Source/WebCore/fileapi/DOMFileSystem.h

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 *     * Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above
 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
 * distribution.
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 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
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#ifndef DOMFileSystem_h
#define DOMFileSystem_h

#if ENABLE(FILE_SYSTEM)

#include "ActiveDOMObject.h"
#include "DOMFileSystemBase.h"
#include "ScriptExecutionContext.h"

namespace WebCore {

class DirectoryEntry;
class File;
class FileCallback;
class FileEntry;
class FileWriterCallback;

class DOMFileSystem : public DOMFileSystemBase, public ActiveDOMObject {
public:
    static PassRefPtr<DOMFileSystem> create(ScriptExecutionContext* context, const String& name, PassOwnPtr<AsyncFileSystem> asyncFileSystem)
    {
        return adoptRef(new DOMFileSystem(context, name, asyncFileSystem));
    }

    PassRefPtr<DirectoryEntry> root();

    // ActiveDOMObject methods.
    virtual void stop();
    virtual bool hasPendingActivity() const;
    virtual void contextDestroyed();

    void createWriter(const FileEntry*, PassRefPtr<FileWriterCallback>, PassRefPtr<ErrorCallback>);
    void createFile(const FileEntry*, PassRefPtr<FileCallback>, PassRefPtr<ErrorCallback>);

    // Schedule a callback. This should not cross threads (should be called on the same context thread).
    // FIXME: move this to a more generic place.
    template <typename CB, typename CBArg>
    static void scheduleCallback(ScriptExecutionContext*, PassRefPtr<CB>, PassRefPtr<CBArg>);

    template <typename CB, typename CBArg>
    void scheduleCallback(PassRefPtr<CB> callback, PassRefPtr<CBArg> callbackArg)
    {
        scheduleCallback(scriptExecutionContext(), callback, callbackArg);
    }

private:
    DOMFileSystem(ScriptExecutionContext*, const String& name, PassOwnPtr<AsyncFileSystem>);

    // A helper template to schedule a callback task.
    template <typename CB, typename CBArg>
    class DispatchCallbackTask : public ScriptExecutionContext::Task {
    public:
        DispatchCallbackTask(PassRefPtr<CB> callback, PassRefPtr<CBArg> arg)
            : m_callback(callback)
            , m_callbackArg(arg)
        {
        }

        virtual void performTask(ScriptExecutionContext*)
        {
            m_callback->handleEvent(m_callbackArg.get());
        }

    private:
        RefPtr<CB> m_callback;
        RefPtr<CBArg> m_callbackArg;
    };
};

template <typename CB, typename CBArg>
void DOMFileSystem::scheduleCallback(ScriptExecutionContext* scriptExecutionContext, PassRefPtr<CB> callback, PassRefPtr<CBArg> arg)
{
    ASSERT(scriptExecutionContext->isContextThread());
    ASSERT(callback);
    scriptExecutionContext->postTask(new DispatchCallbackTask<CB, CBArg>(callback, arg));
}

} // namespace

#endif // ENABLE(FILE_SYSTEM)

#endif // DOMFileSystem_h