2014-07-06 21:18:00 +02:00
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/*
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2016-01-18 00:57:46 +01:00
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Copyright (c) 2010-2016, Arvid Norberg
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2014-07-06 21:18:00 +02:00
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All rights reserved.
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Redistribution and use in source and binary forms, with or without
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modification, are permitted provided that the following conditions
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are met:
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* Redistributions of source code must retain the above copyright
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notice, this list of conditions and the following disclaimer.
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* Redistributions in binary form must reproduce the above copyright
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notice, this list of conditions and the following disclaimer in
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the documentation and/or other materials provided with the distribution.
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* Neither the name of the author nor the names of its
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contributors may be used to endorse or promote products derived
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from this software without specific prior written permission.
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef TORRENT_BLOCK_CACHE
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#define TORRENT_BLOCK_CACHE
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2016-08-29 14:31:23 +02:00
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#include <cstdint>
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#include <list>
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#include <vector>
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2016-09-07 05:37:36 +02:00
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#include <unordered_set>
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2016-08-29 14:31:23 +02:00
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2014-07-06 21:18:00 +02:00
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#include "libtorrent/time.hpp"
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#include "libtorrent/error_code.hpp"
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#include "libtorrent/io_service_fwd.hpp"
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#include "libtorrent/hasher.hpp"
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#include "libtorrent/sliding_average.hpp"
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#include "libtorrent/tailqueue.hpp"
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#include "libtorrent/linked_list.hpp"
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#include "libtorrent/disk_buffer_pool.hpp"
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#include "libtorrent/file.hpp" // for iovec_t
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#include "libtorrent/disk_io_job.hpp"
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2017-01-15 00:53:25 +01:00
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#if TORRENT_USE_ASSERTS
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#include "libtorrent/aux_/vector.hpp"
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#endif
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2014-07-06 21:18:00 +02:00
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namespace libtorrent
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{
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struct disk_io_job;
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2016-11-13 03:45:30 +01:00
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struct storage_interface;
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2014-07-06 21:18:00 +02:00
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struct cache_status;
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struct counters;
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2016-11-18 06:25:27 +01:00
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namespace aux
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{
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struct session_settings;
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struct block_cache_reference;
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}
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2014-07-06 21:18:00 +02:00
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#if TORRENT_USE_ASSERTS
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class file_storage;
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#endif
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2016-09-28 05:21:18 +02:00
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#if TORRENT_USE_ASSERTS || !defined TORRENT_DISABLE_LOGGING
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2014-07-06 21:18:00 +02:00
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struct piece_log_t
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{
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2016-10-08 20:07:11 +02:00
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explicit piece_log_t(int j, int b= -1): job(j), block(b) {}
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2014-07-06 21:18:00 +02:00
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int job;
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int block;
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// these are "jobs" thar cause piece_refcount
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// to be incremented
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enum artificial_jobs
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{
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flushing = disk_io_job::num_job_ids, // 20
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flush_expired,
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try_flush_write_blocks,
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try_flush_write_blocks2,
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flush_range,
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clear_outstanding_jobs,
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set_outstanding_jobs,
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last_job
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};
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2015-04-22 06:24:45 +02:00
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static char const* const job_names[7];
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2014-07-06 21:18:00 +02:00
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};
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char const* job_name(int j);
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2016-09-28 05:21:18 +02:00
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#endif // TORRENT_DISABLE_LOGGING
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#if TORRENT_USE_ASSERTS
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2017-01-15 00:53:25 +01:00
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void print_piece_log(aux::vector<piece_log_t> const& piece_log);
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2015-04-21 02:23:00 +02:00
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void assert_print_piece(cached_piece_entry const* pe);
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2014-07-06 21:18:00 +02:00
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#endif
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2015-04-22 06:24:45 +02:00
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extern const char* const job_action_name[];
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2015-04-21 02:23:00 +02:00
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2014-07-06 21:18:00 +02:00
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struct TORRENT_EXTRA_EXPORT partial_hash
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{
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partial_hash(): offset(0) {}
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// the number of bytes in the piece that has been hashed
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int offset;
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// the sha-1 context
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hasher h;
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};
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struct cached_block_entry
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{
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cached_block_entry()
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: buf(0)
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, refcount(0)
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, dirty(false)
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, pending(false)
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{
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}
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char* buf;
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2014-09-15 00:42:18 +02:00
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enum { max_refcount = (1 << 30) - 1 };
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2014-07-06 21:18:00 +02:00
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// the number of references to this buffer. These references
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2016-03-15 01:43:52 +01:00
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// might be in outstanding asynchronous requests or in peer
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2014-07-06 21:18:00 +02:00
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// connection send buffers. We can't free the buffer until
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// all references are gone and refcount reaches 0. The buf
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// pointer in this struct doesn't count as a reference and
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// is always the last to be cleared
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2016-06-18 20:01:38 +02:00
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std::uint32_t refcount:30;
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2014-07-06 21:18:00 +02:00
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// if this is true, this block needs to be written to
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// disk before it's freed. Typically all blocks in a piece
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// would either be dirty (write coalesce cache) or not dirty
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// (read-ahead cache). Once blocks are written to disk, the
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// dirty flag is cleared and effectively turns the block
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// into a read cache block
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2016-06-18 20:01:38 +02:00
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std::uint32_t dirty:1;
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2014-07-06 21:18:00 +02:00
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// pending means that this buffer has not yet been filled in
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// with valid data. There's an outstanding read job for this.
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// If the dirty flag is set, it means there's an outstanding
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// write job to write this block.
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2016-06-18 20:01:38 +02:00
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std::uint32_t pending:1;
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2014-07-06 21:18:00 +02:00
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#if TORRENT_USE_ASSERTS
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// this many of the references are held by hashing operations
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2016-12-22 16:42:33 +01:00
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int hashing_count = 0;
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2014-07-06 21:18:00 +02:00
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// this block is being used in this many peer's send buffers currently
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2016-12-22 16:42:33 +01:00
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int reading_count = 0;
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2014-07-06 21:18:00 +02:00
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// the number of references held by flushing operations
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2016-12-22 16:42:33 +01:00
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int flushing_count = 0;
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2014-07-06 21:18:00 +02:00
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#endif
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};
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// list_node is here to be able to link this cache entry
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// into one of the LRU lists
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2015-08-20 02:02:46 +02:00
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struct TORRENT_EXTRA_EXPORT cached_piece_entry : list_node<cached_piece_entry>
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2014-07-06 21:18:00 +02:00
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{
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cached_piece_entry();
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~cached_piece_entry();
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2016-10-21 13:37:15 +02:00
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cached_piece_entry(cached_piece_entry&&) = default;
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cached_piece_entry& operator=(cached_piece_entry&&) = default;
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2014-07-06 21:18:00 +02:00
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bool ok_to_evict(bool ignore_hash = false) const
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{
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return refcount == 0
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&& piece_refcount == 0
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&& num_blocks == 0
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&& !hashing
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&& read_jobs.size() == 0
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2014-09-15 00:42:18 +02:00
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&& outstanding_read == 0
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2014-07-06 21:18:00 +02:00
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&& (ignore_hash || !hash || hash->offset == 0);
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}
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// storage this piece belongs to
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2016-11-13 03:45:30 +01:00
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std::shared_ptr<storage_interface> storage;
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2014-07-06 21:18:00 +02:00
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// write jobs hanging off of this piece
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2015-08-19 15:22:00 +02:00
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tailqueue<disk_io_job> jobs;
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2014-07-06 21:18:00 +02:00
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// read jobs waiting for the read job currently outstanding
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// on this piece to complete. These are executed at that point.
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2015-08-19 15:22:00 +02:00
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tailqueue<disk_io_job> read_jobs;
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2014-07-06 21:18:00 +02:00
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2016-12-22 16:42:33 +01:00
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piece_index_t get_piece() const { return piece; }
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2014-07-06 21:18:00 +02:00
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void* get_storage() const { return storage.get(); }
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bool operator==(cached_piece_entry const& rhs) const
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{ return storage.get() == rhs.storage.get() && piece == rhs.piece; }
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// if this is set, we'll be calculating the hash
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// for this piece. This member stores the interim
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2016-01-02 17:24:07 +01:00
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// state while we're calculating the hash.
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2016-10-21 13:37:15 +02:00
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std::unique_ptr<partial_hash> hash;
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2014-07-06 21:18:00 +02:00
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// set to a unique identifier of a peer that last
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// requested from this piece.
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2016-10-21 13:37:15 +02:00
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void* last_requester = nullptr;
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2014-07-06 21:18:00 +02:00
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// the pointers to the block data. If this is a ghost
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// cache entry, there won't be any data here
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2016-10-21 13:37:15 +02:00
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std::unique_ptr<cached_block_entry[]> blocks;
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2014-07-06 21:18:00 +02:00
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// the last time a block was written to this piece
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// plus the minimum amount of time the block is guaranteed
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// to stay in the cache
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//TODO: make this 32 bits and to count seconds since the block cache was created
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2016-10-21 13:37:15 +02:00
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time_point expire = min_time();
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2014-07-06 21:18:00 +02:00
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2016-12-22 16:42:33 +01:00
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piece_index_t piece;
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2014-07-06 21:18:00 +02:00
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// the number of dirty blocks in this piece
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2016-06-18 20:01:38 +02:00
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std::uint64_t num_dirty:14;
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2015-05-19 05:13:49 +02:00
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2014-07-06 21:18:00 +02:00
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// the number of blocks in the cache for this piece
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2016-06-18 20:01:38 +02:00
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std::uint64_t num_blocks:14;
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2014-07-06 21:18:00 +02:00
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// the total number of blocks in this piece (and the number
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// of elements in the blocks array)
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2016-06-18 20:01:38 +02:00
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std::uint64_t blocks_in_piece:14;
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2014-07-06 21:18:00 +02:00
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// ---- 64 bit boundary ----
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// while we have an outstanding async hash operation
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// working on this piece, 'hashing' is set to 1
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// When the operation returns, this is set to 0.
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2016-10-21 13:37:15 +02:00
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std::uint16_t hashing:1;
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2014-07-06 21:18:00 +02:00
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// if we've completed at least one hash job on this
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// piece, and returned it. This is set to one
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2016-10-21 13:37:15 +02:00
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std::uint16_t hashing_done:1;
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2014-07-06 21:18:00 +02:00
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2015-06-14 21:48:11 +02:00
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// if this is true, whenever refcount hits 0,
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2014-07-06 21:18:00 +02:00
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// this piece should be deleted
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2016-10-21 13:37:15 +02:00
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std::uint16_t marked_for_deletion:1;
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2014-07-06 21:18:00 +02:00
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// this is set to true once we flush blocks past
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// the hash cursor. Once this happens, there's
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// no point in keeping cache blocks around for
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// it in avoid_readback mode
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2016-10-21 13:37:15 +02:00
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std::uint16_t need_readback:1;
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2014-07-06 21:18:00 +02:00
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// indicates which LRU list this piece is chained into
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enum cache_state_t
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{
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2016-10-19 07:18:05 +02:00
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// not added to the cache
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none,
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2014-07-06 21:18:00 +02:00
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// this is the LRU list for pieces with dirty blocks
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write_lru,
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// this is the LRU list for volatile pieces. i.e.
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// pieces with very low cache priority. These are
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// always the first ones to be evicted.
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volatile_read_lru,
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// this is the LRU list for read blocks that have
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// been requested once
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read_lru1,
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// the is the LRU list for read blocks that have
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// been requested once recently, but then was evicted.
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// if these are requested again, they will be moved
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// to list 2, the frequently requested pieces
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read_lru1_ghost,
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// this is the LRU of frequently used pieces. Any
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// piece that has been requested by a second peer
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// while pulled in to list 1 by a different peer
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// is moved into this list
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read_lru2,
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// this is the LRU of frequently used pieces but
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// that has been recently evicted. If a piece in
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// this list is requested, it's moved back into list 2.
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read_lru2_ghost,
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num_lrus
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};
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2016-10-21 13:37:15 +02:00
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std::uint16_t cache_state:3;
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2014-07-06 21:18:00 +02:00
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// this is the number of threads that are currently holding
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// a reference to this piece. A piece may not be removed from
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// the cache while this is > 0
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2016-10-21 13:37:15 +02:00
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std::uint16_t piece_refcount:7;
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2014-07-06 21:18:00 +02:00
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// if this is set to one, it means there is an outstanding
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// flush_hashed job for this piece, and there's no need to
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// issue another one.
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2016-10-21 13:37:15 +02:00
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std::uint16_t outstanding_flush:1;
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2014-07-06 21:18:00 +02:00
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// as long as there is a read operation outstanding on this
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// piece, this is set to 1. Otherwise 0.
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// the purpose is to make sure not two threads are reading
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// the same blocks at the same time. If a new read job is
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// added when this is 1, that new job should be hung on the
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// read job queue (read_jobs).
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2016-10-21 13:37:15 +02:00
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std::uint16_t outstanding_read:1;
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2014-07-06 21:18:00 +02:00
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// the number of blocks that have >= 1 refcount
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2016-10-21 13:37:15 +02:00
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std::uint16_t pinned = 0;
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2014-07-06 21:18:00 +02:00
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2015-06-14 21:48:11 +02:00
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// ---- 32 bit boundary ---
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2014-07-06 21:18:00 +02:00
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// the sum of all refcounts in all blocks
|
2016-11-27 14:46:53 +01:00
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|
std::int32_t refcount = 0;
|
2014-07-06 21:18:00 +02:00
|
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|
#if TORRENT_USE_ASSERTS
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// the number of times this piece has finished hashing
|
2016-10-19 07:18:05 +02:00
|
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|
int hash_passes = 0;
|
2014-07-06 21:18:00 +02:00
|
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|
|
// this is a debug facility to keep a log
|
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|
// of which operations have been run on this piece
|
2017-01-15 00:53:25 +01:00
|
|
|
aux::vector<piece_log_t> piece_log;
|
2014-07-06 21:18:00 +02:00
|
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|
2016-10-19 07:18:05 +02:00
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bool in_storage = false;
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bool in_use = true;
|
2014-07-06 21:18:00 +02:00
|
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|
#endif
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};
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struct TORRENT_EXTRA_EXPORT block_cache : disk_buffer_pool
|
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{
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block_cache(int block_size, io_service& ios
|
2016-08-13 03:31:55 +02:00
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, std::function<void()> const& trigger_trim);
|
2014-07-06 21:18:00 +02:00
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private:
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|
2016-09-07 05:37:36 +02:00
|
|
|
struct hash_value
|
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{
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|
std::size_t operator()(cached_piece_entry const& p) const
|
2017-01-15 00:53:25 +01:00
|
|
|
{ return reinterpret_cast<std::size_t>(p.storage.get()) + std::size_t(static_cast<int>(p.piece)); }
|
2016-09-07 05:37:36 +02:00
|
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};
|
2016-11-27 14:46:53 +01:00
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|
using cache_t = std::unordered_set<cached_piece_entry, hash_value>;
|
2014-07-06 21:18:00 +02:00
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public:
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|
2016-11-27 14:46:53 +01:00
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using const_iterator = cache_t::const_iterator;
|
2014-07-06 21:18:00 +02:00
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// returns the number of blocks this job would cause to be read in
|
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|
int pad_job(disk_io_job const* j, int blocks_in_piece
|
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, int read_ahead) const;
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|
2017-01-02 08:00:20 +01:00
|
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|
void reclaim_block(storage_interface* st, aux::block_cache_reference const& ref);
|
2014-07-06 21:18:00 +02:00
|
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|
2016-09-06 04:25:20 +02:00
|
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|
// returns a range of all pieces. This might be a very
|
2014-07-06 21:18:00 +02:00
|
|
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// long list, use carefully
|
2016-09-07 05:37:36 +02:00
|
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|
std::pair<const_iterator, const_iterator> all_pieces() const;
|
2015-11-19 01:51:17 +01:00
|
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|
int num_pieces() const { return int(m_pieces.size()); }
|
2014-07-06 21:18:00 +02:00
|
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|
2015-08-20 02:02:46 +02:00
|
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|
list_iterator<cached_piece_entry> write_lru_pieces() const
|
2014-07-06 21:18:00 +02:00
|
|
|
{ return m_lru[cached_piece_entry::write_lru].iterate(); }
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|
2016-11-27 14:46:53 +01:00
|
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|
int num_write_lru_pieces() const { return m_lru[cached_piece_entry::write_lru].size(); }
|
2014-07-06 21:18:00 +02:00
|
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|
|
// mark this piece for deletion. If there are no outstanding
|
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|
|
// requests to this piece, it's removed immediately, and the
|
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|
|
// passed in iterator will be invalidated
|
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|
|
void mark_for_deletion(cached_piece_entry* p);
|
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|
|
// similar to mark_for_deletion, except for actually marking the
|
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|
|
// piece for deletion. If the piece was actually deleted,
|
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|
|
// the function returns true
|
2015-08-19 15:22:00 +02:00
|
|
|
bool evict_piece(cached_piece_entry* p, tailqueue<disk_io_job>& jobs);
|
2014-07-06 21:18:00 +02:00
|
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|
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|
|
// if this piece is in L1 or L2 proper, move it to
|
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|
|
// its respective ghost list
|
|
|
|
void move_to_ghost(cached_piece_entry* p);
|
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|
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|
|
// returns the number of bytes read on success (cache hit)
|
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|
|
// -1 on cache miss
|
2014-08-01 08:07:48 +02:00
|
|
|
int try_read(disk_io_job* j, bool expect_no_fail = false);
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
// called when we're reading and we found the piece we're
|
|
|
|
// reading from in the hash table (not necessarily that we
|
|
|
|
// hit the block we needed)
|
|
|
|
void cache_hit(cached_piece_entry* p, void* requester, bool volatile_read);
|
|
|
|
|
|
|
|
// free block from piece entry
|
|
|
|
void free_block(cached_piece_entry* pe, int block);
|
|
|
|
|
|
|
|
// erase a piece (typically from the ghost list). Reclaim all
|
|
|
|
// its blocks and unlink it and free it.
|
|
|
|
void erase_piece(cached_piece_entry* p);
|
|
|
|
|
|
|
|
// bump the piece 'p' to the back of the LRU list it's
|
|
|
|
// in (back == MRU)
|
|
|
|
// this is only used for the write cache
|
|
|
|
void bump_lru(cached_piece_entry* p);
|
|
|
|
|
|
|
|
// move p into the correct lru queue
|
|
|
|
void update_cache_state(cached_piece_entry* p);
|
|
|
|
|
|
|
|
// if the piece is marked for deletion and has a refcount
|
|
|
|
// of 0, this function will post any sync jobs and
|
|
|
|
// delete the piece from the cache
|
|
|
|
bool maybe_free_piece(cached_piece_entry* p);
|
|
|
|
|
|
|
|
// either returns the piece in the cache, or allocates
|
|
|
|
// a new empty piece and returns it.
|
|
|
|
// cache_state is one of cache_state_t enum
|
2016-11-25 17:17:25 +01:00
|
|
|
cached_piece_entry* allocate_piece(disk_io_job const* j, std::uint16_t cache_state);
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
// looks for this piece in the cache. If it's there, returns a pointer
|
|
|
|
// to it, otherwise 0.
|
|
|
|
cached_piece_entry* find_piece(disk_io_job const* j);
|
2016-12-22 16:42:33 +01:00
|
|
|
cached_piece_entry* find_piece(storage_interface* st, piece_index_t piece);
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
// clear free all buffers marked as dirty with
|
|
|
|
// refcount of 0.
|
|
|
|
void abort_dirty(cached_piece_entry* p);
|
|
|
|
|
|
|
|
// used to convert dirty blocks into non-dirty ones
|
|
|
|
// i.e. from being part of the write cache to being part
|
|
|
|
// of the read cache. it's used when flushing blocks to disk
|
|
|
|
void blocks_flushed(cached_piece_entry* pe, int const* flushed, int num_flushed);
|
|
|
|
|
|
|
|
// adds a block to the cache, marks it as dirty and
|
|
|
|
// associates the job with it. When the block is
|
|
|
|
// flushed, the callback is posted
|
|
|
|
cached_piece_entry* add_dirty_block(disk_io_job* j);
|
2015-05-19 05:13:49 +02:00
|
|
|
|
2014-07-06 21:18:00 +02:00
|
|
|
enum { blocks_inc_refcount = 1 };
|
2017-01-11 06:42:10 +01:00
|
|
|
void insert_blocks(cached_piece_entry* pe, int block, span<iovec_t const> iov
|
2016-10-27 02:40:56 +02:00
|
|
|
, disk_io_job* j, int flags = 0);
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
#if TORRENT_USE_INVARIANT_CHECKS
|
|
|
|
void check_invariant() const;
|
|
|
|
#endif
|
2015-05-19 05:13:49 +02:00
|
|
|
|
2014-07-06 21:18:00 +02:00
|
|
|
// try to remove num number of read cache blocks from the cache
|
|
|
|
// pick the least recently used ones first
|
|
|
|
// return the number of blocks that was requested to be evicted
|
|
|
|
// that couldn't be
|
2016-10-28 18:28:27 +02:00
|
|
|
int try_evict_blocks(int num, cached_piece_entry* ignore = nullptr);
|
2014-07-06 21:18:00 +02:00
|
|
|
|
2016-03-07 07:05:54 +01:00
|
|
|
// try to evict a single volatile piece, if there is one.
|
|
|
|
void try_evict_one_volatile();
|
|
|
|
|
2015-08-19 15:22:00 +02:00
|
|
|
// if there are any dirty blocks
|
|
|
|
void clear(tailqueue<disk_io_job>& jobs);
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
void update_stats_counters(counters& c) const;
|
2014-10-25 22:07:50 +02:00
|
|
|
#ifndef TORRENT_NO_DEPRECATE
|
2014-07-06 21:18:00 +02:00
|
|
|
void get_stats(cache_status* ret) const;
|
2014-10-25 22:07:50 +02:00
|
|
|
#endif
|
2016-12-26 01:07:31 +01:00
|
|
|
void set_settings(aux::session_settings const& sett);
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
enum reason_t { ref_hashing = 0, ref_reading = 1, ref_flushing = 2 };
|
|
|
|
bool inc_block_refcount(cached_piece_entry* pe, int block, int reason);
|
|
|
|
void dec_block_refcount(cached_piece_entry* pe, int block, int reason);
|
|
|
|
|
|
|
|
int pinned_blocks() const { return m_pinned_blocks; }
|
2016-03-16 07:22:18 +01:00
|
|
|
int read_cache_size() const { return m_read_cache_size; }
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
private:
|
|
|
|
|
|
|
|
// returns number of bytes read on success, -1 on cache miss
|
|
|
|
// (just because the piece is in the cache, doesn't mean all
|
|
|
|
// the blocks are there)
|
|
|
|
int copy_from_piece(cached_piece_entry* p, disk_io_job* j, bool expect_no_fail = false);
|
|
|
|
|
|
|
|
void free_piece(cached_piece_entry* p);
|
|
|
|
int drain_piece_bufs(cached_piece_entry& p, std::vector<char*>& buf);
|
|
|
|
|
|
|
|
// block container
|
|
|
|
cache_t m_pieces;
|
|
|
|
|
|
|
|
// linked list of all elements in m_pieces, in usage order
|
|
|
|
// the most recently used are in the tail. iterating from head
|
|
|
|
// to tail gives the least recently used entries first
|
|
|
|
// the read-list is for read blocks and the write-list is for
|
|
|
|
// dirty blocks that needs flushing before being evicted
|
|
|
|
// [0] = write-LRU
|
|
|
|
// [1] = read-LRU1
|
|
|
|
// [2] = read-LRU1-ghost
|
|
|
|
// [3] = read-LRU2
|
|
|
|
// [4] = read-LRU2-ghost
|
2015-08-20 02:02:46 +02:00
|
|
|
linked_list<cached_piece_entry> m_lru[cached_piece_entry::num_lrus];
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
// this is used to determine whether to evict blocks from
|
|
|
|
// L1 or L2.
|
|
|
|
enum cache_op_t
|
|
|
|
{
|
|
|
|
cache_miss,
|
|
|
|
ghost_hit_lru1,
|
|
|
|
ghost_hit_lru2
|
|
|
|
};
|
|
|
|
int m_last_cache_op;
|
|
|
|
|
|
|
|
// the number of pieces to keep in the ARC ghost lists
|
|
|
|
// this is determined by being a fraction of the cache size
|
|
|
|
int m_ghost_size;
|
|
|
|
|
2016-03-07 07:05:54 +01:00
|
|
|
// the is the max number of volatile read cache blocks are allowed in the
|
|
|
|
// cache. Once this is reached, other volatile blocks will start to be
|
|
|
|
// evicted.
|
|
|
|
int m_max_volatile_blocks;
|
|
|
|
|
|
|
|
// the number of blocks (buffers) allocated by volatile pieces.
|
2016-11-27 14:46:53 +01:00
|
|
|
std::int32_t m_volatile_size;
|
2016-03-07 07:05:54 +01:00
|
|
|
|
2014-07-06 21:18:00 +02:00
|
|
|
// the number of blocks in the cache
|
|
|
|
// that are in the read cache
|
2016-11-27 14:46:53 +01:00
|
|
|
std::int32_t m_read_cache_size;
|
2016-03-07 07:05:54 +01:00
|
|
|
|
2014-07-06 21:18:00 +02:00
|
|
|
// the number of blocks in the cache
|
|
|
|
// that are in the write cache
|
2016-11-27 14:46:53 +01:00
|
|
|
std::int32_t m_write_cache_size;
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
// the number of blocks that are currently sitting
|
|
|
|
// in peer's send buffers. If two peers are sending
|
|
|
|
// the same block, it counts as 2, even though there're
|
|
|
|
// no buffer duplication
|
2016-11-27 14:46:53 +01:00
|
|
|
std::int32_t m_send_buffer_blocks;
|
2014-07-06 21:18:00 +02:00
|
|
|
|
|
|
|
// the number of blocks with a refcount > 0, i.e.
|
|
|
|
// they may not be evicted
|
|
|
|
int m_pinned_blocks;
|
|
|
|
};
|
|
|
|
|
|
|
|
}
|
|
|
|
|
|
|
|
#endif // TORRENT_BLOCK_CACHE
|