root/content/child/quota_message_filter.cc

DEFINITIONS

1. next_request_id_
2. GenerateRequestID
3. ClearThreadRequests
4. OverrideTaskRunnerForMessage
5. OnMessageReceived

// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "content/child/quota_message_filter.h"

#include "base/message_loop/message_loop_proxy.h"
#include "content/child/quota_dispatcher.h"
#include "content/child/thread_safe_sender.h"
#include "content/child/worker_thread_task_runner.h"
#include "content/common/quota_messages.h"

namespace content {

QuotaMessageFilter::QuotaMessageFilter(
    ThreadSafeSender* thread_safe_sender)
    : main_thread_loop_proxy_(base::MessageLoopProxy::current()),
      thread_safe_sender_(thread_safe_sender),
      next_request_id_(0) {
}

QuotaMessageFilter::~QuotaMessageFilter() {}

int QuotaMessageFilter::GenerateRequestID(int thread_id) {
  base::AutoLock lock(request_id_map_lock_);
  request_id_map_[next_request_id_] = thread_id;
  return next_request_id_++;
}

void QuotaMessageFilter::ClearThreadRequests(int thread_id) {
  base::AutoLock lock(request_id_map_lock_);
  for (RequestIdToThreadId::iterator iter = request_id_map_.begin();
       iter != request_id_map_.end();) {
    if (iter->second == thread_id)
      request_id_map_.erase(iter++);
    else
      iter++;
  }
}

base::TaskRunner* QuotaMessageFilter::OverrideTaskRunnerForMessage(
    const IPC::Message& msg) {
  if (IPC_MESSAGE_CLASS(msg) != QuotaMsgStart)
    return NULL;

  int request_id = -1, thread_id = 0;
  const bool success = PickleIterator(msg).ReadInt(&request_id);
  DCHECK(success);

  {
    base::AutoLock lock(request_id_map_lock_);
    RequestIdToThreadId::iterator found = request_id_map_.find(request_id);
    if (found != request_id_map_.end()) {
      thread_id = found->second;
      request_id_map_.erase(found);
    }
  }

  if (!thread_id)
    return main_thread_loop_proxy_.get();
  return new WorkerThreadTaskRunner(thread_id);
}

bool QuotaMessageFilter::OnMessageReceived(const IPC::Message& msg) {
  if (IPC_MESSAGE_CLASS(msg) != QuotaMsgStart)
    return false;
  QuotaDispatcher::ThreadSpecificInstance(thread_safe_sender_.get(), this)
      ->OnMessageReceived(msg);
  return true;
}

}  // namespace content