143 lines
4.2 KiB
C++
143 lines
4.2 KiB
C++
/*
|
|
|
|
Copyright (c) 2010-2016, Arvid Norberg, Daniel Wallin.
|
|
All rights reserved.
|
|
|
|
Redistribution and use in source and binary forms, with or without
|
|
modification, are permitted provided that the following conditions
|
|
are met:
|
|
|
|
* Redistributions of source code must retain the above copyright
|
|
notice, this list of conditions and the following disclaimer.
|
|
* Redistributions in binary form must reproduce the above copyright
|
|
notice, this list of conditions and the following disclaimer in
|
|
the documentation and/or other materials provided with the distribution.
|
|
* Neither the name of the author nor the names of its
|
|
contributors may be used to endorse or promote products derived
|
|
from this software without specific prior written permission.
|
|
|
|
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
|
|
LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
|
CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
|
POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
*/
|
|
|
|
#ifndef TORRENT_PACKET_BUFFER_HPP_INCLUDED
|
|
#define TORRENT_PACKET_BUFFER_HPP_INCLUDED
|
|
|
|
#include "libtorrent/config.hpp"
|
|
#include <boost/cstdint.hpp>
|
|
#include <cstddef>
|
|
|
|
namespace libtorrent
|
|
{
|
|
// this is a circular buffer that automatically resizes
|
|
// itself as elements are inserted. Elements are indexed
|
|
// by integers and are assumed to be sequential. Unless the
|
|
// old elements are removed when new elements are inserted,
|
|
// the buffer will be resized.
|
|
|
|
// m_capacity is the number of elements in m_array
|
|
// and must be an even 2^x.
|
|
// m_first is the lowest index that has an element
|
|
// it also determines which indices the other slots
|
|
// refers to. Since it's a circular buffer, it wraps
|
|
// around. For example
|
|
|
|
// m_first = 9
|
|
// | refers to index 14
|
|
// | |
|
|
// V V
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// | | | | | | | | | | | | | | | | | mask = (m_capacity-1)
|
|
// +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|
|
// ^
|
|
// |
|
|
// refers to index 15
|
|
|
|
// whenever the element at the cursor is removed, the
|
|
// cursor is bumped to the next occupied element
|
|
|
|
class TORRENT_EXTRA_EXPORT packet_buffer_impl
|
|
{
|
|
public:
|
|
typedef boost::uint32_t index_type;
|
|
|
|
packet_buffer_impl();
|
|
~packet_buffer_impl();
|
|
|
|
void* insert(index_type idx, void* value);
|
|
|
|
std::size_t size() const
|
|
{ return m_size; }
|
|
|
|
std::size_t capacity() const
|
|
{ return m_capacity; }
|
|
|
|
void* at(index_type idx) const;
|
|
|
|
void* remove(index_type idx);
|
|
|
|
void reserve(std::size_t size);
|
|
|
|
index_type cursor() const
|
|
{ return m_first; }
|
|
|
|
index_type span() const
|
|
{ return (m_last - m_first) & 0xffff; }
|
|
|
|
#if TORRENT_USE_INVARIANT_CHECKS
|
|
void check_invariant() const;
|
|
#endif
|
|
|
|
private:
|
|
void** m_storage;
|
|
std::size_t m_capacity;
|
|
|
|
// this is the total number of elements that are occupied
|
|
// in the array
|
|
std::size_t m_size;
|
|
|
|
// This defines the first index that is part of the m_storage.
|
|
// last is one passed the last used slot
|
|
index_type m_first;
|
|
index_type m_last;
|
|
};
|
|
|
|
template <typename T>
|
|
class packet_buffer : packet_buffer_impl
|
|
{
|
|
public:
|
|
|
|
using packet_buffer_impl::index_type;
|
|
using packet_buffer_impl::size;
|
|
using packet_buffer_impl::capacity;
|
|
using packet_buffer_impl::reserve;
|
|
using packet_buffer_impl::cursor;
|
|
using packet_buffer_impl::span;
|
|
|
|
T* insert(index_type i, T* p)
|
|
{
|
|
return static_cast<T*>(packet_buffer_impl::insert(i, p));
|
|
}
|
|
|
|
T* at(index_type idx) const
|
|
{ return static_cast<T*>(packet_buffer_impl::at(idx)); }
|
|
|
|
T* remove(index_type idx)
|
|
{ return static_cast<T*>(packet_buffer_impl::remove(idx)); }
|
|
};
|
|
|
|
}
|
|
|
|
#endif // TORRENT_PACKET_BUFFER_HPP_INCLUDED
|
|
|