// Try to create a PurgeableBuffer. We can fail to create one for any of the
// following reasons:
// - shouldUsePurgeableMemory is set to false.
// - the size of the buffer is less than the minimum size required by
// PurgeableBuffer (currently 16k).
// - PurgeableBuffer::createUninitialized() call fails.
void SharedBuffer::createPurgeableBuffer() const
{
if (m_purgeableBuffer)
return;
if (hasPlatformData())
return;
#if USE(NETWORK_CFDATA_ARRAY_CALLBACK)
if (singleDataArrayBuffer())
return;
#endif
if (!m_buffer->hasOneRef())
return;
if (!m_shouldUsePurgeableMemory)
return;
char* destination = 0;
m_purgeableBuffer = PurgeableBuffer::createUninitialized(m_size, destination);
if (!m_purgeableBuffer)
return;
unsigned bufferSize = m_buffer->data.size();
if (bufferSize) {
memcpy(destination, m_buffer->data.data(), bufferSize);
destination += bufferSize;
(const_cast<SharedBuffer*>(this))->clearDataBuffer();
}
copyBufferAndClear(destination, m_size - bufferSize);
}
const char* SharedBuffer::data() const
{
if (hasPlatformData())
return platformData();
#if USE(NETWORK_CFDATA_ARRAY_CALLBACK)
if (const char* buffer = singleDataArrayBuffer())
return buffer;
#endif
return this->buffer().data();
}
void SharedBuffer::createPurgeableBuffer() const
{
if (m_purgeableBuffer)
return;
if (hasPlatformData())
return;
#if USE(NETWORK_CFDATA_ARRAY_CALLBACK)
if (singleDataArrayBuffer())
return;
#endif
m_purgeableBuffer = PurgeableBuffer::create(buffer().data(), m_size);
}
const char* SharedBuffer::data() const
{
#if ENABLE(DISK_IMAGE_CACHE)
if (isMemoryMapped())
return static_cast<const char*>(diskImageCache().dataForItem(m_diskImageCacheId));
#endif
if (hasPlatformData())
return platformData();
#if USE(NETWORK_CFDATA_ARRAY_CALLBACK)
if (const char* buffer = singleDataArrayBuffer())
return buffer;
#endif
createPurgeableBuffer();
if (m_purgeableBuffer)
return m_purgeableBuffer->data();
return this->buffer().data();
}
