boost/asio/detail/buffered_stream_storage.hpp
//
// buffered_stream_storage.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2008 Christopher M. Kohlhoff (chris at kohlhoff 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 BOOST_ASIO_DETAIL_BUFFERED_STREAM_STORAGE_HPP
#define BOOST_ASIO_DETAIL_BUFFERED_STREAM_STORAGE_HPP
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
#include <boost/asio/detail/push_options.hpp>
#include <boost/asio/detail/push_options.hpp>
#include <boost/config.hpp>
#include <cassert>
#include <cstddef>
#include <cstring>
#include <vector>
#include <boost/asio/detail/pop_options.hpp>
namespace boost {
namespace asio {
namespace detail {
class buffered_stream_storage
{
public:
// The type of the bytes stored in the buffer.
typedef unsigned char byte_type;
// The type used for offsets into the buffer.
typedef std::size_t size_type;
// Constructor.
explicit buffered_stream_storage(std::size_t capacity)
: begin_offset_(0),
end_offset_(0),
buffer_(capacity)
{
}
/// Clear the buffer.
void clear()
{
begin_offset_ = 0;
end_offset_ = 0;
}
// Return a pointer to the beginning of the unread data.
byte_type* data()
{
return &buffer_[0] + begin_offset_;
}
// Return a pointer to the beginning of the unread data.
const byte_type* data() const
{
return &buffer_[0] + begin_offset_;
}
// Is there no unread data in the buffer.
bool empty() const
{
return begin_offset_ == end_offset_;
}
// Return the amount of unread data the is in the buffer.
size_type size() const
{
return end_offset_ - begin_offset_;
}
// Resize the buffer to the specified length.
void resize(size_type length)
{
assert(length <= capacity());
if (begin_offset_ + length <= capacity())
{
end_offset_ = begin_offset_ + length;
}
else
{
using namespace std; // For memmove.
memmove(&buffer_[0], &buffer_[0] + begin_offset_, size());
end_offset_ = length;
begin_offset_ = 0;
}
}
// Return the maximum size for data in the buffer.
size_type capacity() const
{
return buffer_.size();
}
// Consume multiple bytes from the beginning of the buffer.
void consume(size_type count)
{
assert(begin_offset_ + count <= end_offset_);
begin_offset_ += count;
if (empty())
clear();
}
private:
// The offset to the beginning of the unread data.
size_type begin_offset_;
// The offset to the end of the unread data.
size_type end_offset_;
// The data in the buffer.
std::vector<byte_type> buffer_;
};
} // namespace detail
} // namespace asio
} // namespace boost
#include <boost/asio/detail/pop_options.hpp>
#endif // BOOST_ASIO_DETAIL_BUFFERED_STREAM_STORAGE_HPP