extensions/renderer/user_script_scheduler.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef EXTENSIONS_RENDERER_USER_SCRIPT_SCHEDULER_H_
   6 #define EXTENSIONS_RENDERER_USER_SCRIPT_SCHEDULER_H_
   7
   8 #include <map>
   9 #include <queue>
  10
  11 #include "base/memory/linked_ptr.h"
  12 #include "base/memory/weak_ptr.h"
  13 #include "extensions/common/user_script.h"
  14
  15 class RenderView;
  16 struct ExtensionMsg_ExecuteCode_Params;
  17
  18 namespace blink {
  19 class WebFrame;
  20 }
  21
  22 namespace extensions {
  23 class Dispatcher;
  24
  25 // Implements support for injecting scripts at different times in the document
  26 // loading process. The different possible time are described in
  27 // UserScript::RunLocation.
  28 //
  29 // Currently, determining idleness is simple: it is whichever of the following
  30 // happens first:
  31 //
  32 // a) When the initial DOM for a page is complete + kUserScriptIdleTimeout,
  33 // b) or when the page has completely loaded including all subresources.
  34 //
  35 // The intent of this mechanism is to prevent user scripts from slowing down
  36 // fast pages (run after load), while still allowing them to run relatively
  37 // timely for pages with lots of slow subresources.
  38 //
  39 // NOTE: this class does not inherit from RenderViewObserver on purpose.  The
  40 // reason is that this object is per frame, and a frame can move across
  41 // RenderViews thanks to adoptNode.  So we have each RenderView's
  42 // ExtensionHelper proxy these calls to the renderer process' Dispatcher,
  43 // which contains the mapping from WebFrame to us.
  44 class UserScriptScheduler {
  45  public:
  46   UserScriptScheduler(blink::WebFrame* frame, Dispatcher* dispatcher);
  47   ~UserScriptScheduler();
  48
  49   void ExecuteCode(const ExtensionMsg_ExecuteCode_Params& params);
  50   void DidCreateDocumentElement();
  51   void DidFinishDocumentLoad();
  52   void DidFinishLoad();
  53   void DidStartProvisionalLoad();
  54
  55  private:
  56   typedef
  57     std::queue<linked_ptr<ExtensionMsg_ExecuteCode_Params> >
  58     ExecutionQueue;
  59
  60   // Run user scripts, except if they've already run for this frame, or the
  61   // frame has been destroyed.
  62   void MaybeRun();
  63
  64   // Backend for the IPC Message ExecuteCode in addition to being used
  65   // internally.
  66   void ExecuteCodeImpl(const ExtensionMsg_ExecuteCode_Params& params);
  67
  68   // Get all child frames of parent_frame, returned by frames_vector.
  69   bool GetAllChildFrames(blink::WebFrame* parent_frame,
  70                          std::vector<blink::WebFrame*>* frames_vector) const;
  71
  72   // Call to signify thet the idle timeout has expired.
  73   void IdleTimeout();
  74
  75   base::WeakPtrFactory<UserScriptScheduler> weak_factory_;
  76
  77   // The Frame we will run scripts in.
  78   blink::WebFrame* frame_;
  79
  80   // The current location in the document loading process.
  81   // Will be UserScript::UNDEFINED if it is before any scripts should be run.
  82   UserScript::RunLocation current_location_;
  83
  84   // Whether we have already run the idle scripts.
  85   bool has_run_idle_;
  86
  87   // This is only used if we're for the main frame.
  88   std::map<UserScript::RunLocation, ExecutionQueue> pending_execution_map_;
  89
  90   Dispatcher* dispatcher_;
  91 };
  92
  93 }  // namespace extensions
  94
  95 #endif  // EXTENSIONS_RENDERER_USER_SCRIPT_SCHEDULER_H_