1 // Copyright 2013 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 CONTENT_CHILD_CHILD_RESOURCE_MESSAGE_FILTER_H_ 6 #define CONTENT_CHILD_CHILD_RESOURCE_MESSAGE_FILTER_H_ 7 8 #include "base/memory/ref_counted.h" 9 #include "ipc/message_filter.h" 10 11 namespace base { 12 class SingleThreadTaskRunner; 13 } 14 15 namespace content { 16 class ResourceDispatcher; 17 18 // Supplies ResourceDispatcher with timestamps for some resource messages. 19 // 20 // Background: ResourceDispatcher converts browser process time to child 21 // process time. This is done to achieve coherent timeline. Conversion is 22 // a linear transformation such that given browser process time range is 23 // mapped to corresponding child process time range. Timestamps for child 24 // process time range should be taken by IO thread when resource messages 25 // arrive. Otherwise, timestamps may be affected by long rendering / JS task. 26 // 27 // When specific message is processed by this filter, new task charged 28 // with timestamp is posted to main thread. This task is processed just before 29 // resource message and invokes ResourceDispatcher::set_io_timestamp. 30 class ChildResourceMessageFilter : public IPC::MessageFilter { 31 public: 32 explicit ChildResourceMessageFilter(ResourceDispatcher* resource_dispatcher); 33 34 // IPC::MessageFilter implementation. 35 virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE; 36 37 private: 38 virtual ~ChildResourceMessageFilter(); 39 40 scoped_refptr<base::SingleThreadTaskRunner> main_thread_task_runner_; 41 ResourceDispatcher* resource_dispatcher_; 42 43 DISALLOW_COPY_AND_ASSIGN(ChildResourceMessageFilter); 44 }; 45 46 } // namespace content 47 48 #endif // CONTENT_CHILD_CHILD_RESOURCE_MESSAGE_FILTER_H_ 49
