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/*
* Copyright (C) 2012 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. 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 INC. 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 "ShareableResource.h"
#if ENABLE(SHAREABLE_RESOURCE)
#include "SharedBuffer.h"
#include <wtf/CheckedArithmetic.h>
namespace WebCore {
ShareableResourceHandle::ShareableResourceHandle(SharedMemory::Handle&& handle, unsigned offset, unsigned size)
: m_handle(WTFMove(handle))
, m_offset(offset)
, m_size(size)
{
}
RefPtr<SharedBuffer> ShareableResource::wrapInSharedBuffer()
{
return SharedBuffer::create(DataSegment::Provider {
[self = Ref { *this }]() { return self->span(); }
});
}
RefPtr<SharedBuffer> ShareableResourceHandle::tryWrapInSharedBuffer() &&
{
RefPtr<ShareableResource> resource = ShareableResource::map(WTFMove(*this));
if (!resource) {
LOG_ERROR("Failed to recreate ShareableResource from handle.");
return nullptr;
}
return resource->wrapInSharedBuffer();
}
RefPtr<ShareableResource> ShareableResource::create(Ref<SharedMemory>&& sharedMemory, unsigned offset, unsigned size)
{
auto totalSize = CheckedSize(offset) + size;
if (totalSize.hasOverflowed()) {
LOG_ERROR("Failed to create ShareableResource from SharedMemory due to overflow.");
return nullptr;
}
if (totalSize > sharedMemory->size()) {
LOG_ERROR("Failed to create ShareableResource from SharedMemory due to mismatched buffer size.");
return nullptr;
}
return adoptRef(*new ShareableResource(WTFMove(sharedMemory), offset, size));
}
RefPtr<ShareableResource> ShareableResource::map(Handle&& handle)
{
auto sharedMemory = SharedMemory::map(WTFMove(handle.m_handle), SharedMemory::Protection::ReadOnly);
if (!sharedMemory)
return nullptr;
return create(sharedMemory.releaseNonNull(), handle.m_offset, handle.m_size);
}
ShareableResource::ShareableResource(Ref<SharedMemory>&& sharedMemory, unsigned offset, unsigned size)
: m_sharedMemory(WTFMove(sharedMemory))
, m_offset(offset)
, m_size(size)
{
}
ShareableResource::~ShareableResource() = default;
auto ShareableResource::createHandle() -> std::optional<Handle>
{
auto memoryHandle = m_sharedMemory->createHandle(SharedMemory::Protection::ReadOnly);
if (!memoryHandle)
return std::nullopt;
return { Handle { WTFMove(*memoryHandle), m_offset, m_size } };
}
std::span<const uint8_t> ShareableResource::span() const
{
return m_sharedMemory->span().subspan(m_offset, m_size);
}
unsigned ShareableResource::size() const
{
return m_size;
}
} // namespace WebCore
#endif // ENABLE(SHAREABLE_RESOURCE)
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