130 lines
4.4 KiB
C++
130 lines
4.4 KiB
C++
/*
|
|
|
|
Copyright (c) 2008-2018, 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.
|
|
|
|
*/
|
|
|
|
#ifndef TORRENT_DISK_BUFFER_HOLDER_HPP_INCLUDED
|
|
#define TORRENT_DISK_BUFFER_HOLDER_HPP_INCLUDED
|
|
|
|
#include "libtorrent/config.hpp"
|
|
#include "libtorrent/assert.hpp"
|
|
#include "libtorrent/disk_io_job.hpp" // for block_cache_reference
|
|
#include <algorithm>
|
|
|
|
#include "libtorrent/aux_/disable_warnings_push.hpp"
|
|
|
|
#include <boost/shared_ptr.hpp>
|
|
#include <boost/function.hpp>
|
|
|
|
#include "libtorrent/aux_/disable_warnings_pop.hpp"
|
|
|
|
namespace libtorrent
|
|
{
|
|
struct disk_io_thread;
|
|
struct disk_observer;
|
|
|
|
struct TORRENT_EXTRA_EXPORT buffer_allocator_interface
|
|
{
|
|
virtual char* allocate_disk_buffer(char const* category) = 0;
|
|
virtual void free_disk_buffer(char* b) = 0;
|
|
virtual void reclaim_block(block_cache_reference ref) = 0;
|
|
virtual char* allocate_disk_buffer(bool& exceeded
|
|
, boost::shared_ptr<disk_observer> o
|
|
, char const* category) = 0;
|
|
protected:
|
|
~buffer_allocator_interface() {}
|
|
};
|
|
|
|
// The disk buffer holder acts like a ``scoped_ptr`` that frees a disk buffer
|
|
// when it's destructed, unless it's released. ``release`` returns the disk
|
|
// buffer and transfers ownership and responsibility to free it to the caller.
|
|
//
|
|
// A disk buffer is freed by passing it to ``session_impl::free_disk_buffer()``.
|
|
//
|
|
// ``get()`` returns the pointer without transferring responsibility. If
|
|
// this buffer has been released, ``buffer()`` will return 0.
|
|
struct TORRENT_EXPORT disk_buffer_holder
|
|
{
|
|
// internal
|
|
disk_buffer_holder(buffer_allocator_interface& alloc, char* buf);
|
|
|
|
// construct a buffer holder that will free the held buffer
|
|
// using a disk buffer pool directly (there's only one
|
|
// disk_buffer_pool per session)
|
|
disk_buffer_holder(buffer_allocator_interface& alloc, disk_io_job const& j);
|
|
|
|
// frees any unreleased disk buffer held by this object
|
|
~disk_buffer_holder();
|
|
|
|
// return the held disk buffer and clear it from the
|
|
// holder. The responsibility to free it is passed on
|
|
// to the caller
|
|
char* release();
|
|
|
|
// return a pointer to the held buffer
|
|
char* get() const { return m_buf; }
|
|
|
|
// set the holder object to hold the specified buffer
|
|
// (or NULL by default). If it's already holding a
|
|
// disk buffer, it will first be freed.
|
|
void reset(char* buf = 0);
|
|
void reset(disk_io_job const& j);
|
|
|
|
// swap pointers of two disk buffer holders.
|
|
void swap(disk_buffer_holder& h)
|
|
{
|
|
TORRENT_ASSERT(&h.m_allocator == &m_allocator);
|
|
std::swap(h.m_buf, m_buf);
|
|
std::swap(h.m_ref, m_ref);
|
|
}
|
|
|
|
block_cache_reference ref() const { return m_ref; }
|
|
|
|
typedef char* (disk_buffer_holder::*unspecified_bool_type)();
|
|
|
|
// internal
|
|
operator unspecified_bool_type() const
|
|
{ return m_buf == 0? 0: &disk_buffer_holder::release; }
|
|
|
|
private:
|
|
// non-copyable
|
|
disk_buffer_holder& operator=(disk_buffer_holder const&);
|
|
disk_buffer_holder(disk_buffer_holder const*);
|
|
|
|
buffer_allocator_interface& m_allocator;
|
|
char* m_buf;
|
|
block_cache_reference m_ref;
|
|
};
|
|
|
|
}
|
|
|
|
#endif
|
|
|