WebCore/fileapi/FileReaderSync.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.
 *     * 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,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef FileReaderSync_h
#define FileReaderSync_h

#if ENABLE(BLOB)

#include "ExceptionCode.h"
#include "ScriptString.h"
#include <wtf/PassRefPtr.h>
#include <wtf/RefCounted.h>

namespace WebCore {

class Blob;
class ScriptExecutionContext;

class FileReaderSync : public RefCounted<FileReaderSync> {
public:
    static PassRefPtr<FileReaderSync> create()
    {
        return adoptRef(new FileReaderSync());
    }

    virtual ~FileReaderSync() { }

    const ScriptString& readAsBinaryString(ScriptExecutionContext*, Blob*, ExceptionCode&);
    const ScriptString& readAsText(ScriptExecutionContext* scriptExecutionContext, Blob* blob, ExceptionCode& ec)
    {
        return readAsText(scriptExecutionContext, blob, "", ec);
    }
    const ScriptString& readAsText(ScriptExecutionContext*, Blob*, const String& encoding, ExceptionCode&);
    const ScriptString& readAsDataURL(ScriptExecutionContext*, Blob*, ExceptionCode&);

private:
    enum ReadType {
        ReadAsBinaryString,
        ReadAsText,
        ReadAsDataURL
    };

    FileReaderSync();
    
    void read(ScriptExecutionContext*, Blob*, ReadType, ExceptionCode&);
    void convertToText(const char* data, int size, ScriptString& result);

    // Like XMLHttpRequest.m_responseText, we keep this as a ScriptString, not a WTF::String.
    // That's because these strings can easily get huge (they are filled from the file) and
    // because JS can easily observe many intermediate states, so it's very useful to be
    // able to share the buffer with JavaScript versions of the whole or partial string.
    // In contrast, this string doesn't interact much with the rest of the engine so it's not that
    // big a cost that it isn't a String.
    ScriptString m_result;

    String m_encoding;
};

} // namespace WebCore

#endif // ENABLE(BLOB)

#endif // FileReaderSync_h