Issue 3860 - Move request blocking logic to a seperate module

lib/requestBlocker.js

Index: lib/requestBlocker.js
===================================================================
rename from webrequest.js
rename to lib/requestBlocker.js
--- a/webrequest.js
+++ b/lib/requestBlocker.js
@@ -15,41 +15,28 @@
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-var FilterNotifier = require("filterNotifier").FilterNotifier;
-var RegExpFilter = require("filterClasses").RegExpFilter;
-var platform = require("info").platform;
-var devtools = require("devtools");
+/** @module requestBlocker */
 
-ext.webRequest.getIndistinguishableTypes().forEach(function(types)
+"use strict";
+
+let {RegExpFilter, BlockingFilter} = require("filterClasses");
+let {defaultMatcher} = require("matcher");
+let {FilterNotifier} = require("filterNotifier");
+let {Prefs} = require("prefs");
+let {checkWhitelisted, getKey} = require("whitelisting");
+let {stringifyURL, extractHostFromFrame, isThirdParty} = require("url");
+let {port} = require("messaging");
+let devtools = require("devtools");
+
+ext.webRequest.getIndistinguishableTypes().forEach(types =>
 {
-  for (var i = 1; i < types.length; i++)
+  for (let i = 1; i < types.length; i++)
     RegExpFilter.typeMap[types[i]] = RegExpFilter.typeMap[types[0]];
 });
 
-FilterNotifier.addListener(function(action, arg)
-{
-  switch (action)
-  {
-    case "filter.added":
-    case "filter.removed":
-    case "filter.disabled":
-      // Only request blocking/whitelisting filters have
-      // an effect on the webRequest handler behavior.
-      if (!(arg instanceof RegExpFilter))
-        break;
-    case "subscription.added":
-    case "subscription.removed":
-    case "subscription.disabled":
-    case "subscription.updated":
-    case "load":
-      ext.webRequest.handlerBehaviorChanged();
-      break;
-  }
-});
-
 function onBeforeRequestAsync(page, url, type, docDomain,
-                              thirdParty, key, specificOnly,
-                              filter)
+                              thirdParty, sitekey,
+                              specificOnly, filter)
 {
   if (filter)
     FilterNotifier.triggerListeners("filter.hitCount", filter, 0, 0, page);
@@ -57,64 +44,125 @@
   if (devtools)
     devtools.logRequest(
       page, url, type, docDomain,
-      thirdParty, key, specificOnly,
-      filter
+      thirdParty, sitekey,
+      specificOnly, filter
     );
 }
 
-function onBeforeRequest(url, type, page, frame)
+ext.webRequest.onBeforeRequest.addListener((url, type, page, frame) =>
 {
   if (checkWhitelisted(page, frame))
     return true;
 
-  var urlString = stringifyURL(url);
-  var docDomain = extractHostFromFrame(frame);
-  var thirdParty = isThirdParty(url, docDomain);
-  var key = getKey(page, frame);
+  let urlString = stringifyURL(url);
+  let docDomain = extractHostFromFrame(frame);
+  let thirdParty = isThirdParty(url, docDomain);
+  let sitekey = getKey(page, frame);
 
-  var specificOnly = !!checkWhitelisted(
+  let specificOnly = !!checkWhitelisted(
     page, frame, RegExpFilter.typeMap.GENERICBLOCK
   );
 
-  var filter = defaultMatcher.matchesAny(
+  let filter = defaultMatcher.matchesAny(
     urlString, RegExpFilter.typeMap[type],
-    docDomain, thirdParty, key, specificOnly
+    docDomain, thirdParty, sitekey, specificOnly
   );
 
   setTimeout(onBeforeRequestAsync, 0, page, urlString,
                                       type, docDomain,
-                                      thirdParty, key,
+                                      thirdParty, sitekey,
                                       specificOnly, filter);
 
   return !(filter instanceof BlockingFilter);
-}
+});
 
-ext.webRequest.onBeforeRequest.addListener(onBeforeRequest);
+port.on("filters.collapse", (message, sender) =>
+{
+  if (checkWhitelisted(sender.page, sender.frame))
+    return false;
 
-if (platform == "chromium")
-{
-  function onHeadersReceived(details)
+  let typeMask = RegExpFilter.typeMap[message.mediatype];
+  let documentHost = extractHostFromFrame(sender.frame);
+  let sitekey = getKey(sender.page, sender.frame);
+  let blocked = false;
+
+  let specificOnly = checkWhitelisted(
+    sender.page, sender.frame,
+    RegExpFilter.typeMap.GENERICBLOCK
+  );
+
+  for (let url of message.urls)
   {
-    var page = new ext.Page({id: details.tabId});
-    var frame = ext.getFrame(details.tabId, details.frameId);
+    let urlObj = new URL(url, message.baseURL);
+    let filter = defaultMatcher.matchesAny(
+      stringifyURL(urlObj),
+      typeMask, documentHost,
+      isThirdParty(urlObj, documentHost),
+      sitekey, specificOnly
+    );
 
-    if (!frame || frame.url.href != details.url)
-      return;
-
-    for (var i = 0; i < details.responseHeaders.length; i++)
+    if (filter instanceof BlockingFilter)
     {
-      var header = details.responseHeaders[i];
-      if (header.name.toLowerCase() == "x-adblock-key" && header.value)
-        processKey(header.value, page, frame);
+      if (filter.collapse != null)
+        return filter.collapse;
+      blocked = true;
     }
   }
 
-  chrome.webRequest.onHeadersReceived.addListener(
-    onHeadersReceived,
+  return blocked && Prefs.hidePlaceholders;
+});
+
+let ignoreFilterNotifications = false;
+FilterNotifier.addListener((action, arg) =>
+{
+  // Avoid triggering filters.behaviorChanged multiple times
+  // when multiple filter hanges happen at the same time.
+  if (ignoreFilterNotifications)
+    return;
+
+  if (action != "load")
+  {
+    let parts = action.split(".");
+    let [category, event] = parts;
+    if (category == "subscription")
     {
-      urls: ["http://*/*", "https://*/*"],
-      types: ["main_frame", "sub_frame"]
-    },
-    ["responseHeaders"]
-  );
-}
+      if (event != "added"  &&
+          event != "removed" &&
+          event != "updated" &&
+          event != "disabled")
+        return;
+
+      // Ignore empty subscriptions. This includes subscriptions
+      // that have just been added, but not downloaded yet.
+      if (arg.filters.length == 0)
+        return;
+    }
+    else if (category == "filter")
+    {
+      if (event != "added" &&
+          event != "removed" &&
+          event != "disabled")
+        return;
+
+      // Ignore all types of filters but request filters,
+      // only these have an effect on the handler behavior.
+      if (!(arg instanceof RegExpFilter))
+        return;
+    }
+    else
+      return;
+
+    // Ignore disabled subscriptions and filters, unless they just got
+    // disabled, otherwise they have no effect on the handler behavior.
+    if (arg.disabled && event != "disabled")
+      return;
+  }
+
+  ignoreFilterNotifications = true;
+  setTimeout(() =>
+  {
+    ignoreFilterNotifications = false;
+    ext.webRequest.handlerBehaviorChanged();
+    FilterNotifier.triggerListeners("filter.behaviorChanged");
+  });
+});