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// Copyright (c) 2011 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.
#ifndef WEBKIT_QUOTA_QUOTA_TASK_H_
#define WEBKIT_QUOTA_QUOTA_TASK_H_
#pragma once
#include <set>
#include "base/basictypes.h"
#include "base/compiler_specific.h"
#include "base/memory/ref_counted.h"
#include "base/message_loop_proxy.h"
namespace base {
class MessageLoopProxy;
}
namespace quota {
class QuotaTaskObserver;
// A base class for quota tasks.
class QuotaTask {
public:
virtual ~QuotaTask();
void Start();
protected:
explicit QuotaTask(QuotaTaskObserver* observer);
// The task body.
virtual void Run() = 0;
// Called upon completion, on the original message loop.
virtual void Completed() = 0;
// Called when the task is aborted.
virtual void Aborted() {}
void CallCompleted();
// Call this to delete itself.
void DeleteSoon();
QuotaTaskObserver* observer() const { return observer_; }
scoped_refptr<base::MessageLoopProxy> original_message_loop() const {
return original_message_loop_;
}
private:
friend class QuotaTaskObserver;
void Abort();
QuotaTaskObserver* observer_;
scoped_refptr<base::MessageLoopProxy> original_message_loop_;
};
// For tasks that post tasks to the other thread.
class QuotaThreadTask : public QuotaTask,
public base::RefCountedThreadSafe<QuotaThreadTask> {
public:
QuotaThreadTask(QuotaTaskObserver* observer,
scoped_refptr<base::MessageLoopProxy> target_message_loop);
protected:
virtual ~QuotaThreadTask();
// One of the following Run methods should be overridden for execution
// on the target thread.
// A task to invoke the CallCompleted() method on the original thread will
// be scheduled immediately upon return from RunOnTargetThread().
virtual void RunOnTargetThread();
// A task to invoke the CallCompleted() method on the original thread will
// only be scheduled if RunOnTargetThreadAsync returns true. If false is
// returned, the derived class should schedule a task to do so upon actual
// completion.
virtual bool RunOnTargetThreadAsync();
virtual void Run() OVERRIDE;
scoped_refptr<base::MessageLoopProxy> target_message_loop() const {
return target_message_loop_;
}
private:
friend class base::RefCountedThreadSafe<QuotaThreadTask>;
friend class QuotaTaskObserver;
void CallRunOnTargetThread();
scoped_refptr<base::MessageLoopProxy> target_message_loop_;
};
class QuotaTaskObserver {
public:
virtual ~QuotaTaskObserver();
protected:
friend class QuotaTask;
friend class QuotaThreadTask;
QuotaTaskObserver();
void RegisterTask(QuotaTask* task);
void UnregisterTask(QuotaTask* task);
typedef std::set<QuotaTask*> TaskSet;
TaskSet running_quota_tasks_;
};
}
#endif // WEBKIT_QUOTA_QUOTA_TASK_H_