mirror of
https://github.com/XRPLF/rippled.git
synced 2025-11-20 02:55:50 +00:00
123 lines
3.5 KiB
C++
123 lines
3.5 KiB
C++
//
|
|
// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
|
|
#ifndef BEAST_CONSUMING_BUFFERS_HPP
|
|
#define BEAST_CONSUMING_BUFFERS_HPP
|
|
|
|
#include <boost/asio/buffer.hpp>
|
|
#include <cstdint>
|
|
#include <iterator>
|
|
#include <type_traits>
|
|
#include <utility>
|
|
|
|
namespace beast {
|
|
|
|
/** Adapter to trim the front of a `BufferSequence`.
|
|
|
|
This adapter wraps a buffer sequence to create a new sequence
|
|
which may be incrementally consumed. Bytes consumed are removed
|
|
from the front of the buffer. The underlying memory is not changed,
|
|
instead the adapter efficiently iterates through a subset of
|
|
the buffers wrapped.
|
|
|
|
The wrapped buffer is not modified, a copy is made instead.
|
|
Ownership of the underlying memory is not transferred, the application
|
|
is still responsible for managing its lifetime.
|
|
|
|
@tparam Buffers The buffer sequence to wrap.
|
|
|
|
@ptaram ValueType The type of buffer of the final buffer sequence. This
|
|
can be different from the buffer type of the wrapped sequence. For
|
|
example, a `MutableBufferSequence` can be transformed into a
|
|
consumable `ConstBufferSequence`. Violations of buffer const safety
|
|
are not permitted, and will result in a compile error.
|
|
*/
|
|
template<class Buffers,
|
|
class ValueType = typename Buffers::value_type>
|
|
class consuming_buffers
|
|
{
|
|
using iter_type =
|
|
typename Buffers::const_iterator;
|
|
|
|
static_assert(std::is_constructible<ValueType,
|
|
typename std::iterator_traits<iter_type>::value_type>::value,
|
|
"ValueType requirements not met");
|
|
|
|
Buffers bs_;
|
|
iter_type begin_;
|
|
std::size_t skip_ = 0;
|
|
|
|
template<class Deduced>
|
|
consuming_buffers(Deduced&& other, std::size_t nbegin)
|
|
: bs_(std::forward<Deduced>(other).bs_)
|
|
, begin_(std::next(bs_.begin(), nbegin))
|
|
, skip_(other.skip_)
|
|
{
|
|
}
|
|
|
|
public:
|
|
/// The type for each element in the list of buffers.
|
|
using value_type = ValueType;
|
|
|
|
#if GENERATING_DOCS
|
|
/// A bidirectional iterator type that may be used to read elements.
|
|
using const_iterator = implementation_defined;
|
|
|
|
#else
|
|
class const_iterator;
|
|
|
|
#endif
|
|
|
|
/// Move constructor.
|
|
consuming_buffers(consuming_buffers&&);
|
|
|
|
/// Copy constructor.
|
|
consuming_buffers(consuming_buffers const&);
|
|
|
|
/// Move assignment.
|
|
consuming_buffers& operator=(consuming_buffers&&);
|
|
|
|
/// Copy assignment.
|
|
consuming_buffers& operator=(consuming_buffers const&);
|
|
|
|
/** Construct to represent a buffer sequence.
|
|
|
|
A copy of the buffer sequence is made. Ownership of the
|
|
underlying memory is not transferred or copied.
|
|
*/
|
|
explicit
|
|
consuming_buffers(Buffers const& buffers);
|
|
|
|
/// Get a bidirectional iterator to the first element.
|
|
const_iterator
|
|
begin() const;
|
|
|
|
/// Get a bidirectional iterator for one past the last element.
|
|
const_iterator
|
|
end() const;
|
|
|
|
/** Remove bytes from the beginning of the sequence.
|
|
|
|
@param n The number of bytes to remove. If this is
|
|
larger than the number of bytes remaining, all the
|
|
bytes remaining are removed.
|
|
*/
|
|
void
|
|
consume(std::size_t n);
|
|
};
|
|
|
|
/// Returns a consumed buffer
|
|
template<class Buffers>
|
|
consuming_buffers<Buffers, typename Buffers::value_type>
|
|
consumed_buffers(Buffers const& bs, std::size_t n);
|
|
|
|
} // beast
|
|
|
|
#include <beast/impl/consuming_buffers.ipp>
|
|
|
|
#endif
|