Bug 1306892 - Fetch stylesheets from network monitor. r=tromey

If the toolbox is open when a stylesheet is loaded, the network monitor should
have recorded the response content.  When a tool asks for stylesheet text, try
asking the network monitor first before falling back to an extra fetch as a last
resort.

MozReview-Commit-ID: E2pQ04ARfQo

--HG--
extra : rebase_source : b10fb44e313ece5757961ca81a3bc0f76753ed8e

devtools/client/styleeditor/test/browser_styleeditor_fetch-from-cache.js

@@ -1,6 +1,6 @@
-/* vim: set ts=2 et sw=2 tw=80: */
 /* Any copyright is dedicated to the Public Domain.
    http://creativecommons.org/publicdomain/zero/1.0/ */
+
 "use strict";
 
 // A test to ensure Style Editor doesn't bybass cache when loading style sheet
@@ -42,8 +42,6 @@ add_task(function* () {
     }
   }
 
-  is(items.length, 2,
-     "Got two requests for doc_uncached.css after Style Editor was loaded.");
-  ok(items[1].fromCache,
-     "Second request was loaded from browser cache");
+  is(items.length, 1,
+     "Got one request for doc_uncached.css after Style Editor was loaded.");
 });

devtools/server/actors/stylesheets.js

@@ -423,6 +423,12 @@ var StyleSheetActor = protocol.ActorClassWithSpec(styleSheetSpec, {
    *         If an error occurs, the promise is rejected with that error.
    */
   fetchStylesheet: Task.async(function* (href) {
+    // Check if network monitor observed this load, and if so, use that.
+    let result = this.fetchStylesheetFromNetworkMonitor(href);
+    if (result) {
+      return result;
+    }
+
     let options = {
       loadFromCache: true,
       policy: Ci.nsIContentPolicy.TYPE_INTERNAL_STYLESHEET,
@@ -442,7 +448,6 @@ var StyleSheetActor = protocol.ActorClassWithSpec(styleSheetSpec, {
       options.principal = this.ownerDocument.nodePrincipal;
     }
 
-    let result;
     try {
       result = yield fetch(this.href, options);
     } catch (e) {
@@ -458,6 +463,43 @@ var StyleSheetActor = protocol.ActorClassWithSpec(styleSheetSpec, {
     return result;
   }),
 
+  /**
+   * Try to locate the console actor if it exists via our parent actor (the tab).
+   */
+  get _consoleActor() {
+    if (this.parentActor.exited) {
+      return null;
+    }
+    let form = this.parentActor.form();
+    return this.conn._getOrCreateActor(form.consoleActor);
+  },
+
+  /**
+   * Try to fetch the stylesheet text from the network monitor.  If it was enabled during
+   * the load, it should have a copy of the text saved.
+   *
+   * @param string href
+   *        The URL of the sheet to fetch.
+   */
+  fetchStylesheetFromNetworkMonitor(href) {
+    let consoleActor = this._consoleActor;
+    if (!consoleActor) {
+      return null;
+    }
+    let request = consoleActor.getNetworkEventActorForURL(href);
+    if (!request) {
+      return null;
+    }
+    let content = request._response.content;
+    if (request._discardResponseBody || !content) {
+      return null;
+    }
+    return {
+      content: content.text,
+      contentType: content.mimeType,
+    };
+  },
+
   /**
    * Protocol method to get the media rules for the stylesheet.
    */

devtools/server/actors/webconsole.js

@@ -68,6 +68,7 @@ function WebConsoleActor(connection, parentActor) {
   this.dbg = this.parentActor.makeDebugger();
 
   this._netEvents = new Map();
+  this._networkEventActorsByURL = new Map();
   this._gripDepth = 0;
   this._listeners = new Set();
   this._lastConsoleInputEvaluation = undefined;
@@ -124,13 +125,23 @@ WebConsoleActor.prototype =
 
   /**
    * Holds a map between nsIChannel objects and NetworkEventActors for requests
-   * created with sendHTTPRequest.
+   * created with sendHTTPRequest or found via the network listener.
    *
    * @private
    * @type Map
    */
   _netEvents: null,
 
+  /**
+   * Holds a map from URL to NetworkEventActors for requests noticed by the network
+   * listener.  Requests are added when they start, so the actor might not yet have all
+   * data for the request until it has completed.
+   *
+   * @private
+   * @type Map
+   */
+  _networkEventActorsByURL: null,
+
   /**
    * Holds a set of all currently registered listeners.
    *
@@ -1632,6 +1643,8 @@ WebConsoleActor.prototype =
     let actor = this.getNetworkEventActor(event.channelId);
     actor.init(event);
 
+    this._networkEventActorsByURL.set(actor._request.url, actor);
+
     let packet = {
       from: this.actorID,
       type: "networkEvent",
@@ -1665,6 +1678,18 @@ WebConsoleActor.prototype =
     return actor;
   },
 
+  /**
+   * Get the NetworkEventActor for a given URL that may have been noticed by the network
+   * listener.  Requests are added when they start, so the actor might not yet have all
+   * data for the request until it has completed.
+   *
+   * @param string url
+   *        The URL of the request to search for.
+   */
+  getNetworkEventActorForURL(url) {
+    return this._networkEventActorsByURL.get(url);
+  },
+
   /**
    * Send a new HTTP request from the target's window.
    *
@@ -1992,6 +2017,9 @@ NetworkEventActor.prototype =
     }
     this._longStringActors = new Set();
 
+    if (this._request.url) {
+      this.parent._networkEventActorsByURL.delete(this._request.url);
+    }
     if (this.channel) {
       this.parent._netEvents.delete(this.channel);
     }