Source/WebCore/fileapi/FileStreamProxy.h

/*
 * Copyright (C) 2010 Google Inc.  All rights reserved.
 * Copyright (C) 2010 Apple 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.
 *     * Neither the name of Google Inc. nor the names of its
 * 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
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

#ifndef FileStreamProxy_h
#define FileStreamProxy_h

#if ENABLE(BLOB) || ENABLE(FILE_SYSTEM)

#include "AsyncFileStream.h"
#include <wtf/Forward.h>
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>
#include <wtf/RefPtr.h>

namespace WebCore {

class FileStream;
class FileThread;
class KURL;
class ScriptExecutionContext;

// A proxy module that asynchronously calls corresponding FileStream methods on the file thread.  Note: you must call stop() first and then release the reference to destruct the FileStreamProxy instance.
class FileStreamProxy : public AsyncFileStream {
public:
    static PassRefPtr<FileStreamProxy> create(ScriptExecutionContext*, FileStreamClient*);
    virtual ~FileStreamProxy();

    virtual void getSize(const String& path, double expectedModificationTime);
    virtual void openForRead(const String& path, long long offset, long long length);
    virtual void openForWrite(const String& path);
    virtual void close();
    virtual void read(char* buffer, int length);
    virtual void write(const KURL& blobURL, long long position, int length);
    virtual void truncate(long long position);

    // Stops the proxy and scedules it to be destructed.  All the pending tasks will be aborted and the file stream will be closed.
    // Note: the caller should deref the instance immediately after calling stop().
    virtual void stop();

private:
    FileStreamProxy(ScriptExecutionContext*, FileStreamClient*);

    FileThread* fileThread();

    // Called on File thread.
    void startOnFileThread();
    void stopOnFileThread();
    void getSizeOnFileThread(const String& path, double expectedModificationTime);
    void openForReadOnFileThread(const String& path, long long offset, long long length);
    void openForWriteOnFileThread(const String& path);
    void closeOnFileThread();
    void readOnFileThread(char* buffer, int length);
    void writeOnFileThread(const KURL& blobURL, long long position, int length);
    void truncateOnFileThread(long long position);

    RefPtr<ScriptExecutionContext> m_context;
    RefPtr<FileStream> m_stream;
};

} // namespace WebCore

#endif // ENABLE(BLOB) || ENABLE(FILE_SYSTEM)

#endif // FileStreamProxy_h