Issue 6402 - Split filter hit / request logging out into own API

lib/devLogger.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/** @module devLogger */
+
 "use strict";
 
 const {RegExpFilter,
        WhitelistFilter,
        ElemHideFilter} = require("filterClasses");
 const {SpecialSubscription} = require("subscriptionClasses");
 const {FilterStorage} = require("filterStorage");
 const {defaultMatcher} = require("matcher");
 const {FilterNotifier} = require("filterNotifier");
 const {extractHostFromFrame} = require("url");
 const {port} = require("messaging");
 
 const nonRequestTypes = ["DOCUMENT", "ELEMHIDE", "GENERICBLOCK", "GENERICHIDE"];
 
-// Mapping of inspected tabs to their devpanel page
+// Mapping of inspected tabs to their listeners
 // and recorded items. We can't use a PageMap here,
 // because data must persist after navigation/reload.
-let panels = new Map();
+let pageLoggers = new Map();
 
-function isActivePanel(panel)
+function isActivePageLogger(pageLogger)
 {
-  return panel && !panel.reload && !panel.reloading;
+  return pageLogger && !pageLogger.reload && !pageLogger.reloading;
 }
 
-function getActivePanel(page)
+function getActivePageLogger(pageId)
 {
-  let panel = panels.get(page.id);
-  if (isActivePanel(panel))
-    return panel;
+  let pageLogger = pageLoggers.get(pageId);
+  if (isActivePageLogger(pageLogger))
+    return pageLogger;
   return null;
 }
 
 function getFilterInfo(filter)
 {
   if (!filter)
     return null;
 
   let userDefined = false;
   let subscriptionTitle = null;
@@ skipping 10 matching lines @@
   }
 
   return {
     text: filter.text,
     whitelisted: filter instanceof WhitelistFilter,
     userDefined,
     subscription: subscriptionTitle
   };
 }
 
-function hasRecord(panel, request, filter)
+function hasRecord(pageLogger, request, filter)
 {
-  return panel.records.some(record =>
+  return pageLogger.records.some(record =>
     record.request.url == request.url &&
     record.request.docDomain == request.docDomain &&
 
     // Ignore partial (e.g. ELEMHIDE) whitelisting if there is already
     // a DOCUMENT exception which disables all means of blocking.
     (record.request.type == "DOCUMENT" ?
        nonRequestTypes.includes(request.type) :
        record.request.type == request.type) &&
 
     // Matched element hiding filters don't relate to a particular request,
     // so we have to compare the selector in order to avoid duplicates.
     (record.filter && record.filter.selector) == (filter && filter.selector)
   );
 }
 
-function addRecord(panel, request, filter)
+function emit(pageLogger, ...args)
 {
-  if (!hasRecord(panel, request, filter))
+  for (let listener of pageLogger.listeners.slice())
+    listener(...args);
+}
+
+function addRecord(pageLogger, request, filter)
+{
+  if (!hasRecord(pageLogger, request, filter))
   {
-    panel.port.postMessage({
+    emit(pageLogger, {
       type: "add-record",
       request,
       filter: getFilterInfo(filter)
     });
 
-    panel.records.push({request, filter});
+    pageLogger.records.push({request, filter});
   }
 }
 
 function matchRequest(request)
 {
   return defaultMatcher.matchesAny(
     request.url,
     RegExpFilter.typeMap[request.type],
     request.docDomain,
     request.thirdParty,
     request.sitekey,
     request.specificOnly
   );
 }
 
 /**
- * Logs a request to the devtools panel.
+ * Logs a request for a page if there's something (e.g. devtools panel)
+ * listening.
  *
  * @param {?Page}    page          The page the request occured on or null if
  *                                 the request isn't associated with a page
  * @param {string}   url           The URL of the request
  * @param {string}   type          The request type
  * @param {string}   docDomain     The IDN-decoded hostname of the document
  * @param {boolean}  thirdParty    Whether the origin of the request and
  *                                 document differs
  * @param {?string}  sitekey       The active sitekey if there is any
  * @param {?boolean} specificOnly  Whether generic filters should be ignored
  * @param {?BlockingFilter} filter The matched filter or null if there is no
  *                                 match
  */
-exports.logRequest = function(page, url, type, docDomain,
-                              thirdParty, sitekey,
+exports.logRequest = function(page, url, type, docDomain, thirdParty, sitekey,
                               specificOnly, filter)
 {
-  if (panels.size == 0)
+  if (pageLoggers.size == 0)
     return;
 
-  let request = {url, type, docDomain, thirdParty, sitekey, specificOnly};
-  for (let [tabId, panel] of panels)
-    if ((!page || page.id == tabId) && isActivePanel(panel))
-      addRecord(panel, request, filter);
+  let request = {url, type, docDomain, thirdParty, sitekey, specificOnly,
+                 pageId: page ? page.id : -1};
+  for (let [pageId, pageLogger] of pageLoggers)
+    if ((!page || page.id == pageId) && isActivePageLogger(pageLogger))
+      addRecord(pageLogger, request, filter);
 };
 
 /**
- * Logs active element hiding filters to the devtools panel.
+ * Logs active element hiding filters for a page if there's something's
+ * (e.g. devtools panel) listening.
  *
- * @param {Page}     page       The page the elements were hidden on
+ * @param {int}      pageId     The page the elements were hidden on
  * @param {string[]} selectors  The selectors of applied ElemHideFilters
  * @param {string[]} filters    The text of applied ElemHideEmulationFilters
  * @param {string}   docDomain  The IDN-decoded hostname of the document
  */
-function logHiddenElements(page, selectors, filters, docDomain)
+exports.logHiddenElements = function(pageId, selectors, filters, docDomain)
 {
-  let panel = getActivePanel(page);
-  if (panel)
+  let pageLogger = getActivePageLogger(pageId);
+  if (pageLogger)
   {
     for (let subscription of FilterStorage.subscriptions)
     {
       if (subscription.disabled)
         continue;
 
       for (let filter of subscription.filters)
       {
         // We only know the exact filter in case of element hiding emulation.
         // For regular element hiding filters, the content script only knows
         // the selector, so we have to find a filter that has an identical
         // selector and is active on the domain the match was reported from.
         let isActiveElemHideFilter = filter instanceof ElemHideFilter &&
                                      selectors.includes(filter.selector) &&
                                      filter.isActiveOnDomain(docDomain);
 
         if (isActiveElemHideFilter || filters.includes(filter.text))
-          addRecord(panel, {type: "ELEMHIDE", docDomain}, filter);
+          addRecord(pageLogger, {type: "ELEMHIDE", docDomain}, filter);
       }
     }
   }
-}
+};
 
 /**
- * Logs a whitelisting filter, that disables (some kind of)
- * blocking for a particular document, to the devtools panel.
+ * Logs a whitelisting filter, that disables (some kind of) blocking
+ * for a particular document if a devtools panel or similiar is listening.
  *
- * @param {Page}         page      The page the whitelisting is active on
+ * @param {number}       pageId    The page the whitelisting is active on
  * @param {string}       url       The url of the whitelisted document
  * @param {number}       typeMask  The bit mask of whitelisting types checked
  *                                 for
  * @param {string}       docDomain The IDN-decoded hostname of the parent
  *                                 document
  * @param {WhitelistFilter} filter The matched whitelisting filter
  */
-exports.logWhitelistedDocument = function(page, url, typeMask, docDomain,
+exports.logWhitelistedDocument = function(pageId, url, typeMask, docDomain,
                                           filter)
 {
-  let panel = getActivePanel(page);
-  if (panel)
+  let pageLogger = getActivePageLogger(pageId);
+  if (pageLogger)
   {
     for (let type of nonRequestTypes)
     {
       if (typeMask & filter.contentType & RegExpFilter.typeMap[type])
-        addRecord(panel, {url, type, docDomain}, filter);
+        addRecord(pageLogger, {pageId, url, type, docDomain}, filter);
     }
   }
 };
 
-/**
- * Checks whether a page is inspected by the devtools panel.
- *
- * @param {Page} page
- * @return {boolean}
- */
-exports.hasPanel = function(page)
-{
-  return panels.has(page.id);
-};
 
 function onBeforeRequest(details)
 {
-  let panel = panels.get(details.tabId);
+  let pageLogger = pageLoggers.get(details.tabId);
 
-  // Clear the devtools panel and reload the inspected tab without caching
+  // Clear the records and reload the inspected tab without caching
   // when a new request is issued. However, make sure that we don't end up
   // in an infinite recursion if we already triggered a reload.
-  if (panel.reloading)
+  if (pageLogger.reloading)
   {
-    panel.reloading = false;
+    pageLogger.reloading = false;
   }
   else
   {
-    panel.records = [];
-    panel.port.postMessage({type: "reset"});
+    pageLogger.records = [];
+    emit(pageLogger, {type: "reset"});
 
     // We can't repeat the request if it isn't a GET request. Chrome would
     // prompt the user to confirm reloading the page, and POST requests are
     // known to cause issues on many websites if repeated.
     if (details.method == "GET")
-      panel.reload = true;
+      pageLogger.reload = true;
   }
 }
 
 function onLoading(page)
 {
   let tabId = page.id;
-  let panel = panels.get(tabId);
+  let pageLogger = pageLoggers.get(tabId);
 
   // Reloading the tab is the only way that allows bypassing all caches, in
   // order to see all requests in the devtools panel. Reloading must not be
   // performed before the tab changes to "loading", otherwise it will load the
   // previous URL.
-  if (panel && panel.reload)
+  if (pageLogger && pageLogger.reload)
   {
     browser.tabs.reload(tabId, {bypassCache: true});
 
-    panel.reload = false;
-    panel.reloading = true;
+    pageLogger.reload = false;
+    pageLogger.reloading = true;
   }
 }
 
 function updateFilters(filters, added)
 {
-  for (let panel of panels.values())
+  for (let pageLogger of pageLoggers.values())
   {
-    for (let i = 0; i < panel.records.length; i++)
+    for (let i = 0; i < pageLogger.records.length; i++)
     {
-      let record = panel.records[i];
+      let record = pageLogger.records[i];
 
-      // If an added filter matches a request shown in the devtools panel,
-      // update that record to show the new filter. Ignore filters that aren't
-      // associated with any sub-resource request. There is no record for these
-      // if they don't already match. In particular, in case of element hiding
-      // filters, we also wouldn't know if any new element matches.
+      // If an added filter matches a logged request,update that record to show
+      // the new filter. Ignore filters that aren't associated with any
+      // sub-resource request. There is no record for these if they don't
+      // already match. In particular, in case of element hiding filters, we
+      // also wouldn't know if any new element matches.
       if (added)
       {
         if (nonRequestTypes.includes(record.request.type))
           continue;
 
         let filter = matchRequest(record.request);
         if (!filters.includes(filter))
           continue;
 
         record.filter = filter;
       }
 
-      // If a filter shown in the devtools panel got removed, update that
-      // record to show the filter that matches now, or none, instead.
+      // If a logged filter got removed, update that record to show the filter
+      // that matches now, or none, instead.
       // For filters that aren't associated with any sub-resource request,
       // just remove the record. We wouldn't know whether another filter
       // matches instead until the page is reloaded.
       else
       {
         if (!filters.includes(record.filter))
           continue;
 
         if (nonRequestTypes.includes(record.request.type))
         {
-          panel.port.postMessage({
-            type: "remove-record",
-            index: i
-          });
-          panel.records.splice(i--, 1);
+          emit(pageLogger, {type: "remove-record", index: i});
+          pageLogger.records.splice(i--, 1);
           continue;
         }
 
         record.filter = matchRequest(record.request);
       }
 
-      panel.port.postMessage({
+      emit(pageLogger, {
         type: "update-record",
         index: i,
         request: record.request,
         filter: getFilterInfo(record.filter)
       });
     }
   }
 }
 
 function onFilterAdded(filter)
 {
   updateFilters([filter], true);
 }
 
 function onFilterRemoved(filter)
 {
   updateFilters([filter], false);
 }
 
 function onSubscriptionAdded(subscription)
 {
   if (subscription instanceof SpecialSubscription)
     updateFilters(subscription.filters, true);
 }
 
-browser.runtime.onConnect.addListener(newPort =>
-{
-  let match = newPort.name.match(/^devtools-(\d+)$/);
-  if (!match)
-    return;
+/**
+ * @namespace
+ * @static
+ */
+let DevLogger = exports.DevLogger = {
+  /**
+   * Adds a callback that is called when a request
+   * or filter hit is logged for the page.
+   *
+   * @param {number}   pageId
+   * @param {function} callback
+   */
+  on(pageId, callback)
+  {
+    if (pageLoggers.size == 0)
+    {
+      ext.pages.onLoading.addListener(onLoading);
+      FilterNotifier.on("filter.added", onFilterAdded);
+      FilterNotifier.on("filter.removed", onFilterRemoved);
+      FilterNotifier.on("subscription.added", onSubscriptionAdded);
+    }
 
-  let inspectedTabId = parseInt(match[1], 10);
-  let localOnBeforeRequest = onBeforeRequest.bind();
+    if (pageLoggers.has(pageId))
+    {
+      pageLoggers.get(pageId).listeners.push(callback);
+    }
+    else
+    {
+      let localOnBeforeRequest = onBeforeRequest.bind();
+      pageLoggers.set(pageId, {
+        listeners: [callback], records: [],
+        reloading: false, reload: false,
+        localOnBeforeRequest
+      });
+      browser.webRequest.onBeforeRequest.addListener(
+        localOnBeforeRequest,
+        {
+          urls: ["http://*/*", "https://*/*"],
+          types: ["main_frame"],
+          tabId: pageId
+        }
+      );
+    }
+  },
 
-  browser.webRequest.onBeforeRequest.addListener(
-    localOnBeforeRequest,
+  /**
+   * Removes a callback for a page.
+   *
+   * @param {number}   pageId
+   * @param {function} callback
+   */
+  off(pageId, callback)
+  {
+    let pageLogger = pageLoggers.get(pageId);
+    if (pageLogger.listeners.length > 1)
     {
-      urls: ["http://*/*", "https://*/*"],
-      types: ["main_frame"],
-      tabId: inspectedTabId
+      let idx = pageLogger.listeners.indexOf(callback);
+      if (idx != -1)
+        pageLogger.listeners.splice(idx, 1);
     }
-  );
+    else
+    {
+      browser.webRequest.onBeforeRequest.removeListener(
+        pageLogger.localOnBeforeRequest
+      );
+      pageLoggers.delete(pageId);
+    }
 
-  if (panels.size == 0)
-  {
-    ext.pages.onLoading.addListener(onLoading);
-    FilterNotifier.on("filter.added", onFilterAdded);
-    FilterNotifier.on("filter.removed", onFilterRemoved);
-    FilterNotifier.on("subscription.added", onSubscriptionAdded);
-  }
-
-  newPort.onDisconnect.addListener(() =>
-  {
-    panels.delete(inspectedTabId);
-    browser.webRequest.onBeforeRequest.removeListener(localOnBeforeRequest);
-
-    if (panels.size == 0)
+    if (pageLoggers.size == 0)
     {
       ext.pages.onLoading.removeListener(onLoading);
       FilterNotifier.off("filter.added", onFilterAdded);
       FilterNotifier.off("filter.removed", onFilterRemoved);
       FilterNotifier.off("subscription.added", onSubscriptionAdded);
     }
-  });
+  },
 
-  panels.set(inspectedTabId, {port: newPort, records: []});
-});
+  /**
+   * Checks whether a page has any devLogging listeners active.
+   *
+   * @param {number}  pageId
+   * @return {boolean}
+   */
+  listening(pageId)
+  {
+    return pageLoggers.has(pageId);
+  }
+};
 
-port.on("devtools.traceElemHide", (message, sender) =>
+port.on("devlogger.traceElemHide", (message, sender) =>
 {
-  logHiddenElements(
+  exports.logHiddenElements(
     sender.page, message.selectors, message.filters,
     extractHostFromFrame(sender.frame)
   );
 });