premiere-libtorrent/include/libtorrent/disk_io_thread.hpp

154 lines
4.1 KiB
C++

/*
Copyright (c) 2007, Arvid Norberg
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.
*/
#ifdef TORRENT_DISK_STATS
#include <fstream>
#endif
#include "libtorrent/storage.hpp"
#include <boost/thread/thread.hpp>
#include <boost/function.hpp>
#include <boost/thread/mutex.hpp>
#include <boost/bind.hpp>
#include <boost/pool/pool.hpp>
#include <boost/noncopyable.hpp>
#include "libtorrent/config.hpp"
namespace libtorrent
{
struct disk_io_job
{
disk_io_job()
: action(read)
, buffer(0)
, buffer_size(0)
, piece(0)
, offset(0)
, priority(0)
{}
enum action_t
{
read
, write
, hash
, move_storage
, release_files
, delete_files
};
action_t action;
char* buffer;
size_type buffer_size;
boost::intrusive_ptr<piece_manager> storage;
// arguments used for read and write
int piece, offset;
// used for move_storage. On errors, this is set
// to the error message
std::string str;
// priority decides whether or not this
// job will skip entries in the queue or
// not. It always skips in front of entries
// with lower priority
int priority;
// this is called when operation completes
boost::function<void(int, disk_io_job const&)> callback;
};
// this is a singleton consisting of the thread and a queue
// of disk io jobs
struct disk_io_thread : boost::noncopyable
{
disk_io_thread(int block_size = 16 * 1024);
~disk_io_thread();
#ifdef TORRENT_STATS
int disk_allocations() const
{ return m_allocations; }
#endif
// aborts read operations
void stop(boost::intrusive_ptr<piece_manager> s);
void add_job(disk_io_job const& j
, boost::function<void(int, disk_io_job const&)> const& f
= boost::function<void(int, disk_io_job const&)>());
#ifndef NDEBUG
disk_io_job find_job(boost::intrusive_ptr<piece_manager> s
, int action, int piece) const;
#endif
// keep track of the number of bytes in the job queue
// at any given time. i.e. the sum of all buffer_size.
// this is used to slow down the download global download
// speed when the queue buffer size is too big.
size_type queue_buffer_size() const
{ return m_queue_buffer_size; }
void operator()();
char* allocate_buffer();
void free_buffer(char* buf);
private:
mutable boost::mutex m_mutex;
boost::condition m_signal;
bool m_abort;
std::deque<disk_io_job> m_jobs;
size_type m_queue_buffer_size;
// memory pool for read and write operations
boost::pool<> m_pool;
#ifndef NDEBUG
int m_block_size;
disk_io_job m_current;
#endif
#ifdef TORRENT_DISK_STATS
std::ofstream m_log;
#endif
#ifdef TORRENT_STATS
int m_allocations;
#endif
// thread for performing blocking disk io operations
boost::thread m_disk_io_thread;
};
}