mirror of
https://github.com/aria2/aria2.git
synced 2026-04-11 23:39:05 +00:00
f314719618
This option enables disk cache. If SIZE is 0, the disk cache is disabled. This feature caches the downloaded data in memory, which grows to at most SIZE bytes. The cache storage is created for aria2 instance and shared by all downloads. The one advantage of the disk cache is reduce the disk seek time because the data is written in larger unit and it is reordered by the offset of the file. If the underlying file is heavily fragmented it is not the case.
84 lines
2.8 KiB
C++
84 lines
2.8 KiB
C++
/* <!-- copyright */
|
|
/*
|
|
* aria2 - The high speed download utility
|
|
*
|
|
* Copyright (C) 2012 Tatsuhiro Tsujikawa
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify
|
|
* it under the terms of the GNU General Public License as published by
|
|
* the Free Software Foundation; either version 2 of the License, or
|
|
* (at your option) any later version.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program; if not, write to the Free Software
|
|
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
|
|
*
|
|
* In addition, as a special exception, the copyright holders give
|
|
* permission to link the code of portions of this program with the
|
|
* OpenSSL library under certain conditions as described in each
|
|
* individual source file, and distribute linked combinations
|
|
* including the two.
|
|
* You must obey the GNU General Public License in all respects
|
|
* for all of the code used other than OpenSSL. If you modify
|
|
* file(s) with this exception, you may extend this exception to your
|
|
* version of the file(s), but you are not obligated to do so. If you
|
|
* do not wish to do so, delete this exception statement from your
|
|
* version. If you delete this exception statement from all source
|
|
* files in the program, then also delete it here.
|
|
*/
|
|
/* copyright --> */
|
|
#ifndef D_WR_DISK_CACHE_H
|
|
#define D_WR_DISK_CACHE_H
|
|
|
|
#include "common.h"
|
|
|
|
#include <set>
|
|
|
|
#include "a2functional.h"
|
|
|
|
namespace aria2 {
|
|
|
|
class WrDiskCacheEntry;
|
|
|
|
class WrDiskCache {
|
|
public:
|
|
WrDiskCache(size_t limit);
|
|
~WrDiskCache();
|
|
// Adds the cache entry |ent| to the storage. The size of cached
|
|
// data of ent is added to total_.
|
|
bool add(WrDiskCacheEntry* ent);
|
|
// Removes the cache entry |ent| from the stroage. The size of
|
|
// cached data of ent is subtracted from total_.
|
|
bool remove(WrDiskCacheEntry* ent);
|
|
// Updates the already added entry |ent|. The |delta| means how many
|
|
// bytes is increased in this update. If the size is reduced, use
|
|
// negative value.
|
|
bool update(WrDiskCacheEntry* ent, ssize_t delta);
|
|
// Evicts entries from storage so that total size of cache is kept
|
|
// under the limit.
|
|
void ensureLimit();
|
|
size_t getSize() const
|
|
{
|
|
return total_;
|
|
}
|
|
private:
|
|
typedef std::set<WrDiskCacheEntry*,
|
|
DerefLess<WrDiskCacheEntry*> > EntrySet;
|
|
// Maximum number of bytes the storage can cache.
|
|
size_t limit_;
|
|
// Current number of bytes cached.
|
|
size_t total_;
|
|
EntrySet set_;
|
|
int64_t clock_;
|
|
};
|
|
|
|
} // namespace aria2
|
|
|
|
#endif // D_WR_DISK_CACHE_H
|
|
|