JYCache/s3fs/cache.h

215 lines
7.6 KiB
C++

/*
* s3fs - FUSE-based file system backed by Amazon S3
*
* Copyright(C) 2007 Randy Rizun <rrizun@gmail.com>
*
* 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.
*/
#ifndef S3FS_CACHE_H_
#define S3FS_CACHE_H_
#include <cstring>
#include "autolock.h"
#include "metaheader.h"
//-------------------------------------------------------------------
// Structure
//-------------------------------------------------------------------
//
// Struct for stats cache
//
struct stat_cache_entry {
struct stat stbuf;
unsigned long hit_count;
struct timespec cache_date;
headers_t meta;
bool isforce;
bool noobjcache; // Flag: cache is no object for no listing.
unsigned long notruncate; // 0<: not remove automatically at checking truncate
stat_cache_entry() : hit_count(0), isforce(false), noobjcache(false), notruncate(0L)
{
memset(&stbuf, 0, sizeof(struct stat));
cache_date.tv_sec = 0;
cache_date.tv_nsec = 0;
meta.clear();
}
};
typedef std::map<std::string, stat_cache_entry> stat_cache_t; // key=path
//
// Struct for symbolic link cache
//
struct symlink_cache_entry {
std::string link;
unsigned long hit_count;
struct timespec cache_date; // The function that operates timespec uses the same as Stats
symlink_cache_entry() : link(""), hit_count(0)
{
cache_date.tv_sec = 0;
cache_date.tv_nsec = 0;
}
};
typedef std::map<std::string, symlink_cache_entry> symlink_cache_t;
//
// Typedefs for No truncate file name cache
//
typedef std::vector<std::string> notruncate_filelist_t; // untruncated file name list in dir
typedef std::map<std::string, notruncate_filelist_t> notruncate_dir_map_t; // key is parent dir path
//-------------------------------------------------------------------
// Class StatCache
//-------------------------------------------------------------------
// [NOTE] About Symbolic link cache
// The Stats cache class now also has a symbolic link cache.
// It is possible to take out the Symbolic link cache in another class,
// but the cache out etc. should be synchronized with the Stats cache
// and implemented in this class.
// Symbolic link cache size and timeout use the same settings as Stats
// cache. This simplifies user configuration, and from a user perspective,
// the symbolic link cache appears to be included in the Stats cache.
//
class StatCache
{
private:
static StatCache singleton;
static pthread_mutex_t stat_cache_lock;
stat_cache_t stat_cache;
bool IsExpireTime;
bool IsExpireIntervalType; // if this flag is true, cache data is updated at last access time.
time_t ExpireTime;
unsigned long CacheSize;
bool IsCacheNoObject;
symlink_cache_t symlink_cache;
notruncate_dir_map_t notruncate_file_cache;
private:
StatCache();
~StatCache();
void Clear();
bool GetStat(const std::string& key, struct stat* pst, headers_t* meta, bool overcheck, const char* petag, bool* pisforce);
// Truncate stat cache
bool TruncateCache(AutoLock::Type locktype = AutoLock::NONE);
// Truncate symbolic link cache
bool TruncateSymlink(AutoLock::Type locktype = AutoLock::NONE);
bool AddNotruncateCache(const std::string& key);
bool DelNotruncateCache(const std::string& key);
public:
// Reference singleton
static StatCache* getStatCacheData()
{
return &singleton;
}
// Attribute
unsigned long GetCacheSize() const;
unsigned long SetCacheSize(unsigned long size);
time_t GetExpireTime() const;
time_t SetExpireTime(time_t expire, bool is_interval = false);
time_t UnsetExpireTime();
bool SetCacheNoObject(bool flag);
bool EnableCacheNoObject()
{
return SetCacheNoObject(true);
}
bool DisableCacheNoObject()
{
return SetCacheNoObject(false);
}
bool GetCacheNoObject() const
{
return IsCacheNoObject;
}
// Get stat cache
bool GetStat(const std::string& key, struct stat* pst, headers_t* meta, bool overcheck = true, bool* pisforce = nullptr)
{
return GetStat(key, pst, meta, overcheck, nullptr, pisforce);
}
bool GetStat(const std::string& key, struct stat* pst, bool overcheck = true)
{
return GetStat(key, pst, nullptr, overcheck, nullptr, nullptr);
}
bool GetStat(const std::string& key, headers_t* meta, bool overcheck = true)
{
return GetStat(key, nullptr, meta, overcheck, nullptr, nullptr);
}
bool HasStat(const std::string& key, bool overcheck = true)
{
return GetStat(key, nullptr, nullptr, overcheck, nullptr, nullptr);
}
bool HasStat(const std::string& key, const char* etag, bool overcheck = true)
{
return GetStat(key, nullptr, nullptr, overcheck, etag, nullptr);
}
bool HasStat(const std::string& key, struct stat* pst, const char* etag)
{
return GetStat(key, pst, nullptr, true, etag, nullptr);
}
// Cache For no object
bool IsNoObjectCache(const std::string& key, bool overcheck = true);
bool AddNoObjectCache(const std::string& key);
// Add stat cache
bool AddStat(const std::string& key, const headers_t& meta, bool forcedir = false, bool no_truncate = false);
// Update meta stats
bool UpdateMetaStats(const std::string& key, const headers_t& meta);
// Change no truncate flag
void ChangeNoTruncateFlag(const std::string& key, bool no_truncate);
// Delete stat cache
bool DelStat(const char* key, AutoLock::Type locktype = AutoLock::NONE);
bool DelStat(const std::string& key, AutoLock::Type locktype = AutoLock::NONE)
{
return DelStat(key.c_str(), locktype);
}
// Cache for symbolic link
bool GetSymlink(const std::string& key, std::string& value);
bool AddSymlink(const std::string& key, const std::string& value);
bool DelSymlink(const char* key, AutoLock::Type locktype = AutoLock::NONE);
// Cache for Notruncate file
bool GetNotruncateCache(const std::string& parentdir, notruncate_filelist_t& list);
};
//-------------------------------------------------------------------
// Functions
//-------------------------------------------------------------------
bool convert_header_to_stat(const char* path, const headers_t& meta, struct stat* pst, bool forcedir = false);
#endif // S3FS_CACHE_H_
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: expandtab sw=4 ts=4 fdm=marker
* vim<600: expandtab sw=4 ts=4
*/