
+          eTag: this._currentPacProviderETag,
+        };
       }
-      return new Date(0).toUTCString();
-
-    },
-
-    setLastModified(newValue = mandatory()) {
-
-      this._currentPacProviderLastModified = newValue;
+      // If it's not for the current provider then lie we have very old imprints. TODO: reconsider.
+      return {
+        lastModifiedStr: new Date(0).toUTCString(),
+        eTag: '',
+      };
 
     },
 
@@ -296,12 +299,16 @@
 
     setCurrentPacProviderKey(
       newKey = mandatory(),
-      lastModified = new Date().toUTCString(),
+      {
+        lastModifiedStr = new Date().toUTCString(),
+        eTag = '',
+      } = {},
     ) {
 
       this.mustBeKey(newKey);
       this._currentPacProviderKey = newKey;
-      this._currentPacProviderLastModified = lastModified;
+      this._currentPacProviderLastModified = lastModifiedStr;
+      this._currentPacProviderETag = eTag;
 
     },
 
@@ -361,11 +368,11 @@
       const pacSetPromise = new Promise(
         (resolve, reject) => setPacScriptFromProviderAsync(
           pacProvider,
-          this.getLastModifiedForKey(key),
-          (err, res, ...warns) => {
+          this.getCacheImprintsForKey(key),
+          (err, cacheImprints, ...warns) => {
 
             if (!err) {
-              this.setCurrentPacProviderKey(key, res.lastModified);
+              this.setCurrentPacProviderKey(key, cacheImprints);
               this.lastPacUpdateStamp = Date.now();
               this.ifFirstInstall = false;
               this.setAlarms();
@@ -535,6 +542,9 @@
     antiCensorRu._currentPacProviderLastModified =
       oldStorage._currentPacProviderLastModified
       || antiCensorRu._currentPacProviderLastModified;
+    antiCensorRu._currentPacProviderETag =
+      oldStorage._currentPacProviderETag
+      || antiCensorRu._currentPacProviderETag;
     console.log(
       'Last PAC update was on',
       new Date(antiCensorRu.lastPacUpdateStamp).toLocaleString('ru-RU'),
@@ -598,8 +608,7 @@
             console.log('Proxies found:', pacMods.filteredCustomsString);
             return; // Own proxies or Tor are used.
           }
-          antiCensorRu.setCurrentPacProviderKey('Антизапрет');
-          antiCensorRu.setLastModified(0);
+          antiCensorRu.setCurrentPacProviderKey('Антизапрет', { lastModifiedStr: new Date(0).toUTCString() });
           await new Promise((resolveSwitch) =>
 
             antiCensorRu.syncWithPacProviderAsync((err, res, warns) => {