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/*
* Copyright (C) 2018 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef NETUTILS_MEMBLOCK_H
#define NETUTILS_MEMBLOCK_H
#include <memory>
#include "netdutils/Slice.h"
namespace android {
namespace netdutils {
// A class to encapsulate self-deleting byte arrays while preserving access
// to the underlying length (without the length being part of the type, e.g.
// std::array<>). By design, the only interface to the underlying bytes is
// via Slice, to encourage safer memory access usage.
//
// No thread-safety guarantees whatsoever.
class MemBlock {
public:
MemBlock() : MemBlock(0U) {}
explicit MemBlock(size_t len)
: mData((len > 0U) ? new uint8_t[len]{} : nullptr),
mLen(len) {}
// Allocate memory of size src.size() and copy src into this MemBlock.
explicit MemBlock(Slice src) : MemBlock(src.size()) {
copy(get(), src);
}
// No copy construction or assignment.
MemBlock(const MemBlock&) = delete;
MemBlock& operator=(const MemBlock&) = delete;
// Move construction and assignment are okay.
MemBlock(MemBlock&&) = default;
MemBlock& operator=(MemBlock&&) = default;
// Even though this method is const, the memory wrapped by the
// returned Slice is mutable.
Slice get() const noexcept { return Slice(mData.get(), mLen); }
// Implicit cast to Slice.
// NOLINTNEXTLINE(google-explicit-constructor)
operator const Slice() const noexcept { return get(); }
private:
std::unique_ptr<uint8_t[]> mData;
size_t mLen;
};
} // namespace netdutils
} // namespace android
#endif /* NETUTILS_MEMBLOCK_H */