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redis.c
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redis.c
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/*
* Copyright (c) 2009-2010, Salvatore Sanfilippo <antirez at gmail dot com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of Redis nor the names of its contributors may be used
* to endorse or promote products derived from this software without
* specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "redis.h"
#ifdef HAVE_BACKTRACE
#include <execinfo.h>
#include <ucontext.h>
#endif /* HAVE_BACKTRACE */
#include <time.h>
#include <signal.h>
#include <sys/wait.h>
#include <errno.h>
#include <assert.h>
#include <ctype.h>
#include <stdarg.h>
#include <arpa/inet.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/time.h>
#include <sys/resource.h>
#include <sys/uio.h>
#include <limits.h>
#include <float.h>
#include <math.h>
#include <pthread.h>
#include <sys/resource.h>
/* Our shared "common" objects */
struct sharedObjectsStruct shared;
/* Global vars that are actally used as constants. The following double
* values are used for double on-disk serialization, and are initialized
* at runtime to avoid strange compiler optimizations. */
double R_Zero, R_PosInf, R_NegInf, R_Nan;
/*================================= Globals ================================= */
/* Global vars */
struct redisServer server; /* server global state */
struct redisCommand *commandTable;
struct redisCommand readonlyCommandTable[] = {
{"get",getCommand,2,0,NULL,1,1,1},
{"set",setCommand,3,REDIS_CMD_DENYOOM,NULL,0,0,0},
{"setnx",setnxCommand,3,REDIS_CMD_DENYOOM,NULL,0,0,0},
{"setex",setexCommand,4,REDIS_CMD_DENYOOM,NULL,0,0,0},
{"append",appendCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"strlen",strlenCommand,2,0,NULL,1,1,1},
{"del",delCommand,-2,0,NULL,0,0,0},
{"exists",existsCommand,2,0,NULL,1,1,1},
{"setbit",setbitCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"getbit",getbitCommand,3,0,NULL,1,1,1},
{"setrange",setrangeCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"getrange",getrangeCommand,4,0,NULL,1,1,1},
{"substr",getrangeCommand,4,0,NULL,1,1,1},
{"incr",incrCommand,2,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"decr",decrCommand,2,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"mget",mgetCommand,-2,0,NULL,1,-1,1},
{"rpush",rpushCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"lpush",lpushCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"rpushx",rpushxCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"lpushx",lpushxCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"linsert",linsertCommand,5,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"rpop",rpopCommand,2,0,NULL,1,1,1},
{"lpop",lpopCommand,2,0,NULL,1,1,1},
{"brpop",brpopCommand,-3,0,NULL,1,1,1},
{"brpoplpush",brpoplpushCommand,4,REDIS_CMD_DENYOOM,NULL,1,2,1},
{"blpop",blpopCommand,-3,0,NULL,1,1,1},
{"llen",llenCommand,2,0,NULL,1,1,1},
{"lindex",lindexCommand,3,0,NULL,1,1,1},
{"lset",lsetCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"lrange",lrangeCommand,4,0,NULL,1,1,1},
{"ltrim",ltrimCommand,4,0,NULL,1,1,1},
{"lrem",lremCommand,4,0,NULL,1,1,1},
{"rpoplpush",rpoplpushCommand,3,REDIS_CMD_DENYOOM,NULL,1,2,1},
{"sadd",saddCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"srem",sremCommand,3,0,NULL,1,1,1},
{"smove",smoveCommand,4,0,NULL,1,2,1},
{"sismember",sismemberCommand,3,0,NULL,1,1,1},
{"scard",scardCommand,2,0,NULL,1,1,1},
{"spop",spopCommand,2,0,NULL,1,1,1},
{"srandmember",srandmemberCommand,2,0,NULL,1,1,1},
{"sinter",sinterCommand,-2,REDIS_CMD_DENYOOM,NULL,1,-1,1},
{"sinterstore",sinterstoreCommand,-3,REDIS_CMD_DENYOOM,NULL,2,-1,1},
{"sunion",sunionCommand,-2,REDIS_CMD_DENYOOM,NULL,1,-1,1},
{"sunionstore",sunionstoreCommand,-3,REDIS_CMD_DENYOOM,NULL,2,-1,1},
{"sdiff",sdiffCommand,-2,REDIS_CMD_DENYOOM,NULL,1,-1,1},
{"sdiffstore",sdiffstoreCommand,-3,REDIS_CMD_DENYOOM,NULL,2,-1,1},
{"smembers",sinterCommand,2,0,NULL,1,1,1},
{"zadd",zaddCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"zincrby",zincrbyCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"zrem",zremCommand,3,0,NULL,1,1,1},
{"zremrangebyscore",zremrangebyscoreCommand,4,0,NULL,1,1,1},
{"zremrangebyrank",zremrangebyrankCommand,4,0,NULL,1,1,1},
{"zunionstore",zunionstoreCommand,-4,REDIS_CMD_DENYOOM,zunionInterBlockClientOnSwappedKeys,0,0,0},
{"zinterstore",zinterstoreCommand,-4,REDIS_CMD_DENYOOM,zunionInterBlockClientOnSwappedKeys,0,0,0},
{"zrange",zrangeCommand,-4,0,NULL,1,1,1},
{"zrangebyscore",zrangebyscoreCommand,-4,0,NULL,1,1,1},
{"zrevrangebyscore",zrevrangebyscoreCommand,-4,0,NULL,1,1,1},
{"zcount",zcountCommand,4,0,NULL,1,1,1},
{"zrevrange",zrevrangeCommand,-4,0,NULL,1,1,1},
{"zcard",zcardCommand,2,0,NULL,1,1,1},
{"zscore",zscoreCommand,3,0,NULL,1,1,1},
{"zrank",zrankCommand,3,0,NULL,1,1,1},
{"zrevrank",zrevrankCommand,3,0,NULL,1,1,1},
{"hset",hsetCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"hsetnx",hsetnxCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"hget",hgetCommand,3,0,NULL,1,1,1},
{"hmset",hmsetCommand,-4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"hmget",hmgetCommand,-3,0,NULL,1,1,1},
{"hincrby",hincrbyCommand,4,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"hdel",hdelCommand,3,0,NULL,1,1,1},
{"hlen",hlenCommand,2,0,NULL,1,1,1},
{"hkeys",hkeysCommand,2,0,NULL,1,1,1},
{"hvals",hvalsCommand,2,0,NULL,1,1,1},
{"hgetall",hgetallCommand,2,0,NULL,1,1,1},
{"hexists",hexistsCommand,3,0,NULL,1,1,1},
{"incrby",incrbyCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"decrby",decrbyCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"getset",getsetCommand,3,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"mset",msetCommand,-3,REDIS_CMD_DENYOOM,NULL,1,-1,2},
{"msetnx",msetnxCommand,-3,REDIS_CMD_DENYOOM,NULL,1,-1,2},
{"randomkey",randomkeyCommand,1,0,NULL,0,0,0},
{"select",selectCommand,2,0,NULL,0,0,0},
{"move",moveCommand,3,0,NULL,1,1,1},
{"rename",renameCommand,3,0,NULL,1,1,1},
{"renamenx",renamenxCommand,3,0,NULL,1,1,1},
{"expire",expireCommand,3,0,NULL,0,0,0},
{"expireat",expireatCommand,3,0,NULL,0,0,0},
{"keys",keysCommand,2,0,NULL,0,0,0},
{"dbsize",dbsizeCommand,1,0,NULL,0,0,0},
{"auth",authCommand,2,0,NULL,0,0,0},
{"ping",pingCommand,1,0,NULL,0,0,0},
{"echo",echoCommand,2,0,NULL,0,0,0},
{"save",saveCommand,1,0,NULL,0,0,0},
{"bgsave",bgsaveCommand,1,0,NULL,0,0,0},
{"bgrewriteaof",bgrewriteaofCommand,1,0,NULL,0,0,0},
{"shutdown",shutdownCommand,1,0,NULL,0,0,0},
{"lastsave",lastsaveCommand,1,0,NULL,0,0,0},
{"type",typeCommand,2,0,NULL,1,1,1},
{"multi",multiCommand,1,0,NULL,0,0,0},
{"exec",execCommand,1,REDIS_CMD_DENYOOM,execBlockClientOnSwappedKeys,0,0,0},
{"discard",discardCommand,1,0,NULL,0,0,0},
{"sync",syncCommand,1,0,NULL,0,0,0},
{"flushdb",flushdbCommand,1,0,NULL,0,0,0},
{"flushall",flushallCommand,1,0,NULL,0,0,0},
{"sort",sortCommand,-2,REDIS_CMD_DENYOOM,NULL,1,1,1},
{"info",infoCommand,1,0,NULL,0,0,0},
{"monitor",monitorCommand,1,0,NULL,0,0,0},
{"ttl",ttlCommand,2,0,NULL,1,1,1},
{"persist",persistCommand,2,0,NULL,1,1,1},
{"slaveof",slaveofCommand,3,0,NULL,0,0,0},
{"debug",debugCommand,-2,0,NULL,0,0,0},
{"config",configCommand,-2,0,NULL,0,0,0},
{"subscribe",subscribeCommand,-2,0,NULL,0,0,0},
{"unsubscribe",unsubscribeCommand,-1,0,NULL,0,0,0},
{"psubscribe",psubscribeCommand,-2,0,NULL,0,0,0},
{"punsubscribe",punsubscribeCommand,-1,0,NULL,0,0,0},
{"publish",publishCommand,3,REDIS_CMD_FORCE_REPLICATION,NULL,0,0,0},
{"watch",watchCommand,-2,0,NULL,0,0,0},
{"unwatch",unwatchCommand,1,0,NULL,0,0,0}
};
/*============================ Utility functions ============================ */
void redisLog(int level, const char *fmt, ...) {
const int syslogLevelMap[] = { LOG_DEBUG, LOG_INFO, LOG_NOTICE, LOG_WARNING };
const char *c = ".-*#";
time_t now = time(NULL);
va_list ap;
FILE *fp;
char buf[64];
char msg[REDIS_MAX_LOGMSG_LEN];
if (level < server.verbosity) return;
fp = (server.logfile == NULL) ? stdout : fopen(server.logfile,"a");
if (!fp) return;
va_start(ap, fmt);
vsnprintf(msg, sizeof(msg), fmt, ap);
va_end(ap);
strftime(buf,sizeof(buf),"%d %b %H:%M:%S",localtime(&now));
fprintf(fp,"[%d] %s %c %s\n",(int)getpid(),buf,c[level],msg);
fflush(fp);
if (server.logfile) fclose(fp);
if (server.syslog_enabled) syslog(syslogLevelMap[level], "%s", msg);
}
/* Redis generally does not try to recover from out of memory conditions
* when allocating objects or strings, it is not clear if it will be possible
* to report this condition to the client since the networking layer itself
* is based on heap allocation for send buffers, so we simply abort.
* At least the code will be simpler to read... */
void oom(const char *msg) {
redisLog(REDIS_WARNING, "%s: Out of memory\n",msg);
sleep(1);
abort();
}
/*====================== Hash table type implementation ==================== */
/* This is an hash table type that uses the SDS dynamic strings libary as
* keys and radis objects as values (objects can hold SDS strings,
* lists, sets). */
void dictVanillaFree(void *privdata, void *val)
{
DICT_NOTUSED(privdata);
zfree(val);
}
void dictListDestructor(void *privdata, void *val)
{
DICT_NOTUSED(privdata);
listRelease((list*)val);
}
int dictSdsKeyCompare(void *privdata, const void *key1,
const void *key2)
{
int l1,l2;
DICT_NOTUSED(privdata);
l1 = sdslen((sds)key1);
l2 = sdslen((sds)key2);
if (l1 != l2) return 0;
return memcmp(key1, key2, l1) == 0;
}
/* A case insensitive version used for the command lookup table. */
int dictSdsKeyCaseCompare(void *privdata, const void *key1,
const void *key2)
{
DICT_NOTUSED(privdata);
return strcasecmp(key1, key2) == 0;
}
void dictRedisObjectDestructor(void *privdata, void *val)
{
DICT_NOTUSED(privdata);
if (val == NULL) return; /* Values of swapped out keys as set to NULL */
decrRefCount(val);
}
void dictSdsDestructor(void *privdata, void *val)
{
DICT_NOTUSED(privdata);
sdsfree(val);
}
int dictObjKeyCompare(void *privdata, const void *key1,
const void *key2)
{
const robj *o1 = key1, *o2 = key2;
return dictSdsKeyCompare(privdata,o1->ptr,o2->ptr);
}
unsigned int dictObjHash(const void *key) {
const robj *o = key;
return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
}
unsigned int dictSdsHash(const void *key) {
return dictGenHashFunction((unsigned char*)key, sdslen((char*)key));
}
unsigned int dictSdsCaseHash(const void *key) {
return dictGenCaseHashFunction((unsigned char*)key, sdslen((char*)key));
}
int dictEncObjKeyCompare(void *privdata, const void *key1,
const void *key2)
{
robj *o1 = (robj*) key1, *o2 = (robj*) key2;
int cmp;
if (o1->encoding == REDIS_ENCODING_INT &&
o2->encoding == REDIS_ENCODING_INT)
return o1->ptr == o2->ptr;
o1 = getDecodedObject(o1);
o2 = getDecodedObject(o2);
cmp = dictSdsKeyCompare(privdata,o1->ptr,o2->ptr);
decrRefCount(o1);
decrRefCount(o2);
return cmp;
}
unsigned int dictEncObjHash(const void *key) {
robj *o = (robj*) key;
if (o->encoding == REDIS_ENCODING_RAW) {
return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
} else {
if (o->encoding == REDIS_ENCODING_INT) {
char buf[32];
int len;
len = ll2string(buf,32,(long)o->ptr);
return dictGenHashFunction((unsigned char*)buf, len);
} else {
unsigned int hash;
o = getDecodedObject(o);
hash = dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
decrRefCount(o);
return hash;
}
}
}
/* Sets type */
dictType setDictType = {
dictEncObjHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictEncObjKeyCompare, /* key compare */
dictRedisObjectDestructor, /* key destructor */
NULL /* val destructor */
};
/* Sorted sets hash (note: a skiplist is used in addition to the hash table) */
dictType zsetDictType = {
dictEncObjHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictEncObjKeyCompare, /* key compare */
dictRedisObjectDestructor, /* key destructor */
NULL /* val destructor */
};
/* Db->dict, keys are sds strings, vals are Redis objects. */
dictType dbDictType = {
dictSdsHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictSdsKeyCompare, /* key compare */
dictSdsDestructor, /* key destructor */
dictRedisObjectDestructor /* val destructor */
};
/* Db->expires */
dictType keyptrDictType = {
dictSdsHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictSdsKeyCompare, /* key compare */
NULL, /* key destructor */
NULL /* val destructor */
};
/* Command table. sds string -> command struct pointer. */
dictType commandTableDictType = {
dictSdsCaseHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictSdsKeyCaseCompare, /* key compare */
dictSdsDestructor, /* key destructor */
NULL /* val destructor */
};
/* Hash type hash table (note that small hashes are represented with zimpaps) */
dictType hashDictType = {
dictEncObjHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictEncObjKeyCompare, /* key compare */
dictRedisObjectDestructor, /* key destructor */
dictRedisObjectDestructor /* val destructor */
};
/* Keylist hash table type has unencoded redis objects as keys and
* lists as values. It's used for blocking operations (BLPOP) and to
* map swapped keys to a list of clients waiting for this keys to be loaded. */
dictType keylistDictType = {
dictObjHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictObjKeyCompare, /* key compare */
dictRedisObjectDestructor, /* key destructor */
dictListDestructor /* val destructor */
};
int htNeedsResize(dict *dict) {
long long size, used;
size = dictSlots(dict);
used = dictSize(dict);
return (size && used && size > DICT_HT_INITIAL_SIZE &&
(used*100/size < REDIS_HT_MINFILL));
}
/* If the percentage of used slots in the HT reaches REDIS_HT_MINFILL
* we resize the hash table to save memory */
void tryResizeHashTables(void) {
int j;
for (j = 0; j < server.dbnum; j++) {
if (htNeedsResize(server.db[j].dict))
dictResize(server.db[j].dict);
if (htNeedsResize(server.db[j].expires))
dictResize(server.db[j].expires);
}
}
/* Our hash table implementation performs rehashing incrementally while
* we write/read from the hash table. Still if the server is idle, the hash
* table will use two tables for a long time. So we try to use 1 millisecond
* of CPU time at every serverCron() loop in order to rehash some key. */
void incrementallyRehash(void) {
int j;
for (j = 0; j < server.dbnum; j++) {
if (dictIsRehashing(server.db[j].dict)) {
dictRehashMilliseconds(server.db[j].dict,1);
break; /* already used our millisecond for this loop... */
}
}
}
/* This function is called once a background process of some kind terminates,
* as we want to avoid resizing the hash tables when there is a child in order
* to play well with copy-on-write (otherwise when a resize happens lots of
* memory pages are copied). The goal of this function is to update the ability
* for dict.c to resize the hash tables accordingly to the fact we have o not
* running childs. */
void updateDictResizePolicy(void) {
if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1)
dictEnableResize();
else
dictDisableResize();
}
/* ======================= Cron: called every 100 ms ======================== */
/* Try to expire a few timed out keys. The algorithm used is adaptive and
* will use few CPU cycles if there are few expiring keys, otherwise
* it will get more aggressive to avoid that too much memory is used by
* keys that can be removed from the keyspace. */
void activeExpireCycle(void) {
int j;
for (j = 0; j < server.dbnum; j++) {
int expired;
redisDb *db = server.db+j;
/* Continue to expire if at the end of the cycle more than 25%
* of the keys were expired. */
do {
long num = dictSize(db->expires);
time_t now = time(NULL);
expired = 0;
if (num > REDIS_EXPIRELOOKUPS_PER_CRON)
num = REDIS_EXPIRELOOKUPS_PER_CRON;
while (num--) {
dictEntry *de;
time_t t;
if ((de = dictGetRandomKey(db->expires)) == NULL) break;
t = (time_t) dictGetEntryVal(de);
if (now > t) {
sds key = dictGetEntryKey(de);
robj *keyobj = createStringObject(key,sdslen(key));
propagateExpire(db,keyobj);
dbDelete(db,keyobj);
decrRefCount(keyobj);
expired++;
server.stat_expiredkeys++;
}
}
} while (expired > REDIS_EXPIRELOOKUPS_PER_CRON/4);
}
}
void updateLRUClock(void) {
server.lruclock = (time(NULL)/REDIS_LRU_CLOCK_RESOLUTION) &
REDIS_LRU_CLOCK_MAX;
}
int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
int j, loops = server.cronloops;
REDIS_NOTUSED(eventLoop);
REDIS_NOTUSED(id);
REDIS_NOTUSED(clientData);
/* We take a cached value of the unix time in the global state because
* with virtual memory and aging there is to store the current time
* in objects at every object access, and accuracy is not needed.
* To access a global var is faster than calling time(NULL) */
server.unixtime = time(NULL);
/* We have just 22 bits per object for LRU information.
* So we use an (eventually wrapping) LRU clock with 10 seconds resolution.
* 2^22 bits with 10 seconds resoluton is more or less 1.5 years.
*
* Note that even if this will wrap after 1.5 years it's not a problem,
* everything will still work but just some object will appear younger
* to Redis. But for this to happen a given object should never be touched
* for 1.5 years.
*
* Note that you can change the resolution altering the
* REDIS_LRU_CLOCK_RESOLUTION define.
*/
updateLRUClock();
/* We received a SIGTERM, shutting down here in a safe way, as it is
* not ok doing so inside the signal handler. */
if (server.shutdown_asap) {
if (prepareForShutdown() == REDIS_OK) exit(0);
redisLog(REDIS_WARNING,"SIGTERM received but errors trying to shut down the server, check the logs for more information");
}
/* Show some info about non-empty databases */
for (j = 0; j < server.dbnum; j++) {
long long size, used, vkeys;
size = dictSlots(server.db[j].dict);
used = dictSize(server.db[j].dict);
vkeys = dictSize(server.db[j].expires);
if (!(loops % 50) && (used || vkeys)) {
redisLog(REDIS_VERBOSE,"DB %d: %lld keys (%lld volatile) in %lld slots HT.",j,used,vkeys,size);
/* dictPrintStats(server.dict); */
}
}
/* We don't want to resize the hash tables while a bacground saving
* is in progress: the saving child is created using fork() that is
* implemented with a copy-on-write semantic in most modern systems, so
* if we resize the HT while there is the saving child at work actually
* a lot of memory movements in the parent will cause a lot of pages
* copied. */
if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1) {
if (!(loops % 10)) tryResizeHashTables();
if (server.activerehashing) incrementallyRehash();
}
/* Show information about connected clients */
if (!(loops % 50)) {
redisLog(REDIS_VERBOSE,"%d clients connected (%d slaves), %zu bytes in use",
listLength(server.clients)-listLength(server.slaves),
listLength(server.slaves),
zmalloc_used_memory());
}
/* Close connections of timedout clients */
if ((server.maxidletime && !(loops % 100)) || server.bpop_blocked_clients)
closeTimedoutClients();
/* Check if a background saving or AOF rewrite in progress terminated */
if (server.bgsavechildpid != -1 || server.bgrewritechildpid != -1) {
int statloc;
pid_t pid;
if ((pid = wait3(&statloc,WNOHANG,NULL)) != 0) {
if (pid == server.bgsavechildpid) {
backgroundSaveDoneHandler(statloc);
} else {
backgroundRewriteDoneHandler(statloc);
}
updateDictResizePolicy();
}
} else {
/* If there is not a background saving in progress check if
* we have to save now */
time_t now = time(NULL);
for (j = 0; j < server.saveparamslen; j++) {
struct saveparam *sp = server.saveparams+j;
if (server.dirty >= sp->changes &&
now-server.lastsave > sp->seconds) {
redisLog(REDIS_NOTICE,"%d changes in %d seconds. Saving...",
sp->changes, sp->seconds);
rdbSaveBackground(server.dbfilename);
break;
}
}
}
/* Expire a few keys per cycle, only if this is a master.
* On slaves we wait for DEL operations synthesized by the master
* in order to guarantee a strict consistency. */
if (server.masterhost == NULL) activeExpireCycle();
/* Swap a few keys on disk if we are over the memory limit and VM
* is enbled. Try to free objects from the free list first. */
if (vmCanSwapOut()) {
while (server.vm_enabled && zmalloc_used_memory() >
server.vm_max_memory)
{
int retval = (server.vm_max_threads == 0) ?
vmSwapOneObjectBlocking() :
vmSwapOneObjectThreaded();
if (retval == REDIS_ERR && !(loops % 300) &&
zmalloc_used_memory() >
(server.vm_max_memory+server.vm_max_memory/10))
{
redisLog(REDIS_WARNING,"WARNING: vm-max-memory limit exceeded by more than 10%% but unable to swap more objects out!");
}
/* Note that when using threade I/O we free just one object,
* because anyway when the I/O thread in charge to swap this
* object out will finish, the handler of completed jobs
* will try to swap more objects if we are still out of memory. */
if (retval == REDIS_ERR || server.vm_max_threads > 0) break;
}
}
/* Replication cron function -- used to reconnect to master and
* to detect transfer failures. */
if (!(loops % 10)) replicationCron();
server.cronloops++;
return 100;
}
/* This function gets called every time Redis is entering the
* main loop of the event driven library, that is, before to sleep
* for ready file descriptors. */
void beforeSleep(struct aeEventLoop *eventLoop) {
REDIS_NOTUSED(eventLoop);
listNode *ln;
redisClient *c;
/* Awake clients that got all the swapped keys they requested */
if (server.vm_enabled && listLength(server.io_ready_clients)) {
listIter li;
listRewind(server.io_ready_clients,&li);
while((ln = listNext(&li))) {
c = ln->value;
struct redisCommand *cmd;
/* Resume the client. */
listDelNode(server.io_ready_clients,ln);
c->flags &= (~REDIS_IO_WAIT);
server.vm_blocked_clients--;
aeCreateFileEvent(server.el, c->fd, AE_READABLE,
readQueryFromClient, c);
cmd = lookupCommand(c->argv[0]->ptr);
redisAssert(cmd != NULL);
call(c,cmd);
resetClient(c);
/* There may be more data to process in the input buffer. */
if (c->querybuf && sdslen(c->querybuf) > 0)
processInputBuffer(c);
}
}
/* Try to process pending commands for clients that were just unblocked. */
while (listLength(server.unblocked_clients)) {
ln = listFirst(server.unblocked_clients);
redisAssert(ln != NULL);
c = ln->value;
listDelNode(server.unblocked_clients,ln);
c->flags &= ~REDIS_UNBLOCKED;
/* Process remaining data in the input buffer. */
if (c->querybuf && sdslen(c->querybuf) > 0)
processInputBuffer(c);
}
/* Write the AOF buffer on disk */
flushAppendOnlyFile();
}
/* =========================== Server initialization ======================== */
void createSharedObjects(void) {
int j;
shared.crlf = createObject(REDIS_STRING,sdsnew("\r\n"));
shared.ok = createObject(REDIS_STRING,sdsnew("+OK\r\n"));
shared.err = createObject(REDIS_STRING,sdsnew("-ERR\r\n"));
shared.emptybulk = createObject(REDIS_STRING,sdsnew("$0\r\n\r\n"));
shared.czero = createObject(REDIS_STRING,sdsnew(":0\r\n"));
shared.cone = createObject(REDIS_STRING,sdsnew(":1\r\n"));
shared.cnegone = createObject(REDIS_STRING,sdsnew(":-1\r\n"));
shared.nullbulk = createObject(REDIS_STRING,sdsnew("$-1\r\n"));
shared.nullmultibulk = createObject(REDIS_STRING,sdsnew("*-1\r\n"));
shared.emptymultibulk = createObject(REDIS_STRING,sdsnew("*0\r\n"));
shared.pong = createObject(REDIS_STRING,sdsnew("+PONG\r\n"));
shared.queued = createObject(REDIS_STRING,sdsnew("+QUEUED\r\n"));
shared.wrongtypeerr = createObject(REDIS_STRING,sdsnew(
"-ERR Operation against a key holding the wrong kind of value\r\n"));
shared.nokeyerr = createObject(REDIS_STRING,sdsnew(
"-ERR no such key\r\n"));
shared.syntaxerr = createObject(REDIS_STRING,sdsnew(
"-ERR syntax error\r\n"));
shared.sameobjecterr = createObject(REDIS_STRING,sdsnew(
"-ERR source and destination objects are the same\r\n"));
shared.outofrangeerr = createObject(REDIS_STRING,sdsnew(
"-ERR index out of range\r\n"));
shared.loadingerr = createObject(REDIS_STRING,sdsnew(
"-LOADING Redis is loading the dataset in memory\r\n"));
shared.space = createObject(REDIS_STRING,sdsnew(" "));
shared.colon = createObject(REDIS_STRING,sdsnew(":"));
shared.plus = createObject(REDIS_STRING,sdsnew("+"));
shared.select0 = createStringObject("select 0\r\n",10);
shared.select1 = createStringObject("select 1\r\n",10);
shared.select2 = createStringObject("select 2\r\n",10);
shared.select3 = createStringObject("select 3\r\n",10);
shared.select4 = createStringObject("select 4\r\n",10);
shared.select5 = createStringObject("select 5\r\n",10);
shared.select6 = createStringObject("select 6\r\n",10);
shared.select7 = createStringObject("select 7\r\n",10);
shared.select8 = createStringObject("select 8\r\n",10);
shared.select9 = createStringObject("select 9\r\n",10);
shared.messagebulk = createStringObject("$7\r\nmessage\r\n",13);
shared.pmessagebulk = createStringObject("$8\r\npmessage\r\n",14);
shared.subscribebulk = createStringObject("$9\r\nsubscribe\r\n",15);
shared.unsubscribebulk = createStringObject("$11\r\nunsubscribe\r\n",18);
shared.psubscribebulk = createStringObject("$10\r\npsubscribe\r\n",17);
shared.punsubscribebulk = createStringObject("$12\r\npunsubscribe\r\n",19);
shared.mbulk3 = createStringObject("*3\r\n",4);
shared.mbulk4 = createStringObject("*4\r\n",4);
for (j = 0; j < REDIS_SHARED_INTEGERS; j++) {
shared.integers[j] = createObject(REDIS_STRING,(void*)(long)j);
shared.integers[j]->encoding = REDIS_ENCODING_INT;
}
}
void initServerConfig() {
server.port = REDIS_SERVERPORT;
server.bindaddr = NULL;
server.unixsocket = NULL;
server.ipfd = -1;
server.sofd = -1;
server.dbnum = REDIS_DEFAULT_DBNUM;
server.verbosity = REDIS_VERBOSE;
server.maxidletime = REDIS_MAXIDLETIME;
server.saveparams = NULL;
server.loading = 0;
server.logfile = NULL; /* NULL = log on standard output */
server.syslog_enabled = 0;
server.syslog_ident = zstrdup("redis");
server.syslog_facility = LOG_LOCAL0;
server.daemonize = 0;
server.appendonly = 0;
server.appendfsync = APPENDFSYNC_EVERYSEC;
server.no_appendfsync_on_rewrite = 0;
server.lastfsync = time(NULL);
server.appendfd = -1;
server.appendseldb = -1; /* Make sure the first time will not match */
server.pidfile = zstrdup("/var/run/redis.pid");
server.dbfilename = zstrdup("dump.rdb");
server.appendfilename = zstrdup("appendonly.aof");
server.requirepass = NULL;
server.rdbcompression = 1;
server.activerehashing = 1;
server.maxclients = 0;
server.bpop_blocked_clients = 0;
server.maxmemory = 0;
server.maxmemory_policy = REDIS_MAXMEMORY_VOLATILE_LRU;
server.maxmemory_samples = 3;
server.vm_enabled = 0;
server.vm_swap_file = zstrdup("/tmp/redis-%p.vm");
server.vm_page_size = 256; /* 256 bytes per page */
server.vm_pages = 1024*1024*100; /* 104 millions of pages */
server.vm_max_memory = 1024LL*1024*1024*1; /* 1 GB of RAM */
server.vm_max_threads = 4;
server.vm_blocked_clients = 0;
server.hash_max_zipmap_entries = REDIS_HASH_MAX_ZIPMAP_ENTRIES;
server.hash_max_zipmap_value = REDIS_HASH_MAX_ZIPMAP_VALUE;
server.list_max_ziplist_entries = REDIS_LIST_MAX_ZIPLIST_ENTRIES;
server.list_max_ziplist_value = REDIS_LIST_MAX_ZIPLIST_VALUE;
server.set_max_intset_entries = REDIS_SET_MAX_INTSET_ENTRIES;
server.shutdown_asap = 0;
updateLRUClock();
resetServerSaveParams();
appendServerSaveParams(60*60,1); /* save after 1 hour and 1 change */
appendServerSaveParams(300,100); /* save after 5 minutes and 100 changes */
appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
/* Replication related */
server.isslave = 0;
server.masterauth = NULL;
server.masterhost = NULL;
server.masterport = 6379;
server.master = NULL;
server.replstate = REDIS_REPL_NONE;
server.repl_serve_stale_data = 1;
/* Double constants initialization */
R_Zero = 0.0;
R_PosInf = 1.0/R_Zero;
R_NegInf = -1.0/R_Zero;
R_Nan = R_Zero/R_Zero;
/* Command table -- we intiialize it here as it is part of the
* initial configuration, since command names may be changed via
* redis.conf using the rename-command directive. */
server.commands = dictCreate(&commandTableDictType,NULL);
populateCommandTable();
server.delCommand = lookupCommandByCString("del");
server.multiCommand = lookupCommandByCString("multi");
}
void initServer() {
int j;
signal(SIGHUP, SIG_IGN);
signal(SIGPIPE, SIG_IGN);
setupSigSegvAction();
if (server.syslog_enabled) {
openlog(server.syslog_ident, LOG_PID | LOG_NDELAY | LOG_NOWAIT,
server.syslog_facility);
}
server.mainthread = pthread_self();
server.clients = listCreate();
server.slaves = listCreate();
server.monitors = listCreate();
server.unblocked_clients = listCreate();
createSharedObjects();
server.el = aeCreateEventLoop();
server.db = zmalloc(sizeof(redisDb)*server.dbnum);
if (server.port != 0)
server.ipfd = anetTcpServer(server.neterr,server.port,server.bindaddr);
if (server.ipfd == ANET_ERR) {
redisLog(REDIS_WARNING, "Opening port: %s", server.neterr);
exit(1);
}
if (server.unixsocket != NULL) {
unlink(server.unixsocket); /* don't care if this fails */
server.sofd = anetUnixServer(server.neterr,server.unixsocket);
if (server.sofd == ANET_ERR) {
redisLog(REDIS_WARNING, "Opening socket: %s", server.neterr);
exit(1);
}
}
if (server.ipfd < 0 && server.sofd < 0) {
redisLog(REDIS_WARNING, "Configured to not listen anywhere, exiting.");
exit(1);
}
for (j = 0; j < server.dbnum; j++) {
server.db[j].dict = dictCreate(&dbDictType,NULL);
server.db[j].expires = dictCreate(&keyptrDictType,NULL);
server.db[j].blocking_keys = dictCreate(&keylistDictType,NULL);
server.db[j].watched_keys = dictCreate(&keylistDictType,NULL);
if (server.vm_enabled)
server.db[j].io_keys = dictCreate(&keylistDictType,NULL);
server.db[j].id = j;
}
server.pubsub_channels = dictCreate(&keylistDictType,NULL);
server.pubsub_patterns = listCreate();
listSetFreeMethod(server.pubsub_patterns,freePubsubPattern);
listSetMatchMethod(server.pubsub_patterns,listMatchPubsubPattern);
server.cronloops = 0;
server.bgsavechildpid = -1;
server.bgrewritechildpid = -1;
server.bgrewritebuf = sdsempty();
server.aofbuf = sdsempty();
server.lastsave = time(NULL);
server.dirty = 0;
server.stat_numcommands = 0;
server.stat_numconnections = 0;
server.stat_expiredkeys = 0;
server.stat_evictedkeys = 0;
server.stat_starttime = time(NULL);
server.stat_keyspace_misses = 0;
server.stat_keyspace_hits = 0;
server.unixtime = time(NULL);
aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL);
if (server.ipfd > 0 && aeCreateFileEvent(server.el,server.ipfd,AE_READABLE,
acceptTcpHandler,NULL) == AE_ERR) oom("creating file event");
if (server.sofd > 0 && aeCreateFileEvent(server.el,server.sofd,AE_READABLE,
acceptUnixHandler,NULL) == AE_ERR) oom("creating file event");
if (server.appendonly) {
server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT,0644);
if (server.appendfd == -1) {
redisLog(REDIS_WARNING, "Can't open the append-only file: %s",
strerror(errno));
exit(1);
}
}
if (server.vm_enabled) vmInit();
}
/* Populates the Redis Command Table starting from the hard coded list
* we have on top of redis.c file. */
void populateCommandTable(void) {
int j;
int numcommands = sizeof(readonlyCommandTable)/sizeof(struct redisCommand);
for (j = 0; j < numcommands; j++) {
struct redisCommand *c = readonlyCommandTable+j;
int retval;
retval = dictAdd(server.commands, sdsnew(c->name), c);
assert(retval == DICT_OK);
}
}
/* ====================== Commands lookup and execution ===================== */
struct redisCommand *lookupCommand(sds name) {
return dictFetchValue(server.commands, name);
}
struct redisCommand *lookupCommandByCString(char *s) {
struct redisCommand *cmd;
sds name = sdsnew(s);
cmd = dictFetchValue(server.commands, name);
sdsfree(name);
return cmd;
}
/* Call() is the core of Redis execution of a command */
void call(redisClient *c, struct redisCommand *cmd) {
long long dirty;
dirty = server.dirty;
cmd->proc(c);
dirty = server.dirty-dirty;
if (server.appendonly && dirty)
feedAppendOnlyFile(cmd,c->db->id,c->argv,c->argc);
if ((dirty || cmd->flags & REDIS_CMD_FORCE_REPLICATION) &&
listLength(server.slaves))
replicationFeedSlaves(server.slaves,c->db->id,c->argv,c->argc);
if (listLength(server.monitors))
replicationFeedMonitors(server.monitors,c->db->id,c->argv,c->argc);
server.stat_numcommands++;
}
/* If this function gets called we already read a whole
* command, argments are in the client argv/argc fields.
* processCommand() execute the command or prepare the
* server for a bulk read from the client.
*
* If 1 is returned the client is still alive and valid and
* and other operations can be performed by the caller. Otherwise
* if 0 is returned the client was destroied (i.e. after QUIT). */
int processCommand(redisClient *c) {
struct redisCommand *cmd;
/* The QUIT command is handled separately. Normal command procs will
* go through checking for replication and QUIT will cause trouble
* when FORCE_REPLICATION is enabled and would be implemented in
* a regular command proc. */
if (!strcasecmp(c->argv[0]->ptr,"quit")) {
addReply(c,shared.ok);
c->flags |= REDIS_CLOSE_AFTER_REPLY;
return REDIS_ERR;
}
/* Now lookup the command and check ASAP about trivial error conditions
* such wrong arity, bad command name and so forth. */
cmd = lookupCommand(c->argv[0]->ptr);
if (!cmd) {
addReplyErrorFormat(c,"unknown command '%s'",
(char*)c->argv[0]->ptr);
return REDIS_OK;
} else if ((cmd->arity > 0 && cmd->arity != c->argc) ||
(c->argc < -cmd->arity)) {
addReplyErrorFormat(c,"wrong number of arguments for '%s' command",
cmd->name);