src/redis.c

   1 /*
   2  * Copyright (c) 2009-2010, Salvatore Sanfilippo <antirez at gmail dot com>
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions are met:
   7  *
   8  *   * Redistributions of source code must retain the above copyright notice,
   9  *     this list of conditions and the following disclaimer.
  10  *   * Redistributions in binary form must reproduce the above copyright
  11  *     notice, this list of conditions and the following disclaimer in the
  12  *     documentation and/or other materials provided with the distribution.
  13  *   * Neither the name of Redis nor the names of its contributors may be used
  14  *     to endorse or promote products derived from this software without
  15  *     specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  18  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  21  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  22  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  23  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  24  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  25  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  26  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  27  * POSSIBILITY OF SUCH DAMAGE.
  28  */
  29
  30 #include "redis.h"
  31 #include "slowlog.h"
  32 #include "bio.h"
  33
  34 #ifdef HAVE_BACKTRACE
  35 #include <execinfo.h>
  36 #include <ucontext.h>
  37 #endif /* HAVE_BACKTRACE */
  38
  39 #include <time.h>
  40 #include <signal.h>
  41 #include <sys/wait.h>
  42 #include <errno.h>
  43 #include <assert.h>
  44 #include <ctype.h>
  45 #include <stdarg.h>
  46 #include <arpa/inet.h>
  47 #include <sys/stat.h>
  48 #include <fcntl.h>
  49 #include <sys/time.h>
  50 #include <sys/resource.h>
  51 #include <sys/uio.h>
  52 #include <limits.h>
  53 #include <float.h>
  54 #include <math.h>
  55 #include <sys/resource.h>
  56
  57 /* Our shared "common" objects */
  58
  59 struct sharedObjectsStruct shared;
  60
  61 /* Global vars that are actually used as constants. The following double
  62  * values are used for double on-disk serialization, and are initialized
  63  * at runtime to avoid strange compiler optimizations. */
  64
  65 double R_Zero, R_PosInf, R_NegInf, R_Nan;
  66
  67 /*================================= Globals ================================= */
  68
  69 /* Global vars */
  70 struct redisServer server; /* server global state */
  71 struct redisCommand *commandTable;
  72
  73 /* Our command table. Command flags are expressed using strings where every
  74  * character represents a flag. Later the populateCommandTable() function will
  75  * take care of populating the real 'flags' field using this characters.
  76  *
  77  * This is the meaning of the flags:
  78  *
  79  * w: write command (may modify the key space).
  80  * r: read command  (will never modify the key space).
  81  * m: may increase memory usage once called. Don't allow if out of memory.
  82  * a: admin command, like SAVE or SHUTDOWN.
  83  * p: Pub/Sub related command.
  84  * f: force replication of this command, regarless of server.dirty.
  85  * s: command not allowed in scripts.
  86  * R: random command. Command is not deterministic, that is, the same command
  87  *    with the same arguments, with the same key space, may have different
  88  *    results. For instance SPOP and RANDOMKEY are two random commands. */
  89 struct redisCommand redisCommandTable[] = {
  90     {"get",getCommand,2,"r",0,NULL,1,1,1,0,0},
  91     {"set",setCommand,3,"wm",0,noPreloadGetKeys,1,1,1,0,0},
  92     {"setnx",setnxCommand,3,"wm",0,noPreloadGetKeys,1,1,1,0,0},
  93     {"setex",setexCommand,4,"wm",0,noPreloadGetKeys,2,2,1,0,0},
  94     {"psetex",psetexCommand,4,"wm",0,noPreloadGetKeys,2,2,1,0,0},
  95     {"append",appendCommand,3,"wm",0,NULL,1,1,1,0,0},
  96     {"strlen",strlenCommand,2,"r",0,NULL,1,1,1,0,0},
  97     {"del",delCommand,-2,"w",0,noPreloadGetKeys,1,-1,1,0,0},
  98     {"exists",existsCommand,2,"r",0,NULL,1,1,1,0,0},
  99     {"setbit",setbitCommand,4,"wm",0,NULL,1,1,1,0,0},
 100     {"getbit",getbitCommand,3,"r",0,NULL,1,1,1,0,0},
 101     {"setrange",setrangeCommand,4,"wm",0,NULL,1,1,1,0,0},
 102     {"getrange",getrangeCommand,4,"r",0,NULL,1,1,1,0,0},
 103     {"substr",getrangeCommand,4,"r",0,NULL,1,1,1,0,0},
 104     {"incr",incrCommand,2,"wm",0,NULL,1,1,1,0,0},
 105     {"decr",decrCommand,2,"wm",0,NULL,1,1,1,0,0},
 106     {"mget",mgetCommand,-2,"r",0,NULL,1,-1,1,0,0},
 107     {"rpush",rpushCommand,-3,"wm",0,NULL,1,1,1,0,0},
 108     {"lpush",lpushCommand,-3,"wm",0,NULL,1,1,1,0,0},
 109     {"rpushx",rpushxCommand,3,"wm",0,NULL,1,1,1,0,0},
 110     {"lpushx",lpushxCommand,3,"wm",0,NULL,1,1,1,0,0},
 111     {"linsert",linsertCommand,5,"wm",0,NULL,1,1,1,0,0},
 112     {"rpop",rpopCommand,2,"w",0,NULL,1,1,1,0,0},
 113     {"lpop",lpopCommand,2,"w",0,NULL,1,1,1,0,0},
 114     {"brpop",brpopCommand,-3,"ws",0,NULL,1,1,1,0,0},
 115     {"brpoplpush",brpoplpushCommand,4,"wms",0,NULL,1,2,1,0,0},
 116     {"blpop",blpopCommand,-3,"ws",0,NULL,1,-2,1,0,0},
 117     {"llen",llenCommand,2,"r",0,NULL,1,1,1,0,0},
 118     {"lindex",lindexCommand,3,"r",0,NULL,1,1,1,0,0},
 119     {"lset",lsetCommand,4,"wm",0,NULL,1,1,1,0,0},
 120     {"lrange",lrangeCommand,4,"r",0,NULL,1,1,1,0,0},
 121     {"ltrim",ltrimCommand,4,"w",0,NULL,1,1,1,0,0},
 122     {"lrem",lremCommand,4,"w",0,NULL,1,1,1,0,0},
 123     {"rpoplpush",rpoplpushCommand,3,"wm",0,NULL,1,2,1,0,0},
 124     {"sadd",saddCommand,-3,"wm",0,NULL,1,1,1,0,0},
 125     {"srem",sremCommand,-3,"w",0,NULL,1,1,1,0,0},
 126     {"smove",smoveCommand,4,"w",0,NULL,1,2,1,0,0},
 127     {"sismember",sismemberCommand,3,"r",0,NULL,1,1,1,0,0},
 128     {"scard",scardCommand,2,"r",0,NULL,1,1,1,0,0},
 129     {"spop",spopCommand,2,"wRs",0,NULL,1,1,1,0,0},
 130     {"srandmember",srandmemberCommand,2,"rR",0,NULL,1,1,1,0,0},
 131     {"sinter",sinterCommand,-2,"r",0,NULL,1,-1,1,0,0},
 132     {"sinterstore",sinterstoreCommand,-3,"wm",0,NULL,2,-1,1,0,0},
 133     {"sunion",sunionCommand,-2,"r",0,NULL,1,-1,1,0,0},
 134     {"sunionstore",sunionstoreCommand,-3,"wm",0,NULL,2,-1,1,0,0},
 135     {"sdiff",sdiffCommand,-2,"r",0,NULL,1,-1,1,0,0},
 136     {"sdiffstore",sdiffstoreCommand,-3,"wm",0,NULL,2,-1,1,0,0},
 137     {"smembers",sinterCommand,2,"r",0,NULL,1,1,1,0,0},
 138     {"zadd",zaddCommand,-4,"wm",0,NULL,1,1,1,0,0},
 139     {"zincrby",zincrbyCommand,4,"wm",0,NULL,1,1,1,0,0},
 140     {"zrem",zremCommand,-3,"w",0,NULL,1,1,1,0,0},
 141     {"zremrangebyscore",zremrangebyscoreCommand,4,"w",0,NULL,1,1,1,0,0},
 142     {"zremrangebyrank",zremrangebyrankCommand,4,"w",0,NULL,1,1,1,0,0},
 143     {"zunionstore",zunionstoreCommand,-4,"wm",0,zunionInterGetKeys,0,0,0,0,0},
 144     {"zinterstore",zinterstoreCommand,-4,"wm",0,zunionInterGetKeys,0,0,0,0,0},
 145     {"zrange",zrangeCommand,-4,"r",0,NULL,1,1,1,0,0},
 146     {"zrangebyscore",zrangebyscoreCommand,-4,"r",0,NULL,1,1,1,0,0},
 147     {"zrevrangebyscore",zrevrangebyscoreCommand,-4,"r",0,NULL,1,1,1,0,0},
 148     {"zcount",zcountCommand,4,"r",0,NULL,1,1,1,0,0},
 149     {"zrevrange",zrevrangeCommand,-4,"r",0,NULL,1,1,1,0,0},
 150     {"zcard",zcardCommand,2,"r",0,NULL,1,1,1,0,0},
 151     {"zscore",zscoreCommand,3,"r",0,NULL,1,1,1,0,0},
 152     {"zrank",zrankCommand,3,"r",0,NULL,1,1,1,0,0},
 153     {"zrevrank",zrevrankCommand,3,"r",0,NULL,1,1,1,0,0},
 154     {"hset",hsetCommand,4,"wm",0,NULL,1,1,1,0,0},
 155     {"hsetnx",hsetnxCommand,4,"wm",0,NULL,1,1,1,0,0},
 156     {"hget",hgetCommand,3,"r",0,NULL,1,1,1,0,0},
 157     {"hmset",hmsetCommand,-4,"wm",0,NULL,1,1,1,0,0},
 158     {"hmget",hmgetCommand,-3,"r",0,NULL,1,1,1,0,0},
 159     {"hincrby",hincrbyCommand,4,"wm",0,NULL,1,1,1,0,0},
 160     {"hincrbyfloat",hincrbyfloatCommand,4,"wm",0,NULL,1,1,1,0,0},
 161     {"hdel",hdelCommand,-3,"w",0,NULL,1,1,1,0,0},
 162     {"hlen",hlenCommand,2,"r",0,NULL,1,1,1,0,0},
 163     {"hkeys",hkeysCommand,2,"r",0,NULL,1,1,1,0,0},
 164     {"hvals",hvalsCommand,2,"r",0,NULL,1,1,1,0,0},
 165     {"hgetall",hgetallCommand,2,"r",0,NULL,1,1,1,0,0},
 166     {"hexists",hexistsCommand,3,"r",0,NULL,1,1,1,0,0},
 167     {"incrby",incrbyCommand,3,"wm",0,NULL,1,1,1,0,0},
 168     {"decrby",decrbyCommand,3,"wm",0,NULL,1,1,1,0,0},
 169     {"incrbyfloat",incrbyfloatCommand,3,"wm",0,NULL,1,1,1,0,0},
 170     {"getset",getsetCommand,3,"wm",0,NULL,1,1,1,0,0},
 171     {"mset",msetCommand,-3,"wm",0,NULL,1,-1,2,0,0},
 172     {"msetnx",msetnxCommand,-3,"wm",0,NULL,1,-1,2,0,0},
 173     {"randomkey",randomkeyCommand,1,"rR",0,NULL,0,0,0,0,0},
 174     {"select",selectCommand,2,"r",0,NULL,0,0,0,0,0},
 175     {"move",moveCommand,3,"w",0,NULL,1,1,1,0,0},
 176     {"rename",renameCommand,3,"w",0,renameGetKeys,1,2,1,0,0},
 177     {"renamenx",renamenxCommand,3,"w",0,renameGetKeys,1,2,1,0,0},
 178     {"expire",expireCommand,3,"w",0,NULL,1,1,1,0,0},
 179     {"expireat",expireatCommand,3,"w",0,NULL,1,1,1,0,0},
 180     {"pexpire",pexpireCommand,3,"w",0,NULL,1,1,1,0,0},
 181     {"pexpireat",pexpireatCommand,3,"w",0,NULL,1,1,1,0,0},
 182     {"keys",keysCommand,2,"r",0,NULL,0,0,0,0,0},
 183     {"dbsize",dbsizeCommand,1,"r",0,NULL,0,0,0,0,0},
 184     {"auth",authCommand,2,"rs",0,NULL,0,0,0,0,0},
 185     {"ping",pingCommand,1,"r",0,NULL,0,0,0,0,0},
 186     {"echo",echoCommand,2,"r",0,NULL,0,0,0,0,0},
 187     {"save",saveCommand,1,"ars",0,NULL,0,0,0,0,0},
 188     {"bgsave",bgsaveCommand,1,"ar",0,NULL,0,0,0,0,0},
 189     {"bgrewriteaof",bgrewriteaofCommand,1,"ar",0,NULL,0,0,0,0,0},
 190     {"shutdown",shutdownCommand,-1,"ar",0,NULL,0,0,0,0,0},
 191     {"lastsave",lastsaveCommand,1,"r",0,NULL,0,0,0,0,0},
 192     {"type",typeCommand,2,"r",0,NULL,1,1,1,0,0},
 193     {"multi",multiCommand,1,"rs",0,NULL,0,0,0,0,0},
 194     {"exec",execCommand,1,"wms",0,NULL,0,0,0,0,0},
 195     {"discard",discardCommand,1,"rs",0,NULL,0,0,0,0,0},
 196     {"sync",syncCommand,1,"ars",0,NULL,0,0,0,0,0},
 197     {"flushdb",flushdbCommand,1,"w",0,NULL,0,0,0,0,0},
 198     {"flushall",flushallCommand,1,"w",0,NULL,0,0,0,0,0},
 199     {"sort",sortCommand,-2,"wm",0,NULL,1,1,1,0,0},
 200     {"info",infoCommand,-1,"r",0,NULL,0,0,0,0,0},
 201     {"monitor",monitorCommand,1,"ars",0,NULL,0,0,0,0,0},
 202     {"ttl",ttlCommand,2,"r",0,NULL,1,1,1,0,0},
 203     {"pttl",pttlCommand,2,"r",0,NULL,1,1,1,0,0},
 204     {"persist",persistCommand,2,"w",0,NULL,1,1,1,0,0},
 205     {"slaveof",slaveofCommand,3,"aws",0,NULL,0,0,0,0,0},
 206     {"debug",debugCommand,-2,"aws",0,NULL,0,0,0,0,0},
 207     {"config",configCommand,-2,"ar",0,NULL,0,0,0,0,0},
 208     {"subscribe",subscribeCommand,-2,"rps",0,NULL,0,0,0,0,0},
 209     {"unsubscribe",unsubscribeCommand,-1,"rps",0,NULL,0,0,0,0,0},
 210     {"psubscribe",psubscribeCommand,-2,"rps",0,NULL,0,0,0,0,0},
 211     {"punsubscribe",punsubscribeCommand,-1,"rps",0,NULL,0,0,0,0,0},
 212     {"publish",publishCommand,3,"rpf",0,NULL,0,0,0,0,0},
 213     {"watch",watchCommand,-2,"rs",0,noPreloadGetKeys,1,-1,1,0,0},
 214     {"unwatch",unwatchCommand,1,"rs",0,NULL,0,0,0,0,0},
 215     {"cluster",clusterCommand,-2,"ar",0,NULL,0,0,0,0,0},
 216     {"restore",restoreCommand,4,"awm",0,NULL,1,1,1,0,0},
 217     {"migrate",migrateCommand,6,"aw",0,NULL,0,0,0,0,0},
 218     {"asking",askingCommand,1,"r",0,NULL,0,0,0,0,0},
 219     {"dump",dumpCommand,2,"ar",0,NULL,0,0,0,0,0},
 220     {"object",objectCommand,-2,"r",0,NULL,0,0,0,0,0},
 221     {"client",clientCommand,-2,"ar",0,NULL,0,0,0,0,0},
 222     {"eval",evalCommand,-3,"wms",0,zunionInterGetKeys,0,0,0,0,0},
 223     {"evalsha",evalShaCommand,-3,"wms",0,zunionInterGetKeys,0,0,0,0,0},
 224     {"slowlog",slowlogCommand,-2,"r",0,NULL,0,0,0,0,0},
 225     {"script",scriptCommand,-2,"ras",0,NULL,0,0,0,0,0}
 226 };
 227
 228 /*============================ Utility functions ============================ */
 229
 230 /* Low level logging. To use only for very big messages, otherwise
 231  * redisLog() is to prefer. */
 232 void redisLogRaw(int level, const char *msg) {
 233     const int syslogLevelMap[] = { LOG_DEBUG, LOG_INFO, LOG_NOTICE, LOG_WARNING };
 234     const char *c = ".-*#";
 235     time_t now = time(NULL);
 236     FILE *fp;
 237     char buf[64];
 238     int rawmode = (level & REDIS_LOG_RAW);
 239
 240     level &= 0xff; /* clear flags */
 241     if (level < server.verbosity) return;
 242
 243     fp = (server.logfile == NULL) ? stdout : fopen(server.logfile,"a");
 244     if (!fp) return;
 245
 246     if (rawmode) {
 247         fprintf(fp,"%s",msg);
 248     } else {
 249         strftime(buf,sizeof(buf),"%d %b %H:%M:%S",localtime(&now));
 250         fprintf(fp,"[%d] %s %c %s\n",(int)getpid(),buf,c[level],msg);
 251     }
 252     fflush(fp);
 253
 254     if (server.logfile) fclose(fp);
 255
 256     if (server.syslog_enabled) syslog(syslogLevelMap[level], "%s", msg);
 257 }
 258
 259 /* Like redisLogRaw() but with printf-alike support. This is the funciton that
 260  * is used across the code. The raw version is only used in order to dump
 261  * the INFO output on crash. */
 262 void redisLog(int level, const char *fmt, ...) {
 263     va_list ap;
 264     char msg[REDIS_MAX_LOGMSG_LEN];
 265
 266     if ((level&0xff) < server.verbosity) return;
 267
 268     va_start(ap, fmt);
 269     vsnprintf(msg, sizeof(msg), fmt, ap);
 270     va_end(ap);
 271
 272     redisLogRaw(level,msg);
 273 }
 274
 275 /* Redis generally does not try to recover from out of memory conditions
 276  * when allocating objects or strings, it is not clear if it will be possible
 277  * to report this condition to the client since the networking layer itself
 278  * is based on heap allocation for send buffers, so we simply abort.
 279  * At least the code will be simpler to read... */
 280 void oom(const char *msg) {
 281     redisLog(REDIS_WARNING, "%s: Out of memory\n",msg);
 282     sleep(1);
 283     abort();
 284 }
 285
 286 /* Return the UNIX time in microseconds */
 287 long long ustime(void) {
 288     struct timeval tv;
 289     long long ust;
 290
 291     gettimeofday(&tv, NULL);
 292     ust = ((long long)tv.tv_sec)*1000000;
 293     ust += tv.tv_usec;
 294     return ust;
 295 }
 296
 297 /* Return the UNIX time in milliseconds */
 298 long long mstime(void) {
 299     return ustime()/1000;
 300 }
 301
 302 /*====================== Hash table type implementation  ==================== */
 303
 304 /* This is an hash table type that uses the SDS dynamic strings libary as
 305  * keys and radis objects as values (objects can hold SDS strings,
 306  * lists, sets). */
 307
 308 void dictVanillaFree(void *privdata, void *val)
 309 {
 310     DICT_NOTUSED(privdata);
 311     zfree(val);
 312 }
 313
 314 void dictListDestructor(void *privdata, void *val)
 315 {
 316     DICT_NOTUSED(privdata);
 317     listRelease((list*)val);
 318 }
 319
 320 int dictSdsKeyCompare(void *privdata, const void *key1,
 321         const void *key2)
 322 {
 323     int l1,l2;
 324     DICT_NOTUSED(privdata);
 325
 326     l1 = sdslen((sds)key1);
 327     l2 = sdslen((sds)key2);
 328     if (l1 != l2) return 0;
 329     return memcmp(key1, key2, l1) == 0;
 330 }
 331
 332 /* A case insensitive version used for the command lookup table. */
 333 int dictSdsKeyCaseCompare(void *privdata, const void *key1,
 334         const void *key2)
 335 {
 336     DICT_NOTUSED(privdata);
 337
 338     return strcasecmp(key1, key2) == 0;
 339 }
 340
 341 void dictRedisObjectDestructor(void *privdata, void *val)
 342 {
 343     DICT_NOTUSED(privdata);
 344
 345     if (val == NULL) return; /* Values of swapped out keys as set to NULL */
 346     decrRefCount(val);
 347 }
 348
 349 void dictSdsDestructor(void *privdata, void *val)
 350 {
 351     DICT_NOTUSED(privdata);
 352
 353     sdsfree(val);
 354 }
 355
 356 int dictObjKeyCompare(void *privdata, const void *key1,
 357         const void *key2)
 358 {
 359     const robj *o1 = key1, *o2 = key2;
 360     return dictSdsKeyCompare(privdata,o1->ptr,o2->ptr);
 361 }
 362
 363 unsigned int dictObjHash(const void *key) {
 364     const robj *o = key;
 365     return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 366 }
 367
 368 unsigned int dictSdsHash(const void *key) {
 369     return dictGenHashFunction((unsigned char*)key, sdslen((char*)key));
 370 }
 371
 372 unsigned int dictSdsCaseHash(const void *key) {
 373     return dictGenCaseHashFunction((unsigned char*)key, sdslen((char*)key));
 374 }
 375
 376 int dictEncObjKeyCompare(void *privdata, const void *key1,
 377         const void *key2)
 378 {
 379     robj *o1 = (robj*) key1, *o2 = (robj*) key2;
 380     int cmp;
 381
 382     if (o1->encoding == REDIS_ENCODING_INT &&
 383         o2->encoding == REDIS_ENCODING_INT)
 384             return o1->ptr == o2->ptr;
 385
 386     o1 = getDecodedObject(o1);
 387     o2 = getDecodedObject(o2);
 388     cmp = dictSdsKeyCompare(privdata,o1->ptr,o2->ptr);
 389     decrRefCount(o1);
 390     decrRefCount(o2);
 391     return cmp;
 392 }
 393
 394 unsigned int dictEncObjHash(const void *key) {
 395     robj *o = (robj*) key;
 396
 397     if (o->encoding == REDIS_ENCODING_RAW) {
 398         return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 399     } else {
 400         if (o->encoding == REDIS_ENCODING_INT) {
 401             char buf[32];
 402             int len;
 403
 404             len = ll2string(buf,32,(long)o->ptr);
 405             return dictGenHashFunction((unsigned char*)buf, len);
 406         } else {
 407             unsigned int hash;
 408
 409             o = getDecodedObject(o);
 410             hash = dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 411             decrRefCount(o);
 412             return hash;
 413         }
 414     }
 415 }
 416
 417 /* Sets type hash table */
 418 dictType setDictType = {
 419     dictEncObjHash,            /* hash function */
 420     NULL,                      /* key dup */
 421     NULL,                      /* val dup */
 422     dictEncObjKeyCompare,      /* key compare */
 423     dictRedisObjectDestructor, /* key destructor */
 424     NULL                       /* val destructor */
 425 };
 426
 427 /* Sorted sets hash (note: a skiplist is used in addition to the hash table) */
 428 dictType zsetDictType = {
 429     dictEncObjHash,            /* hash function */
 430     NULL,                      /* key dup */
 431     NULL,                      /* val dup */
 432     dictEncObjKeyCompare,      /* key compare */
 433     dictRedisObjectDestructor, /* key destructor */
 434     NULL                       /* val destructor */
 435 };
 436
 437 /* Db->dict, keys are sds strings, vals are Redis objects. */
 438 dictType dbDictType = {
 439     dictSdsHash,                /* hash function */
 440     NULL,                       /* key dup */
 441     NULL,                       /* val dup */
 442     dictSdsKeyCompare,          /* key compare */
 443     dictSdsDestructor,          /* key destructor */
 444     dictRedisObjectDestructor   /* val destructor */
 445 };
 446
 447 /* Db->expires */
 448 dictType keyptrDictType = {
 449     dictSdsHash,               /* hash function */
 450     NULL,                      /* key dup */
 451     NULL,                      /* val dup */
 452     dictSdsKeyCompare,         /* key compare */
 453     NULL,                      /* key destructor */
 454     NULL                       /* val destructor */
 455 };
 456
 457 /* Command table. sds string -> command struct pointer. */
 458 dictType commandTableDictType = {
 459     dictSdsCaseHash,           /* hash function */
 460     NULL,                      /* key dup */
 461     NULL,                      /* val dup */
 462     dictSdsKeyCaseCompare,     /* key compare */
 463     dictSdsDestructor,         /* key destructor */
 464     NULL                       /* val destructor */
 465 };
 466
 467 /* Hash type hash table (note that small hashes are represented with zimpaps) */
 468 dictType hashDictType = {
 469     dictEncObjHash,             /* hash function */
 470     NULL,                       /* key dup */
 471     NULL,                       /* val dup */
 472     dictEncObjKeyCompare,       /* key compare */
 473     dictRedisObjectDestructor,  /* key destructor */
 474     dictRedisObjectDestructor   /* val destructor */
 475 };
 476
 477 /* Keylist hash table type has unencoded redis objects as keys and
 478  * lists as values. It's used for blocking operations (BLPOP) and to
 479  * map swapped keys to a list of clients waiting for this keys to be loaded. */
 480 dictType keylistDictType = {
 481     dictObjHash,                /* hash function */
 482     NULL,                       /* key dup */
 483     NULL,                       /* val dup */
 484     dictObjKeyCompare,          /* key compare */
 485     dictRedisObjectDestructor,  /* key destructor */
 486     dictListDestructor          /* val destructor */
 487 };
 488
 489 /* Cluster nodes hash table, mapping nodes addresses 1.2.3.4:6379 to
 490  * clusterNode structures. */
 491 dictType clusterNodesDictType = {
 492     dictSdsHash,                /* hash function */
 493     NULL,                       /* key dup */
 494     NULL,                       /* val dup */
 495     dictSdsKeyCompare,          /* key compare */
 496     dictSdsDestructor,          /* key destructor */
 497     NULL                        /* val destructor */
 498 };
 499
 500 int htNeedsResize(dict *dict) {
 501     long long size, used;
 502
 503     size = dictSlots(dict);
 504     used = dictSize(dict);
 505     return (size && used && size > DICT_HT_INITIAL_SIZE &&
 506             (used*100/size < REDIS_HT_MINFILL));
 507 }
 508
 509 /* If the percentage of used slots in the HT reaches REDIS_HT_MINFILL
 510  * we resize the hash table to save memory */
 511 void tryResizeHashTables(void) {
 512     int j;
 513
 514     for (j = 0; j < server.dbnum; j++) {
 515         if (htNeedsResize(server.db[j].dict))
 516             dictResize(server.db[j].dict);
 517         if (htNeedsResize(server.db[j].expires))
 518             dictResize(server.db[j].expires);
 519     }
 520 }
 521
 522 /* Our hash table implementation performs rehashing incrementally while
 523  * we write/read from the hash table. Still if the server is idle, the hash
 524  * table will use two tables for a long time. So we try to use 1 millisecond
 525  * of CPU time at every serverCron() loop in order to rehash some key. */
 526 void incrementallyRehash(void) {
 527     int j;
 528
 529     for (j = 0; j < server.dbnum; j++) {
 530         if (dictIsRehashing(server.db[j].dict)) {
 531             dictRehashMilliseconds(server.db[j].dict,1);
 532             break; /* already used our millisecond for this loop... */
 533         }
 534     }
 535 }
 536
 537 /* This function is called once a background process of some kind terminates,
 538  * as we want to avoid resizing the hash tables when there is a child in order
 539  * to play well with copy-on-write (otherwise when a resize happens lots of
 540  * memory pages are copied). The goal of this function is to update the ability
 541  * for dict.c to resize the hash tables accordingly to the fact we have o not
 542  * running childs. */
 543 void updateDictResizePolicy(void) {
 544     if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1)
 545         dictEnableResize();
 546     else
 547         dictDisableResize();
 548 }
 549
 550 /* ======================= Cron: called every 100 ms ======================== */
 551
 552 /* Try to expire a few timed out keys. The algorithm used is adaptive and
 553  * will use few CPU cycles if there are few expiring keys, otherwise
 554  * it will get more aggressive to avoid that too much memory is used by
 555  * keys that can be removed from the keyspace. */
 556 void activeExpireCycle(void) {
 557     int j;
 558
 559     for (j = 0; j < server.dbnum; j++) {
 560         int expired;
 561         redisDb *db = server.db+j;
 562
 563         /* Continue to expire if at the end of the cycle more than 25%
 564          * of the keys were expired. */
 565         do {
 566             long num = dictSize(db->expires);
 567             long long now = mstime();
 568
 569             expired = 0;
 570             if (num > REDIS_EXPIRELOOKUPS_PER_CRON)
 571                 num = REDIS_EXPIRELOOKUPS_PER_CRON;
 572             while (num--) {
 573                 dictEntry *de;
 574                 long long t;
 575
 576                 if ((de = dictGetRandomKey(db->expires)) == NULL) break;
 577                 t = dictGetSignedIntegerVal(de);
 578                 if (now > t) {
 579                     sds key = dictGetKey(de);
 580                     robj *keyobj = createStringObject(key,sdslen(key));
 581
 582                     propagateExpire(db,keyobj);
 583                     dbDelete(db,keyobj);
 584                     decrRefCount(keyobj);
 585                     expired++;
 586                     server.stat_expiredkeys++;
 587                 }
 588             }
 589         } while (expired > REDIS_EXPIRELOOKUPS_PER_CRON/4);
 590     }
 591 }
 592
 593 void updateLRUClock(void) {
 594     server.lruclock = (time(NULL)/REDIS_LRU_CLOCK_RESOLUTION) &
 595                                                 REDIS_LRU_CLOCK_MAX;
 596 }
 597
 598 int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
 599     int j, loops = server.cronloops;
 600     REDIS_NOTUSED(eventLoop);
 601     REDIS_NOTUSED(id);
 602     REDIS_NOTUSED(clientData);
 603
 604     /* We take a cached value of the unix time in the global state because
 605      * with virtual memory and aging there is to store the current time
 606      * in objects at every object access, and accuracy is not needed.
 607      * To access a global var is faster than calling time(NULL) */
 608     server.unixtime = time(NULL);
 609
 610     /* We have just 22 bits per object for LRU information.
 611      * So we use an (eventually wrapping) LRU clock with 10 seconds resolution.
 612      * 2^22 bits with 10 seconds resoluton is more or less 1.5 years.
 613      *
 614      * Note that even if this will wrap after 1.5 years it's not a problem,
 615      * everything will still work but just some object will appear younger
 616      * to Redis. But for this to happen a given object should never be touched
 617      * for 1.5 years.
 618      *
 619      * Note that you can change the resolution altering the
 620      * REDIS_LRU_CLOCK_RESOLUTION define.
 621      */
 622     updateLRUClock();
 623
 624     /* Record the max memory used since the server was started. */
 625     if (zmalloc_used_memory() > server.stat_peak_memory)
 626         server.stat_peak_memory = zmalloc_used_memory();
 627
 628     /* We received a SIGTERM, shutting down here in a safe way, as it is
 629      * not ok doing so inside the signal handler. */
 630     if (server.shutdown_asap) {
 631         if (prepareForShutdown(0) == REDIS_OK) exit(0);
 632         redisLog(REDIS_WARNING,"SIGTERM received but errors trying to shut down the server, check the logs for more information");
 633     }
 634
 635     /* Show some info about non-empty databases */
 636     for (j = 0; j < server.dbnum; j++) {
 637         long long size, used, vkeys;
 638
 639         size = dictSlots(server.db[j].dict);
 640         used = dictSize(server.db[j].dict);
 641         vkeys = dictSize(server.db[j].expires);
 642         if (!(loops % 50) && (used || vkeys)) {
 643             redisLog(REDIS_VERBOSE,"DB %d: %lld keys (%lld volatile) in %lld slots HT.",j,used,vkeys,size);
 644             /* dictPrintStats(server.dict); */
 645         }
 646     }
 647
 648     /* We don't want to resize the hash tables while a bacground saving
 649      * is in progress: the saving child is created using fork() that is
 650      * implemented with a copy-on-write semantic in most modern systems, so
 651      * if we resize the HT while there is the saving child at work actually
 652      * a lot of memory movements in the parent will cause a lot of pages
 653      * copied. */
 654     if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1) {
 655         if (!(loops % 10)) tryResizeHashTables();
 656         if (server.activerehashing) incrementallyRehash();
 657     }
 658
 659     /* Show information about connected clients */
 660     if (!(loops % 50)) {
 661         redisLog(REDIS_VERBOSE,"%d clients connected (%d slaves), %zu bytes in use",
 662             listLength(server.clients)-listLength(server.slaves),
 663             listLength(server.slaves),
 664             zmalloc_used_memory());
 665     }
 666
 667     /* Close connections of timedout clients */
 668     if ((server.maxidletime && !(loops % 100)) || server.bpop_blocked_clients)
 669         closeTimedoutClients();
 670
 671     /* Start a scheduled AOF rewrite if this was requested by the user while
 672      * a BGSAVE was in progress. */
 673     if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1 &&
 674         server.aofrewrite_scheduled)
 675     {
 676         rewriteAppendOnlyFileBackground();
 677     }
 678
 679     /* Check if a background saving or AOF rewrite in progress terminated. */
 680     if (server.bgsavechildpid != -1 || server.bgrewritechildpid != -1) {
 681         int statloc;
 682         pid_t pid;
 683
 684         if ((pid = wait3(&statloc,WNOHANG,NULL)) != 0) {
 685             int exitcode = WEXITSTATUS(statloc);
 686             int bysignal = 0;
 687
 688             if (WIFSIGNALED(statloc)) bysignal = WTERMSIG(statloc);
 689
 690             if (pid == server.bgsavechildpid) {
 691                 backgroundSaveDoneHandler(exitcode,bysignal);
 692             } else {
 693                 backgroundRewriteDoneHandler(exitcode,bysignal);
 694             }
 695             updateDictResizePolicy();
 696         }
 697     } else {
 698          time_t now = time(NULL);
 699
 700         /* If there is not a background saving/rewrite in progress check if
 701          * we have to save/rewrite now */
 702          for (j = 0; j < server.saveparamslen; j++) {
 703             struct saveparam *sp = server.saveparams+j;
 704
 705             if (server.dirty >= sp->changes &&
 706                 now-server.lastsave > sp->seconds) {
 707                 redisLog(REDIS_NOTICE,"%d changes in %d seconds. Saving...",
 708                     sp->changes, sp->seconds);
 709                 rdbSaveBackground(server.dbfilename);
 710                 break;
 711             }
 712          }
 713
 714          /* Trigger an AOF rewrite if needed */
 715          if (server.bgsavechildpid == -1 &&
 716              server.bgrewritechildpid == -1 &&
 717              server.auto_aofrewrite_perc &&
 718              server.appendonly_current_size > server.auto_aofrewrite_min_size)
 719          {
 720             long long base = server.auto_aofrewrite_base_size ?
 721                             server.auto_aofrewrite_base_size : 1;
 722             long long growth = (server.appendonly_current_size*100/base) - 100;
 723             if (growth >= server.auto_aofrewrite_perc) {
 724                 redisLog(REDIS_NOTICE,"Starting automatic rewriting of AOF on %lld%% growth",growth);
 725                 rewriteAppendOnlyFileBackground();
 726             }
 727          }
 728     }
 729
 730
 731     /* If we postponed an AOF buffer flush, let's try to do it every time the
 732      * cron function is called. */
 733     if (server.aof_flush_postponed_start) flushAppendOnlyFile(0);
 734
 735     /* Expire a few keys per cycle, only if this is a master.
 736      * On slaves we wait for DEL operations synthesized by the master
 737      * in order to guarantee a strict consistency. */
 738     if (server.masterhost == NULL) activeExpireCycle();
 739
 740     /* Replication cron function -- used to reconnect to master and
 741      * to detect transfer failures. */
 742     if (!(loops % 10)) replicationCron();
 743
 744     /* Run other sub-systems specific cron jobs */
 745     if (server.cluster_enabled && !(loops % 10)) clusterCron();
 746
 747     server.cronloops++;
 748     return 100;
 749 }
 750
 751 /* This function gets called every time Redis is entering the
 752  * main loop of the event driven library, that is, before to sleep
 753  * for ready file descriptors. */
 754 void beforeSleep(struct aeEventLoop *eventLoop) {
 755     REDIS_NOTUSED(eventLoop);
 756     listNode *ln;
 757     redisClient *c;
 758
 759     /* Try to process pending commands for clients that were just unblocked. */
 760     while (listLength(server.unblocked_clients)) {
 761         ln = listFirst(server.unblocked_clients);
 762         redisAssert(ln != NULL);
 763         c = ln->value;
 764         listDelNode(server.unblocked_clients,ln);
 765         c->flags &= ~REDIS_UNBLOCKED;
 766
 767         /* Process remaining data in the input buffer. */
 768         if (c->querybuf && sdslen(c->querybuf) > 0)
 769             processInputBuffer(c);
 770     }
 771
 772     /* Write the AOF buffer on disk */
 773     flushAppendOnlyFile(0);
 774 }
 775
 776 /* =========================== Server initialization ======================== */
 777
 778 void createSharedObjects(void) {
 779     int j;
 780
 781     shared.crlf = createObject(REDIS_STRING,sdsnew("\r\n"));
 782     shared.ok = createObject(REDIS_STRING,sdsnew("+OK\r\n"));
 783     shared.err = createObject(REDIS_STRING,sdsnew("-ERR\r\n"));
 784     shared.emptybulk = createObject(REDIS_STRING,sdsnew("$0\r\n\r\n"));
 785     shared.czero = createObject(REDIS_STRING,sdsnew(":0\r\n"));
 786     shared.cone = createObject(REDIS_STRING,sdsnew(":1\r\n"));
 787     shared.cnegone = createObject(REDIS_STRING,sdsnew(":-1\r\n"));
 788     shared.nullbulk = createObject(REDIS_STRING,sdsnew("$-1\r\n"));
 789     shared.nullmultibulk = createObject(REDIS_STRING,sdsnew("*-1\r\n"));
 790     shared.emptymultibulk = createObject(REDIS_STRING,sdsnew("*0\r\n"));
 791     shared.pong = createObject(REDIS_STRING,sdsnew("+PONG\r\n"));
 792     shared.queued = createObject(REDIS_STRING,sdsnew("+QUEUED\r\n"));
 793     shared.wrongtypeerr = createObject(REDIS_STRING,sdsnew(
 794         "-ERR Operation against a key holding the wrong kind of value\r\n"));
 795     shared.nokeyerr = createObject(REDIS_STRING,sdsnew(
 796         "-ERR no such key\r\n"));
 797     shared.syntaxerr = createObject(REDIS_STRING,sdsnew(
 798         "-ERR syntax error\r\n"));
 799     shared.sameobjecterr = createObject(REDIS_STRING,sdsnew(
 800         "-ERR source and destination objects are the same\r\n"));
 801     shared.outofrangeerr = createObject(REDIS_STRING,sdsnew(
 802         "-ERR index out of range\r\n"));
 803     shared.noscripterr = createObject(REDIS_STRING,sdsnew(
 804         "-NOSCRIPT No matching script. Please use EVAL.\r\n"));
 805     shared.loadingerr = createObject(REDIS_STRING,sdsnew(
 806         "-LOADING Redis is loading the dataset in memory\r\n"));
 807     shared.slowscripterr = createObject(REDIS_STRING,sdsnew(
 808         "-BUSY Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE.\r\n"));
 809     shared.space = createObject(REDIS_STRING,sdsnew(" "));
 810     shared.colon = createObject(REDIS_STRING,sdsnew(":"));
 811     shared.plus = createObject(REDIS_STRING,sdsnew("+"));
 812     shared.select0 = createStringObject("select 0\r\n",10);
 813     shared.select1 = createStringObject("select 1\r\n",10);
 814     shared.select2 = createStringObject("select 2\r\n",10);
 815     shared.select3 = createStringObject("select 3\r\n",10);
 816     shared.select4 = createStringObject("select 4\r\n",10);
 817     shared.select5 = createStringObject("select 5\r\n",10);
 818     shared.select6 = createStringObject("select 6\r\n",10);
 819     shared.select7 = createStringObject("select 7\r\n",10);
 820     shared.select8 = createStringObject("select 8\r\n",10);
 821     shared.select9 = createStringObject("select 9\r\n",10);
 822     shared.messagebulk = createStringObject("$7\r\nmessage\r\n",13);
 823     shared.pmessagebulk = createStringObject("$8\r\npmessage\r\n",14);
 824     shared.subscribebulk = createStringObject("$9\r\nsubscribe\r\n",15);
 825     shared.unsubscribebulk = createStringObject("$11\r\nunsubscribe\r\n",18);
 826     shared.psubscribebulk = createStringObject("$10\r\npsubscribe\r\n",17);
 827     shared.punsubscribebulk = createStringObject("$12\r\npunsubscribe\r\n",19);
 828     shared.mbulk3 = createStringObject("*3\r\n",4);
 829     shared.mbulk4 = createStringObject("*4\r\n",4);
 830     for (j = 0; j < REDIS_SHARED_INTEGERS; j++) {
 831         shared.integers[j] = createObject(REDIS_STRING,(void*)(long)j);
 832         shared.integers[j]->encoding = REDIS_ENCODING_INT;
 833     }
 834 }
 835
 836 void initServerConfig() {
 837     server.port = REDIS_SERVERPORT;
 838     server.bindaddr = NULL;
 839     server.unixsocket = NULL;
 840     server.unixsocketperm = 0;
 841     server.ipfd = -1;
 842     server.sofd = -1;
 843     server.dbnum = REDIS_DEFAULT_DBNUM;
 844     server.verbosity = REDIS_VERBOSE;
 845     server.maxidletime = REDIS_MAXIDLETIME;
 846     server.client_max_querybuf_len = REDIS_MAX_QUERYBUF_LEN;
 847     server.saveparams = NULL;
 848     server.loading = 0;
 849     server.logfile = NULL; /* NULL = log on standard output */
 850     server.syslog_enabled = 0;
 851     server.syslog_ident = zstrdup("redis");
 852     server.syslog_facility = LOG_LOCAL0;
 853     server.daemonize = 0;
 854     server.appendonly = 0;
 855     server.appendfsync = APPENDFSYNC_EVERYSEC;
 856     server.no_appendfsync_on_rewrite = 0;
 857     server.auto_aofrewrite_perc = REDIS_AUTO_AOFREWRITE_PERC;
 858     server.auto_aofrewrite_min_size = REDIS_AUTO_AOFREWRITE_MIN_SIZE;
 859     server.auto_aofrewrite_base_size = 0;
 860     server.aofrewrite_scheduled = 0;
 861     server.lastfsync = time(NULL);
 862     server.appendfd = -1;
 863     server.appendseldb = -1; /* Make sure the first time will not match */
 864     server.aof_flush_postponed_start = 0;
 865     server.pidfile = zstrdup("/var/run/redis.pid");
 866     server.dbfilename = zstrdup("dump.rdb");
 867     server.appendfilename = zstrdup("appendonly.aof");
 868     server.requirepass = NULL;
 869     server.rdbcompression = 1;
 870     server.activerehashing = 1;
 871     server.maxclients = REDIS_MAX_CLIENTS;
 872     server.bpop_blocked_clients = 0;
 873     server.maxmemory = 0;
 874     server.maxmemory_policy = REDIS_MAXMEMORY_VOLATILE_LRU;
 875     server.maxmemory_samples = 3;
 876     server.hash_max_zipmap_entries = REDIS_HASH_MAX_ZIPMAP_ENTRIES;
 877     server.hash_max_zipmap_value = REDIS_HASH_MAX_ZIPMAP_VALUE;
 878     server.list_max_ziplist_entries = REDIS_LIST_MAX_ZIPLIST_ENTRIES;
 879     server.list_max_ziplist_value = REDIS_LIST_MAX_ZIPLIST_VALUE;
 880     server.set_max_intset_entries = REDIS_SET_MAX_INTSET_ENTRIES;
 881     server.zset_max_ziplist_entries = REDIS_ZSET_MAX_ZIPLIST_ENTRIES;
 882     server.zset_max_ziplist_value = REDIS_ZSET_MAX_ZIPLIST_VALUE;
 883     server.shutdown_asap = 0;
 884     server.repl_ping_slave_period = REDIS_REPL_PING_SLAVE_PERIOD;
 885     server.repl_timeout = REDIS_REPL_TIMEOUT;
 886     server.cluster_enabled = 0;
 887     server.cluster.configfile = zstrdup("nodes.conf");
 888     server.lua_caller = NULL;
 889     server.lua_time_limit = REDIS_LUA_TIME_LIMIT;
 890     server.lua_client = NULL;
 891     server.lua_timedout = 0;
 892
 893     updateLRUClock();
 894     resetServerSaveParams();
 895
 896     appendServerSaveParams(60*60,1);  /* save after 1 hour and 1 change */
 897     appendServerSaveParams(300,100);  /* save after 5 minutes and 100 changes */
 898     appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
 899     /* Replication related */
 900     server.isslave = 0;
 901     server.masterauth = NULL;
 902     server.masterhost = NULL;
 903     server.masterport = 6379;
 904     server.master = NULL;
 905     server.replstate = REDIS_REPL_NONE;
 906     server.repl_syncio_timeout = REDIS_REPL_SYNCIO_TIMEOUT;
 907     server.repl_serve_stale_data = 1;
 908     server.repl_down_since = -1;
 909
 910     /* Double constants initialization */
 911     R_Zero = 0.0;
 912     R_PosInf = 1.0/R_Zero;
 913     R_NegInf = -1.0/R_Zero;
 914     R_Nan = R_Zero/R_Zero;
 915
 916     /* Command table -- we intiialize it here as it is part of the
 917      * initial configuration, since command names may be changed via
 918      * redis.conf using the rename-command directive. */
 919     server.commands = dictCreate(&commandTableDictType,NULL);
 920     populateCommandTable();
 921     server.delCommand = lookupCommandByCString("del");
 922     server.multiCommand = lookupCommandByCString("multi");
 923
 924     /* Slow log */
 925     server.slowlog_log_slower_than = REDIS_SLOWLOG_LOG_SLOWER_THAN;
 926     server.slowlog_max_len = REDIS_SLOWLOG_MAX_LEN;
 927 }
 928
 929 void initServer() {
 930     int j;
 931
 932     signal(SIGHUP, SIG_IGN);
 933     signal(SIGPIPE, SIG_IGN);
 934     setupSignalHandlers();
 935
 936     if (server.syslog_enabled) {
 937         openlog(server.syslog_ident, LOG_PID | LOG_NDELAY | LOG_NOWAIT,
 938             server.syslog_facility);
 939     }
 940
 941     server.clients = listCreate();
 942     server.slaves = listCreate();
 943     server.monitors = listCreate();
 944     server.unblocked_clients = listCreate();
 945
 946     createSharedObjects();
 947     server.el = aeCreateEventLoop();
 948     server.db = zmalloc(sizeof(redisDb)*server.dbnum);
 949
 950     if (server.port != 0) {
 951         server.ipfd = anetTcpServer(server.neterr,server.port,server.bindaddr);
 952         if (server.ipfd == ANET_ERR) {
 953             redisLog(REDIS_WARNING, "Opening port %d: %s",
 954                 server.port, server.neterr);
 955             exit(1);
 956         }
 957     }
 958     if (server.unixsocket != NULL) {
 959         unlink(server.unixsocket); /* don't care if this fails */
 960         server.sofd = anetUnixServer(server.neterr,server.unixsocket,server.unixsocketperm);
 961         if (server.sofd == ANET_ERR) {
 962             redisLog(REDIS_WARNING, "Opening socket: %s", server.neterr);
 963             exit(1);
 964         }
 965     }
 966     if (server.ipfd < 0 && server.sofd < 0) {
 967         redisLog(REDIS_WARNING, "Configured to not listen anywhere, exiting.");
 968         exit(1);
 969     }
 970     for (j = 0; j < server.dbnum; j++) {
 971         server.db[j].dict = dictCreate(&dbDictType,NULL);
 972         server.db[j].expires = dictCreate(&keyptrDictType,NULL);
 973         server.db[j].blocking_keys = dictCreate(&keylistDictType,NULL);
 974         server.db[j].watched_keys = dictCreate(&keylistDictType,NULL);
 975         server.db[j].id = j;
 976     }
 977     server.pubsub_channels = dictCreate(&keylistDictType,NULL);
 978     server.pubsub_patterns = listCreate();
 979     listSetFreeMethod(server.pubsub_patterns,freePubsubPattern);
 980     listSetMatchMethod(server.pubsub_patterns,listMatchPubsubPattern);
 981     server.cronloops = 0;
 982     server.bgsavechildpid = -1;
 983     server.bgrewritechildpid = -1;
 984     server.bgrewritebuf = sdsempty();
 985     server.aofbuf = sdsempty();
 986     server.lastsave = time(NULL);
 987     server.dirty = 0;
 988     server.stat_numcommands = 0;
 989     server.stat_numconnections = 0;
 990     server.stat_expiredkeys = 0;
 991     server.stat_evictedkeys = 0;
 992     server.stat_starttime = time(NULL);
 993     server.stat_keyspace_misses = 0;
 994     server.stat_keyspace_hits = 0;
 995     server.stat_peak_memory = 0;
 996     server.stat_fork_time = 0;
 997     server.unixtime = time(NULL);
 998     aeCreateTimeEvent(server.el, 1, serverCron, NULL, NULL);
 999     if (server.ipfd > 0 && aeCreateFileEvent(server.el,server.ipfd,AE_READABLE,
1000         acceptTcpHandler,NULL) == AE_ERR) oom("creating file event");
1001     if (server.sofd > 0 && aeCreateFileEvent(server.el,server.sofd,AE_READABLE,
1002         acceptUnixHandler,NULL) == AE_ERR) oom("creating file event");
1003
1004     if (server.appendonly) {
1005         server.appendfd = open(server.appendfilename,O_WRONLY|O_APPEND|O_CREAT,0644);
1006         if (server.appendfd == -1) {
1007             redisLog(REDIS_WARNING, "Can't open the append-only file: %s",
1008                 strerror(errno));
1009             exit(1);
1010         }
1011     }
1012
1013     if (server.cluster_enabled) clusterInit();
1014     scriptingInit();
1015     slowlogInit();
1016     bioInit();
1017     srand(time(NULL)^getpid());
1018
1019     /* Try to raise the max number of open files accordingly to the
1020      * configured max number of clients. Also account for 32 additional
1021      * file descriptors as we need a few more for persistence, listening
1022      * sockets, log files and so forth. */
1023     {
1024         rlim_t maxfiles = server.maxclients+32;
1025         struct rlimit limit;
1026
1027         if (maxfiles < 1024) maxfiles = 1024;
1028         if (getrlimit(RLIMIT_NOFILE,&limit) == -1) {
1029             redisLog(REDIS_WARNING,"Unable to obtain the current NOFILE limit (%s), assuming 1024 and setting the max clients configuration accordingly.",
1030                 strerror(errno));
1031             server.maxclients = 1024-32;
1032         } else {
1033             rlim_t oldlimit = limit.rlim_cur;
1034
1035             /* Set the max number of files if the current limit is not enough
1036              * for our needs. */
1037             if (oldlimit < maxfiles) {
1038                 limit.rlim_cur = maxfiles;
1039                 limit.rlim_max = maxfiles;
1040                 if (setrlimit(RLIMIT_NOFILE,&limit) == -1) {
1041                     server.maxclients = oldlimit-32;
1042                     redisLog(REDIS_WARNING,"Unable to set the max number of files limit to %d (%s), setting the max clients configuration to %d.",
1043                         (int) maxfiles, strerror(errno), (int) server.maxclients);
1044                 } else {
1045                     redisLog(REDIS_NOTICE,"Max number of open files set to %d",
1046                         (int) maxfiles);
1047                 }
1048             }
1049         }
1050     }
1051 }
1052
1053 /* Populates the Redis Command Table starting from the hard coded list
1054  * we have on top of redis.c file. */
1055 void populateCommandTable(void) {
1056     int j;
1057     int numcommands = sizeof(redisCommandTable)/sizeof(struct redisCommand);
1058
1059     for (j = 0; j < numcommands; j++) {
1060         struct redisCommand *c = redisCommandTable+j;
1061         char *f = c->sflags;
1062         int retval;
1063
1064         while(*f != '\0') {
1065             switch(*f) {
1066             case 'w': c->flags |= REDIS_CMD_WRITE; break;
1067             case 'r': c->flags |= REDIS_CMD_READONLY; break;
1068             case 'm': c->flags |= REDIS_CMD_DENYOOM; break;
1069             case 'a': c->flags |= REDIS_CMD_ADMIN; break;
1070             case 'p': c->flags |= REDIS_CMD_PUBSUB; break;
1071             case 'f': c->flags |= REDIS_CMD_FORCE_REPLICATION; break;
1072             case 's': c->flags |= REDIS_CMD_NOSCRIPT; break;
1073             case 'R': c->flags |= REDIS_CMD_RANDOM; break;
1074             default: redisPanic("Unsupported command flag"); break;
1075             }
1076             f++;
1077         }
1078
1079         retval = dictAdd(server.commands, sdsnew(c->name), c);
1080         assert(retval == DICT_OK);
1081     }
1082 }
1083
1084 void resetCommandTableStats(void) {
1085     int numcommands = sizeof(redisCommandTable)/sizeof(struct redisCommand);
1086     int j;
1087
1088     for (j = 0; j < numcommands; j++) {
1089         struct redisCommand *c = redisCommandTable+j;
1090
1091         c->microseconds = 0;
1092         c->calls = 0;
1093     }
1094 }
1095
1096 /* ====================== Commands lookup and execution ===================== */
1097
1098 struct redisCommand *lookupCommand(sds name) {
1099     return dictFetchValue(server.commands, name);
1100 }
1101
1102 struct redisCommand *lookupCommandByCString(char *s) {
1103     struct redisCommand *cmd;
1104     sds name = sdsnew(s);
1105
1106     cmd = dictFetchValue(server.commands, name);
1107     sdsfree(name);
1108     return cmd;
1109 }
1110
1111 /* Call() is the core of Redis execution of a command */
1112 void call(redisClient *c) {
1113     long long dirty, start = ustime(), duration;
1114
1115     dirty = server.dirty;
1116     c->cmd->proc(c);
1117     dirty = server.dirty-dirty;
1118     duration = ustime()-start;
1119     c->cmd->microseconds += duration;
1120     slowlogPushEntryIfNeeded(c->argv,c->argc,duration);
1121     c->cmd->calls++;
1122
1123     if (server.appendonly && dirty > 0)
1124         feedAppendOnlyFile(c->cmd,c->db->id,c->argv,c->argc);
1125     if ((dirty > 0 || c->cmd->flags & REDIS_CMD_FORCE_REPLICATION) &&
1126         listLength(server.slaves))
1127         replicationFeedSlaves(server.slaves,c->db->id,c->argv,c->argc);
1128     if (listLength(server.monitors))
1129         replicationFeedMonitors(server.monitors,c->db->id,c->argv,c->argc);
1130     server.stat_numcommands++;
1131 }
1132
1133 /* If this function gets called we already read a whole
1134  * command, argments are in the client argv/argc fields.
1135  * processCommand() execute the command or prepare the
1136  * server for a bulk read from the client.
1137  *
1138  * If 1 is returned the client is still alive and valid and
1139  * and other operations can be performed by the caller. Otherwise
1140  * if 0 is returned the client was destroied (i.e. after QUIT). */
1141 int processCommand(redisClient *c) {
1142     /* The QUIT command is handled separately. Normal command procs will
1143      * go through checking for replication and QUIT will cause trouble
1144      * when FORCE_REPLICATION is enabled and would be implemented in
1145      * a regular command proc. */
1146     if (!strcasecmp(c->argv[0]->ptr,"quit")) {
1147         addReply(c,shared.ok);
1148         c->flags |= REDIS_CLOSE_AFTER_REPLY;
1149         return REDIS_ERR;
1150     }
1151
1152     /* Now lookup the command and check ASAP about trivial error conditions
1153      * such as wrong arity, bad command name and so forth. */
1154     c->cmd = lookupCommand(c->argv[0]->ptr);
1155     if (!c->cmd) {
1156         addReplyErrorFormat(c,"unknown command '%s'",
1157             (char*)c->argv[0]->ptr);
1158         return REDIS_OK;
1159     } else if ((c->cmd->arity > 0 && c->cmd->arity != c->argc) ||
1160                (c->argc < -c->cmd->arity)) {
1161         addReplyErrorFormat(c,"wrong number of arguments for '%s' command",
1162             c->cmd->name);
1163         return REDIS_OK;
1164     }
1165
1166     /* Check if the user is authenticated */
1167     if (server.requirepass && !c->authenticated && c->cmd->proc != authCommand)
1168     {
1169         addReplyError(c,"operation not permitted");
1170         return REDIS_OK;
1171     }
1172
1173     /* If cluster is enabled, redirect here */
1174     if (server.cluster_enabled &&
1175                 !(c->cmd->getkeys_proc == NULL && c->cmd->firstkey == 0)) {
1176         int hashslot;
1177
1178         if (server.cluster.state != REDIS_CLUSTER_OK) {
1179             addReplyError(c,"The cluster is down. Check with CLUSTER INFO for more information");
1180             return REDIS_OK;
1181         } else {
1182             int ask;
1183             clusterNode *n = getNodeByQuery(c,c->cmd,c->argv,c->argc,&hashslot,&ask);
1184             if (n == NULL) {
1185                 addReplyError(c,"Multi keys request invalid in cluster");
1186                 return REDIS_OK;
1187             } else if (n != server.cluster.myself) {
1188                 addReplySds(c,sdscatprintf(sdsempty(),
1189                     "-%s %d %s:%d\r\n", ask ? "ASK" : "MOVED",
1190                     hashslot,n->ip,n->port));
1191                 return REDIS_OK;
1192             }
1193         }
1194     }
1195
1196     /* Handle the maxmemory directive.
1197      *
1198      * First we try to free some memory if possible (if there are volatile
1199      * keys in the dataset). If there are not the only thing we can do
1200      * is returning an error. */
1201     if (server.maxmemory) freeMemoryIfNeeded();
1202     if (server.maxmemory && (c->cmd->flags & REDIS_CMD_DENYOOM) &&
1203         zmalloc_used_memory() > server.maxmemory)
1204     {
1205         addReplyError(c,"command not allowed when used memory > 'maxmemory'");
1206         return REDIS_OK;
1207     }
1208
1209     /* Only allow SUBSCRIBE and UNSUBSCRIBE in the context of Pub/Sub */
1210     if ((dictSize(c->pubsub_channels) > 0 || listLength(c->pubsub_patterns) > 0)
1211         &&
1212         c->cmd->proc != subscribeCommand &&
1213         c->cmd->proc != unsubscribeCommand &&
1214         c->cmd->proc != psubscribeCommand &&
1215         c->cmd->proc != punsubscribeCommand) {
1216         addReplyError(c,"only (P)SUBSCRIBE / (P)UNSUBSCRIBE / QUIT allowed in this context");
1217         return REDIS_OK;
1218     }
1219
1220     /* Only allow INFO and SLAVEOF when slave-serve-stale-data is no and
1221      * we are a slave with a broken link with master. */
1222     if (server.masterhost && server.replstate != REDIS_REPL_CONNECTED &&
1223         server.repl_serve_stale_data == 0 &&
1224         c->cmd->proc != infoCommand && c->cmd->proc != slaveofCommand)
1225     {
1226         addReplyError(c,
1227             "link with MASTER is down and slave-serve-stale-data is set to no");
1228         return REDIS_OK;
1229     }
1230
1231     /* Loading DB? Return an error if the command is not INFO */
1232     if (server.loading && c->cmd->proc != infoCommand) {
1233         addReply(c, shared.loadingerr);
1234         return REDIS_OK;
1235     }
1236
1237     /* Lua script too slow? Only allow SHUTDOWN NOSAVE and SCRIPT KILL. */
1238     if (server.lua_timedout &&
1239         !(c->cmd->proc != shutdownCommand &&
1240           c->argc == 2 &&
1241           tolower(((char*)c->argv[1]->ptr)[0]) == 'n') &&
1242         !(c->cmd->proc == scriptCommand &&
1243           c->argc == 2 &&
1244           tolower(((char*)c->argv[1]->ptr)[0]) == 'k'))
1245     {
1246         addReply(c, shared.slowscripterr);
1247         return REDIS_OK;
1248     }
1249
1250     /* Exec the command */
1251     if (c->flags & REDIS_MULTI &&
1252         c->cmd->proc != execCommand && c->cmd->proc != discardCommand &&
1253         c->cmd->proc != multiCommand && c->cmd->proc != watchCommand)
1254     {
1255         queueMultiCommand(c);
1256         addReply(c,shared.queued);
1257     } else {
1258         call(c);
1259     }
1260     return REDIS_OK;
1261 }
1262
1263 /*================================== Shutdown =============================== */
1264
1265 int prepareForShutdown(int flags) {
1266     int save = flags & REDIS_SHUTDOWN_SAVE;
1267     int nosave = flags & REDIS_SHUTDOWN_NOSAVE;
1268
1269     redisLog(REDIS_WARNING,"User requested shutdown...");
1270     /* Kill the saving child if there is a background saving in progress.
1271        We want to avoid race conditions, for instance our saving child may
1272        overwrite the synchronous saving did by SHUTDOWN. */
1273     if (server.bgsavechildpid != -1) {
1274         redisLog(REDIS_WARNING,"There is a child saving an .rdb. Killing it!");
1275         kill(server.bgsavechildpid,SIGKILL);
1276         rdbRemoveTempFile(server.bgsavechildpid);
1277     }
1278     if (server.appendonly) {
1279         /* Kill the AOF saving child as the AOF we already have may be longer
1280          * but contains the full dataset anyway. */
1281         if (server.bgrewritechildpid != -1) {
1282             redisLog(REDIS_WARNING,
1283                 "There is a child rewriting the AOF. Killing it!");
1284             kill(server.bgrewritechildpid,SIGKILL);
1285         }
1286         /* Append only file: fsync() the AOF and exit */
1287         redisLog(REDIS_NOTICE,"Calling fsync() on the AOF file.");
1288         aof_fsync(server.appendfd);
1289     }
1290     if ((server.saveparamslen > 0 && !nosave) || save) {
1291         redisLog(REDIS_NOTICE,"Saving the final RDB snapshot before exiting.");
1292         /* Snapshotting. Perform a SYNC SAVE and exit */
1293         if (rdbSave(server.dbfilename) != REDIS_OK) {
1294             /* Ooops.. error saving! The best we can do is to continue
1295              * operating. Note that if there was a background saving process,
1296              * in the next cron() Redis will be notified that the background
1297              * saving aborted, handling special stuff like slaves pending for
1298              * synchronization... */
1299             redisLog(REDIS_WARNING,"Error trying to save the DB, can't exit.");
1300             return REDIS_ERR;
1301         }
1302     }
1303     if (server.daemonize) {
1304         redisLog(REDIS_NOTICE,"Removing the pid file.");
1305         unlink(server.pidfile);
1306     }
1307     /* Close the listening sockets. Apparently this allows faster restarts. */
1308     if (server.ipfd != -1) close(server.ipfd);
1309     if (server.sofd != -1) close(server.sofd);
1310     if (server.unixsocket) {
1311         redisLog(REDIS_NOTICE,"Removing the unix socket file.");
1312         unlink(server.unixsocket); /* don't care if this fails */
1313     }
1314
1315     redisLog(REDIS_WARNING,"Redis is now ready to exit, bye bye...");
1316     return REDIS_OK;
1317 }
1318
1319 /*================================== Commands =============================== */
1320
1321 void authCommand(redisClient *c) {
1322     if (!server.requirepass) {
1323         addReplyError(c,"Client sent AUTH, but no password is set");
1324     } else if (!strcmp(c->argv[1]->ptr, server.requirepass)) {
1325       c->authenticated = 1;
1326       addReply(c,shared.ok);
1327     } else {
1328       c->authenticated = 0;
1329       addReplyError(c,"invalid password");
1330     }
1331 }
1332
1333 void pingCommand(redisClient *c) {
1334     addReply(c,shared.pong);
1335 }
1336
1337 void echoCommand(redisClient *c) {
1338     addReplyBulk(c,c->argv[1]);
1339 }
1340
1341 /* Convert an amount of bytes into a human readable string in the form
1342  * of 100B, 2G, 100M, 4K, and so forth. */
1343 void bytesToHuman(char *s, unsigned long long n) {
1344     double d;
1345
1346     if (n < 1024) {
1347         /* Bytes */
1348         sprintf(s,"%lluB",n);
1349         return;
1350     } else if (n < (1024*1024)) {
1351         d = (double)n/(1024);
1352         sprintf(s,"%.2fK",d);
1353     } else if (n < (1024LL*1024*1024)) {
1354         d = (double)n/(1024*1024);
1355         sprintf(s,"%.2fM",d);
1356     } else if (n < (1024LL*1024*1024*1024)) {
1357         d = (double)n/(1024LL*1024*1024);
1358         sprintf(s,"%.2fG",d);
1359     }
1360 }
1361
1362 /* Create the string returned by the INFO command. This is decoupled
1363  * by the INFO command itself as we need to report the same information
1364  * on memory corruption problems. */
1365 sds genRedisInfoString(char *section) {
1366     sds info = sdsempty();
1367     time_t uptime = time(NULL)-server.stat_starttime;
1368     int j, numcommands;
1369     struct rusage self_ru, c_ru;
1370     unsigned long lol, bib;
1371     int allsections = 0, defsections = 0;
1372     int sections = 0;
1373
1374     if (section) {
1375         allsections = strcasecmp(section,"all") == 0;
1376         defsections = strcasecmp(section,"default") == 0;
1377     }
1378
1379     getrusage(RUSAGE_SELF, &self_ru);
1380     getrusage(RUSAGE_CHILDREN, &c_ru);
1381     getClientsMaxBuffers(&lol,&bib);
1382
1383     /* Server */
1384     if (allsections || defsections || !strcasecmp(section,"server")) {
1385         if (sections++) info = sdscat(info,"\r\n");
1386         info = sdscatprintf(info,
1387             "# Server\r\n"
1388             "redis_version:%s\r\n"
1389             "redis_git_sha1:%s\r\n"
1390             "redis_git_dirty:%d\r\n"
1391             "arch_bits:%s\r\n"
1392             "multiplexing_api:%s\r\n"
1393             "process_id:%ld\r\n"
1394             "tcp_port:%d\r\n"
1395             "uptime_in_seconds:%ld\r\n"
1396             "uptime_in_days:%ld\r\n"
1397             "lru_clock:%ld\r\n",
1398             REDIS_VERSION,
1399             redisGitSHA1(),
1400             strtol(redisGitDirty(),NULL,10) > 0,
1401             (sizeof(long) == 8) ? "64" : "32",
1402             aeGetApiName(),
1403             (long) getpid(),
1404             server.port,
1405             uptime,
1406             uptime/(3600*24),
1407             (unsigned long) server.lruclock);
1408     }
1409
1410     /* Clients */
1411     if (allsections || defsections || !strcasecmp(section,"clients")) {
1412         if (sections++) info = sdscat(info,"\r\n");
1413         info = sdscatprintf(info,
1414             "# Clients\r\n"
1415             "connected_clients:%d\r\n"
1416             "client_longest_output_list:%lu\r\n"
1417             "client_biggest_input_buf:%lu\r\n"
1418             "blocked_clients:%d\r\n",
1419             listLength(server.clients)-listLength(server.slaves),
1420             lol, bib,
1421             server.bpop_blocked_clients);
1422     }
1423
1424     /* Memory */
1425     if (allsections || defsections || !strcasecmp(section,"memory")) {
1426         char hmem[64];
1427         char peak_hmem[64];
1428
1429         bytesToHuman(hmem,zmalloc_used_memory());
1430         bytesToHuman(peak_hmem,server.stat_peak_memory);
1431         if (sections++) info = sdscat(info,"\r\n");
1432         info = sdscatprintf(info,
1433             "# Memory\r\n"
1434             "used_memory:%zu\r\n"
1435             "used_memory_human:%s\r\n"
1436             "used_memory_rss:%zu\r\n"
1437             "used_memory_peak:%zu\r\n"
1438             "used_memory_peak_human:%s\r\n"
1439             "used_memory_lua:%lld\r\n"
1440             "mem_fragmentation_ratio:%.2f\r\n"
1441             "mem_allocator:%s\r\n",
1442             zmalloc_used_memory(),
1443             hmem,
1444             zmalloc_get_rss(),
1445             server.stat_peak_memory,
1446             peak_hmem,
1447             ((long long)lua_gc(server.lua,LUA_GCCOUNT,0))*1024LL,
1448             zmalloc_get_fragmentation_ratio(),
1449             ZMALLOC_LIB
1450             );
1451     }
1452
1453     /* Persistence */
1454     if (allsections || defsections || !strcasecmp(section,"persistence")) {
1455         if (sections++) info = sdscat(info,"\r\n");
1456         info = sdscatprintf(info,
1457             "# Persistence\r\n"
1458             "loading:%d\r\n"
1459             "aof_enabled:%d\r\n"
1460             "changes_since_last_save:%lld\r\n"
1461             "bgsave_in_progress:%d\r\n"
1462             "last_save_time:%ld\r\n"
1463             "bgrewriteaof_in_progress:%d\r\n",
1464             server.loading,
1465             server.appendonly,
1466             server.dirty,
1467             server.bgsavechildpid != -1,
1468             server.lastsave,
1469             server.bgrewritechildpid != -1);
1470
1471         if (server.appendonly) {
1472             info = sdscatprintf(info,
1473                 "aof_current_size:%lld\r\n"
1474                 "aof_base_size:%lld\r\n"
1475                 "aof_pending_rewrite:%d\r\n",
1476                 (long long) server.appendonly_current_size,
1477                 (long long) server.auto_aofrewrite_base_size,
1478                 server.aofrewrite_scheduled);
1479         }
1480
1481         if (server.loading) {
1482             double perc;
1483             time_t eta, elapsed;
1484             off_t remaining_bytes = server.loading_total_bytes-
1485                                     server.loading_loaded_bytes;
1486
1487             perc = ((double)server.loading_loaded_bytes /
1488                    server.loading_total_bytes) * 100;
1489
1490             elapsed = time(NULL)-server.loading_start_time;
1491             if (elapsed == 0) {
1492                 eta = 1; /* A fake 1 second figure if we don't have
1493                             enough info */
1494             } else {
1495                 eta = (elapsed*remaining_bytes)/server.loading_loaded_bytes;
1496             }
1497
1498             info = sdscatprintf(info,
1499                 "loading_start_time:%ld\r\n"
1500                 "loading_total_bytes:%llu\r\n"
1501                 "loading_loaded_bytes:%llu\r\n"
1502                 "loading_loaded_perc:%.2f\r\n"
1503                 "loading_eta_seconds:%ld\r\n"
1504                 ,(unsigned long) server.loading_start_time,
1505                 (unsigned long long) server.loading_total_bytes,
1506                 (unsigned long long) server.loading_loaded_bytes,
1507                 perc,
1508                 eta
1509             );
1510         }
1511     }
1512
1513     /* Stats */
1514     if (allsections || defsections || !strcasecmp(section,"stats")) {
1515         if (sections++) info = sdscat(info,"\r\n");
1516         info = sdscatprintf(info,
1517             "# Stats\r\n"
1518             "total_connections_received:%lld\r\n"
1519             "total_commands_processed:%lld\r\n"
1520             "expired_keys:%lld\r\n"
1521             "evicted_keys:%lld\r\n"
1522             "keyspace_hits:%lld\r\n"
1523             "keyspace_misses:%lld\r\n"
1524             "pubsub_channels:%ld\r\n"
1525             "pubsub_patterns:%u\r\n"
1526             "latest_fork_usec:%lld\r\n",
1527             server.stat_numconnections,
1528             server.stat_numcommands,
1529             server.stat_expiredkeys,
1530             server.stat_evictedkeys,
1531             server.stat_keyspace_hits,
1532             server.stat_keyspace_misses,
1533             dictSize(server.pubsub_channels),
1534             listLength(server.pubsub_patterns),
1535             server.stat_fork_time);
1536     }
1537
1538     /* Replication */
1539     if (allsections || defsections || !strcasecmp(section,"replication")) {
1540         if (sections++) info = sdscat(info,"\r\n");
1541         info = sdscatprintf(info,
1542             "# Replication\r\n"
1543             "role:%s\r\n",
1544             server.masterhost == NULL ? "master" : "slave");
1545         if (server.masterhost) {
1546             info = sdscatprintf(info,
1547                 "master_host:%s\r\n"
1548                 "master_port:%d\r\n"
1549                 "master_link_status:%s\r\n"
1550                 "master_last_io_seconds_ago:%d\r\n"
1551                 "master_sync_in_progress:%d\r\n"
1552                 ,server.masterhost,
1553                 server.masterport,
1554                 (server.replstate == REDIS_REPL_CONNECTED) ?
1555                     "up" : "down",
1556                 server.master ?
1557                 ((int)(time(NULL)-server.master->lastinteraction)) : -1,
1558                 server.replstate == REDIS_REPL_TRANSFER
1559             );
1560
1561             if (server.replstate == REDIS_REPL_TRANSFER) {
1562                 info = sdscatprintf(info,
1563                     "master_sync_left_bytes:%ld\r\n"
1564                     "master_sync_last_io_seconds_ago:%d\r\n"
1565                     ,(long)server.repl_transfer_left,
1566                     (int)(time(NULL)-server.repl_transfer_lastio)
1567                 );
1568             }
1569
1570             if (server.replstate != REDIS_REPL_CONNECTED) {
1571                 info = sdscatprintf(info,
1572                     "master_link_down_since_seconds:%ld\r\n",
1573                     (long)time(NULL)-server.repl_down_since);
1574             }
1575         }
1576         info = sdscatprintf(info,
1577             "connected_slaves:%d\r\n",
1578             listLength(server.slaves));
1579     }
1580
1581     /* CPU */
1582     if (allsections || defsections || !strcasecmp(section,"cpu")) {
1583         if (sections++) info = sdscat(info,"\r\n");
1584         info = sdscatprintf(info,
1585         "# CPU\r\n"
1586         "used_cpu_sys:%.2f\r\n"
1587         "used_cpu_user:%.2f\r\n"
1588         "used_cpu_sys_children:%.2f\r\n"
1589         "used_cpu_user_children:%.2f\r\n",
1590         (float)self_ru.ru_stime.tv_sec+(float)self_ru.ru_stime.tv_usec/1000000,
1591         (float)self_ru.ru_utime.tv_sec+(float)self_ru.ru_utime.tv_usec/1000000,
1592         (float)c_ru.ru_stime.tv_sec+(float)c_ru.ru_stime.tv_usec/1000000,
1593         (float)c_ru.ru_utime.tv_sec+(float)c_ru.ru_utime.tv_usec/1000000);
1594     }
1595
1596     /* cmdtime */
1597     if (allsections || !strcasecmp(section,"commandstats")) {
1598         if (sections++) info = sdscat(info,"\r\n");
1599         info = sdscatprintf(info, "# Commandstats\r\n");
1600         numcommands = sizeof(redisCommandTable)/sizeof(struct redisCommand);
1601         for (j = 0; j < numcommands; j++) {
1602             struct redisCommand *c = redisCommandTable+j;
1603
1604             if (!c->calls) continue;
1605             info = sdscatprintf(info,
1606                 "cmdstat_%s:calls=%lld,usec=%lld,usec_per_call=%.2f\r\n",
1607                 c->name, c->calls, c->microseconds,
1608                 (c->calls == 0) ? 0 : ((float)c->microseconds/c->calls));
1609         }
1610     }
1611
1612     /* Clusetr */
1613     if (allsections || defsections || !strcasecmp(section,"cluster")) {
1614         if (sections++) info = sdscat(info,"\r\n");
1615         info = sdscatprintf(info,
1616         "# Cluster\r\n"
1617         "cluster_enabled:%d\r\n",
1618         server.cluster_enabled);
1619     }
1620
1621     /* Key space */
1622     if (allsections || defsections || !strcasecmp(section,"keyspace")) {
1623         if (sections++) info = sdscat(info,"\r\n");
1624         info = sdscatprintf(info, "# Keyspace\r\n");
1625         for (j = 0; j < server.dbnum; j++) {
1626             long long keys, vkeys;
1627
1628             keys = dictSize(server.db[j].dict);
1629             vkeys = dictSize(server.db[j].expires);
1630             if (keys || vkeys) {
1631                 info = sdscatprintf(info, "db%d:keys=%lld,expires=%lld\r\n",
1632                     j, keys, vkeys);
1633             }
1634         }
1635     }
1636     return info;
1637 }
1638
1639 void infoCommand(redisClient *c) {
1640     char *section = c->argc == 2 ? c->argv[1]->ptr : "default";
1641
1642     if (c->argc > 2) {
1643         addReply(c,shared.syntaxerr);
1644         return;
1645     }
1646     sds info = genRedisInfoString(section);
1647     addReplySds(c,sdscatprintf(sdsempty(),"$%lu\r\n",
1648         (unsigned long)sdslen(info)));
1649     addReplySds(c,info);
1650     addReply(c,shared.crlf);
1651 }
1652
1653 void monitorCommand(redisClient *c) {
1654     /* ignore MONITOR if aleady slave or in monitor mode */
1655     if (c->flags & REDIS_SLAVE) return;
1656
1657     c->flags |= (REDIS_SLAVE|REDIS_MONITOR);
1658     c->slaveseldb = 0;
1659     listAddNodeTail(server.monitors,c);
1660     addReply(c,shared.ok);
1661 }
1662
1663 /* ============================ Maxmemory directive  ======================== */
1664
1665 /* This function gets called when 'maxmemory' is set on the config file to limit
1666  * the max memory used by the server, and we are out of memory.
1667  * This function will try to, in order:
1668  *
1669  * - Free objects from the free list
1670  * - Try to remove keys with an EXPIRE set
1671  *
1672  * It is not possible to free enough memory to reach used-memory < maxmemory
1673  * the server will start refusing commands that will enlarge even more the
1674  * memory usage.
1675  */
1676 void freeMemoryIfNeeded(void) {
1677     /* Remove keys accordingly to the active policy as long as we are
1678      * over the memory limit. */
1679     if (server.maxmemory_policy == REDIS_MAXMEMORY_NO_EVICTION) return;
1680
1681     while (server.maxmemory && zmalloc_used_memory() > server.maxmemory) {
1682         int j, k, freed = 0;
1683
1684         for (j = 0; j < server.dbnum; j++) {
1685             long bestval = 0; /* just to prevent warning */
1686             sds bestkey = NULL;
1687             struct dictEntry *de;
1688             redisDb *db = server.db+j;
1689             dict *dict;
1690
1691             if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_LRU ||
1692                 server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_RANDOM)
1693             {
1694                 dict = server.db[j].dict;
1695             } else {
1696                 dict = server.db[j].expires;
1697             }
1698             if (dictSize(dict) == 0) continue;
1699
1700             /* volatile-random and allkeys-random policy */
1701             if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_RANDOM ||
1702                 server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_RANDOM)
1703             {
1704                 de = dictGetRandomKey(dict);
1705                 bestkey = dictGetKey(de);
1706             }
1707
1708             /* volatile-lru and allkeys-lru policy */
1709             else if (server.maxmemory_policy == REDIS_MAXMEMORY_ALLKEYS_LRU ||
1710                 server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_LRU)
1711             {
1712                 for (k = 0; k < server.maxmemory_samples; k++) {
1713                     sds thiskey;
1714                     long thisval;
1715                     robj *o;
1716
1717                     de = dictGetRandomKey(dict);
1718                     thiskey = dictGetKey(de);
1719                     /* When policy is volatile-lru we need an additonal lookup
1720                      * to locate the real key, as dict is set to db->expires. */
1721                     if (server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_LRU)
1722                         de = dictFind(db->dict, thiskey);
1723                     o = dictGetVal(de);
1724                     thisval = estimateObjectIdleTime(o);
1725
1726                     /* Higher idle time is better candidate for deletion */
1727                     if (bestkey == NULL || thisval > bestval) {
1728                         bestkey = thiskey;
1729                         bestval = thisval;
1730                     }
1731                 }
1732             }
1733
1734             /* volatile-ttl */
1735             else if (server.maxmemory_policy == REDIS_MAXMEMORY_VOLATILE_TTL) {
1736                 for (k = 0; k < server.maxmemory_samples; k++) {
1737                     sds thiskey;
1738                     long thisval;
1739
1740                     de = dictGetRandomKey(dict);
1741                     thiskey = dictGetKey(de);
1742                     thisval = (long) dictGetVal(de);
1743
1744                     /* Expire sooner (minor expire unix timestamp) is better
1745                      * candidate for deletion */
1746                     if (bestkey == NULL || thisval < bestval) {
1747                         bestkey = thiskey;
1748                         bestval = thisval;
1749                     }
1750                 }
1751             }
1752
1753             /* Finally remove the selected key. */
1754             if (bestkey) {
1755                 robj *keyobj = createStringObject(bestkey,sdslen(bestkey));
1756                 propagateExpire(db,keyobj);
1757                 dbDelete(db,keyobj);
1758                 server.stat_evictedkeys++;
1759                 decrRefCount(keyobj);
1760                 freed++;
1761             }
1762         }
1763         if (!freed) return; /* nothing to free... */
1764     }
1765 }
1766
1767 /* =================================== Main! ================================ */
1768
1769 #ifdef __linux__
1770 int linuxOvercommitMemoryValue(void) {
1771     FILE *fp = fopen("/proc/sys/vm/overcommit_memory","r");
1772     char buf[64];
1773
1774     if (!fp) return -1;
1775     if (fgets(buf,64,fp) == NULL) {
1776         fclose(fp);
1777         return -1;
1778     }
1779     fclose(fp);
1780
1781     return atoi(buf);
1782 }
1783
1784 void linuxOvercommitMemoryWarning(void) {
1785     if (linuxOvercommitMemoryValue() == 0) {
1786         redisLog(REDIS_WARNING,"WARNING overcommit_memory is set to 0! Background save may fail under low memory condition. To fix this issue add 'vm.overcommit_memory = 1' to /etc/sysctl.conf and then reboot or run the command 'sysctl vm.overcommit_memory=1' for this to take effect.");
1787     }
1788 }
1789 #endif /* __linux__ */
1790
1791 void createPidFile(void) {
1792     /* Try to write the pid file in a best-effort way. */
1793     FILE *fp = fopen(server.pidfile,"w");
1794     if (fp) {
1795         fprintf(fp,"%d\n",(int)getpid());
1796         fclose(fp);
1797     }
1798 }
1799
1800 void daemonize(void) {
1801     int fd;
1802
1803     if (fork() != 0) exit(0); /* parent exits */
1804     setsid(); /* create a new session */
1805
1806     /* Every output goes to /dev/null. If Redis is daemonized but
1807      * the 'logfile' is set to 'stdout' in the configuration file
1808      * it will not log at all. */
1809     if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
1810         dup2(fd, STDIN_FILENO);
1811         dup2(fd, STDOUT_FILENO);
1812         dup2(fd, STDERR_FILENO);
1813         if (fd > STDERR_FILENO) close(fd);
1814     }
1815 }
1816
1817 void version() {
1818     printf("Redis server version %s (%s:%d)\n", REDIS_VERSION,
1819         redisGitSHA1(), atoi(redisGitDirty()) > 0);
1820     exit(0);
1821 }
1822
1823 void usage() {
1824     fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
1825     fprintf(stderr,"       ./redis-server - (read config from stdin)\n");
1826     exit(1);
1827 }
1828
1829 void redisAsciiArt(void) {
1830 #include "asciilogo.h"
1831     char *buf = zmalloc(1024*16);
1832
1833     snprintf(buf,1024*16,ascii_logo,
1834         REDIS_VERSION,
1835         redisGitSHA1(),
1836         strtol(redisGitDirty(),NULL,10) > 0,
1837         (sizeof(long) == 8) ? "64" : "32",
1838         server.cluster_enabled ? "cluster" : "stand alone",
1839         server.port,
1840         (long) getpid()
1841     );
1842     redisLogRaw(REDIS_NOTICE|REDIS_LOG_RAW,buf);
1843     zfree(buf);
1844 }
1845
1846 int main(int argc, char **argv) {
1847     long long start;
1848
1849     zmalloc_enable_thread_safeness();
1850     initServerConfig();
1851     if (argc == 2) {
1852         if (strcmp(argv[1], "-v") == 0 ||
1853             strcmp(argv[1], "--version") == 0) version();
1854         if (strcmp(argv[1], "--help") == 0) usage();
1855         resetServerSaveParams();
1856         loadServerConfig(argv[1]);
1857     } else if ((argc > 2)) {
1858         usage();
1859     } else {
1860         redisLog(REDIS_WARNING,"Warning: no config file specified, using the default config. In order to specify a config file use 'redis-server /path/to/redis.conf'");
1861     }
1862     if (server.daemonize) daemonize();
1863     initServer();
1864     if (server.daemonize) createPidFile();
1865     redisAsciiArt();
1866     redisLog(REDIS_NOTICE,"Server started, Redis version " REDIS_VERSION);
1867 #ifdef __linux__
1868     linuxOvercommitMemoryWarning();
1869 #endif
1870     start = ustime();
1871     if (server.appendonly) {
1872         if (loadAppendOnlyFile(server.appendfilename) == REDIS_OK)
1873             redisLog(REDIS_NOTICE,"DB loaded from append only file: %.3f seconds",(float)(ustime()-start)/1000000);
1874     } else {
1875         if (rdbLoad(server.dbfilename) == REDIS_OK) {
1876             redisLog(REDIS_NOTICE,"DB loaded from disk: %.3f seconds",
1877                 (float)(ustime()-start)/1000000);
1878         } else if (errno != ENOENT) {
1879             redisLog(REDIS_WARNING,"Fatal error loading the DB. Exiting.");
1880             exit(1);
1881         }
1882     }
1883     if (server.ipfd > 0)
1884         redisLog(REDIS_NOTICE,"The server is now ready to accept connections on port %d", server.port);
1885     if (server.sofd > 0)
1886         redisLog(REDIS_NOTICE,"The server is now ready to accept connections at %s", server.unixsocket);
1887     aeSetBeforeSleepProc(server.el,beforeSleep);
1888     aeMain(server.el);
1889     aeDeleteEventLoop(server.el);
1890     return 0;
1891 }
1892
1893 #ifdef HAVE_BACKTRACE
1894 static void *getMcontextEip(ucontext_t *uc) {
1895 #if defined(__FreeBSD__)
1896     return (void*) uc->uc_mcontext.mc_eip;
1897 #elif defined(__dietlibc__)
1898     return (void*) uc->uc_mcontext.eip;
1899 #elif defined(__APPLE__) && !defined(MAC_OS_X_VERSION_10_6)
1900   #if __x86_64__
1901     return (void*) uc->uc_mcontext->__ss.__rip;
1902   #elif __i386__
1903     return (void*) uc->uc_mcontext->__ss.__eip;
1904   #else
1905     return (void*) uc->uc_mcontext->__ss.__srr0;
1906   #endif
1907 #elif defined(__APPLE__) && defined(MAC_OS_X_VERSION_10_6)
1908   #if defined(_STRUCT_X86_THREAD_STATE64) && !defined(__i386__)
1909     return (void*) uc->uc_mcontext->__ss.__rip;
1910   #else
1911     return (void*) uc->uc_mcontext->__ss.__eip;
1912   #endif
1913 #elif defined(__i386__)
1914     return (void*) uc->uc_mcontext.gregs[14]; /* Linux 32 */
1915 #elif defined(__X86_64__) || defined(__x86_64__)
1916     return (void*) uc->uc_mcontext.gregs[16]; /* Linux 64 */
1917 #elif defined(__ia64__) /* Linux IA64 */
1918     return (void*) uc->uc_mcontext.sc_ip;
1919 #else
1920     return NULL;
1921 #endif
1922 }
1923
1924 static void sigsegvHandler(int sig, siginfo_t *info, void *secret) {
1925     void *trace[100];
1926     char **messages = NULL;
1927     int i, trace_size = 0;
1928     ucontext_t *uc = (ucontext_t*) secret;
1929     sds infostring;
1930     struct sigaction act;
1931     REDIS_NOTUSED(info);
1932
1933     redisLog(REDIS_WARNING,
1934         "======= Ooops! Redis %s got signal: -%d- =======", REDIS_VERSION, sig);
1935     infostring = genRedisInfoString("all");
1936     redisLogRaw(REDIS_WARNING, infostring);
1937     /* It's not safe to sdsfree() the returned string under memory
1938      * corruption conditions. Let it leak as we are going to abort */
1939
1940     trace_size = backtrace(trace, 100);
1941     /* overwrite sigaction with caller's address */
1942     if (getMcontextEip(uc) != NULL) {
1943         trace[1] = getMcontextEip(uc);
1944     }
1945     messages = backtrace_symbols(trace, trace_size);
1946
1947     for (i=1; i<trace_size; ++i)
1948         redisLog(REDIS_WARNING,"%s", messages[i]);
1949
1950     /* free(messages); Don't call free() with possibly corrupted memory. */
1951     if (server.daemonize) unlink(server.pidfile);
1952
1953     /* Make sure we exit with the right signal at the end. So for instance
1954      * the core will be dumped if enabled. */
1955     sigemptyset (&act.sa_mask);
1956     /* When the SA_SIGINFO flag is set in sa_flags then sa_sigaction
1957      * is used. Otherwise, sa_handler is used */
1958     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
1959     act.sa_handler = SIG_DFL;
1960     sigaction (sig, &act, NULL);
1961     kill(getpid(),sig);
1962 }
1963 #endif /* HAVE_BACKTRACE */
1964
1965 static void sigtermHandler(int sig) {
1966     REDIS_NOTUSED(sig);
1967
1968     redisLog(REDIS_WARNING,"Received SIGTERM, scheduling shutdown...");
1969     server.shutdown_asap = 1;
1970 }
1971
1972 void setupSignalHandlers(void) {
1973     struct sigaction act;
1974
1975     /* When the SA_SIGINFO flag is set in sa_flags then sa_sigaction is used.
1976      * Otherwise, sa_handler is used. */
1977     sigemptyset(&act.sa_mask);
1978     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND;
1979     act.sa_handler = sigtermHandler;
1980     sigaction(SIGTERM, &act, NULL);
1981
1982 #ifdef HAVE_BACKTRACE
1983     sigemptyset(&act.sa_mask);
1984     act.sa_flags = SA_NODEFER | SA_ONSTACK | SA_RESETHAND | SA_SIGINFO;
1985     act.sa_sigaction = sigsegvHandler;
1986     sigaction(SIGSEGV, &act, NULL);
1987     sigaction(SIGBUS, &act, NULL);
1988     sigaction(SIGFPE, &act, NULL);
1989     sigaction(SIGILL, &act, NULL);
1990 #endif
1991     return;
1992 }
1993
1994 /* The End */