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authorShimeng (Simon) Wang <swang@google.com>2010-12-07 17:22:45 -0800
committerShimeng (Simon) Wang <swang@google.com>2010-12-22 14:15:40 -0800
commit4576aa36e9a9671459299c7963ac95aa94beaea9 (patch)
tree3863574e050f168c0126ecb47c83319fab0972d8 /WebCore/html/canvas/DataView.cpp
parent55323ac613cc31553107b68603cb627264d22bb0 (diff)
downloadexternal_webkit-4576aa36e9a9671459299c7963ac95aa94beaea9.zip
external_webkit-4576aa36e9a9671459299c7963ac95aa94beaea9.tar.gz
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Merge WebKit at r73109: Initial merge by git.
Change-Id: I61f1a66d9642e3d8405d3ac6ccab2a53421c75d8
Diffstat (limited to 'WebCore/html/canvas/DataView.cpp')
-rwxr-xr-xWebCore/html/canvas/DataView.cpp228
1 files changed, 228 insertions, 0 deletions
diff --git a/WebCore/html/canvas/DataView.cpp b/WebCore/html/canvas/DataView.cpp
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+++ b/WebCore/html/canvas/DataView.cpp
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+/*
+ * 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)