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// Copyright 2020 The Dawn & Tint Authors
//
// 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.
//
// 3. Neither the name of the copyright holder nor the names of its
// contributors may be used to endorse or promote products derived from
// this software without specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT HOLDER 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 "dawn/wire/ChunkedCommandHandler.h"
#include <algorithm>
#include <cstring>
#include <utility>
#include "dawn/common/Alloc.h"
namespace dawn::wire {
ChunkedCommandHandler::ChunkedCommandHandler() = default;
ChunkedCommandHandler::~ChunkedCommandHandler() = default;
const volatile char* ChunkedCommandHandler::HandleCommands(const volatile char* commands,
size_t size) {
if (mChunkedCommandRemainingSize > 0) {
// If there is a chunked command in flight, append the command data.
// We append at most |mChunkedCommandRemainingSize| which is enough to finish the
// in-flight chunked command, and then pass the rest along to a second call to
// |HandleCommandsImpl|.
size_t chunkSize = std::min(size, mChunkedCommandRemainingSize);
memcpy(mChunkedCommandData.get() + mChunkedCommandPutOffset,
const_cast<const char*>(commands), chunkSize);
mChunkedCommandPutOffset += chunkSize;
mChunkedCommandRemainingSize -= chunkSize;
commands += chunkSize;
size -= chunkSize;
if (mChunkedCommandRemainingSize == 0) {
// Once the chunked command is complete, pass the data to the command handler
// implemenation.
auto chunkedCommandData = std::move(mChunkedCommandData);
if (HandleCommandsImpl(chunkedCommandData.get(), mChunkedCommandPutOffset) == nullptr) {
// |HandleCommandsImpl| returns nullptr on error. Forward any errors
// out.
return nullptr;
}
}
}
return HandleCommandsImpl(commands, size);
}
ChunkedCommandHandler::ChunkedCommandsResult ChunkedCommandHandler::BeginChunkedCommandData(
const volatile char* commands,
size_t commandSize,
size_t initialSize) {
DAWN_ASSERT(!mChunkedCommandData);
// Reserve space for all the command data we're expecting, and copy the initial data
// to the start of the memory.
mChunkedCommandData.reset(AllocNoThrow<char>(commandSize));
if (!mChunkedCommandData) {
return ChunkedCommandsResult::Error;
}
memcpy(mChunkedCommandData.get(), const_cast<const char*>(commands), initialSize);
mChunkedCommandPutOffset = initialSize;
mChunkedCommandRemainingSize = commandSize - initialSize;
return ChunkedCommandsResult::Consumed;
}
} // namespace dawn::wire