Source/WebCore/fileapi/BlobLoader.h

/*
 * Copyright (C) 2019 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:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS 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 APPLE INC. OR ITS 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 (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

#pragma once

#include "Blob.h"
#include "Document.h"
#include "ExceptionCode.h"
#include "FileReaderLoader.h"
#include "FileReaderLoaderClient.h"
#include "SharedBuffer.h"
#include <JavaScriptCore/ArrayBuffer.h>
#include <wtf/CompletionHandler.h>
#include <wtf/Optional.h>

namespace WebCore {

class BlobLoader final : public FileReaderLoaderClient {
    WTF_MAKE_FAST_ALLOCATED;
public:
    BlobLoader(Document*, Blob&, Function<void()>&&);
    ~BlobLoader();

    bool isLoading() const { return !!m_loader; }
    const RefPtr<JSC::ArrayBuffer>& result() const { return m_buffer; }
    Optional<ExceptionCode> errorCode() const { return m_errorCode; }

private:
    void didStartLoading() final { }
    void didReceiveData() final { }

    void didFinishLoading() final;
    void didFail(ExceptionCode errorCode) final;
    void complete();

    std::unique_ptr<FileReaderLoader> m_loader;
    RefPtr<JSC::ArrayBuffer> m_buffer;
    Optional<ExceptionCode> m_errorCode;
    Function<void()> m_completionHandler;
};

inline BlobLoader::BlobLoader(WebCore::Document* document, Blob& blob, Function<void()>&& completionHandler)
    : m_loader(makeUnique<FileReaderLoader>(FileReaderLoader::ReadAsArrayBuffer, this))
    , m_completionHandler(WTFMove(completionHandler))
{
    m_loader->start(document, blob);
}

inline BlobLoader::~BlobLoader()
{
    if (m_loader)
        m_loader->cancel();
    // FIXME: Call m_completionHandler to migrate it from a Function to a CompletionHandler.
}

inline void BlobLoader::didFinishLoading()
{
    m_buffer = m_loader->arrayBufferResult();
    complete();
}

inline void BlobLoader::didFail(ExceptionCode errorCode)
{
    m_errorCode = errorCode;
    complete();
}

inline void BlobLoader::complete()
{
    m_loader = nullptr;
    m_completionHandler();
}

} // namespace WebCore