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- // Copyright (c) 2012 The Chromium Authors. All rights reserved.
- // Use of this source code is governed by a BSD-style license that can be
- // found in the LICENSE file.
- #ifndef REMOTING_BASE_TYPED_BUFFER_H_
- #define REMOTING_BASE_TYPED_BUFFER_H_
- #include <assert.h>
- #include <stdint.h>
- #include <algorithm>
- #include "base/memory/raw_ptr.h"
- namespace remoting {
- // A scoper for a variable-length structure such as SID, SECURITY_DESCRIPTOR and
- // similar. These structures typically consist of a header followed by variable-
- // length data, so the size may not match sizeof(T). The class supports
- // move-only semantics and typed buffer getters.
- template <typename T>
- class TypedBuffer {
- public:
- TypedBuffer() : TypedBuffer(0) {}
- // Creates an instance of the object allocating a buffer of the given size.
- explicit TypedBuffer(uint32_t length) : buffer_(nullptr), length_(length) {
- if (length_ > 0)
- buffer_ = reinterpret_cast<T*>(new uint8_t[length_]);
- }
- TypedBuffer(TypedBuffer&& rvalue) : TypedBuffer() { Swap(rvalue); }
- TypedBuffer(const TypedBuffer&) = delete;
- TypedBuffer& operator=(const TypedBuffer&) = delete;
- ~TypedBuffer() {
- if (buffer_) {
- delete[] reinterpret_cast<uint8_t*>(buffer_.get());
- buffer_ = nullptr;
- }
- }
- TypedBuffer& operator=(TypedBuffer&& rvalue) {
- Swap(rvalue);
- return *this;
- }
- // Accessors to get the owned buffer.
- // operator* and operator-> will assert() if there is no current buffer.
- T& operator*() const {
- assert(buffer_);
- return *buffer_;
- }
- T* operator->() const {
- assert(buffer_);
- return buffer_;
- }
- T* get() const { return buffer_; }
- uint32_t length() const { return length_; }
- // Helper returning a pointer to the structure starting at a specified byte
- // offset.
- T* GetAtOffset(uint32_t offset) {
- return reinterpret_cast<T*>(reinterpret_cast<uint8_t*>(buffer_.get()) +
- offset);
- }
- // Allow TypedBuffer<T> to be used in boolean expressions.
- explicit operator bool() const { return buffer_ != nullptr; }
- // Swap two buffers.
- void Swap(TypedBuffer& other) {
- std::swap(buffer_, other.buffer_);
- std::swap(length_, other.length_);
- }
- private:
- // Points to the owned buffer.
- raw_ptr<T> buffer_;
- // Length of the owned buffer in bytes.
- uint32_t length_;
- };
- } // namespace remoting
- #endif // REMOTING_BASE_TYPED_BUFFER_H_
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