Source/WebCore/fileapi/Blob.cpp

/*
 * Copyright (C) 2010 Google Inc. All rights reserved.
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 * 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.
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 * copyright notice, this list of conditions and the following disclaimer
 * in the documentation and/or other materials provided with the
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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
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#include "config.h"
#include "Blob.h"

#include "BlobBuilder.h"
#include "BlobPart.h"
#include "BlobURL.h"
#include "File.h"
#include "ScriptExecutionContext.h"
#include "SharedBuffer.h"
#include "ThreadableBlobRegistry.h"
#include <wtf/IsoMallocInlines.h>
#include <wtf/NeverDestroyed.h>
#include <wtf/text/CString.h>

namespace WebCore {

WTF_MAKE_ISO_ALLOCATED_IMPL(Blob);

class BlobURLRegistry final : public URLRegistry {
public:
    void registerURL(ScriptExecutionContext&, const URL&, URLRegistrable&) final;
    void unregisterURL(const URL&) final;

    static URLRegistry& registry();
};


void BlobURLRegistry::registerURL(ScriptExecutionContext& context, const URL& publicURL, URLRegistrable& blob)
{
    ASSERT(&blob.registry() == this);
    ThreadableBlobRegistry::registerBlobURL(context.securityOrigin(), publicURL, static_cast<Blob&>(blob).url());
}

void BlobURLRegistry::unregisterURL(const URL& url)
{
    ThreadableBlobRegistry::unregisterBlobURL(url);
}

URLRegistry& BlobURLRegistry::registry()
{
    static NeverDestroyed<BlobURLRegistry> instance;
    return instance;
}

Blob::Blob(UninitializedContructor, URL&& url, String&& type)
    : m_internalURL(WTFMove(url))
    , m_type(WTFMove(type))
{
}

Blob::Blob()
    : m_size(0)
{
    m_internalURL = BlobURL::createInternalURL();
    ThreadableBlobRegistry::registerBlobURL(m_internalURL, { },  { });
}

Blob::Blob(Vector<BlobPartVariant>&& blobPartVariants, const BlobPropertyBag& propertyBag)
    : m_internalURL(BlobURL::createInternalURL())
    , m_type(normalizedContentType(propertyBag.type))
{
    BlobBuilder builder(propertyBag.endings);
    for (auto& blobPartVariant : blobPartVariants) {
        WTF::switchOn(blobPartVariant,
            [&] (auto& part) {
                builder.append(WTFMove(part));
            }
        );
    }

    ThreadableBlobRegistry::registerBlobURL(m_internalURL, builder.finalize(), m_type);
}

Blob::Blob(const SharedBuffer& buffer, const String& contentType)
    : m_type(contentType)
    , m_size(buffer.size())
{
    Vector<uint8_t> data;
    data.append(buffer.data(), buffer.size());

    Vector<BlobPart> blobParts;
    blobParts.append(BlobPart(WTFMove(data)));
    m_internalURL = BlobURL::createInternalURL();
    ThreadableBlobRegistry::registerBlobURL(m_internalURL, WTFMove(blobParts), contentType);
}

Blob::Blob(Vector<uint8_t>&& data, const String& contentType)
    : m_type(contentType)
    , m_size(data.size())
{
    Vector<BlobPart> blobParts;
    blobParts.append(BlobPart(WTFMove(data)));
    m_internalURL = BlobURL::createInternalURL();
    ThreadableBlobRegistry::registerBlobURL(m_internalURL, WTFMove(blobParts), contentType);
}

Blob::Blob(ReferencingExistingBlobConstructor, const Blob& blob)
    : m_internalURL(BlobURL::createInternalURL())
    , m_type(blob.type())
    , m_size(blob.size())
{
    ThreadableBlobRegistry::registerBlobURL(m_internalURL, { BlobPart(blob.url()) } , m_type);
}

Blob::Blob(DeserializationContructor, const URL& srcURL, const String& type, Optional<unsigned long long> size, const String& fileBackedPath)
    : m_type(normalizedContentType(type))
    , m_size(size)
{
    m_internalURL = BlobURL::createInternalURL();
    if (fileBackedPath.isEmpty())
        ThreadableBlobRegistry::registerBlobURL(nullptr, m_internalURL, srcURL);
    else
        ThreadableBlobRegistry::registerBlobURLOptionallyFileBacked(m_internalURL, srcURL, fileBackedPath, m_type);
}

Blob::Blob(const URL& srcURL, long long start, long long end, const String& type)
    : m_type(normalizedContentType(type))
    // m_size is not necessarily equal to end - start so we do not initialize it here.
{
    m_internalURL = BlobURL::createInternalURL();
    ThreadableBlobRegistry::registerBlobURLForSlice(m_internalURL, srcURL, start, end);
}

Blob::~Blob()
{
    ThreadableBlobRegistry::unregisterBlobURL(m_internalURL);
}

unsigned long long Blob::size() const
{
    if (!m_size) {
        // FIXME: JavaScript cannot represent sizes as large as unsigned long long, we need to
        // come up with an exception to throw if file size is not representable.
        unsigned long long actualSize = ThreadableBlobRegistry::blobSize(m_internalURL);
        m_size = WTF::isInBounds<long long>(actualSize) ? actualSize : 0;
    }

    return *m_size;
}

bool Blob::isValidContentType(const String& contentType)
{
    // FIXME: Do we really want to treat the empty string and null string as valid content types?
    unsigned length = contentType.length();
    for (unsigned i = 0; i < length; ++i) {
        if (contentType[i] < 0x20 || contentType[i] > 0x7e)
            return false;
    }
    return true;
}

String Blob::normalizedContentType(const String& contentType)
{
    if (!isValidContentType(contentType))
        return emptyString();
    return contentType.convertToASCIILowercase();
}

#if !ASSERT_DISABLED
bool Blob::isNormalizedContentType(const String& contentType)
{
    // FIXME: Do we really want to treat the empty string and null string as valid content types?
    unsigned length = contentType.length();
    for (size_t i = 0; i < length; ++i) {
        if (contentType[i] < 0x20 || contentType[i] > 0x7e)
            return false;
        if (isASCIIUpper(contentType[i]))
            return false;
    }
    return true;
}

bool Blob::isNormalizedContentType(const CString& contentType)
{
    // FIXME: Do we really want to treat the empty string and null string as valid content types?
    size_t length = contentType.length();
    const char* characters = contentType.data();
    for (size_t i = 0; i < length; ++i) {
        if (characters[i] < 0x20 || characters[i] > 0x7e)
            return false;
        if (isASCIIUpper(characters[i]))
            return false;
    }
    return true;
}
#endif

URLRegistry& Blob::registry() const
{
    return BlobURLRegistry::registry();
}


} // namespace WebCore