diff -r 000000000000 -r 4f2f89ce4247 WebCore/platform/SharedBuffer.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/WebCore/platform/SharedBuffer.cpp	Fri Sep 17 09:02:29 2010 +0300
@@ -0,0 +1,273 @@
+/*
+ * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
+ * Copyright (C) Research In Motion Limited 2009-2010. 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 COMPUTER, 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 COMPUTER, 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. 
+ */
+
+#include "config.h"
+#include "SharedBuffer.h"
+
+#include "PurgeableBuffer.h"
+#include <wtf/PassOwnPtr.h>
+
+using namespace std;
+
+namespace WebCore {
+
+static const unsigned segmentSize = 0x1000;
+static const unsigned segmentPositionMask = 0x0FFF;
+
+static inline unsigned segmentIndex(unsigned position)
+{
+    return position / segmentSize;
+}
+
+static inline unsigned offsetInSegment(unsigned position)
+{
+    return position & segmentPositionMask;
+}
+
+static inline char* allocateSegment()
+{
+    return static_cast<char*>(fastMalloc(segmentSize));
+}
+
+static inline void freeSegment(char* p)
+{
+    fastFree(p);
+}
+
+SharedBuffer::SharedBuffer()
+    : m_size(0)
+{
+}
+
+SharedBuffer::SharedBuffer(const char* data, int size)
+    : m_size(0)
+{
+    append(data, size);
+}
+
+SharedBuffer::SharedBuffer(const unsigned char* data, int size)
+    : m_size(0)
+{
+    append(reinterpret_cast<const char*>(data), size);
+}
+    
+SharedBuffer::~SharedBuffer()
+{
+    clear();
+}
+
+PassRefPtr<SharedBuffer> SharedBuffer::adoptVector(Vector<char>& vector)
+{
+    RefPtr<SharedBuffer> buffer = create();
+    buffer->m_buffer.swap(vector);
+    buffer->m_size = buffer->m_buffer.size();
+    return buffer.release();
+}
+
+PassRefPtr<SharedBuffer> SharedBuffer::adoptPurgeableBuffer(PassOwnPtr<PurgeableBuffer> purgeableBuffer) 
+{ 
+    ASSERT(!purgeableBuffer->isPurgeable());
+    RefPtr<SharedBuffer> buffer = create();
+    buffer->m_purgeableBuffer = purgeableBuffer;
+    return buffer.release();
+}
+
+unsigned SharedBuffer::size() const
+{
+    if (hasPlatformData())
+        return platformDataSize();
+    
+    if (m_purgeableBuffer)
+        return m_purgeableBuffer->size();
+    
+    return m_size;
+}
+
+const char* SharedBuffer::data() const
+{
+    if (hasPlatformData())
+        return platformData();
+    
+    if (m_purgeableBuffer)
+        return m_purgeableBuffer->data();
+    
+    return buffer().data();
+}
+
+void SharedBuffer::append(const char* data, unsigned length)
+{
+    ASSERT(!m_purgeableBuffer);
+
+    maybeTransferPlatformData();
+    
+    unsigned positionInSegment = offsetInSegment(m_size - m_buffer.size());
+    m_size += length;
+
+    if (m_size <= segmentSize) {
+        // No need to use segments for small resource data
+        m_buffer.append(data, length);
+        return;
+    }
+
+    char* segment;
+    if (!positionInSegment) {
+        segment = allocateSegment();
+        m_segments.append(segment);
+    } else
+        segment = m_segments.last() + positionInSegment;
+
+    unsigned segmentFreeSpace = segmentSize - positionInSegment;
+    unsigned bytesToCopy = min(length, segmentFreeSpace);
+
+    for (;;) {
+        memcpy(segment, data, bytesToCopy);
+        if (static_cast<unsigned>(length) == bytesToCopy)
+            break;
+
+        length -= bytesToCopy;
+        data += bytesToCopy;
+        segment = allocateSegment();
+        m_segments.append(segment);
+        bytesToCopy = min(length, segmentSize);
+    }
+}
+
+void SharedBuffer::clear()
+{
+    clearPlatformData();
+    
+    for (unsigned i = 0; i < m_segments.size(); ++i)
+        freeSegment(m_segments[i]);
+
+    m_segments.clear();
+    m_size = 0;
+
+    m_buffer.clear();
+    m_purgeableBuffer.clear();
+}
+
+PassRefPtr<SharedBuffer> SharedBuffer::copy() const
+{
+    RefPtr<SharedBuffer> clone(adoptRef(new SharedBuffer));
+    if (m_purgeableBuffer || hasPlatformData()) {
+        clone->append(data(), size());
+        return clone;
+    }
+
+    clone->m_size = m_size;
+    clone->m_buffer.reserveCapacity(m_size);
+    clone->m_buffer.append(m_buffer.data(), m_buffer.size());
+    for (unsigned i = 0; i < m_segments.size(); ++i)
+        clone->m_buffer.append(m_segments[i], segmentSize);
+    return clone;
+}
+
+PassOwnPtr<PurgeableBuffer> SharedBuffer::releasePurgeableBuffer()
+{ 
+    ASSERT(hasOneRef()); 
+    return m_purgeableBuffer.release(); 
+}
+
+const Vector<char>& SharedBuffer::buffer() const
+{
+    unsigned bufferSize = m_buffer.size();
+    if (m_size > bufferSize) {
+        m_buffer.resize(m_size);
+        char* destination = m_buffer.data() + bufferSize;
+        unsigned bytesLeft = m_size - bufferSize;
+        for (unsigned i = 0; i < m_segments.size(); ++i) {
+            unsigned bytesToCopy = min(bytesLeft, segmentSize);
+            memcpy(destination, m_segments[i], bytesToCopy);
+            destination += bytesToCopy;
+            bytesLeft -= bytesToCopy;
+            freeSegment(m_segments[i]);
+        }
+        m_segments.clear();
+    }
+    return m_buffer;
+}
+
+unsigned SharedBuffer::getSomeData(const char*& someData, unsigned position) const
+{
+    if (hasPlatformData() || m_purgeableBuffer) {
+        someData = data() + position;
+        return size() - position;
+    }
+
+    if (position >= m_size) {
+        someData = 0;
+        return 0;
+    }
+
+    unsigned consecutiveSize = m_buffer.size();
+    if (position < consecutiveSize) {
+        someData = m_buffer.data() + position;
+        return consecutiveSize - position;
+    }
+ 
+    position -= consecutiveSize;
+    unsigned segmentedSize = m_size - consecutiveSize;
+    unsigned segments = m_segments.size();
+    unsigned segment = segmentIndex(position);
+    ASSERT(segment < segments);
+
+    unsigned positionInSegment = offsetInSegment(position);
+    someData = m_segments[segment] + positionInSegment;
+    return segment == segments - 1 ? segmentedSize - position : segmentSize - positionInSegment;
+}
+
+#if !PLATFORM(CF)
+
+inline void SharedBuffer::clearPlatformData()
+{
+}
+
+inline void SharedBuffer::maybeTransferPlatformData()
+{
+}
+
+inline bool SharedBuffer::hasPlatformData() const
+{
+    return false;
+}
+
+inline const char* SharedBuffer::platformData() const
+{
+    ASSERT_NOT_REACHED();
+
+    return 0;
+}
+
+inline unsigned SharedBuffer::platformDataSize() const
+{
+    ASSERT_NOT_REACHED();
+    
+    return 0;
+}
+
+#endif
+
+}