| /* |
| * 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" |
| #include "core/html/canvas/DataView.h" |
| |
| #include "bindings/v8/ExceptionState.h" |
| #include "core/dom/ExceptionCode.h" |
| #include "platform/CheckedInt.h" |
| #include "wtf/CPU.h" |
| |
| namespace { |
| |
| template<typename T> |
| union Value { |
| T data; |
| char bytes[sizeof(T)]; |
| }; |
| |
| } |
| |
| namespace WebCore { |
| |
| PassRefPtr<DataView> DataView::create(unsigned length) |
| { |
| RefPtr<ArrayBuffer> buffer = ArrayBuffer::create(length, sizeof(uint8_t)); |
| if (!buffer.get()) |
| return 0; |
| return create(buffer, 0, length); |
| } |
| |
| PassRefPtr<DataView> DataView::create(PassRefPtr<ArrayBuffer> buffer, unsigned byteOffset, unsigned byteLength) |
| { |
| if (byteOffset > buffer->byteLength()) |
| return 0; |
| CheckedInt<uint32_t> checkedOffset(byteOffset); |
| CheckedInt<uint32_t> checkedLength(byteLength); |
| CheckedInt<uint32_t> checkedMax = checkedOffset + checkedLength; |
| if (!checkedMax.isValid() || checkedMax.value() > 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) |
| { |
| ScriptWrappable::init(this); |
| } |
| |
| 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, ExceptionState& exceptionState) const |
| { |
| if (beyondRange<T>(byteOffset)) { |
| exceptionState.throwUninformativeAndGenericDOMException(IndexSizeError); |
| 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, ExceptionState& exceptionState) |
| { |
| if (beyondRange<T>(byteOffset)) { |
| exceptionState.throwUninformativeAndGenericDOMException(IndexSizeError); |
| 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)); |
| } |
| |
| int8_t DataView::getInt8(unsigned byteOffset, ExceptionState& exceptionState) |
| { |
| return getData<int8_t>(byteOffset, false, exceptionState); |
| } |
| |
| uint8_t DataView::getUint8(unsigned byteOffset, ExceptionState& exceptionState) |
| { |
| return getData<uint8_t>(byteOffset, false, exceptionState); |
| } |
| |
| int16_t DataView::getInt16(unsigned byteOffset, bool littleEndian, ExceptionState& exceptionState) |
| { |
| return getData<int16_t>(byteOffset, littleEndian, exceptionState); |
| } |
| |
| uint16_t DataView::getUint16(unsigned byteOffset, bool littleEndian, ExceptionState& exceptionState) |
| { |
| return getData<uint16_t>(byteOffset, littleEndian, exceptionState); |
| } |
| |
| int32_t DataView::getInt32(unsigned byteOffset, bool littleEndian, ExceptionState& exceptionState) |
| { |
| return getData<int32_t>(byteOffset, littleEndian, exceptionState); |
| } |
| |
| uint32_t DataView::getUint32(unsigned byteOffset, bool littleEndian, ExceptionState& exceptionState) |
| { |
| return getData<uint32_t>(byteOffset, littleEndian, exceptionState); |
| } |
| |
| float DataView::getFloat32(unsigned byteOffset, bool littleEndian, ExceptionState& exceptionState) |
| { |
| return getData<float>(byteOffset, littleEndian, exceptionState); |
| } |
| |
| double DataView::getFloat64(unsigned byteOffset, bool littleEndian, ExceptionState& exceptionState) |
| { |
| return getData<double>(byteOffset, littleEndian, exceptionState); |
| } |
| |
| void DataView::setInt8(unsigned byteOffset, int8_t value, ExceptionState& exceptionState) |
| { |
| setData<int8_t>(byteOffset, value, false, exceptionState); |
| } |
| |
| void DataView::setUint8(unsigned byteOffset, uint8_t value, ExceptionState& exceptionState) |
| { |
| setData<uint8_t>(byteOffset, value, false, exceptionState); |
| } |
| |
| void DataView::setInt16(unsigned byteOffset, short value, bool littleEndian, ExceptionState& exceptionState) |
| { |
| setData<int16_t>(byteOffset, value, littleEndian, exceptionState); |
| } |
| |
| void DataView::setUint16(unsigned byteOffset, uint16_t value, bool littleEndian, ExceptionState& exceptionState) |
| { |
| setData<uint16_t>(byteOffset, value, littleEndian, exceptionState); |
| } |
| |
| void DataView::setInt32(unsigned byteOffset, int32_t value, bool littleEndian, ExceptionState& exceptionState) |
| { |
| setData<int32_t>(byteOffset, value, littleEndian, exceptionState); |
| } |
| |
| void DataView::setUint32(unsigned byteOffset, uint32_t value, bool littleEndian, ExceptionState& exceptionState) |
| { |
| setData<uint32_t>(byteOffset, value, littleEndian, exceptionState); |
| } |
| |
| void DataView::setFloat32(unsigned byteOffset, float value, bool littleEndian, ExceptionState& exceptionState) |
| { |
| setData<float>(byteOffset, value, littleEndian, exceptionState); |
| } |
| |
| void DataView::setFloat64(unsigned byteOffset, double value, bool littleEndian, ExceptionState& exceptionState) |
| { |
| setData<double>(byteOffset, value, littleEndian, exceptionState); |
| } |
| |
| void DataView::neuter() |
| { |
| ArrayBufferView::neuter(); |
| m_byteLength = 0; |
| } |
| |
| } |