s3fs-fuse/src/cache.cpp
2015-01-28 17:13:11 +00:00

446 lines
11 KiB
C++

/*
* s3fs - FUSE-based file system backed by Amazon S3
*
* Copyright 2007-2008 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.
*/
#include <stdio.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#include <stdint.h>
#include <pthread.h>
#include <string.h>
#include <assert.h>
#include <syslog.h>
#include <string>
#include <map>
#include <algorithm>
#include <list>
#include "cache.h"
#include "s3fs.h"
#include "s3fs_util.h"
#include "string_util.h"
using namespace std;
//-------------------------------------------------------------------
// Static
//-------------------------------------------------------------------
StatCache StatCache::singleton;
pthread_mutex_t StatCache::stat_cache_lock;
//-------------------------------------------------------------------
// Constructor/Destructor
//-------------------------------------------------------------------
StatCache::StatCache() : IsExpireTime(false), ExpireTime(0), CacheSize(1000), IsCacheNoObject(false)
{
if(this == StatCache::getStatCacheData()){
stat_cache.clear();
pthread_mutex_init(&(StatCache::stat_cache_lock), NULL);
}else{
assert(false);
}
}
StatCache::~StatCache()
{
if(this == StatCache::getStatCacheData()){
Clear();
pthread_mutex_destroy(&(StatCache::stat_cache_lock));
}else{
assert(false);
}
}
//-------------------------------------------------------------------
// Methods
//-------------------------------------------------------------------
unsigned long StatCache::GetCacheSize(void) const
{
return CacheSize;
}
unsigned long StatCache::SetCacheSize(unsigned long size)
{
unsigned long old = CacheSize;
CacheSize = size;
return old;
}
time_t StatCache::GetExpireTime(void) const
{
return (IsExpireTime ? ExpireTime : (-1));
}
time_t StatCache::SetExpireTime(time_t expire)
{
time_t old = ExpireTime;
ExpireTime = expire;
IsExpireTime = true;
return old;
}
time_t StatCache::UnsetExpireTime(void)
{
time_t old = IsExpireTime ? ExpireTime : (-1);
ExpireTime = 0;
IsExpireTime = false;
return old;
}
bool StatCache::SetCacheNoObject(bool flag)
{
bool old = IsCacheNoObject;
IsCacheNoObject = flag;
return old;
}
void StatCache::Clear(void)
{
pthread_mutex_lock(&StatCache::stat_cache_lock);
for(stat_cache_t::iterator iter = stat_cache.begin(); iter != stat_cache.end(); stat_cache.erase(iter++)){
if((*iter).second){
delete (*iter).second;
}
}
S3FS_MALLOCTRIM(0);
pthread_mutex_unlock(&StatCache::stat_cache_lock);
}
bool StatCache::GetStat(string& key, struct stat* pst, headers_t* meta, bool overcheck, const char* petag, bool* pisforce)
{
bool is_delete_cache = false;
string strpath = key;
pthread_mutex_lock(&StatCache::stat_cache_lock);
stat_cache_t::iterator iter = stat_cache.end();
if(overcheck && '/' != strpath[strpath.length() - 1]){
strpath += "/";
iter = stat_cache.find(strpath.c_str());
}
if(iter == stat_cache.end()){
strpath = key;
iter = stat_cache.find(strpath.c_str());
}
if(iter != stat_cache.end() && (*iter).second){
stat_cache_entry* ent = (*iter).second;
if(!IsExpireTime|| (ent->cache_date + ExpireTime) >= time(NULL)){
if(ent->noobjcache){
pthread_mutex_unlock(&StatCache::stat_cache_lock);
if(!IsCacheNoObject){
// need to delete this cache.
DelStat(strpath);
}else{
// noobjcache = true means no object.
}
return false;
}
// hit without checking etag
if(petag){
string stretag = ent->meta["ETag"];
if('\0' != petag[0] && 0 != strcmp(petag, stretag.c_str())){
is_delete_cache = true;
}
}
if(is_delete_cache){
// not hit by different ETag
DPRNNN("stat cache not hit by ETag[path=%s][time=%jd][hit count=%lu][ETag(%s)!=(%s)]",
strpath.c_str(), (intmax_t)(ent->cache_date), ent->hit_count, petag ? petag : "null", ent->meta["ETag"].c_str());
}else{
// hit
DPRNNN("stat cache hit [path=%s][time=%jd][hit count=%lu]", strpath.c_str(), (intmax_t)(ent->cache_date), ent->hit_count);
if(pst!= NULL){
*pst= ent->stbuf;
}
if(meta != NULL){
*meta = ent->meta;
}
if(pisforce != NULL){
(*pisforce) = ent->isforce;
}
ent->hit_count++;
ent->cache_date = time(NULL);
pthread_mutex_unlock(&StatCache::stat_cache_lock);
return true;
}
}else{
// timeout
is_delete_cache = true;
}
}
pthread_mutex_unlock(&StatCache::stat_cache_lock);
if(is_delete_cache){
DelStat(strpath);
}
return false;
}
bool StatCache::IsNoObjectCache(string& key, bool overcheck)
{
bool is_delete_cache = false;
string strpath = key;
if(!IsCacheNoObject){
return false;
}
pthread_mutex_lock(&StatCache::stat_cache_lock);
stat_cache_t::iterator iter = stat_cache.end();
if(overcheck && '/' != strpath[strpath.length() - 1]){
strpath += "/";
iter = stat_cache.find(strpath.c_str());
}
if(iter == stat_cache.end()){
strpath = key;
iter = stat_cache.find(strpath.c_str());
}
if(iter != stat_cache.end() && (*iter).second) {
if(!IsExpireTime|| ((*iter).second->cache_date + ExpireTime) >= time(NULL)){
if((*iter).second->noobjcache){
// noobjcache = true means no object.
(*iter).second->cache_date = time(NULL);
pthread_mutex_unlock(&StatCache::stat_cache_lock);
return true;
}
}else{
// timeout
is_delete_cache = true;
}
}
pthread_mutex_unlock(&StatCache::stat_cache_lock);
if(is_delete_cache){
DelStat(strpath);
}
return false;
}
bool StatCache::AddStat(std::string& key, headers_t& meta, bool forcedir)
{
if(CacheSize< 1){
return true;
}
DPRNNN("add stat cache entry[path=%s]", key.c_str());
if(stat_cache.end() != stat_cache.find(key)){
DelStat(key.c_str());
}else{
if(stat_cache.size() > CacheSize){
if(!TruncateCache()){
return false;
}
}
}
// make new
stat_cache_entry* ent = new stat_cache_entry();
if(!convert_header_to_stat(key.c_str(), meta, &(ent->stbuf), forcedir)){
delete ent;
return false;
}
ent->hit_count = 0;
ent->cache_date = time(NULL); // Set time.
ent->isforce = forcedir;
ent->noobjcache = false;
ent->meta.clear();
//copy only some keys
for(headers_t::iterator iter = meta.begin(); iter != meta.end(); ++iter){
string tag = lower(iter->first);
string value = iter->second;
if(tag == "content-type"){
ent->meta[iter->first] = value;
}else if(tag == "content-length"){
ent->meta[iter->first] = value;
}else if(tag == "etag"){
ent->meta[iter->first] = value;
}else if(tag == "last-modified"){
ent->meta[iter->first] = value;
}else if(tag.substr(0, 5) == "x-amz"){
ent->meta[tag] = value; // key is lower case for "x-amz"
}
}
// add
pthread_mutex_lock(&StatCache::stat_cache_lock);
stat_cache[key] = ent;
pthread_mutex_unlock(&StatCache::stat_cache_lock);
return true;
}
bool StatCache::AddNoObjectCache(string& key)
{
if(!IsCacheNoObject){
return true; // pretend successful
}
if(CacheSize < 1){
return true;
}
DPRNNN("add no object cache entry[path=%s]", key.c_str());
if(stat_cache.end() != stat_cache.find(key)){
DelStat(key.c_str());
}else{
if(stat_cache.size() > CacheSize){
if(!TruncateCache()){
return false;
}
}
}
// make new
stat_cache_entry* ent = new stat_cache_entry();
memset(&(ent->stbuf), 0, sizeof(struct stat));
ent->hit_count = 0;
ent->cache_date = time(NULL); // Set time.
ent->isforce = false;
ent->noobjcache = true;
ent->meta.clear();
// add
pthread_mutex_lock(&StatCache::stat_cache_lock);
stat_cache[key] = ent;
pthread_mutex_unlock(&StatCache::stat_cache_lock);
return true;
}
bool StatCache::TruncateCache(void)
{
if(0 == stat_cache.size()){
return true;
}
pthread_mutex_lock(&StatCache::stat_cache_lock);
time_t lowest_time = time(NULL) + 1;
stat_cache_t::iterator iter_to_delete = stat_cache.end();
stat_cache_t::iterator iter;
for(iter = stat_cache.begin(); iter != stat_cache.end(); iter++) {
if((*iter).second){
if(lowest_time > (*iter).second->cache_date){
lowest_time = (*iter).second->cache_date;
iter_to_delete = iter;
}
}
}
if(stat_cache.end() != iter_to_delete){
DPRNNN("truncate stat cache[path=%s]", (*iter_to_delete).first.c_str());
if((*iter_to_delete).second){
delete (*iter_to_delete).second;
}
stat_cache.erase(iter_to_delete);
S3FS_MALLOCTRIM(0);
}
pthread_mutex_unlock(&StatCache::stat_cache_lock);
return true;
}
bool StatCache::DelStat(const char* key)
{
if(!key){
return false;
}
DPRNNN("delete stat cache entry[path=%s]", key);
pthread_mutex_lock(&StatCache::stat_cache_lock);
stat_cache_t::iterator iter;
if(stat_cache.end() != (iter = stat_cache.find(string(key)))){
if((*iter).second){
delete (*iter).second;
}
stat_cache.erase(iter);
}
if(0 < strlen(key) && 0 != strcmp(key, "/")){
string strpath = key;
if('/' == strpath[strpath.length() - 1]){
// If there is "path" cache, delete it.
strpath = strpath.substr(0, strpath.length() - 1);
}else{
// If there is "path/" cache, delete it.
strpath += "/";
}
if(stat_cache.end() != (iter = stat_cache.find(strpath.c_str()))){
if((*iter).second){
delete (*iter).second;
}
stat_cache.erase(iter);
}
}
S3FS_MALLOCTRIM(0);
pthread_mutex_unlock(&StatCache::stat_cache_lock);
return true;
}
//-------------------------------------------------------------------
// Functions
//-------------------------------------------------------------------
bool convert_header_to_stat(const char* path, headers_t& meta, struct stat* pst, bool forcedir)
{
if(!path || !pst){
return false;
}
memset(pst, 0, sizeof(struct stat));
pst->st_nlink = 1; // see fuse FAQ
// mode
pst->st_mode = get_mode(meta, path, true, forcedir);
// blocks
if(S_ISREG(pst->st_mode)){
pst->st_blocks = get_blocks(pst->st_size);
}
pst->st_blksize = 4096;
// mtime
pst->st_mtime = get_mtime(meta);
// size
pst->st_size = get_size(meta);
// uid/gid
pst->st_uid = get_uid(meta);
pst->st_gid = get_gid(meta);
return true;
}
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
* vim600: noet sw=4 ts=4 fdm=marker
* vim<600: noet sw=4 ts=4
*/