74 lines
2.3 KiB
C++
74 lines
2.3 KiB
C++
// Copyright 2021 The Dawn Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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#ifndef DAWNWIRE_BUFFERCONSUMER_IMPL_H_
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#define DAWNWIRE_BUFFERCONSUMER_IMPL_H_
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#include "dawn_wire/BufferConsumer.h"
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#include <limits>
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#include <type_traits>
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namespace dawn_wire {
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template <typename BufferT>
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template <typename T>
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WireResult BufferConsumer<BufferT>::Peek(T** data) {
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if (sizeof(T) > mSize) {
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return WireResult::FatalError;
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}
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*data = reinterpret_cast<T*>(mBuffer);
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return WireResult::Success;
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}
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template <typename BufferT>
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template <typename T>
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WireResult BufferConsumer<BufferT>::Next(T** data) {
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if (sizeof(T) > mSize) {
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return WireResult::FatalError;
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}
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*data = reinterpret_cast<T*>(mBuffer);
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mBuffer += sizeof(T);
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mSize -= sizeof(T);
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return WireResult::Success;
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}
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template <typename BufferT>
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template <typename T, typename N>
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WireResult BufferConsumer<BufferT>::NextN(N count, T** data) {
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static_assert(std::is_unsigned<N>::value, "|count| argument of NextN must be unsigned.");
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constexpr size_t kMaxCountWithoutOverflows = std::numeric_limits<size_t>::max() / sizeof(T);
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if (count > kMaxCountWithoutOverflows) {
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return WireResult::FatalError;
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}
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// Cannot overflow because |count| is not greater than |kMaxCountWithoutOverflows|.
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size_t totalSize = sizeof(T) * count;
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if (totalSize > mSize) {
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return WireResult::FatalError;
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}
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*data = reinterpret_cast<T*>(mBuffer);
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mBuffer += totalSize;
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mSize -= totalSize;
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return WireResult::Success;
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}
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} // namespace dawn_wire
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#endif // DAWNWIRE_BUFFERCONSUMER_IMPL_H_
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