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Diffstat (limited to 'WebCore/loader/CachedMetadata.h')
-rw-r--r-- | WebCore/loader/CachedMetadata.h | 125 |
1 files changed, 125 insertions, 0 deletions
diff --git a/WebCore/loader/CachedMetadata.h b/WebCore/loader/CachedMetadata.h new file mode 100644 index 0000000..d26539e --- /dev/null +++ b/WebCore/loader/CachedMetadata.h @@ -0,0 +1,125 @@ +/* + * 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 + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef CachedMetadata_h +#define CachedMetadata_h + +#include <wtf/RefCounted.h> +#include <wtf/Vector.h> + +namespace WebCore { + +// Metadata retrieved from the embedding application's cache. +// +// Serialized data is NOT portable across architectures. However, reading the +// data type ID will reject data generated with a different byte-order. +class CachedMetadata : public RefCounted<CachedMetadata> { +public: + static PassRefPtr<CachedMetadata> create(unsigned dataTypeID, const char* data, size_t size) + { + return adoptRef(new CachedMetadata(dataTypeID, data, size)); + } + + static PassRefPtr<CachedMetadata> deserialize(const char* data, size_t size) + { + return adoptRef(new CachedMetadata(data, size)); + } + + const Vector<char>& serialize() const + { + return m_serializedData; + } + + ~CachedMetadata() { } + + unsigned dataTypeID() const + { + return readUnsigned(dataTypeIDStart); + } + + const char* data() const + { + if (m_serializedData.size() < dataStart) + return 0; + return m_serializedData.data() + dataStart; + } + + size_t size() const + { + if (m_serializedData.size() < dataStart) + return 0; + return m_serializedData.size() - dataStart; + } + +private: + // Reads an unsigned value at position. Returns 0 on error. + unsigned readUnsigned(size_t position) const + { + if (m_serializedData.size() < position + sizeof(unsigned)) + return 0; + return *reinterpret_cast<unsigned*>(const_cast<char*>(m_serializedData.data() + position)); + } + + // Appends an unsigned value to the end of the serialized data. + void appendUnsigned(unsigned value) + { + m_serializedData.append(reinterpret_cast<const char*>(&value), sizeof(unsigned)); + } + + CachedMetadata(const char* data, size_t size) + { + // Serialized metadata should have non-empty data. + ASSERT(size > dataStart); + + m_serializedData.append(data, size); + } + + CachedMetadata(unsigned dataTypeID, const char* data, size_t size) + { + // Don't allow an ID of 0, it is used internally to indicate errors. + ASSERT(dataTypeID); + ASSERT(data); + + appendUnsigned(dataTypeID); + m_serializedData.append(data, size); + } + + // Serialization offsets. Format: [DATA_TYPE_ID][DATA]. + static const size_t dataTypeIDStart = 0; + static const size_t dataStart = sizeof(unsigned); + + // Since the serialization format supports random access, storing it in + // serialized form avoids need for a copy during serialization. + Vector<char> m_serializedData; +}; + +} + +#endif |