/
redis.c
3318 lines (2973 loc) · 127 KB
/
redis.c
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/*
* Copyright (c) 2009-2012, 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"
#include "slowlog.h"
#include "bio.h"
#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 <sys/resource.h>
#include <sys/utsname.h>
#include <locale.h>
/* Our shared "common" objects */
struct sharedObjectsStruct shared;
/* Global vars that are actually 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;
/* Our command table.
*
* Every entry is composed of the following fields:
*
* name: a string representing the command name.
* function: pointer to the C function implementing the command.
* arity: number of arguments, it is possible to use -N to say >= N
* sflags: command flags as string. See below for a table of flags.
* flags: flags as bitmask. Computed by Redis using the 'sflags' field.
* get_keys_proc: an optional function to get key arguments from a command.
* This is only used when the following three fields are not
* enough to specify what arguments are keys.
* first_key_index: first argument that is a key
* last_key_index: last argument that is a key
* key_step: step to get all the keys from first to last argument. For instance
* in MSET the step is two since arguments are key,val,key,val,...
* microseconds: microseconds of total execution time for this command.
* calls: total number of calls of this command.
*
* The flags, microseconds and calls fields are computed by Redis and should
* always be set to zero.
*
* Command flags are expressed using strings where every character represents
* a flag. Later the populateCommandTable() function will take care of
* populating the real 'flags' field using this characters.
*
* This is the meaning of the flags:
*
* w: write command (may modify the key space).
* r: read command (will never modify the key space).
* m: may increase memory usage once called. Don't allow if out of memory.
* a: admin command, like SAVE or SHUTDOWN.
* p: Pub/Sub related command.
* f: force replication of this command, regardless of server.dirty.
* s: command not allowed in scripts.
* R: random command. Command is not deterministic, that is, the same command
* with the same arguments, with the same key space, may have different
* results. For instance SPOP and RANDOMKEY are two random commands.
* S: Sort command output array if called from script, so that the output
* is deterministic.
* l: Allow command while loading the database.
* t: Allow command while a slave has stale data but is not allowed to
* server this data. Normally no command is accepted in this condition
* but just a few.
* M: Do not automatically propagate the command on MONITOR.
* F: Fast command: O(1) or O(log(N)) command that should never delay
* its execution as long as the kernel scheduler is giving us time.
* Note that commands that may trigger a DEL as a side effect (like SET)
* are not fast commands.
*/
struct redisCommand redisCommandTable[] = {
{"get",getCommand,2,"rF",0,NULL,1,1,1,0,0},
{"set",setCommand,-3,"wm",0,NULL,1,1,1,0,0},
{"setnx",setnxCommand,3,"wmF",0,NULL,1,1,1,0,0},
{"setex",setexCommand,4,"wm",0,NULL,1,1,1,0,0},
{"psetex",psetexCommand,4,"wm",0,NULL,1,1,1,0,0},
{"append",appendCommand,3,"wm",0,NULL,1,1,1,0,0},
{"strlen",strlenCommand,2,"rF",0,NULL,1,1,1,0,0},
{"del",delCommand,-2,"w",0,NULL,1,-1,1,0,0},
{"exists",existsCommand,2,"rF",0,NULL,1,1,1,0,0},
{"setbit",setbitCommand,4,"wm",0,NULL,1,1,1,0,0},
{"getbit",getbitCommand,3,"rF",0,NULL,1,1,1,0,0},
{"setrange",setrangeCommand,4,"wm",0,NULL,1,1,1,0,0},
{"getrange",getrangeCommand,4,"r",0,NULL,1,1,1,0,0},
{"substr",getrangeCommand,4,"r",0,NULL,1,1,1,0,0},
{"incr",incrCommand,2,"wmF",0,NULL,1,1,1,0,0},
{"decr",decrCommand,2,"wmF",0,NULL,1,1,1,0,0},
{"mget",mgetCommand,-2,"r",0,NULL,1,-1,1,0,0},
{"rpush",rpushCommand,-3,"wmF",0,NULL,1,1,1,0,0},
{"lpush",lpushCommand,-3,"wmF",0,NULL,1,1,1,0,0},
{"rpushx",rpushxCommand,3,"wmF",0,NULL,1,1,1,0,0},
{"lpushx",lpushxCommand,3,"wmF",0,NULL,1,1,1,0,0},
{"linsert",linsertCommand,5,"wm",0,NULL,1,1,1,0,0},
{"rpop",rpopCommand,2,"wF",0,NULL,1,1,1,0,0},
{"lpop",lpopCommand,2,"wF",0,NULL,1,1,1,0,0},
{"brpop",brpopCommand,-3,"ws",0,NULL,1,1,1,0,0},
{"brpoplpush",brpoplpushCommand,4,"wms",0,NULL,1,2,1,0,0},
{"blpop",blpopCommand,-3,"ws",0,NULL,1,-2,1,0,0},
{"llen",llenCommand,2,"rF",0,NULL,1,1,1,0,0},
{"lindex",lindexCommand,3,"r",0,NULL,1,1,1,0,0},
{"lset",lsetCommand,4,"wm",0,NULL,1,1,1,0,0},
{"lrange",lrangeCommand,4,"r",0,NULL,1,1,1,0,0},
{"ltrim",ltrimCommand,4,"w",0,NULL,1,1,1,0,0},
{"lrem",lremCommand,4,"w",0,NULL,1,1,1,0,0},
{"rpoplpush",rpoplpushCommand,3,"wm",0,NULL,1,2,1,0,0},
{"sadd",saddCommand,-3,"wmF",0,NULL,1,1,1,0,0},
{"srem",sremCommand,-3,"wF",0,NULL,1,1,1,0,0},
{"smove",smoveCommand,4,"wF",0,NULL,1,2,1,0,0},
{"sismember",sismemberCommand,3,"rF",0,NULL,1,1,1,0,0},
{"scard",scardCommand,2,"rF",0,NULL,1,1,1,0,0},
{"spop",spopCommand,2,"wRsF",0,NULL,1,1,1,0,0},
{"srandmember",srandmemberCommand,-2,"rR",0,NULL,1,1,1,0,0},
{"sinter",sinterCommand,-2,"rS",0,NULL,1,-1,1,0,0},
{"sinterstore",sinterstoreCommand,-3,"wm",0,NULL,1,-1,1,0,0},
{"sunion",sunionCommand,-2,"rS",0,NULL,1,-1,1,0,0},
{"sunionstore",sunionstoreCommand,-3,"wm",0,NULL,1,-1,1,0,0},
{"sdiff",sdiffCommand,-2,"rS",0,NULL,1,-1,1,0,0},
{"sdiffstore",sdiffstoreCommand,-3,"wm",0,NULL,1,-1,1,0,0},
{"smembers",sinterCommand,2,"rS",0,NULL,1,1,1,0,0},
{"sscan",sscanCommand,-3,"rR",0,NULL,1,1,1,0,0},
{"zadd",zaddCommand,-4,"wmF",0,NULL,1,1,1,0,0},
{"zincrby",zincrbyCommand,4,"wmF",0,NULL,1,1,1,0,0},
{"zrem",zremCommand,-3,"wF",0,NULL,1,1,1,0,0},
{"zremrangebyscore",zremrangebyscoreCommand,4,"w",0,NULL,1,1,1,0,0},
{"zremrangebyrank",zremrangebyrankCommand,4,"w",0,NULL,1,1,1,0,0},
{"zremrangebylex",zremrangebylexCommand,4,"w",0,NULL,1,1,1,0,0},
{"zunionstore",zunionstoreCommand,-4,"wm",0,zunionInterGetKeys,0,0,0,0,0},
{"zinterstore",zinterstoreCommand,-4,"wm",0,zunionInterGetKeys,0,0,0,0,0},
{"zrange",zrangeCommand,-4,"r",0,NULL,1,1,1,0,0},
{"zrangebyscore",zrangebyscoreCommand,-4,"r",0,NULL,1,1,1,0,0},
{"zrevrangebyscore",zrevrangebyscoreCommand,-4,"r",0,NULL,1,1,1,0,0},
{"zrangebylex",zrangebylexCommand,-4,"r",0,NULL,1,1,1,0,0},
{"zrevrangebylex",zrevrangebylexCommand,-4,"r",0,NULL,1,1,1,0,0},
{"zcount",zcountCommand,4,"rF",0,NULL,1,1,1,0,0},
{"zlexcount",zlexcountCommand,4,"rF",0,NULL,1,1,1,0,0},
{"zrevrange",zrevrangeCommand,-4,"r",0,NULL,1,1,1,0,0},
{"zcard",zcardCommand,2,"rF",0,NULL,1,1,1,0,0},
{"zscore",zscoreCommand,3,"rF",0,NULL,1,1,1,0,0},
{"zrank",zrankCommand,3,"rF",0,NULL,1,1,1,0,0},
{"zrevrank",zrevrankCommand,3,"rF",0,NULL,1,1,1,0,0},
{"zscan",zscanCommand,-3,"rR",0,NULL,1,1,1,0,0},
{"hset",hsetCommand,4,"wmF",0,NULL,1,1,1,0,0},
{"hsetnx",hsetnxCommand,4,"wmF",0,NULL,1,1,1,0,0},
{"hget",hgetCommand,3,"rF",0,NULL,1,1,1,0,0},
{"hmset",hmsetCommand,-4,"wm",0,NULL,1,1,1,0,0},
{"hmget",hmgetCommand,-3,"r",0,NULL,1,1,1,0,0},
{"hincrby",hincrbyCommand,4,"wmF",0,NULL,1,1,1,0,0},
{"hincrbyfloat",hincrbyfloatCommand,4,"wmF",0,NULL,1,1,1,0,0},
{"hdel",hdelCommand,-3,"wF",0,NULL,1,1,1,0,0},
{"hlen",hlenCommand,2,"rF",0,NULL,1,1,1,0,0},
{"hkeys",hkeysCommand,2,"rS",0,NULL,1,1,1,0,0},
{"hvals",hvalsCommand,2,"rS",0,NULL,1,1,1,0,0},
{"hgetall",hgetallCommand,2,"r",0,NULL,1,1,1,0,0},
{"hexists",hexistsCommand,3,"rF",0,NULL,1,1,1,0,0},
{"hscan",hscanCommand,-3,"rR",0,NULL,1,1,1,0,0},
{"incrby",incrbyCommand,3,"wmF",0,NULL,1,1,1,0,0},
{"decrby",decrbyCommand,3,"wmF",0,NULL,1,1,1,0,0},
{"incrbyfloat",incrbyfloatCommand,3,"wmF",0,NULL,1,1,1,0,0},
{"getset",getsetCommand,3,"wm",0,NULL,1,1,1,0,0},
{"mset",msetCommand,-3,"wm",0,NULL,1,-1,2,0,0},
{"msetnx",msetnxCommand,-3,"wm",0,NULL,1,-1,2,0,0},
{"randomkey",randomkeyCommand,1,"rR",0,NULL,0,0,0,0,0},
{"select",selectCommand,2,"rlF",0,NULL,0,0,0,0,0},
{"move",moveCommand,3,"wF",0,NULL,1,1,1,0,0},
{"rename",renameCommand,3,"w",0,NULL,1,2,1,0,0},
{"renamenx",renamenxCommand,3,"wF",0,NULL,1,2,1,0,0},
{"expire",expireCommand,3,"wF",0,NULL,1,1,1,0,0},
{"expireat",expireatCommand,3,"wF",0,NULL,1,1,1,0,0},
{"pexpire",pexpireCommand,3,"wF",0,NULL,1,1,1,0,0},
{"pexpireat",pexpireatCommand,3,"wF",0,NULL,1,1,1,0,0},
{"keys",keysCommand,2,"rS",0,NULL,0,0,0,0,0},
{"scan",scanCommand,-2,"rR",0,NULL,0,0,0,0,0},
{"dbsize",dbsizeCommand,1,"rF",0,NULL,0,0,0,0,0},
{"auth",authCommand,2,"rsltF",0,NULL,0,0,0,0,0},
{"ping",pingCommand,-1,"rtF",0,NULL,0,0,0,0,0},
{"echo",echoCommand,2,"rF",0,NULL,0,0,0,0,0},
{"save",saveCommand,1,"ars",0,NULL,0,0,0,0,0},
{"bgsave",bgsaveCommand,1,"ar",0,NULL,0,0,0,0,0},
{"bgrewriteaof",bgrewriteaofCommand,1,"ar",0,NULL,0,0,0,0,0},
{"shutdown",shutdownCommand,-1,"arlt",0,NULL,0,0,0,0,0},
{"lastsave",lastsaveCommand,1,"rRF",0,NULL,0,0,0,0,0},
{"type",typeCommand,2,"rF",0,NULL,1,1,1,0,0},
{"multi",multiCommand,1,"rsF",0,NULL,0,0,0,0,0},
{"exec",execCommand,1,"sM",0,NULL,0,0,0,0,0},
{"discard",discardCommand,1,"rsF",0,NULL,0,0,0,0,0},
{"sync",syncCommand,1,"ars",0,NULL,0,0,0,0,0},
{"psync",syncCommand,3,"ars",0,NULL,0,0,0,0,0},
{"replconf",replconfCommand,-1,"arslt",0,NULL,0,0,0,0,0},
{"flushdb",flushdbCommand,1,"w",0,NULL,0,0,0,0,0},
{"flushall",flushallCommand,1,"w",0,NULL,0,0,0,0,0},
{"sort",sortCommand,-2,"wm",0,NULL,1,1,1,0,0},
{"info",infoCommand,-1,"rlt",0,NULL,0,0,0,0,0},
{"monitor",monitorCommand,1,"ars",0,NULL,0,0,0,0,0},
{"ttl",ttlCommand,2,"rF",0,NULL,1,1,1,0,0},
{"pttl",pttlCommand,2,"rF",0,NULL,1,1,1,0,0},
{"persist",persistCommand,2,"wF",0,NULL,1,1,1,0,0},
{"slaveof",slaveofCommand,3,"ast",0,NULL,0,0,0,0,0},
{"role",roleCommand,1,"last",0,NULL,0,0,0,0,0},
{"debug",debugCommand,-2,"as",0,NULL,0,0,0,0,0},
{"config",configCommand,-2,"art",0,NULL,0,0,0,0,0},
{"subscribe",subscribeCommand,-2,"rpslt",0,NULL,0,0,0,0,0},
{"unsubscribe",unsubscribeCommand,-1,"rpslt",0,NULL,0,0,0,0,0},
{"psubscribe",psubscribeCommand,-2,"rpslt",0,NULL,0,0,0,0,0},
{"punsubscribe",punsubscribeCommand,-1,"rpslt",0,NULL,0,0,0,0,0},
{"publish",publishCommand,3,"pltrF",0,NULL,0,0,0,0,0},
{"pubsub",pubsubCommand,-2,"pltrR",0,NULL,0,0,0,0,0},
{"watch",watchCommand,-2,"rsF",0,NULL,1,-1,1,0,0},
{"unwatch",unwatchCommand,1,"rsF",0,NULL,0,0,0,0,0},
{"restore",restoreCommand,4,"awm",0,NULL,1,1,1,0,0},
{"migrate",migrateCommand,6,"aw",0,NULL,0,0,0,0,0},
{"dump",dumpCommand,2,"ar",0,NULL,1,1,1,0,0},
{"object",objectCommand,3,"r",0,NULL,2,2,2,0,0},
{"client",clientCommand,-2,"ar",0,NULL,0,0,0,0,0},
{"eval",evalCommand,-3,"s",0,zunionInterGetKeys,0,0,0,0,0},
{"evalsha",evalShaCommand,-3,"s",0,zunionInterGetKeys,0,0,0,0,0},
{"slowlog",slowlogCommand,-2,"r",0,NULL,0,0,0,0,0},
{"script",scriptCommand,-2,"ras",0,NULL,0,0,0,0,0},
{"time",timeCommand,1,"rRF",0,NULL,0,0,0,0,0},
{"bitop",bitopCommand,-4,"wm",0,NULL,2,-1,1,0,0},
{"bitcount",bitcountCommand,-2,"r",0,NULL,1,1,1,0,0},
{"bitpos",bitposCommand,-3,"r",0,NULL,1,1,1,0,0},
{"command",commandCommand,0,"rlt",0,NULL,0,0,0,0,0},
{"pfselftest",pfselftestCommand,1,"r",0,NULL,0,0,0,0,0},
{"pfadd",pfaddCommand,-2,"wmF",0,NULL,1,1,1,0,0},
{"pfcount",pfcountCommand,-2,"w",0,NULL,1,1,1,0,0},
{"pfmerge",pfmergeCommand,-2,"wm",0,NULL,1,-1,1,0,0},
{"pfdebug",pfdebugCommand,-3,"w",0,NULL,0,0,0,0,0},
{"latency",latencyCommand,-2,"arslt",0,NULL,0,0,0,0,0}
};
/*============================ Utility functions ============================ */
/* Low level logging. To use only for very big messages, otherwise
* redisLog() is to prefer. */
void redisLogRaw(int level, const char *msg) {
const int syslogLevelMap[] = { LOG_DEBUG, LOG_INFO, LOG_NOTICE, LOG_WARNING };
const char *c = ".-*#";
FILE *fp;
char buf[64];
int rawmode = (level & REDIS_LOG_RAW);
int log_to_stdout = server.logfile[0] == '\0';
level &= 0xff; /* clear flags */
if (level < server.verbosity) return;
fp = log_to_stdout ? stdout : fopen(server.logfile,"a");
if (!fp) return;
if (rawmode) {
fprintf(fp,"%s",msg);
} else {
int off;
struct timeval tv;
gettimeofday(&tv,NULL);
off = strftime(buf,sizeof(buf),"%d %b %H:%M:%S.",localtime(&tv.tv_sec));
snprintf(buf+off,sizeof(buf)-off,"%03d",(int)tv.tv_usec/1000);
fprintf(fp,"[%d] %s %c %s\n",(int)getpid(),buf,c[level],msg);
}
fflush(fp);
if (!log_to_stdout) fclose(fp);
if (server.syslog_enabled) syslog(syslogLevelMap[level], "%s", msg);
}
/* Like redisLogRaw() but with printf-alike support. This is the function that
* is used across the code. The raw version is only used in order to dump
* the INFO output on crash. */
void redisLog(int level, const char *fmt, ...) {
va_list ap;
char msg[REDIS_MAX_LOGMSG_LEN];
if ((level&0xff) < server.verbosity) return;
va_start(ap, fmt);
vsnprintf(msg, sizeof(msg), fmt, ap);
va_end(ap);
redisLogRaw(level,msg);
}
/* Log a fixed message without printf-alike capabilities, in a way that is
* safe to call from a signal handler.
*
* We actually use this only for signals that are not fatal from the point
* of view of Redis. Signals that are going to kill the server anyway and
* where we need printf-alike features are served by redisLog(). */
void redisLogFromHandler(int level, const char *msg) {
int fd;
int log_to_stdout = server.logfile[0] == '\0';
char buf[64];
if ((level&0xff) < server.verbosity || (log_to_stdout && server.daemonize))
return;
fd = log_to_stdout ? STDOUT_FILENO :
open(server.logfile, O_APPEND|O_CREAT|O_WRONLY, 0644);
if (fd == -1) return;
ll2string(buf,sizeof(buf),getpid());
if (write(fd,"[",1) == -1) goto err;
if (write(fd,buf,strlen(buf)) == -1) goto err;
if (write(fd," | signal handler] (",20) == -1) goto err;
ll2string(buf,sizeof(buf),time(NULL));
if (write(fd,buf,strlen(buf)) == -1) goto err;
if (write(fd,") ",2) == -1) goto err;
if (write(fd,msg,strlen(msg)) == -1) goto err;
if (write(fd,"\n",1) == -1) goto err;
err:
if (!log_to_stdout) close(fd);
}
/* Return the UNIX time in microseconds */
long long ustime(void) {
struct timeval tv;
long long ust;
gettimeofday(&tv, NULL);
ust = ((long long)tv.tv_sec)*1000000;
ust += tv.tv_usec;
return ust;
}
/* Return the UNIX time in milliseconds */
long long mstime(void) {
return ustime()/1000;
}
/* After an RDB dump or AOF rewrite we exit from children using _exit() instead of
* exit(), because the latter may interact with the same file objects used by
* the parent process. However if we are testing the coverage normal exit() is
* used in order to obtain the right coverage information. */
void exitFromChild(int retcode) {
#ifdef COVERAGE_TEST
exit(retcode);
#else
_exit(retcode);
#endif
}
/*====================== Hash table type implementation ==================== */
/* This is a hash table type that uses the SDS dynamic strings library 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 and other
* places where case insensitive non binary-safe comparison is needed. */
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 hash table */
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 */
};
/* server.lua_scripts sha (as sds string) -> scripts (as robj) cache. */
dictType shaScriptObjectDictType = {
dictSdsCaseHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictSdsKeyCaseCompare, /* 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 ziplists) */
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 */
};
/* Replication cached script dict (server.repl_scriptcache_dict).
* Keys are sds SHA1 strings, while values are not used at all in the current
* implementation. */
dictType replScriptCacheDictType = {
dictSdsCaseHash, /* hash function */
NULL, /* key dup */
NULL, /* val dup */
dictSdsKeyCaseCompare, /* key compare */
dictSdsDestructor, /* key destructor */
NULL /* 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(int dbid) {
if (htNeedsResize(server.db[dbid].dict))
dictResize(server.db[dbid].dict);
if (htNeedsResize(server.db[dbid].expires))
dictResize(server.db[dbid].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 call of this function to perform some rehahsing.
*
* The function returns 1 if some rehashing was performed, otherwise 0
* is returned. */
int incrementallyRehash(int dbid) {
/* Keys dictionary */
if (dictIsRehashing(server.db[dbid].dict)) {
dictRehashMilliseconds(server.db[dbid].dict,1);
return 1; /* already used our millisecond for this loop... */
}
/* Expires */
if (dictIsRehashing(server.db[dbid].expires)) {
dictRehashMilliseconds(server.db[dbid].expires,1);
return 1; /* already used our millisecond for this loop... */
}
return 0;
}
/* 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.rdb_child_pid == -1 && server.aof_child_pid == -1)
dictEnableResize();
else
dictDisableResize();
}
/* ======================= Cron: called every 100 ms ======================== */
/* Helper function for the activeExpireCycle() function.
* This function will try to expire the key that is stored in the hash table
* entry 'de' of the 'expires' hash table of a Redis database.
*
* If the key is found to be expired, it is removed from the database and
* 1 is returned. Otherwise no operation is performed and 0 is returned.
*
* When a key is expired, server.stat_expiredkeys is incremented.
*
* The parameter 'now' is the current time in milliseconds as is passed
* to the function to avoid too many gettimeofday() syscalls. */
int activeExpireCycleTryExpire(redisDb *db, struct dictEntry *de, long long now) {
long long t = dictGetSignedIntegerVal(de);
if (now > t) {
sds key = dictGetKey(de);
robj *keyobj = createStringObject(key,sdslen(key));
propagateExpire(db,keyobj);
dbDelete(db,keyobj);
notifyKeyspaceEvent(REDIS_NOTIFY_EXPIRED,
"expired",keyobj,db->id);
decrRefCount(keyobj);
server.stat_expiredkeys++;
return 1;
} else {
return 0;
}
}
/* 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.
*
* No more than REDIS_DBCRON_DBS_PER_CALL databases are tested at every
* iteration.
*
* This kind of call is used when Redis detects that timelimit_exit is
* true, so there is more work to do, and we do it more incrementally from
* the beforeSleep() function of the event loop.
*
* Expire cycle type:
*
* If type is ACTIVE_EXPIRE_CYCLE_FAST the function will try to run a
* "fast" expire cycle that takes no longer than EXPIRE_FAST_CYCLE_DURATION
* microseconds, and is not repeated again before the same amount of time.
*
* If type is ACTIVE_EXPIRE_CYCLE_SLOW, that normal expire cycle is
* executed, where the time limit is a percentage of the REDIS_HZ period
* as specified by the REDIS_EXPIRELOOKUPS_TIME_PERC define. */
void activeExpireCycle(int type) {
/* This function has some global state in order to continue the work
* incrementally across calls. */
static unsigned int current_db = 0; /* Last DB tested. */
static int timelimit_exit = 0; /* Time limit hit in previous call? */
static long long last_fast_cycle = 0; /* When last fast cycle ran. */
int j, iteration = 0;
int dbs_per_call = REDIS_DBCRON_DBS_PER_CALL;
long long start = ustime(), timelimit;
if (type == ACTIVE_EXPIRE_CYCLE_FAST) {
/* Don't start a fast cycle if the previous cycle did not exited
* for time limt. Also don't repeat a fast cycle for the same period
* as the fast cycle total duration itself. */
if (!timelimit_exit) return;
if (start < last_fast_cycle + ACTIVE_EXPIRE_CYCLE_FAST_DURATION*2) return;
last_fast_cycle = start;
}
/* We usually should test REDIS_DBCRON_DBS_PER_CALL per iteration, with
* two exceptions:
*
* 1) Don't test more DBs than we have.
* 2) If last time we hit the time limit, we want to scan all DBs
* in this iteration, as there is work to do in some DB and we don't want
* expired keys to use memory for too much time. */
if (dbs_per_call > server.dbnum || timelimit_exit)
dbs_per_call = server.dbnum;
/* We can use at max ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC percentage of CPU time
* per iteration. Since this function gets called with a frequency of
* server.hz times per second, the following is the max amount of
* microseconds we can spend in this function. */
timelimit = 1000000*ACTIVE_EXPIRE_CYCLE_SLOW_TIME_PERC/server.hz/100;
timelimit_exit = 0;
if (timelimit <= 0) timelimit = 1;
if (type == ACTIVE_EXPIRE_CYCLE_FAST)
timelimit = ACTIVE_EXPIRE_CYCLE_FAST_DURATION; /* in microseconds. */
for (j = 0; j < dbs_per_call; j++) {
int expired;
redisDb *db = server.db+(current_db % server.dbnum);
/* Increment the DB now so we are sure if we run out of time
* in the current DB we'll restart from the next. This allows to
* distribute the time evenly across DBs. */
current_db++;
/* Continue to expire if at the end of the cycle more than 25%
* of the keys were expired. */
do {
unsigned long num, slots;
long long now, ttl_sum;
int ttl_samples;
/* If there is nothing to expire try next DB ASAP. */
if ((num = dictSize(db->expires)) == 0) {
db->avg_ttl = 0;
break;
}
slots = dictSlots(db->expires);
now = mstime();
/* When there are less than 1% filled slots getting random
* keys is expensive, so stop here waiting for better times...
* The dictionary will be resized asap. */
if (num && slots > DICT_HT_INITIAL_SIZE &&
(num*100/slots < 1)) break;
/* The main collection cycle. Sample random keys among keys
* with an expire set, checking for expired ones. */
expired = 0;
ttl_sum = 0;
ttl_samples = 0;
if (num > ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP)
num = ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP;
while (num--) {
dictEntry *de;
long long ttl;
if ((de = dictGetRandomKey(db->expires)) == NULL) break;
ttl = dictGetSignedIntegerVal(de)-now;
if (activeExpireCycleTryExpire(db,de,now)) expired++;
if (ttl < 0) ttl = 0;
ttl_sum += ttl;
ttl_samples++;
}
/* Update the average TTL stats for this database. */
if (ttl_samples) {
long long avg_ttl = ttl_sum/ttl_samples;
if (db->avg_ttl == 0) db->avg_ttl = avg_ttl;
/* Smooth the value averaging with the previous one. */
db->avg_ttl = (db->avg_ttl+avg_ttl)/2;
}
/* We can't block forever here even if there are many keys to
* expire. So after a given amount of milliseconds return to the
* caller waiting for the other active expire cycle. */
iteration++;
if ((iteration & 0xf) == 0) { /* check once every 16 iterations. */
long long elapsed = ustime()-start;
latencyAddSampleIfNeeded("expire-cycle",elapsed/1000);
if (elapsed > timelimit) timelimit_exit = 1;
}
if (timelimit_exit) return;
/* We don't repeat the cycle if there are less than 25% of keys
* found expired in the current DB. */
} while (expired > ACTIVE_EXPIRE_CYCLE_LOOKUPS_PER_LOOP/4);
}
}
void updateLRUClock(void) {
server.lruclock = (server.unixtime/REDIS_LRU_CLOCK_RESOLUTION) &
REDIS_LRU_CLOCK_MAX;
}
/* Add a sample to the operations per second array of samples. */
void trackOperationsPerSecond(void) {
long long t = mstime() - server.ops_sec_last_sample_time;
long long ops = server.stat_numcommands - server.ops_sec_last_sample_ops;
long long ops_sec;
ops_sec = t > 0 ? (ops*1000/t) : 0;
server.ops_sec_samples[server.ops_sec_idx] = ops_sec;
server.ops_sec_idx = (server.ops_sec_idx+1) % REDIS_OPS_SEC_SAMPLES;
server.ops_sec_last_sample_time = mstime();
server.ops_sec_last_sample_ops = server.stat_numcommands;
}
/* Return the mean of all the samples. */
long long getOperationsPerSecond(void) {
int j;
long long sum = 0;
for (j = 0; j < REDIS_OPS_SEC_SAMPLES; j++)
sum += server.ops_sec_samples[j];
return sum / REDIS_OPS_SEC_SAMPLES;
}
/* Check for timeouts. Returns non-zero if the client was terminated */
int clientsCronHandleTimeout(redisClient *c) {
time_t now = server.unixtime;
if (server.maxidletime &&
!(c->flags & REDIS_SLAVE) && /* no timeout for slaves */
!(c->flags & REDIS_MASTER) && /* no timeout for masters */
!(c->flags & REDIS_BLOCKED) && /* no timeout for BLPOP */
!(c->flags & REDIS_PUBSUB) && /* no timeout for Pub/Sub clients */
(now - c->lastinteraction > server.maxidletime))
{
redisLog(REDIS_VERBOSE,"Closing idle client");
freeClient(c);
return 1;
} else if (c->flags & REDIS_BLOCKED) {
if (c->bpop.timeout != 0 && c->bpop.timeout < now) {
addReply(c,shared.nullmultibulk);
unblockClientWaitingData(c);
}
}
return 0;
}
/* The client query buffer is an sds.c string that can end with a lot of
* free space not used, this function reclaims space if needed.
*
* The function always returns 0 as it never terminates the client. */
int clientsCronResizeQueryBuffer(redisClient *c) {
size_t querybuf_size = sdsAllocSize(c->querybuf);
time_t idletime = server.unixtime - c->lastinteraction;
/* There are two conditions to resize the query buffer:
* 1) Query buffer is > BIG_ARG and too big for latest peak.
* 2) Client is inactive and the buffer is bigger than 1k. */
if (((querybuf_size > REDIS_MBULK_BIG_ARG) &&
(querybuf_size/(c->querybuf_peak+1)) > 2) ||
(querybuf_size > 1024 && idletime > 2))
{
/* Only resize the query buffer if it is actually wasting space. */
if (sdsavail(c->querybuf) > 1024) {
c->querybuf = sdsRemoveFreeSpace(c->querybuf);
}
}
/* Reset the peak again to capture the peak memory usage in the next
* cycle. */
c->querybuf_peak = 0;
return 0;
}
void clientsCron(void) {
/* Make sure to process at least 1/(server.hz*10) of clients per call.
* Since this function is called server.hz times per second we are sure that
* in the worst case we process all the clients in 10 seconds.
* In normal conditions (a reasonable number of clients) we process
* all the clients in a shorter time. */
int numclients = listLength(server.clients);
int iterations = numclients/(server.hz*10);
if (iterations < 50)
iterations = (numclients < 50) ? numclients : 50;
while(listLength(server.clients) && iterations--) {
redisClient *c;
listNode *head;
/* Rotate the list, take the current head, process.
* This way if the client must be removed from the list it's the
* first element and we don't incur into O(N) computation. */
listRotate(server.clients);
head = listFirst(server.clients);
c = listNodeValue(head);
/* The following functions do different service checks on the client.
* The protocol is that they return non-zero if the client was
* terminated. */
if (clientsCronHandleTimeout(c)) continue;
if (clientsCronResizeQueryBuffer(c)) continue;
}
}
/* This function handles 'background' operations we are required to do
* incrementally in Redis databases, such as active key expiring, resizing,
* rehashing. */
void databasesCron(void) {
/* Expire keys by random sampling. Not required for slaves
* as master will synthesize DELs for us. */
if (server.active_expire_enabled && server.masterhost == NULL)
activeExpireCycle(ACTIVE_EXPIRE_CYCLE_SLOW);
/* Perform hash tables rehashing if needed, but only if there are no
* other processes saving the DB on disk. Otherwise rehashing is bad
* as will cause a lot of copy-on-write of memory pages. */
if (server.rdb_child_pid == -1 && server.aof_child_pid == -1) {
/* We use global counters so if we stop the computation at a given
* DB we'll be able to start from the successive in the next
* cron loop iteration. */
static unsigned int resize_db = 0;
static unsigned int rehash_db = 0;
int dbs_per_call = REDIS_DBCRON_DBS_PER_CALL;
int j;
/* Don't test more DBs than we have. */
if (dbs_per_call > server.dbnum) dbs_per_call = server.dbnum;
/* Resize */
for (j = 0; j < dbs_per_call; j++) {
tryResizeHashTables(resize_db % server.dbnum);
resize_db++;
}
/* Rehash */
if (server.activerehashing) {
for (j = 0; j < dbs_per_call; j++) {
int work_done = incrementallyRehash(rehash_db % server.dbnum);
rehash_db++;
if (work_done) {
/* If the function did some work, stop here, we'll do
* more at the next cron loop. */
break;
}
}
}
}
}
/* 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
* a lot faster than calling time(NULL) */
void updateCachedTime(void) {
server.unixtime = time(NULL);
server.mstime = mstime();
}
/* This is our timer interrupt, called server.hz times per second.
* Here is where we do a number of things that need to be done asynchronously.
* For instance:
*
* - Active expired keys collection (it is also performed in a lazy way on
* lookup).
* - Software watchdog.
* - Update some statistic.
* - Incremental rehashing of the DBs hash tables.
* - Triggering BGSAVE / AOF rewrite, and handling of terminated children.
* - Clients timeout of different kinds.
* - Replication reconnection.
* - Many more...
*
* Everything directly called here will be called server.hz times per second,
* so in order to throttle execution of things we want to do less frequently
* a macro is used: run_with_period(milliseconds) { .... }
*/