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+/*
+ * Copyright (C) 2009, 2013 Apple 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 INC. ``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 INC. 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 ArrayBuffer_h
+#define ArrayBuffer_h
+
+#include "GCIncomingRefCounted.h"
+#include "Weak.h"
+#include <wtf/PassRefPtr.h>
+#include <wtf/StdLibExtras.h>
+#include <wtf/Vector.h>
+
+namespace JSC {
+
+class ArrayBuffer;
+class ArrayBufferView;
+class JSArrayBuffer;
+
+class ArrayBufferContents {
+ WTF_MAKE_NONCOPYABLE(ArrayBufferContents);
+public:
+ ArrayBufferContents()
+ : m_data(0)
+ , m_sizeInBytes(0)
+ { }
+
+ inline ~ArrayBufferContents();
+
+ void* data() { return m_data; }
+ unsigned sizeInBytes() { return m_sizeInBytes; }
+
+private:
+ ArrayBufferContents(void* data, unsigned sizeInBytes)
+ : m_data(data)
+ , m_sizeInBytes(sizeInBytes)
+ { }
+
+ friend class ArrayBuffer;
+
+ enum InitializationPolicy {
+ ZeroInitialize,
+ DontInitialize
+ };
+
+ static inline void tryAllocate(unsigned numElements, unsigned elementByteSize, InitializationPolicy, ArrayBufferContents&);
+ void transfer(ArrayBufferContents& other)
+ {
+ ASSERT(!other.m_data);
+ other.m_data = m_data;
+ other.m_sizeInBytes = m_sizeInBytes;
+ m_data = 0;
+ m_sizeInBytes = 0;
+ }
+
+ void copyTo(ArrayBufferContents& other)
+ {
+ ASSERT(!other.m_data);
+ ArrayBufferContents::tryAllocate(m_sizeInBytes, sizeof(char), ArrayBufferContents::DontInitialize, other);
+ if (!other.m_data)
+ return;
+ memcpy(other.m_data, m_data, m_sizeInBytes);
+ other.m_sizeInBytes = m_sizeInBytes;
+ }
+
+ void* m_data;
+ unsigned m_sizeInBytes;
+};
+
+class ArrayBuffer : public GCIncomingRefCounted<ArrayBuffer> {
+public:
+ static inline PassRefPtr<ArrayBuffer> create(unsigned numElements, unsigned elementByteSize);
+ static inline PassRefPtr<ArrayBuffer> create(ArrayBuffer*);
+ static inline PassRefPtr<ArrayBuffer> create(const void* source, unsigned byteLength);
+ static inline PassRefPtr<ArrayBuffer> create(ArrayBufferContents&);
+ static inline PassRefPtr<ArrayBuffer> createAdopted(const void* data, unsigned byteLength);
+
+ // Only for use by Uint8ClampedArray::createUninitialized and SharedBuffer::createArrayBuffer.
+ static inline PassRefPtr<ArrayBuffer> createUninitialized(unsigned numElements, unsigned elementByteSize);
+
+ inline void* data();
+ inline const void* data() const;
+ inline unsigned byteLength() const;
+
+ inline size_t gcSizeEstimateInBytes() const;
+
+ inline PassRefPtr<ArrayBuffer> slice(int begin, int end) const;
+ inline PassRefPtr<ArrayBuffer> slice(int begin) const;
+
+ inline void pin();
+ inline void unpin();
+
+ JS_EXPORT_PRIVATE bool transfer(ArrayBufferContents&);
+ bool isNeutered() { return !m_contents.m_data; }
+
+ static ptrdiff_t offsetOfData() { return OBJECT_OFFSETOF(ArrayBuffer, m_contents) + OBJECT_OFFSETOF(ArrayBufferContents, m_data); }
+
+ ~ArrayBuffer() { }
+
+private:
+ static inline PassRefPtr<ArrayBuffer> create(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy);
+
+ inline ArrayBuffer(ArrayBufferContents&);
+ inline PassRefPtr<ArrayBuffer> sliceImpl(unsigned begin, unsigned end) const;
+ inline unsigned clampIndex(int index) const;
+ static inline int clampValue(int x, int left, int right);
+
+ unsigned m_pinCount;
+ ArrayBufferContents m_contents;
+
+public:
+ Weak<JSArrayBuffer> m_wrapper;
+};
+
+int ArrayBuffer::clampValue(int x, int left, int right)
+{
+ ASSERT(left <= right);
+ if (x < left)
+ x = left;
+ if (right < x)
+ x = right;
+ return x;
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::create(unsigned numElements, unsigned elementByteSize)
+{
+ return create(numElements, elementByteSize, ArrayBufferContents::ZeroInitialize);
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::create(ArrayBuffer* other)
+{
+ return ArrayBuffer::create(other->data(), other->byteLength());
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::create(const void* source, unsigned byteLength)
+{
+ ArrayBufferContents contents;
+ ArrayBufferContents::tryAllocate(byteLength, 1, ArrayBufferContents::ZeroInitialize, contents);
+ if (!contents.m_data)
+ return 0;
+ RefPtr<ArrayBuffer> buffer = adoptRef(new ArrayBuffer(contents));
+ ASSERT(!byteLength || source);
+ memcpy(buffer->data(), source, byteLength);
+ return buffer.release();
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::create(ArrayBufferContents& contents)
+{
+ return adoptRef(new ArrayBuffer(contents));
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::createAdopted(const void* data, unsigned byteLength)
+{
+ ArrayBufferContents contents(const_cast<void*>(data), byteLength);
+ return create(contents);
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::createUninitialized(unsigned numElements, unsigned elementByteSize)
+{
+ return create(numElements, elementByteSize, ArrayBufferContents::DontInitialize);
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::create(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy policy)
+{
+ ArrayBufferContents contents;
+ ArrayBufferContents::tryAllocate(numElements, elementByteSize, policy, contents);
+ if (!contents.m_data)
+ return 0;
+ return adoptRef(new ArrayBuffer(contents));
+}
+
+ArrayBuffer::ArrayBuffer(ArrayBufferContents& contents)
+ : m_pinCount(0)
+{
+ contents.transfer(m_contents);
+}
+
+void* ArrayBuffer::data()
+{
+ return m_contents.m_data;
+}
+
+const void* ArrayBuffer::data() const
+{
+ return m_contents.m_data;
+}
+
+unsigned ArrayBuffer::byteLength() const
+{
+ return m_contents.m_sizeInBytes;
+}
+
+size_t ArrayBuffer::gcSizeEstimateInBytes() const
+{
+ return sizeof(ArrayBuffer) + static_cast<size_t>(byteLength());
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::slice(int begin, int end) const
+{
+ return sliceImpl(clampIndex(begin), clampIndex(end));
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::slice(int begin) const
+{
+ return sliceImpl(clampIndex(begin), byteLength());
+}
+
+PassRefPtr<ArrayBuffer> ArrayBuffer::sliceImpl(unsigned begin, unsigned end) const
+{
+ unsigned size = begin <= end ? end - begin : 0;
+ return ArrayBuffer::create(static_cast<const char*>(data()) + begin, size);
+}
+
+unsigned ArrayBuffer::clampIndex(int index) const
+{
+ unsigned currentLength = byteLength();
+ if (index < 0)
+ index = currentLength + index;
+ return clampValue(index, 0, currentLength);
+}
+
+void ArrayBuffer::pin()
+{
+ m_pinCount++;
+}
+
+void ArrayBuffer::unpin()
+{
+ m_pinCount--;
+}
+
+void ArrayBufferContents::tryAllocate(unsigned numElements, unsigned elementByteSize, ArrayBufferContents::InitializationPolicy policy, ArrayBufferContents& result)
+{
+ // Do not allow 31-bit overflow of the total size.
+ if (numElements) {
+ unsigned totalSize = numElements * elementByteSize;
+ if (totalSize / numElements != elementByteSize
+ || totalSize > static_cast<unsigned>(std::numeric_limits<int32_t>::max())) {
+ result.m_data = 0;
+ return;
+ }
+ }
+ bool allocationSucceeded = false;
+ if (policy == ZeroInitialize)
+ allocationSucceeded = WTF::tryFastCalloc(numElements, elementByteSize).getValue(result.m_data);
+ else {
+ ASSERT(policy == DontInitialize);
+ allocationSucceeded = WTF::tryFastMalloc(numElements * elementByteSize).getValue(result.m_data);
+ }
+
+ if (allocationSucceeded) {
+ result.m_sizeInBytes = numElements * elementByteSize;
+ return;
+ }
+ result.m_data = 0;
+}
+
+ArrayBufferContents::~ArrayBufferContents()
+{
+ WTF::fastFree(m_data);
+}
+
+} // namespace JSC
+
+using JSC::ArrayBuffer;
+
+#endif // ArrayBuffer_h
+