extensions/renderer/wake_event_page.h

   1 // Copyright 2015 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_WAKE_EVENT_PAGE_H_
   6 #define EXTENSIONS_RENDERER_WAKE_EVENT_PAGE_H_
   7
   8 #include <string>
   9
  10 #include "base/callback.h"
  11 #include "base/containers/scoped_ptr_hash_map.h"
  12 #include "base/macros.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/memory/weak_ptr.h"
  16 #include "base/synchronization/lock.h"
  17 #include "content/public/renderer/render_process_observer.h"
  18 #include "ipc/ipc_sync_message_filter.h"
  19 #include "v8/include/v8.h"
  20
  21 namespace content {
  22 class RenderThread;
  23 }
  24
  25 namespace extensions {
  26 class ScriptContext;
  27
  28 // This class implements the wake-event-page JavaScript function, which wakes
  29 // an event page and runs a callback when done.
  30 //
  31 // Note, the function will do a round trip to the browser even if event page is
  32 // open. Any optimisation to prevent this must be at the JavaScript level.
  33 class WakeEventPage : public content::RenderProcessObserver {
  34  public:
  35   WakeEventPage();
  36   ~WakeEventPage() override;
  37
  38   // Returns the single instance of the WakeEventPage object.
  39   //
  40   // Thread safe.
  41   static WakeEventPage* Get();
  42
  43   // Initializes the WakeEventPage.
  44   //
  45   // This must be called before any bindings are installed, and must be called
  46   // on the render thread.
  47   void Init(content::RenderThread* render_thread);
  48
  49   // Returns the wake-event-page function bound to a given context. The
  50   // function will be cached as a hidden value in the context's global object.
  51   //
  52   // To mix C++ and JavaScript, example usage might be:
  53   //
  54   // WakeEventPage::Get().GetForContext(context)(function() {
  55   //   ...
  56   // });
  57   //
  58   // Thread safe.
  59   v8::Local<v8::Function> GetForContext(ScriptContext* context);
  60
  61  private:
  62   class WakeEventPageNativeHandler;
  63
  64   // The response from an ExtensionHostMsg_WakeEvent call, passed true if the
  65   // call was successful, false on failure.
  66   using OnResponseCallback = base::Callback<void(bool)>;
  67
  68   // Makes an ExtensionHostMsg_WakeEvent request for an extension ID. The
  69   // second argument is a callback to run when the request has completed.
  70   using MakeRequestCallback =
  71       base::Callback<void(const std::string&, const OnResponseCallback&)>;
  72
  73   // For |requests_|.
  74   struct RequestData {
  75     RequestData(int thread_id, const OnResponseCallback& on_response);
  76     ~RequestData();
  77
  78     // The thread ID the request was made on. |on_response| must be called on
  79     // that thread.
  80     int thread_id;
  81
  82     // Callback to run when the response to the request arrives.
  83     OnResponseCallback on_response;
  84   };
  85
  86   // Runs |on_response|, passing it |success|.
  87   static void RunOnResponseWithResult(const OnResponseCallback& on_response,
  88                                       bool success);
  89
  90   // Sends the ExtensionHostMsg_WakeEvent IPC for |extension_id|, and
  91   // updates |requests_| bookkeeping.
  92   void MakeRequest(const std::string& extension_id,
  93                    const OnResponseCallback& on_response);
  94
  95   // content::RenderProcessObserver:
  96   bool OnControlMessageReceived(const IPC::Message& message) override;
  97
  98   // OnControlMessageReceived handlers:
  99   void OnWakeEventPageResponse(int request_id, bool success);
 100
 101   // IPC sender. Belongs to the render thread, but thread safe.
 102   scoped_refptr<IPC::SyncMessageFilter> message_filter_;
 103
 104   // All in-flight requests, keyed by request ID. Used on multiple threads, so
 105   // must be guarded by |requests_lock_|.
 106   base::ScopedPtrHashMap<int, scoped_ptr<RequestData>> requests_;
 107
 108   // Lock for |requests_|.
 109   base::Lock requests_lock_;
 110
 111   DISALLOW_COPY_AND_ASSIGN(WakeEventPage);
 112 };
 113
 114 }  //  namespace extensions
 115
 116 #endif  // EXTENSIONS_RENDERER_WAKE_EVENT_PAGE_H_