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// Copyright 2014 MongoDB Inc.
//
// 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.
#pragma once
#include <cstdlib>
#include <memory>
#include <bsoncxx/document/view.hpp>
#include <bsoncxx/config/prelude.hpp>
namespace bsoncxx {
BSONCXX_INLINE_NAMESPACE_BEGIN
namespace document {
///
/// A read-only BSON document that owns its underlying buffer. When a document::value goes
/// out of scope, the underlying buffer is freed. Generally this class should be used
/// sparingly; document::view should be used instead wherever possible.
///
class BSONCXX_API value {
public:
using deleter_type = void (*)(std::uint8_t*);
using unique_ptr_type = std::unique_ptr<uint8_t[], deleter_type>;
///
/// Constructs a value from a buffer.
/// This constructor transfers ownership of the buffer to the resulting
/// value. A user-provided deleter is used to destroy the buffer.
///
/// @param data
/// A pointer to a buffer containing a valid BSON document.
/// @param length
/// The length of the document.
/// @param dtor
/// A user provided deleter.
///
value(std::uint8_t* data, std::size_t length, deleter_type dtor);
///
/// Constructs a value from a std::unique_ptr to a buffer. The ownership
/// of the buffer is transferred to the constructed value.
///
/// @param ptr
/// A pointer to a buffer containing a valid BSON document.
/// @param length
/// The length of the document.
///
value(unique_ptr_type ptr, std::size_t length);
///
/// Constructs a value from a view of a document. The data referenced
/// by the document::view will be copied into a new buffer managed by the
/// constructed value.
///
/// @param view
/// A view of another document to copy.
///
explicit value(document::view view);
value(const value&);
value& operator=(const value&);
value(value&&) noexcept = default;
value& operator=(value&&) noexcept = default;
///
/// Get a view over the document owned by this value.
///
BSONCXX_INLINE document::view view() const noexcept;
///
/// Conversion operator that provides a view given a value.
///
/// @return A view over the value.
///
BSONCXX_INLINE operator document::view() const noexcept;
///
/// Transfer ownership of the underlying buffer to the caller.
///
/// @warning
/// After calling release() it is illegal to call any methods
/// on this class, unless it is subsequently moved into.
///
/// @return A std::unique_ptr with ownership of the buffer.
///
unique_ptr_type release();
private:
unique_ptr_type _data;
std::size_t _length{0};
};
BSONCXX_INLINE document::view value::view() const noexcept {
return document::view{static_cast<uint8_t*>(_data.get()), _length};
}
BSONCXX_INLINE value::operator document::view() const noexcept {
return view();
}
} // namespace document
BSONCXX_INLINE_NAMESPACE_END
} // namespace bsoncxx
#include <bsoncxx/config/postlude.hpp>