s3fs-fuse/src/cache.cpp
Andrew Gaul 7638b5b3e3
Prefer std::string::rbegin over operator[] (#1673)
This is more concise and safer due to not repeating the variable name.
We cannot use std::string::back since it is not available in C++03.
2021-06-13 13:26:38 +09:00

870 lines
25 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.
*/
#include <cstdio>
#include <cstdlib>
#ifndef HAVE_CLOCK_GETTIME
#include <sys/time.h>
#endif
#include <algorithm>
#include "common.h"
#include "s3fs.h"
#include "cache.h"
#include "autolock.h"
#include "string_util.h"
//-------------------------------------------------------------------
// Utility
//-------------------------------------------------------------------
#ifndef CLOCK_REALTIME
#define CLOCK_REALTIME 0
#endif
#ifndef CLOCK_MONOTONIC
#define CLOCK_MONOTONIC CLOCK_REALTIME
#endif
#ifndef CLOCK_MONOTONIC_COARSE
#define CLOCK_MONOTONIC_COARSE CLOCK_MONOTONIC
#endif
#ifdef HAVE_CLOCK_GETTIME
static int s3fs_clock_gettime(int clk_id, struct timespec* ts)
{
return clock_gettime(static_cast<clockid_t>(clk_id), ts);
}
#else
static int s3fs_clock_gettime(int clk_id, struct timespec* ts)
{
struct timeval now;
if(0 != gettimeofday(&now, NULL)){
return -1;
}
ts->tv_sec = now.tv_sec;
ts->tv_nsec = now.tv_usec * 1000;
return 0;
}
#endif
inline void SetStatCacheTime(struct timespec& ts)
{
if(-1 == s3fs_clock_gettime(CLOCK_MONOTONIC_COARSE, &ts)){
ts.tv_sec = time(NULL);
ts.tv_nsec = 0;
}
}
inline void InitStatCacheTime(struct timespec& ts)
{
ts.tv_sec = 0;
ts.tv_nsec = 0;
}
inline int CompareStatCacheTime(const struct timespec& ts1, const struct timespec& ts2)
{
// return -1: ts1 < ts2
// 0: ts1 == ts2
// 1: ts1 > ts2
if(ts1.tv_sec < ts2.tv_sec){
return -1;
}else if(ts1.tv_sec > ts2.tv_sec){
return 1;
}else{
if(ts1.tv_nsec < ts2.tv_nsec){
return -1;
}else if(ts1.tv_nsec > ts2.tv_nsec){
return 1;
}
}
return 0;
}
inline bool IsExpireStatCacheTime(const struct timespec& ts, const time_t& expire)
{
struct timespec nowts;
SetStatCacheTime(nowts);
nowts.tv_sec -= expire;
return (0 < CompareStatCacheTime(nowts, ts));
}
//
// For stats cache out
//
typedef std::vector<stat_cache_t::iterator> statiterlist_t;
struct sort_statiterlist{
// ascending order
bool operator()(const stat_cache_t::iterator& src1, const stat_cache_t::iterator& src2) const
{
int result = CompareStatCacheTime(src1->second->cache_date, src2->second->cache_date);
if(0 == result){
if(src1->second->hit_count < src2->second->hit_count){
result = -1;
}
}
return (result < 0);
}
};
//
// For symbolic link cache out
//
typedef std::vector<symlink_cache_t::iterator> symlinkiterlist_t;
struct sort_symlinkiterlist{
// ascending order
bool operator()(const symlink_cache_t::iterator& src1, const symlink_cache_t::iterator& src2) const
{
int result = CompareStatCacheTime(src1->second->cache_date, src2->second->cache_date); // use the same as Stats
if(0 == result){
if(src1->second->hit_count < src2->second->hit_count){
result = -1;
}
}
return (result < 0);
}
};
//-------------------------------------------------------------------
// Static
//-------------------------------------------------------------------
StatCache StatCache::singleton;
pthread_mutex_t StatCache::stat_cache_lock;
//-------------------------------------------------------------------
// Constructor/Destructor
//-------------------------------------------------------------------
StatCache::StatCache() : IsExpireTime(true), IsExpireIntervalType(false), ExpireTime(15 * 60), CacheSize(100000), IsCacheNoObject(false)
{
if(this == StatCache::getStatCacheData()){
stat_cache.clear();
pthread_mutexattr_t attr;
pthread_mutexattr_init(&attr);
#if S3FS_PTHREAD_ERRORCHECK
pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_ERRORCHECK);
#endif
int result;
if(0 != (result = pthread_mutex_init(&StatCache::stat_cache_lock, &attr))){
S3FS_PRN_CRIT("failed to init stat_cache_lock: %d", result);
abort();
}
}else{
abort();
}
}
StatCache::~StatCache()
{
if(this == StatCache::getStatCacheData()){
Clear();
int result = pthread_mutex_destroy(&StatCache::stat_cache_lock);
if(result != 0){
S3FS_PRN_CRIT("failed to destroy stat_cache_lock: %d", result);
abort();
}
}else{
abort();
}
}
//-------------------------------------------------------------------
// Methods
//-------------------------------------------------------------------
unsigned long StatCache::GetCacheSize() const
{
return CacheSize;
}
unsigned long StatCache::SetCacheSize(unsigned long size)
{
unsigned long old = CacheSize;
CacheSize = size;
return old;
}
time_t StatCache::GetExpireTime() const
{
return (IsExpireTime ? ExpireTime : (-1));
}
time_t StatCache::SetExpireTime(time_t expire, bool is_interval)
{
time_t old = ExpireTime;
ExpireTime = expire;
IsExpireTime = true;
IsExpireIntervalType = is_interval;
return old;
}
time_t StatCache::UnsetExpireTime()
{
time_t old = IsExpireTime ? ExpireTime : (-1);
ExpireTime = 0;
IsExpireTime = false;
IsExpireIntervalType = false;
return old;
}
bool StatCache::SetCacheNoObject(bool flag)
{
bool old = IsCacheNoObject;
IsCacheNoObject = flag;
return old;
}
void StatCache::Clear()
{
AutoLock lock(&StatCache::stat_cache_lock);
for(stat_cache_t::iterator iter = stat_cache.begin(); iter != stat_cache.end(); ++iter){
delete (*iter).second;
}
stat_cache.clear();
S3FS_MALLOCTRIM(0);
}
bool StatCache::GetStat(const std::string& key, struct stat* pst, headers_t* meta, bool overcheck, const char* petag, bool* pisforce)
{
bool is_delete_cache = false;
std::string strpath = key;
AutoLock lock(&StatCache::stat_cache_lock);
stat_cache_t::iterator iter = stat_cache.end();
if(overcheck && '/' != *strpath.rbegin()){
strpath += "/";
iter = stat_cache.find(strpath);
}
if(iter == stat_cache.end()){
strpath = key;
iter = stat_cache.find(strpath);
}
if(iter != stat_cache.end() && (*iter).second){
stat_cache_entry* ent = (*iter).second;
if(0 < ent->notruncate || !IsExpireTime || !IsExpireStatCacheTime(ent->cache_date, ExpireTime)){
if(ent->noobjcache){
if(!IsCacheNoObject){
// need to delete this cache.
DelStat(strpath, /*lock_already_held=*/ true);
}else{
// noobjcache = true means no object.
}
return false;
}
// hit without checking etag
std::string stretag;
if(petag){
// find & check ETag
for(headers_t::iterator hiter = ent->meta.begin(); hiter != ent->meta.end(); ++hiter){
std::string tag = lower(hiter->first);
if(tag == "etag"){
stretag = hiter->second;
if('\0' != petag[0] && 0 != strcmp(petag, stretag.c_str())){
is_delete_cache = true;
}
break;
}
}
}
if(is_delete_cache){
// not hit by different ETag
S3FS_PRN_DBG("stat cache not hit by ETag[path=%s][time=%lld.%09ld][hit count=%lu][ETag(%s)!=(%s)]",
strpath.c_str(), static_cast<long long>(ent->cache_date.tv_sec), ent->cache_date.tv_nsec, ent->hit_count, petag ? petag : "null", stretag.c_str());
}else{
// hit
S3FS_PRN_DBG("stat cache hit [path=%s][time=%lld.%09ld][hit count=%lu]",
strpath.c_str(), static_cast<long long>(ent->cache_date.tv_sec), ent->cache_date.tv_nsec, ent->hit_count);
if(pst!= NULL){
*pst= ent->stbuf;
}
if(meta != NULL){
*meta = ent->meta;
}
if(pisforce != NULL){
(*pisforce) = ent->isforce;
}
ent->hit_count++;
if(IsExpireIntervalType){
SetStatCacheTime(ent->cache_date);
}
return true;
}
}else{
// timeout
is_delete_cache = true;
}
}
if(is_delete_cache){
DelStat(strpath, /*lock_already_held=*/ true);
}
return false;
}
bool StatCache::IsNoObjectCache(const std::string& key, bool overcheck)
{
bool is_delete_cache = false;
std::string strpath = key;
if(!IsCacheNoObject){
return false;
}
AutoLock lock(&StatCache::stat_cache_lock);
stat_cache_t::iterator iter = stat_cache.end();
if(overcheck && '/' != *strpath.rbegin()){
strpath += "/";
iter = stat_cache.find(strpath);
}
if(iter == stat_cache.end()){
strpath = key;
iter = stat_cache.find(strpath);
}
if(iter != stat_cache.end() && (*iter).second) {
stat_cache_entry* ent = (*iter).second;
if(0 < ent->notruncate || !IsExpireTime || !IsExpireStatCacheTime((*iter).second->cache_date, ExpireTime)){
if((*iter).second->noobjcache){
// noobjcache = true means no object.
SetStatCacheTime((*iter).second->cache_date);
return true;
}
}else{
// timeout
is_delete_cache = true;
}
}
if(is_delete_cache){
DelStat(strpath, /*lock_already_held=*/ true);
}
return false;
}
bool StatCache::AddStat(const std::string& key, headers_t& meta, bool forcedir, bool no_truncate)
{
if(!no_truncate && CacheSize< 1){
return true;
}
S3FS_PRN_INFO3("add stat cache entry[path=%s]", key.c_str());
bool found;
bool do_truncate;
{
AutoLock lock(&StatCache::stat_cache_lock);
found = stat_cache.end() != stat_cache.find(key);
do_truncate = stat_cache.size() > CacheSize;
}
if(found){
DelStat(key.c_str());
}else{
if(do_truncate){
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->isforce = forcedir;
ent->noobjcache = false;
ent->notruncate = (no_truncate ? 1L : 0L);
ent->meta.clear();
SetStatCacheTime(ent->cache_date); // Set time.
//copy only some keys
for(headers_t::iterator iter = meta.begin(); iter != meta.end(); ++iter){
std::string tag = lower(iter->first);
std::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(is_prefix(tag.c_str(), "x-amz")){
ent->meta[tag] = value; // key is lower case for "x-amz"
}
}
// add
AutoLock lock(&StatCache::stat_cache_lock);
std::pair<stat_cache_t::iterator, bool> pair = stat_cache.insert(std::make_pair(key, ent));
if(!pair.second){
delete pair.first->second;
pair.first->second = ent;
}
// check symbolic link cache
if(!S_ISLNK(ent->stbuf.st_mode)){
if(symlink_cache.end() != symlink_cache.find(key)){
// if symbolic link cache has key, thus remove it.
DelSymlink(key.c_str(), true);
}
}
return true;
}
// [NOTE]
// Updates only meta data if cached data exists.
// And when these are updated, it also updates the cache time.
//
bool StatCache::UpdateMetaStats(const std::string& key, headers_t& meta)
{
if(CacheSize < 1){
return true;
}
S3FS_PRN_INFO3("update stat cache entry[path=%s]", key.c_str());
AutoLock lock(&StatCache::stat_cache_lock);
stat_cache_t::iterator iter = stat_cache.find(key);
if(stat_cache.end() == iter || !(iter->second)){
return true;
}
stat_cache_entry* ent = iter->second;
// update only meta keys
for(headers_t::iterator metaiter = meta.begin(); metaiter != meta.end(); ++metaiter){
std::string tag = lower(metaiter->first);
std::string value = metaiter->second;
if(tag == "content-type"){
ent->meta[metaiter->first] = value;
}else if(tag == "content-length"){
ent->meta[metaiter->first] = value;
}else if(tag == "etag"){
ent->meta[metaiter->first] = value;
}else if(tag == "last-modified"){
ent->meta[metaiter->first] = value;
}else if(is_prefix(tag.c_str(), "x-amz")){
ent->meta[tag] = value; // key is lower case for "x-amz"
}
}
// Update time.
SetStatCacheTime(ent->cache_date);
return true;
}
bool StatCache::AddNoObjectCache(const std::string& key)
{
if(!IsCacheNoObject){
return true; // pretend successful
}
if(CacheSize < 1){
return true;
}
S3FS_PRN_INFO3("add no object cache entry[path=%s]", key.c_str());
bool found;
bool do_truncate;
{
AutoLock lock(&StatCache::stat_cache_lock);
found = stat_cache.end() != stat_cache.find(key);
do_truncate = stat_cache.size() > CacheSize;
}
if(found){
DelStat(key.c_str());
}else{
if(do_truncate){
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->isforce = false;
ent->noobjcache = true;
ent->notruncate = 0L;
ent->meta.clear();
SetStatCacheTime(ent->cache_date); // Set time.
// add
AutoLock lock(&StatCache::stat_cache_lock);
std::pair<stat_cache_t::iterator, bool> pair = stat_cache.insert(std::make_pair(key, ent));
if(!pair.second){
delete pair.first->second;
pair.first->second = ent;
}
// check symbolic link cache
if(symlink_cache.end() != symlink_cache.find(key)){
// if symbolic link cache has key, thus remove it.
DelSymlink(key.c_str(), true);
}
return true;
}
void StatCache::ChangeNoTruncateFlag(const std::string& key, bool no_truncate)
{
AutoLock lock(&StatCache::stat_cache_lock);
stat_cache_t::iterator iter = stat_cache.find(key);
if(stat_cache.end() != iter){
stat_cache_entry* ent = iter->second;
if(ent){
if(no_truncate){
++(ent->notruncate);
}else{
if(0L < ent->notruncate){
--(ent->notruncate);
}
}
}
}
}
bool StatCache::TruncateCache()
{
AutoLock lock(&StatCache::stat_cache_lock);
if(stat_cache.empty()){
return true;
}
// 1) erase over expire time
if(IsExpireTime){
for(stat_cache_t::iterator iter = stat_cache.begin(); iter != stat_cache.end(); ){
stat_cache_entry* entry = iter->second;
if(!entry || (0L == entry->notruncate && IsExpireStatCacheTime(entry->cache_date, ExpireTime))){
delete entry;
stat_cache.erase(iter++);
}else{
++iter;
}
}
}
// 2) check stat cache count
if(stat_cache.size() < CacheSize){
return true;
}
// 3) erase from the old cache in order
size_t erase_count= stat_cache.size() - CacheSize + 1;
statiterlist_t erase_iters;
for(stat_cache_t::iterator iter = stat_cache.begin(); iter != stat_cache.end() && 0 < erase_count; ++iter){
// check no truncate
stat_cache_entry* ent = iter->second;
if(ent && 0L < ent->notruncate){
// skip for no truncate entry and keep extra counts for this entity.
if(0 < erase_count){
--erase_count; // decrement
}
}else{
// iter is not have notruncate flag
erase_iters.push_back(iter);
}
if(erase_count < erase_iters.size()){
sort(erase_iters.begin(), erase_iters.end(), sort_statiterlist());
while(erase_count < erase_iters.size()){
erase_iters.pop_back();
}
}
}
for(statiterlist_t::iterator iiter = erase_iters.begin(); iiter != erase_iters.end(); ++iiter){
stat_cache_t::iterator siter = *iiter;
S3FS_PRN_DBG("truncate stat cache[path=%s]", siter->first.c_str());
delete siter->second;
stat_cache.erase(siter);
}
S3FS_MALLOCTRIM(0);
return true;
}
bool StatCache::DelStat(const char* key, bool lock_already_held)
{
if(!key){
return false;
}
S3FS_PRN_INFO3("delete stat cache entry[path=%s]", key);
AutoLock lock(&StatCache::stat_cache_lock, lock_already_held ? AutoLock::ALREADY_LOCKED : AutoLock::NONE);
stat_cache_t::iterator iter;
if(stat_cache.end() != (iter = stat_cache.find(std::string(key)))){
delete (*iter).second;
stat_cache.erase(iter);
}
if(0 < strlen(key) && 0 != strcmp(key, "/")){
std::string strpath = key;
if('/' == *strpath.rbegin()){
// If there is "path" cache, delete it.
strpath.erase(strpath.length() - 1);
}else{
// If there is "path/" cache, delete it.
strpath += "/";
}
if(stat_cache.end() != (iter = stat_cache.find(strpath))){
delete (*iter).second;
stat_cache.erase(iter);
}
}
S3FS_MALLOCTRIM(0);
return true;
}
bool StatCache::GetSymlink(const std::string& key, std::string& value)
{
bool is_delete_cache = false;
const std::string& strpath = key;
AutoLock lock(&StatCache::stat_cache_lock);
symlink_cache_t::iterator iter = symlink_cache.find(strpath);
if(iter != symlink_cache.end() && iter->second){
symlink_cache_entry* ent = iter->second;
if(!IsExpireTime || !IsExpireStatCacheTime(ent->cache_date, ExpireTime)){ // use the same as Stats
// found
S3FS_PRN_DBG("symbolic link cache hit [path=%s][time=%lld.%09ld][hit count=%lu]",
strpath.c_str(), static_cast<long long>(ent->cache_date.tv_sec), ent->cache_date.tv_nsec, ent->hit_count);
value = ent->link;
ent->hit_count++;
if(IsExpireIntervalType){
SetStatCacheTime(ent->cache_date);
}
return true;
}else{
// timeout
is_delete_cache = true;
}
}
if(is_delete_cache){
DelSymlink(strpath.c_str(), /*lock_already_held=*/ true);
}
return false;
}
bool StatCache::AddSymlink(const std::string& key, const std::string& value)
{
if(CacheSize< 1){
return true;
}
S3FS_PRN_INFO3("add symbolic link cache entry[path=%s, value=%s]", key.c_str(), value.c_str());
bool found;
bool do_truncate;
{
AutoLock lock(&StatCache::stat_cache_lock);
found = symlink_cache.end() != symlink_cache.find(key);
do_truncate = symlink_cache.size() > CacheSize;
}
if(found){
DelSymlink(key.c_str());
}else{
if(do_truncate){
if(!TruncateSymlink()){
return false;
}
}
}
// make new
symlink_cache_entry* ent = new symlink_cache_entry();
ent->link = value;
ent->hit_count = 0;
SetStatCacheTime(ent->cache_date); // Set time(use the same as Stats).
// add
AutoLock lock(&StatCache::stat_cache_lock);
std::pair<symlink_cache_t::iterator, bool> pair = symlink_cache.insert(std::make_pair(key, ent));
if(!pair.second){
delete pair.first->second;
pair.first->second = ent;
}
return true;
}
bool StatCache::TruncateSymlink()
{
AutoLock lock(&StatCache::stat_cache_lock);
if(symlink_cache.empty()){
return true;
}
// 1) erase over expire time
if(IsExpireTime){
for(symlink_cache_t::iterator iter = symlink_cache.begin(); iter != symlink_cache.end(); ){
symlink_cache_entry* entry = iter->second;
if(!entry || IsExpireStatCacheTime(entry->cache_date, ExpireTime)){ // use the same as Stats
delete entry;
symlink_cache.erase(iter++);
}else{
++iter;
}
}
}
// 2) check stat cache count
if(symlink_cache.size() < CacheSize){
return true;
}
// 3) erase from the old cache in order
size_t erase_count= symlink_cache.size() - CacheSize + 1;
symlinkiterlist_t erase_iters;
for(symlink_cache_t::iterator iter = symlink_cache.begin(); iter != symlink_cache.end(); ++iter){
erase_iters.push_back(iter);
sort(erase_iters.begin(), erase_iters.end(), sort_symlinkiterlist());
if(erase_count < erase_iters.size()){
erase_iters.pop_back();
}
}
for(symlinkiterlist_t::iterator iiter = erase_iters.begin(); iiter != erase_iters.end(); ++iiter){
symlink_cache_t::iterator siter = *iiter;
S3FS_PRN_DBG("truncate symbolic link cache[path=%s]", siter->first.c_str());
delete siter->second;
symlink_cache.erase(siter);
}
S3FS_MALLOCTRIM(0);
return true;
}
bool StatCache::DelSymlink(const char* key, bool lock_already_held)
{
if(!key){
return false;
}
S3FS_PRN_INFO3("delete symbolic link cache entry[path=%s]", key);
AutoLock lock(&StatCache::stat_cache_lock, lock_already_held ? AutoLock::ALREADY_LOCKED : AutoLock::NONE);
symlink_cache_t::iterator iter;
if(symlink_cache.end() != (iter = symlink_cache.find(std::string(key)))){
delete iter->second;
symlink_cache.erase(iter);
}
S3FS_MALLOCTRIM(0);
return true;
}
//-------------------------------------------------------------------
// Functions
//-------------------------------------------------------------------
bool convert_header_to_stat(const char* path, const 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
struct timespec mtime = get_mtime(meta);
if(pst->st_mtime < 0){
pst->st_mtime = 0L;
}else{
#if defined(__APPLE__)
pst->st_mtime = mtime.tv_sec;
#else
pst->st_mtim.tv_sec = mtime.tv_sec;
pst->st_mtim.tv_nsec = mtime.tv_nsec;
#endif
}
// ctime
struct timespec ctime = get_ctime(meta);
if(pst->st_ctime < 0){
pst->st_ctime = 0L;
}else{
#if defined(__APPLE__)
pst->st_ctime = ctime.tv_sec;
#else
pst->st_ctim.tv_sec = ctime.tv_sec;
pst->st_ctim.tv_nsec = ctime.tv_nsec;
#endif
}
// atime
struct timespec atime = get_atime(meta);
if(pst->st_atime < 0){
pst->st_atime = 0L;
}else{
#if defined(__APPLE__)
pst->st_atime = atime.tv_sec;
#else
pst->st_atim.tv_sec = atime.tv_sec;
pst->st_atim.tv_nsec = atime.tv_nsec;
#endif
}
// 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: expandtab sw=4 ts=4 fdm=marker
* vim<600: expandtab sw=4 ts=4
*/