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author | Shimeng (Simon) Wang <swang@google.com> | 2010-12-07 17:22:45 -0800 |
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committer | Shimeng (Simon) Wang <swang@google.com> | 2010-12-22 14:15:40 -0800 |
commit | 4576aa36e9a9671459299c7963ac95aa94beaea9 (patch) | |
tree | 3863574e050f168c0126ecb47c83319fab0972d8 /WebCore/html/canvas/DataView.cpp | |
parent | 55323ac613cc31553107b68603cb627264d22bb0 (diff) | |
download | external_webkit-4576aa36e9a9671459299c7963ac95aa94beaea9.zip external_webkit-4576aa36e9a9671459299c7963ac95aa94beaea9.tar.gz external_webkit-4576aa36e9a9671459299c7963ac95aa94beaea9.tar.bz2 |
Merge WebKit at r73109: Initial merge by git.
Change-Id: I61f1a66d9642e3d8405d3ac6ccab2a53421c75d8
Diffstat (limited to 'WebCore/html/canvas/DataView.cpp')
-rwxr-xr-x | WebCore/html/canvas/DataView.cpp | 228 |
1 files changed, 228 insertions, 0 deletions
diff --git a/WebCore/html/canvas/DataView.cpp b/WebCore/html/canvas/DataView.cpp new file mode 100755 index 0000000..d030211 --- /dev/null +++ b/WebCore/html/canvas/DataView.cpp @@ -0,0 +1,228 @@ +/* + * 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: + * + * 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 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 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. + */ + +#include "config.h" + +#if ENABLE(3D_CANVAS) || ENABLE(BLOB) + +#include "DataView.h" + +namespace { + +template<typename T> +union Value { + T data; + char bytes[sizeof(T)]; +}; + +} + +namespace WebCore { + +PassRefPtr<DataView> DataView::create(PassRefPtr<ArrayBuffer> buffer, unsigned byteOffset, unsigned byteLength) +{ + if (byteOffset + byteLength > buffer->byteLength()) + return 0; + return adoptRef(new DataView(buffer, byteOffset, byteLength)); +} + +DataView::DataView(PassRefPtr<ArrayBuffer> buffer, unsigned byteOffset, unsigned byteLength) + : ArrayBufferView(buffer, byteOffset) + , m_byteLength(byteLength) +{ +} + +static bool needToFlipBytes(bool littleEndian) +{ +#if CPU(BIG_ENDIAN) + return littleEndian; +#else + return !littleEndian; +#endif +} + +inline void swapBytes(char* p, char* q) +{ + char temp = *p; + *p = *q; + *q = temp; +} + +static void flipBytesFor16Bits(char* p) +{ + swapBytes(p, p + 1); +} + +static void flipBytesFor32Bits(char* p) +{ + swapBytes(p, p + 3); + swapBytes(p + 1, p + 2); +} + +static void flipBytesFor64Bits(char* p) +{ + swapBytes(p, p + 7); + swapBytes(p + 1, p + 6); + swapBytes(p + 2, p + 5); + swapBytes(p + 3, p + 4); +} + +static void flipBytesIfNeeded(char* value, size_t size, bool littleEndian) +{ + if (!needToFlipBytes(littleEndian)) + return; + + switch (size) { + case 1: + // Nothing to do. + break; + case 2: + flipBytesFor16Bits(value); + break; + case 4: + flipBytesFor32Bits(value); + break; + case 8: + flipBytesFor64Bits(value); + break; + default: + ASSERT_NOT_REACHED(); + break; + } +} + +template<typename T> +T DataView::getData(unsigned byteOffset, bool littleEndian, ExceptionCode& ec) const +{ + if (beyondRange<T>(byteOffset)) { + ec = INDEX_SIZE_ERR; + return 0; + } + + // We do not want to load the data directly since it would cause a bus error on architectures that don't support unaligned loads. + Value<T> value; + memcpy(value.bytes, static_cast<const char*>(m_baseAddress) + byteOffset, sizeof(T)); + flipBytesIfNeeded(value.bytes, sizeof(T), littleEndian); + return value.data; +} + +template<typename T> +void DataView::setData(unsigned byteOffset, T value, bool littleEndian, ExceptionCode& ec) +{ + if (beyondRange<T>(byteOffset)) { + ec = INDEX_SIZE_ERR; + return; + } + + // We do not want to store the data directly since it would cause a bus error on architectures that don't support unaligned stores. + Value<T> tempValue; + tempValue.data = value; + flipBytesIfNeeded(tempValue.bytes, sizeof(T), littleEndian); + memcpy(static_cast<char*>(m_baseAddress) + byteOffset, tempValue.bytes, sizeof(T)); +} + +char DataView::getInt8(unsigned byteOffset, ExceptionCode& ec) +{ + return getData<char>(byteOffset, false, ec); +} + +unsigned char DataView::getUint8(unsigned byteOffset, ExceptionCode& ec) +{ + return getData<unsigned char>(byteOffset, false, ec); +} + +short DataView::getInt16(unsigned byteOffset, bool littleEndian, ExceptionCode& ec) +{ + return getData<short>(byteOffset, littleEndian, ec); +} + +unsigned short DataView::getUint16(unsigned byteOffset, bool littleEndian, ExceptionCode& ec) +{ + return getData<unsigned short>(byteOffset, littleEndian, ec); +} + +int DataView::getInt32(unsigned byteOffset, bool littleEndian, ExceptionCode& ec) +{ + return getData<int>(byteOffset, littleEndian, ec); +} + +unsigned DataView::getUint32(unsigned byteOffset, bool littleEndian, ExceptionCode& ec) +{ + return getData<unsigned>(byteOffset, littleEndian, ec); +} + +float DataView::getFloat32(unsigned byteOffset, bool littleEndian, ExceptionCode& ec) +{ + return getData<float>(byteOffset, littleEndian, ec); +} + +double DataView::getFloat64(unsigned byteOffset, bool littleEndian, ExceptionCode& ec) +{ + return getData<double>(byteOffset, littleEndian, ec); +} + +void DataView::setInt8(unsigned byteOffset, char value, ExceptionCode& ec) +{ + setData<char>(byteOffset, value, false, ec); +} + +void DataView::setUint8(unsigned byteOffset, unsigned char value, ExceptionCode& ec) +{ + setData<unsigned char>(byteOffset, value, false, ec); +} + +void DataView::setInt16(unsigned byteOffset, short value, bool littleEndian, ExceptionCode& ec) +{ + setData<short>(byteOffset, value, littleEndian, ec); +} + +void DataView::setUint16(unsigned byteOffset, unsigned short value, bool littleEndian, ExceptionCode& ec) +{ + setData<unsigned short>(byteOffset, value, littleEndian, ec); +} + +void DataView::setInt32(unsigned byteOffset, int value, bool littleEndian, ExceptionCode& ec) +{ + setData<int>(byteOffset, value, littleEndian, ec); +} + +void DataView::setUint32(unsigned byteOffset, unsigned value, bool littleEndian, ExceptionCode& ec) +{ + setData<unsigned>(byteOffset, value, littleEndian, ec); +} + +void DataView::setFloat32(unsigned byteOffset, float value, bool littleEndian, ExceptionCode& ec) +{ + setData<float>(byteOffset, value, littleEndian, ec); +} + +void DataView::setFloat64(unsigned byteOffset, double value, bool littleEndian, ExceptionCode& ec) +{ + setData<double>(byteOffset, value, littleEndian, ec); +} + +} + +#endif // ENABLE(3D_CANVAS) || ENABLE(BLOB) |