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

lib/devLogger.js

Index: lib/devLogger.js
diff --git a/lib/devtools.js b/lib/devLogger.js
similarity index 60%
copy from lib/devtools.js
copy to lib/devLogger.js
index 167a7650e990cb3819b50d719a3e25501caf9e5f..6e13cafe9a7c6557b3c14e498578b0b3ed30a270 100644
--- a/lib/devtools.js
+++ b/lib/devLogger.js
@@ -15,6 +15,8 @@
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+/** @module devLogger */
+
 "use strict";
 
 const {RegExpFilter,
@@ -29,21 +31,21 @@ 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;
 }
 
@@ -74,9 +76,9 @@ function getFilterInfo(filter)
   };
 }
 
-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 &&
 
@@ -92,17 +94,23 @@ function hasRecord(panel, request, filter)
   );
 }
 
-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});
   }
 }
 
@@ -119,7 +127,8 @@ function matchRequest(request)
 }
 
 /**
- * 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
@@ -133,31 +142,32 @@ function matchRequest(request)
  * @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)
     {
@@ -175,17 +185,17 @@ function logHiddenElements(page, selectors, filters, docDomain)
                                      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
@@ -193,86 +203,76 @@ function logHiddenElements(page, selectors, filters, docDomain)
  *                                 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))
@@ -285,8 +285,8 @@ function updateFilters(filters, added)
         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.
@@ -297,18 +297,15 @@ function updateFilters(filters, added)
 
         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,
@@ -334,52 +331,98 @@ function onSubscriptionAdded(subscription)
     updateFilters(subscription.filters, true);
 }
 
-browser.runtime.onConnect.addListener(newPort =>
-{
-  let match = newPort.name.match(/^devtools-(\d+)$/);
-  if (!match)
-    return;
-
-  let inspectedTabId = parseInt(match[1], 10);
-  let localOnBeforeRequest = onBeforeRequest.bind();
-
-  browser.webRequest.onBeforeRequest.addListener(
-    localOnBeforeRequest,
+/**
+ * @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)
     {
-      urls: ["http://*/*", "https://*/*"],
-      types: ["main_frame"],
-      tabId: inspectedTabId
+      ext.pages.onLoading.addListener(onLoading);
+      FilterNotifier.on("filter.added", onFilterAdded);
+      FilterNotifier.on("filter.removed", onFilterRemoved);
+      FilterNotifier.on("subscription.added", onSubscriptionAdded);
     }
-  );
 
-  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(() =>
+    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
+        }
+      );
+    }
+  },
+
+  /**
+   * Removes a callback for a page.
+   *
+   * @param {number}   pageId
+   * @param {function} callback
+   */
+  off(pageId, callback)
   {
-    panels.delete(inspectedTabId);
-    browser.webRequest.onBeforeRequest.removeListener(localOnBeforeRequest);
+    let pageLogger = pageLoggers.get(pageId);
+    if (pageLogger.listeners.length > 1)
+    {
+      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)
+    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)
   );