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
15class RenderView;
16struct ExtensionMsg_ExecuteCode_Params;
17
18namespace blink {
19class WebFrame;
20}
21
22namespace extensions {
23class 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.
44class 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_
96