redis.c

   1 /*
   2  * Copyright (c) 2006-2009, 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 #define REDIS_VERSION "0.091"
  31
  32 #include "fmacros.h"
  33
  34 #include <stdio.h>
  35 #include <stdlib.h>
  36 #include <string.h>
  37 #include <time.h>
  38 #include <unistd.h>
  39 #include <signal.h>
  40 #include <sys/wait.h>
  41 #include <errno.h>
  42 #include <assert.h>
  43 #include <ctype.h>
  44 #include <stdarg.h>
  45 #include <inttypes.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 <limits.h>
  52
  53 #include "ae.h"     /* Event driven programming library */
  54 #include "sds.h"    /* Dynamic safe strings */
  55 #include "anet.h"   /* Networking the easy way */
  56 #include "dict.h"   /* Hash tables */
  57 #include "adlist.h" /* Linked lists */
  58 #include "zmalloc.h" /* total memory usage aware version of malloc/free */
  59 #include "lzf.h"
  60
  61 /* Error codes */
  62 #define REDIS_OK                0
  63 #define REDIS_ERR               -1
  64
  65 /* Static server configuration */
  66 #define REDIS_SERVERPORT        6379    /* TCP port */
  67 #define REDIS_MAXIDLETIME       (60*5)  /* default client timeout */
  68 #define REDIS_IOBUF_LEN         1024
  69 #define REDIS_LOADBUF_LEN       1024
  70 #define REDIS_MAX_ARGS          16
  71 #define REDIS_DEFAULT_DBNUM     16
  72 #define REDIS_CONFIGLINE_MAX    1024
  73 #define REDIS_OBJFREELIST_MAX   1000000 /* Max number of objects to cache */
  74 #define REDIS_MAX_SYNC_TIME     60      /* Slave can't take more to sync */
  75 #define REDIS_EXPIRELOOKUPS_PER_CRON    100 /* try to expire 100 keys/second */
  76
  77 /* Hash table parameters */
  78 #define REDIS_HT_MINFILL        10      /* Minimal hash table fill 10% */
  79 #define REDIS_HT_MINSLOTS       16384   /* Never resize the HT under this */
  80
  81 /* Command flags */
  82 #define REDIS_CMD_BULK          1
  83 #define REDIS_CMD_INLINE        2
  84
  85 /* Object types */
  86 #define REDIS_STRING 0
  87 #define REDIS_LIST 1
  88 #define REDIS_SET 2
  89 #define REDIS_HASH 3
  90
  91 /* Object types only used for dumping to disk */
  92 #define REDIS_EXPIRETIME 253
  93 #define REDIS_SELECTDB 254
  94 #define REDIS_EOF 255
  95
  96 /* Defines related to the dump file format. To store 32 bits lengths for short
  97  * keys requires a lot of space, so we check the most significant 2 bits of
  98  * the first byte to interpreter the length:
  99  *
 100  * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
 101  * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
 102  * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
 103  * 11|000000 this means: specially encoded object will follow. The six bits
 104  *           number specify the kind of object that follows.
 105  *           See the REDIS_RDB_ENC_* defines.
 106  *
 107  * Lenghts up to 63 are stored using a single byte, most DB keys, and may
 108  * values, will fit inside. */
 109 #define REDIS_RDB_6BITLEN 0
 110 #define REDIS_RDB_14BITLEN 1
 111 #define REDIS_RDB_32BITLEN 2
 112 #define REDIS_RDB_ENCVAL 3
 113 #define REDIS_RDB_LENERR UINT_MAX
 114
 115 /* When a length of a string object stored on disk has the first two bits
 116  * set, the remaining two bits specify a special encoding for the object
 117  * accordingly to the following defines: */
 118 #define REDIS_RDB_ENC_INT8 0        /* 8 bit signed integer */
 119 #define REDIS_RDB_ENC_INT16 1       /* 16 bit signed integer */
 120 #define REDIS_RDB_ENC_INT32 2       /* 32 bit signed integer */
 121 #define REDIS_RDB_ENC_LZF 3         /* string compressed with FASTLZ */
 122
 123 /* Client flags */
 124 #define REDIS_CLOSE 1       /* This client connection should be closed ASAP */
 125 #define REDIS_SLAVE 2       /* This client is a slave server */
 126 #define REDIS_MASTER 4      /* This client is a master server */
 127 #define REDIS_MONITOR 8      /* This client is a slave monitor, see MONITOR */
 128
 129 /* Slave replication state - slave side */
 130 #define REDIS_REPL_NONE 0   /* No active replication */
 131 #define REDIS_REPL_CONNECT 1    /* Must connect to master */
 132 #define REDIS_REPL_CONNECTED 2  /* Connected to master */
 133
 134 /* Slave replication state - from the point of view of master
 135  * Note that in SEND_BULK and ONLINE state the slave receives new updates
 136  * in its output queue. In the WAIT_BGSAVE state instead the server is waiting
 137  * to start the next background saving in order to send updates to it. */
 138 #define REDIS_REPL_WAIT_BGSAVE_START 3 /* master waits bgsave to start feeding it */
 139 #define REDIS_REPL_WAIT_BGSAVE_END 4 /* master waits bgsave to start bulk DB transmission */
 140 #define REDIS_REPL_SEND_BULK 5 /* master is sending the bulk DB */
 141 #define REDIS_REPL_ONLINE 6 /* bulk DB already transmitted, receive updates */
 142
 143 /* List related stuff */
 144 #define REDIS_HEAD 0
 145 #define REDIS_TAIL 1
 146
 147 /* Sort operations */
 148 #define REDIS_SORT_GET 0
 149 #define REDIS_SORT_DEL 1
 150 #define REDIS_SORT_INCR 2
 151 #define REDIS_SORT_DECR 3
 152 #define REDIS_SORT_ASC 4
 153 #define REDIS_SORT_DESC 5
 154 #define REDIS_SORTKEY_MAX 1024
 155
 156 /* Log levels */
 157 #define REDIS_DEBUG 0
 158 #define REDIS_NOTICE 1
 159 #define REDIS_WARNING 2
 160
 161 /* Anti-warning macro... */
 162 #define REDIS_NOTUSED(V) ((void) V)
 163
 164 /*================================= Data types ============================== */
 165
 166 /* A redis object, that is a type able to hold a string / list / set */
 167 typedef struct redisObject {
 168     void *ptr;
 169     int type;
 170     int refcount;
 171 } robj;
 172
 173 typedef struct redisDb {
 174     dict *dict;
 175     dict *expires;
 176     int id;
 177 } redisDb;
 178
 179 /* With multiplexing we need to take per-clinet state.
 180  * Clients are taken in a liked list. */
 181 typedef struct redisClient {
 182     int fd;
 183     redisDb *db;
 184     int dictid;
 185     sds querybuf;
 186     robj *argv[REDIS_MAX_ARGS];
 187     int argc;
 188     int bulklen;            /* bulk read len. -1 if not in bulk read mode */
 189     list *reply;
 190     int sentlen;
 191     time_t lastinteraction; /* time of the last interaction, used for timeout */
 192     int flags;              /* REDIS_CLOSE | REDIS_SLAVE | REDIS_MONITOR */
 193     int slaveseldb;         /* slave selected db, if this client is a slave */
 194     int authenticated;      /* when requirepass is non-NULL */
 195     int replstate;          /* replication state if this is a slave */
 196     int repldbfd;           /* replication DB file descriptor */
 197     long repldboff;          /* replication DB file offset */
 198     off_t repldbsize;       /* replication DB file size */
 199 } redisClient;
 200
 201 struct saveparam {
 202     time_t seconds;
 203     int changes;
 204 };
 205
 206 /* Global server state structure */
 207 struct redisServer {
 208     int port;
 209     int fd;
 210     redisDb *db;
 211     dict *sharingpool;
 212     unsigned int sharingpoolsize;
 213     long long dirty;            /* changes to DB from the last save */
 214     list *clients;
 215     list *slaves, *monitors;
 216     char neterr[ANET_ERR_LEN];
 217     aeEventLoop *el;
 218     int cronloops;              /* number of times the cron function run */
 219     list *objfreelist;          /* A list of freed objects to avoid malloc() */
 220     time_t lastsave;            /* Unix time of last save succeeede */
 221     size_t usedmemory;             /* Used memory in megabytes */
 222     /* Fields used only for stats */
 223     time_t stat_starttime;         /* server start time */
 224     long long stat_numcommands;    /* number of processed commands */
 225     long long stat_numconnections; /* number of connections received */
 226     /* Configuration */
 227     int verbosity;
 228     int glueoutputbuf;
 229     int maxidletime;
 230     int dbnum;
 231     int daemonize;
 232     char *pidfile;
 233     int bgsaveinprogress;
 234     struct saveparam *saveparams;
 235     int saveparamslen;
 236     char *logfile;
 237     char *bindaddr;
 238     char *dbfilename;
 239     char *requirepass;
 240     int shareobjects;
 241     /* Replication related */
 242     int isslave;
 243     char *masterhost;
 244     int masterport;
 245     redisClient *master;    /* client that is master for this slave */
 246     int replstate;
 247     /* Sort parameters - qsort_r() is only available under BSD so we
 248      * have to take this state global, in order to pass it to sortCompare() */
 249     int sort_desc;
 250     int sort_alpha;
 251     int sort_bypattern;
 252 };
 253
 254 typedef void redisCommandProc(redisClient *c);
 255 struct redisCommand {
 256     char *name;
 257     redisCommandProc *proc;
 258     int arity;
 259     int flags;
 260 };
 261
 262 typedef struct _redisSortObject {
 263     robj *obj;
 264     union {
 265         double score;
 266         robj *cmpobj;
 267     } u;
 268 } redisSortObject;
 269
 270 typedef struct _redisSortOperation {
 271     int type;
 272     robj *pattern;
 273 } redisSortOperation;
 274
 275 struct sharedObjectsStruct {
 276     robj *crlf, *ok, *err, *emptybulk, *czero, *cone, *pong, *space,
 277     *colon, *nullbulk, *nullmultibulk,
 278     *emptymultibulk, *wrongtypeerr, *nokeyerr, *syntaxerr, *sameobjecterr,
 279     *outofrangeerr, *plus,
 280     *select0, *select1, *select2, *select3, *select4,
 281     *select5, *select6, *select7, *select8, *select9;
 282 } shared;
 283
 284 /*================================ Prototypes =============================== */
 285
 286 static void freeStringObject(robj *o);
 287 static void freeListObject(robj *o);
 288 static void freeSetObject(robj *o);
 289 static void decrRefCount(void *o);
 290 static robj *createObject(int type, void *ptr);
 291 static void freeClient(redisClient *c);
 292 static int rdbLoad(char *filename);
 293 static void addReply(redisClient *c, robj *obj);
 294 static void addReplySds(redisClient *c, sds s);
 295 static void incrRefCount(robj *o);
 296 static int rdbSaveBackground(char *filename);
 297 static robj *createStringObject(char *ptr, size_t len);
 298 static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc);
 299 static int syncWithMaster(void);
 300 static robj *tryObjectSharing(robj *o);
 301 static int removeExpire(redisDb *db, robj *key);
 302 static int expireIfNeeded(redisDb *db, robj *key);
 303 static int deleteIfVolatile(redisDb *db, robj *key);
 304 static int deleteKey(redisDb *db, robj *key);
 305 static time_t getExpire(redisDb *db, robj *key);
 306 static int setExpire(redisDb *db, robj *key, time_t when);
 307 static void updateSalvesWaitingBgsave(int bgsaveerr);
 308
 309 static void authCommand(redisClient *c);
 310 static void pingCommand(redisClient *c);
 311 static void echoCommand(redisClient *c);
 312 static void setCommand(redisClient *c);
 313 static void setnxCommand(redisClient *c);
 314 static void getCommand(redisClient *c);
 315 static void delCommand(redisClient *c);
 316 static void existsCommand(redisClient *c);
 317 static void incrCommand(redisClient *c);
 318 static void decrCommand(redisClient *c);
 319 static void incrbyCommand(redisClient *c);
 320 static void decrbyCommand(redisClient *c);
 321 static void selectCommand(redisClient *c);
 322 static void randomkeyCommand(redisClient *c);
 323 static void keysCommand(redisClient *c);
 324 static void dbsizeCommand(redisClient *c);
 325 static void lastsaveCommand(redisClient *c);
 326 static void saveCommand(redisClient *c);
 327 static void bgsaveCommand(redisClient *c);
 328 static void shutdownCommand(redisClient *c);
 329 static void moveCommand(redisClient *c);
 330 static void renameCommand(redisClient *c);
 331 static void renamenxCommand(redisClient *c);
 332 static void lpushCommand(redisClient *c);
 333 static void rpushCommand(redisClient *c);
 334 static void lpopCommand(redisClient *c);
 335 static void rpopCommand(redisClient *c);
 336 static void llenCommand(redisClient *c);
 337 static void lindexCommand(redisClient *c);
 338 static void lrangeCommand(redisClient *c);
 339 static void ltrimCommand(redisClient *c);
 340 static void typeCommand(redisClient *c);
 341 static void lsetCommand(redisClient *c);
 342 static void saddCommand(redisClient *c);
 343 static void sremCommand(redisClient *c);
 344 static void smoveCommand(redisClient *c);
 345 static void sismemberCommand(redisClient *c);
 346 static void scardCommand(redisClient *c);
 347 static void sinterCommand(redisClient *c);
 348 static void sinterstoreCommand(redisClient *c);
 349 static void sunionCommand(redisClient *c);
 350 static void sunionstoreCommand(redisClient *c);
 351 static void syncCommand(redisClient *c);
 352 static void flushdbCommand(redisClient *c);
 353 static void flushallCommand(redisClient *c);
 354 static void sortCommand(redisClient *c);
 355 static void lremCommand(redisClient *c);
 356 static void infoCommand(redisClient *c);
 357 static void mgetCommand(redisClient *c);
 358 static void monitorCommand(redisClient *c);
 359 static void expireCommand(redisClient *c);
 360 static void getSetCommand(redisClient *c);
 361
 362 /*================================= Globals ================================= */
 363
 364 /* Global vars */
 365 static struct redisServer server; /* server global state */
 366 static struct redisCommand cmdTable[] = {
 367     {"get",getCommand,2,REDIS_CMD_INLINE},
 368     {"set",setCommand,3,REDIS_CMD_BULK},
 369     {"setnx",setnxCommand,3,REDIS_CMD_BULK},
 370     {"del",delCommand,2,REDIS_CMD_INLINE},
 371     {"exists",existsCommand,2,REDIS_CMD_INLINE},
 372     {"incr",incrCommand,2,REDIS_CMD_INLINE},
 373     {"decr",decrCommand,2,REDIS_CMD_INLINE},
 374     {"mget",mgetCommand,-2,REDIS_CMD_INLINE},
 375     {"rpush",rpushCommand,3,REDIS_CMD_BULK},
 376     {"lpush",lpushCommand,3,REDIS_CMD_BULK},
 377     {"rpop",rpopCommand,2,REDIS_CMD_INLINE},
 378     {"lpop",lpopCommand,2,REDIS_CMD_INLINE},
 379     {"llen",llenCommand,2,REDIS_CMD_INLINE},
 380     {"lindex",lindexCommand,3,REDIS_CMD_INLINE},
 381     {"lset",lsetCommand,4,REDIS_CMD_BULK},
 382     {"lrange",lrangeCommand,4,REDIS_CMD_INLINE},
 383     {"ltrim",ltrimCommand,4,REDIS_CMD_INLINE},
 384     {"lrem",lremCommand,4,REDIS_CMD_BULK},
 385     {"sadd",saddCommand,3,REDIS_CMD_BULK},
 386     {"srem",sremCommand,3,REDIS_CMD_BULK},
 387     {"smove",smoveCommand,4,REDIS_CMD_BULK},
 388     {"sismember",sismemberCommand,3,REDIS_CMD_BULK},
 389     {"scard",scardCommand,2,REDIS_CMD_INLINE},
 390     {"sinter",sinterCommand,-2,REDIS_CMD_INLINE},
 391     {"sinterstore",sinterstoreCommand,-3,REDIS_CMD_INLINE},
 392     {"sunion",sunionCommand,-2,REDIS_CMD_INLINE},
 393     {"sunionstore",sunionstoreCommand,-3,REDIS_CMD_INLINE},
 394     {"smembers",sinterCommand,2,REDIS_CMD_INLINE},
 395     {"incrby",incrbyCommand,3,REDIS_CMD_INLINE},
 396     {"decrby",decrbyCommand,3,REDIS_CMD_INLINE},
 397     {"getset",getSetCommand,3,REDIS_CMD_BULK},
 398     {"randomkey",randomkeyCommand,1,REDIS_CMD_INLINE},
 399     {"select",selectCommand,2,REDIS_CMD_INLINE},
 400     {"move",moveCommand,3,REDIS_CMD_INLINE},
 401     {"rename",renameCommand,3,REDIS_CMD_INLINE},
 402     {"renamenx",renamenxCommand,3,REDIS_CMD_INLINE},
 403     {"keys",keysCommand,2,REDIS_CMD_INLINE},
 404     {"dbsize",dbsizeCommand,1,REDIS_CMD_INLINE},
 405     {"auth",authCommand,2,REDIS_CMD_INLINE},
 406     {"ping",pingCommand,1,REDIS_CMD_INLINE},
 407     {"echo",echoCommand,2,REDIS_CMD_BULK},
 408     {"save",saveCommand,1,REDIS_CMD_INLINE},
 409     {"bgsave",bgsaveCommand,1,REDIS_CMD_INLINE},
 410     {"shutdown",shutdownCommand,1,REDIS_CMD_INLINE},
 411     {"lastsave",lastsaveCommand,1,REDIS_CMD_INLINE},
 412     {"type",typeCommand,2,REDIS_CMD_INLINE},
 413     {"sync",syncCommand,1,REDIS_CMD_INLINE},
 414     {"flushdb",flushdbCommand,1,REDIS_CMD_INLINE},
 415     {"flushall",flushallCommand,1,REDIS_CMD_INLINE},
 416     {"sort",sortCommand,-2,REDIS_CMD_INLINE},
 417     {"info",infoCommand,1,REDIS_CMD_INLINE},
 418     {"monitor",monitorCommand,1,REDIS_CMD_INLINE},
 419     {"expire",expireCommand,3,REDIS_CMD_INLINE},
 420     {NULL,NULL,0,0}
 421 };
 422
 423 /*============================ Utility functions ============================ */
 424
 425 /* Glob-style pattern matching. */
 426 int stringmatchlen(const char *pattern, int patternLen,
 427         const char *string, int stringLen, int nocase)
 428 {
 429     while(patternLen) {
 430         switch(pattern[0]) {
 431         case '*':
 432             while (pattern[1] == '*') {
 433                 pattern++;
 434                 patternLen--;
 435             }
 436             if (patternLen == 1)
 437                 return 1; /* match */
 438             while(stringLen) {
 439                 if (stringmatchlen(pattern+1, patternLen-1,
 440                             string, stringLen, nocase))
 441                     return 1; /* match */
 442                 string++;
 443                 stringLen--;
 444             }
 445             return 0; /* no match */
 446             break;
 447         case '?':
 448             if (stringLen == 0)
 449                 return 0; /* no match */
 450             string++;
 451             stringLen--;
 452             break;
 453         case '[':
 454         {
 455             int not, match;
 456
 457             pattern++;
 458             patternLen--;
 459             not = pattern[0] == '^';
 460             if (not) {
 461                 pattern++;
 462                 patternLen--;
 463             }
 464             match = 0;
 465             while(1) {
 466                 if (pattern[0] == '\\') {
 467                     pattern++;
 468                     patternLen--;
 469                     if (pattern[0] == string[0])
 470                         match = 1;
 471                 } else if (pattern[0] == ']') {
 472                     break;
 473                 } else if (patternLen == 0) {
 474                     pattern--;
 475                     patternLen++;
 476                     break;
 477                 } else if (pattern[1] == '-' && patternLen >= 3) {
 478                     int start = pattern[0];
 479                     int end = pattern[2];
 480                     int c = string[0];
 481                     if (start > end) {
 482                         int t = start;
 483                         start = end;
 484                         end = t;
 485                     }
 486                     if (nocase) {
 487                         start = tolower(start);
 488                         end = tolower(end);
 489                         c = tolower(c);
 490                     }
 491                     pattern += 2;
 492                     patternLen -= 2;
 493                     if (c >= start && c <= end)
 494                         match = 1;
 495                 } else {
 496                     if (!nocase) {
 497                         if (pattern[0] == string[0])
 498                             match = 1;
 499                     } else {
 500                         if (tolower((int)pattern[0]) == tolower((int)string[0]))
 501                             match = 1;
 502                     }
 503                 }
 504                 pattern++;
 505                 patternLen--;
 506             }
 507             if (not)
 508                 match = !match;
 509             if (!match)
 510                 return 0; /* no match */
 511             string++;
 512             stringLen--;
 513             break;
 514         }
 515         case '\\':
 516             if (patternLen >= 2) {
 517                 pattern++;
 518                 patternLen--;
 519             }
 520             /* fall through */
 521         default:
 522             if (!nocase) {
 523                 if (pattern[0] != string[0])
 524                     return 0; /* no match */
 525             } else {
 526                 if (tolower((int)pattern[0]) != tolower((int)string[0]))
 527                     return 0; /* no match */
 528             }
 529             string++;
 530             stringLen--;
 531             break;
 532         }
 533         pattern++;
 534         patternLen--;
 535         if (stringLen == 0) {
 536             while(*pattern == '*') {
 537                 pattern++;
 538                 patternLen--;
 539             }
 540             break;
 541         }
 542     }
 543     if (patternLen == 0 && stringLen == 0)
 544         return 1;
 545     return 0;
 546 }
 547
 548 void redisLog(int level, const char *fmt, ...)
 549 {
 550     va_list ap;
 551     FILE *fp;
 552
 553     fp = (server.logfile == NULL) ? stdout : fopen(server.logfile,"a");
 554     if (!fp) return;
 555
 556     va_start(ap, fmt);
 557     if (level >= server.verbosity) {
 558         char *c = ".-*";
 559         fprintf(fp,"%c ",c[level]);
 560         vfprintf(fp, fmt, ap);
 561         fprintf(fp,"\n");
 562         fflush(fp);
 563     }
 564     va_end(ap);
 565
 566     if (server.logfile) fclose(fp);
 567 }
 568
 569 /*====================== Hash table type implementation  ==================== */
 570
 571 /* This is an hash table type that uses the SDS dynamic strings libary as
 572  * keys and radis objects as values (objects can hold SDS strings,
 573  * lists, sets). */
 574
 575 static int sdsDictKeyCompare(void *privdata, const void *key1,
 576         const void *key2)
 577 {
 578     int l1,l2;
 579     DICT_NOTUSED(privdata);
 580
 581     l1 = sdslen((sds)key1);
 582     l2 = sdslen((sds)key2);
 583     if (l1 != l2) return 0;
 584     return memcmp(key1, key2, l1) == 0;
 585 }
 586
 587 static void dictRedisObjectDestructor(void *privdata, void *val)
 588 {
 589     DICT_NOTUSED(privdata);
 590
 591     decrRefCount(val);
 592 }
 593
 594 static int dictSdsKeyCompare(void *privdata, const void *key1,
 595         const void *key2)
 596 {
 597     const robj *o1 = key1, *o2 = key2;
 598     return sdsDictKeyCompare(privdata,o1->ptr,o2->ptr);
 599 }
 600
 601 static unsigned int dictSdsHash(const void *key) {
 602     const robj *o = key;
 603     return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 604 }
 605
 606 static dictType setDictType = {
 607     dictSdsHash,               /* hash function */
 608     NULL,                      /* key dup */
 609     NULL,                      /* val dup */
 610     dictSdsKeyCompare,         /* key compare */
 611     dictRedisObjectDestructor, /* key destructor */
 612     NULL                       /* val destructor */
 613 };
 614
 615 static dictType hashDictType = {
 616     dictSdsHash,                /* hash function */
 617     NULL,                       /* key dup */
 618     NULL,                       /* val dup */
 619     dictSdsKeyCompare,          /* key compare */
 620     dictRedisObjectDestructor,  /* key destructor */
 621     dictRedisObjectDestructor   /* val destructor */
 622 };
 623
 624 /* ========================= Random utility functions ======================= */
 625
 626 /* Redis generally does not try to recover from out of memory conditions
 627  * when allocating objects or strings, it is not clear if it will be possible
 628  * to report this condition to the client since the networking layer itself
 629  * is based on heap allocation for send buffers, so we simply abort.
 630  * At least the code will be simpler to read... */
 631 static void oom(const char *msg) {
 632     fprintf(stderr, "%s: Out of memory\n",msg);
 633     fflush(stderr);
 634     sleep(1);
 635     abort();
 636 }
 637
 638 /* ====================== Redis server networking stuff ===================== */
 639 void closeTimedoutClients(void) {
 640     redisClient *c;
 641     listNode *ln;
 642     time_t now = time(NULL);
 643
 644     listRewind(server.clients);
 645     while ((ln = listYield(server.clients)) != NULL) {
 646         c = listNodeValue(ln);
 647         if (!(c->flags & REDIS_SLAVE) &&    /* no timeout for slaves */
 648              (now - c->lastinteraction > server.maxidletime)) {
 649             redisLog(REDIS_DEBUG,"Closing idle client");
 650             freeClient(c);
 651         }
 652     }
 653 }
 654
 655 int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
 656     int j, loops = server.cronloops++;
 657     REDIS_NOTUSED(eventLoop);
 658     REDIS_NOTUSED(id);
 659     REDIS_NOTUSED(clientData);
 660
 661     /* Update the global state with the amount of used memory */
 662     server.usedmemory = zmalloc_used_memory();
 663
 664     /* If the percentage of used slots in the HT reaches REDIS_HT_MINFILL
 665      * we resize the hash table to save memory */
 666     for (j = 0; j < server.dbnum; j++) {
 667         int size, used, vkeys;
 668
 669         size = dictSlots(server.db[j].dict);
 670         used = dictSize(server.db[j].dict);
 671         vkeys = dictSize(server.db[j].expires);
 672         if (!(loops % 5) && used > 0) {
 673             redisLog(REDIS_DEBUG,"DB %d: %d keys (%d volatile) in %d slots HT.",j,used,vkeys,size);
 674             /* dictPrintStats(server.dict); */
 675         }
 676         if (size && used && size > REDIS_HT_MINSLOTS &&
 677             (used*100/size < REDIS_HT_MINFILL)) {
 678             redisLog(REDIS_NOTICE,"The hash table %d is too sparse, resize it...",j);
 679             dictResize(server.db[j].dict);
 680             redisLog(REDIS_NOTICE,"Hash table %d resized.",j);
 681         }
 682     }
 683
 684     /* Show information about connected clients */
 685     if (!(loops % 5)) {
 686         redisLog(REDIS_DEBUG,"%d clients connected (%d slaves), %zu bytes in use",
 687             listLength(server.clients)-listLength(server.slaves),
 688             listLength(server.slaves),
 689             server.usedmemory,
 690             dictSize(server.sharingpool));
 691     }
 692
 693     /* Close connections of timedout clients */
 694     if (!(loops % 10))
 695         closeTimedoutClients();
 696
 697     /* Check if a background saving in progress terminated */
 698     if (server.bgsaveinprogress) {
 699         int statloc;
 700         /* XXX: TODO handle the case of the saving child killed */
 701         if (wait4(-1,&statloc,WNOHANG,NULL)) {
 702             int exitcode = WEXITSTATUS(statloc);
 703             if (exitcode == 0) {
 704                 redisLog(REDIS_NOTICE,
 705                     "Background saving terminated with success");
 706                 server.dirty = 0;
 707                 server.lastsave = time(NULL);
 708             } else {
 709                 redisLog(REDIS_WARNING,
 710                     "Background saving error");
 711             }
 712             server.bgsaveinprogress = 0;
 713             updateSalvesWaitingBgsave(exitcode == 0 ? REDIS_OK : REDIS_ERR);
 714         }
 715     } else {
 716         /* If there is not a background saving in progress check if
 717          * we have to save now */
 718          time_t now = time(NULL);
 719          for (j = 0; j < server.saveparamslen; j++) {
 720             struct saveparam *sp = server.saveparams+j;
 721
 722             if (server.dirty >= sp->changes &&
 723                 now-server.lastsave > sp->seconds) {
 724                 redisLog(REDIS_NOTICE,"%d changes in %d seconds. Saving...",
 725                     sp->changes, sp->seconds);
 726                 rdbSaveBackground(server.dbfilename);
 727                 break;
 728             }
 729          }
 730     }
 731
 732     /* Try to expire a few timed out keys */
 733     for (j = 0; j < server.dbnum; j++) {
 734         redisDb *db = server.db+j;
 735         int num = dictSize(db->expires);
 736
 737         if (num) {
 738             time_t now = time(NULL);
 739
 740             if (num > REDIS_EXPIRELOOKUPS_PER_CRON)
 741                 num = REDIS_EXPIRELOOKUPS_PER_CRON;
 742             while (num--) {
 743                 dictEntry *de;
 744                 time_t t;
 745
 746                 if ((de = dictGetRandomKey(db->expires)) == NULL) break;
 747                 t = (time_t) dictGetEntryVal(de);
 748                 if (now > t) {
 749                     deleteKey(db,dictGetEntryKey(de));
 750                 }
 751             }
 752         }
 753     }
 754
 755     /* Check if we should connect to a MASTER */
 756     if (server.replstate == REDIS_REPL_CONNECT) {
 757         redisLog(REDIS_NOTICE,"Connecting to MASTER...");
 758         if (syncWithMaster() == REDIS_OK) {
 759             redisLog(REDIS_NOTICE,"MASTER <-> SLAVE sync succeeded");
 760         }
 761     }
 762     return 1000;
 763 }
 764
 765 static void createSharedObjects(void) {
 766     shared.crlf = createObject(REDIS_STRING,sdsnew("\r\n"));
 767     shared.ok = createObject(REDIS_STRING,sdsnew("+OK\r\n"));
 768     shared.err = createObject(REDIS_STRING,sdsnew("-ERR\r\n"));
 769     shared.emptybulk = createObject(REDIS_STRING,sdsnew("$0\r\n\r\n"));
 770     shared.czero = createObject(REDIS_STRING,sdsnew(":0\r\n"));
 771     shared.cone = createObject(REDIS_STRING,sdsnew(":1\r\n"));
 772     shared.nullbulk = createObject(REDIS_STRING,sdsnew("$-1\r\n"));
 773     shared.nullmultibulk = createObject(REDIS_STRING,sdsnew("*-1\r\n"));
 774     shared.emptymultibulk = createObject(REDIS_STRING,sdsnew("*0\r\n"));
 775     /* no such key */
 776     shared.pong = createObject(REDIS_STRING,sdsnew("+PONG\r\n"));
 777     shared.wrongtypeerr = createObject(REDIS_STRING,sdsnew(
 778         "-ERR Operation against a key holding the wrong kind of value\r\n"));
 779     shared.nokeyerr = createObject(REDIS_STRING,sdsnew(
 780         "-ERR no such key\r\n"));
 781     shared.syntaxerr = createObject(REDIS_STRING,sdsnew(
 782         "-ERR syntax error\r\n"));
 783     shared.sameobjecterr = createObject(REDIS_STRING,sdsnew(
 784         "-ERR source and destination objects are the same\r\n"));
 785     shared.outofrangeerr = createObject(REDIS_STRING,sdsnew(
 786         "-ERR index out of range\r\n"));
 787     shared.space = createObject(REDIS_STRING,sdsnew(" "));
 788     shared.colon = createObject(REDIS_STRING,sdsnew(":"));
 789     shared.plus = createObject(REDIS_STRING,sdsnew("+"));
 790     shared.select0 = createStringObject("select 0\r\n",10);
 791     shared.select1 = createStringObject("select 1\r\n",10);
 792     shared.select2 = createStringObject("select 2\r\n",10);
 793     shared.select3 = createStringObject("select 3\r\n",10);
 794     shared.select4 = createStringObject("select 4\r\n",10);
 795     shared.select5 = createStringObject("select 5\r\n",10);
 796     shared.select6 = createStringObject("select 6\r\n",10);
 797     shared.select7 = createStringObject("select 7\r\n",10);
 798     shared.select8 = createStringObject("select 8\r\n",10);
 799     shared.select9 = createStringObject("select 9\r\n",10);
 800 }
 801
 802 static void appendServerSaveParams(time_t seconds, int changes) {
 803     server.saveparams = zrealloc(server.saveparams,sizeof(struct saveparam)*(server.saveparamslen+1));
 804     if (server.saveparams == NULL) oom("appendServerSaveParams");
 805     server.saveparams[server.saveparamslen].seconds = seconds;
 806     server.saveparams[server.saveparamslen].changes = changes;
 807     server.saveparamslen++;
 808 }
 809
 810 static void ResetServerSaveParams() {
 811     zfree(server.saveparams);
 812     server.saveparams = NULL;
 813     server.saveparamslen = 0;
 814 }
 815
 816 static void initServerConfig() {
 817     server.dbnum = REDIS_DEFAULT_DBNUM;
 818     server.port = REDIS_SERVERPORT;
 819     server.verbosity = REDIS_DEBUG;
 820     server.maxidletime = REDIS_MAXIDLETIME;
 821     server.saveparams = NULL;
 822     server.logfile = NULL; /* NULL = log on standard output */
 823     server.bindaddr = NULL;
 824     server.glueoutputbuf = 1;
 825     server.daemonize = 0;
 826     server.pidfile = "/var/run/redis.pid";
 827     server.dbfilename = "dump.rdb";
 828     server.requirepass = NULL;
 829     server.shareobjects = 0;
 830     ResetServerSaveParams();
 831
 832     appendServerSaveParams(60*60,1);  /* save after 1 hour and 1 change */
 833     appendServerSaveParams(300,100);  /* save after 5 minutes and 100 changes */
 834     appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
 835     /* Replication related */
 836     server.isslave = 0;
 837     server.masterhost = NULL;
 838     server.masterport = 6379;
 839     server.master = NULL;
 840     server.replstate = REDIS_REPL_NONE;
 841 }
 842
 843 static void initServer() {
 844     int j;
 845
 846     signal(SIGHUP, SIG_IGN);
 847     signal(SIGPIPE, SIG_IGN);
 848
 849     server.clients = listCreate();
 850     server.slaves = listCreate();
 851     server.monitors = listCreate();
 852     server.objfreelist = listCreate();
 853     createSharedObjects();
 854     server.el = aeCreateEventLoop();
 855     server.db = zmalloc(sizeof(redisDb)*server.dbnum);
 856     server.sharingpool = dictCreate(&setDictType,NULL);
 857     server.sharingpoolsize = 1024;
 858     if (!server.db || !server.clients || !server.slaves || !server.monitors || !server.el || !server.objfreelist)
 859         oom("server initialization"); /* Fatal OOM */
 860     server.fd = anetTcpServer(server.neterr, server.port, server.bindaddr);
 861     if (server.fd == -1) {
 862         redisLog(REDIS_WARNING, "Opening TCP port: %s", server.neterr);
 863         exit(1);
 864     }
 865     for (j = 0; j < server.dbnum; j++) {
 866         server.db[j].dict = dictCreate(&hashDictType,NULL);
 867         server.db[j].expires = dictCreate(&setDictType,NULL);
 868         server.db[j].id = j;
 869     }
 870     server.cronloops = 0;
 871     server.bgsaveinprogress = 0;
 872     server.lastsave = time(NULL);
 873     server.dirty = 0;
 874     server.usedmemory = 0;
 875     server.stat_numcommands = 0;
 876     server.stat_numconnections = 0;
 877     server.stat_starttime = time(NULL);
 878     aeCreateTimeEvent(server.el, 1000, serverCron, NULL, NULL);
 879 }
 880
 881 /* Empty the whole database */
 882 static long long emptyDb() {
 883     int j;
 884     long long removed = 0;
 885
 886     for (j = 0; j < server.dbnum; j++) {
 887         removed += dictSize(server.db[j].dict);
 888         dictEmpty(server.db[j].dict);
 889         dictEmpty(server.db[j].expires);
 890     }
 891     return removed;
 892 }
 893
 894 static int yesnotoi(char *s) {
 895     if (!strcasecmp(s,"yes")) return 1;
 896     else if (!strcasecmp(s,"no")) return 0;
 897     else return -1;
 898 }
 899
 900 /* I agree, this is a very rudimental way to load a configuration...
 901    will improve later if the config gets more complex */
 902 static void loadServerConfig(char *filename) {
 903     FILE *fp = fopen(filename,"r");
 904     char buf[REDIS_CONFIGLINE_MAX+1], *err = NULL;
 905     int linenum = 0;
 906     sds line = NULL;
 907
 908     if (!fp) {
 909         redisLog(REDIS_WARNING,"Fatal error, can't open config file");
 910         exit(1);
 911     }
 912     while(fgets(buf,REDIS_CONFIGLINE_MAX+1,fp) != NULL) {
 913         sds *argv;
 914         int argc, j;
 915
 916         linenum++;
 917         line = sdsnew(buf);
 918         line = sdstrim(line," \t\r\n");
 919
 920         /* Skip comments and blank lines*/
 921         if (line[0] == '#' || line[0] == '\0') {
 922             sdsfree(line);
 923             continue;
 924         }
 925
 926         /* Split into arguments */
 927         argv = sdssplitlen(line,sdslen(line)," ",1,&argc);
 928         sdstolower(argv[0]);
 929
 930         /* Execute config directives */
 931         if (!strcasecmp(argv[0],"timeout") && argc == 2) {
 932             server.maxidletime = atoi(argv[1]);
 933             if (server.maxidletime < 1) {
 934                 err = "Invalid timeout value"; goto loaderr;
 935             }
 936         } else if (!strcasecmp(argv[0],"port") && argc == 2) {
 937             server.port = atoi(argv[1]);
 938             if (server.port < 1 || server.port > 65535) {
 939                 err = "Invalid port"; goto loaderr;
 940             }
 941         } else if (!strcasecmp(argv[0],"bind") && argc == 2) {
 942             server.bindaddr = zstrdup(argv[1]);
 943         } else if (!strcasecmp(argv[0],"save") && argc == 3) {
 944             int seconds = atoi(argv[1]);
 945             int changes = atoi(argv[2]);
 946             if (seconds < 1 || changes < 0) {
 947                 err = "Invalid save parameters"; goto loaderr;
 948             }
 949             appendServerSaveParams(seconds,changes);
 950         } else if (!strcasecmp(argv[0],"dir") && argc == 2) {
 951             if (chdir(argv[1]) == -1) {
 952                 redisLog(REDIS_WARNING,"Can't chdir to '%s': %s",
 953                     argv[1], strerror(errno));
 954                 exit(1);
 955             }
 956         } else if (!strcasecmp(argv[0],"loglevel") && argc == 2) {
 957             if (!strcasecmp(argv[1],"debug")) server.verbosity = REDIS_DEBUG;
 958             else if (!strcasecmp(argv[1],"notice")) server.verbosity = REDIS_NOTICE;
 959             else if (!strcasecmp(argv[1],"warning")) server.verbosity = REDIS_WARNING;
 960             else {
 961                 err = "Invalid log level. Must be one of debug, notice, warning";
 962                 goto loaderr;
 963             }
 964         } else if (!strcasecmp(argv[0],"logfile") && argc == 2) {
 965             FILE *fp;
 966
 967             server.logfile = zstrdup(argv[1]);
 968             if (!strcasecmp(server.logfile,"stdout")) {
 969                 zfree(server.logfile);
 970                 server.logfile = NULL;
 971             }
 972             if (server.logfile) {
 973                 /* Test if we are able to open the file. The server will not
 974                  * be able to abort just for this problem later... */
 975                 fp = fopen(server.logfile,"a");
 976                 if (fp == NULL) {
 977                     err = sdscatprintf(sdsempty(),
 978                         "Can't open the log file: %s", strerror(errno));
 979                     goto loaderr;
 980                 }
 981                 fclose(fp);
 982             }
 983         } else if (!strcasecmp(argv[0],"databases") && argc == 2) {
 984             server.dbnum = atoi(argv[1]);
 985             if (server.dbnum < 1) {
 986                 err = "Invalid number of databases"; goto loaderr;
 987             }
 988         } else if (!strcasecmp(argv[0],"slaveof") && argc == 3) {
 989             server.masterhost = sdsnew(argv[1]);
 990             server.masterport = atoi(argv[2]);
 991             server.replstate = REDIS_REPL_CONNECT;
 992         } else if (!strcasecmp(argv[0],"glueoutputbuf") && argc == 2) {
 993             if ((server.glueoutputbuf = yesnotoi(argv[1])) == -1) {
 994                 err = "argument must be 'yes' or 'no'"; goto loaderr;
 995             }
 996         } else if (!strcasecmp(argv[0],"shareobjects") && argc == 2) {
 997             if ((server.shareobjects = yesnotoi(argv[1])) == -1) {
 998                 err = "argument must be 'yes' or 'no'"; goto loaderr;
 999             }
1000         } else if (!strcasecmp(argv[0],"daemonize") && argc == 2) {
1001             if ((server.daemonize = yesnotoi(argv[1])) == -1) {
1002                 err = "argument must be 'yes' or 'no'"; goto loaderr;
1003             }
1004         } else if (!strcasecmp(argv[0],"requirepass") && argc == 2) {
1005           server.requirepass = zstrdup(argv[1]);
1006         } else if (!strcasecmp(argv[0],"pidfile") && argc == 2) {
1007           server.pidfile = zstrdup(argv[1]);
1008         } else if (!strcasecmp(argv[0],"dbfilename") && argc == 2) {
1009           server.dbfilename = zstrdup(argv[1]);
1010         } else {
1011             err = "Bad directive or wrong number of arguments"; goto loaderr;
1012         }
1013         for (j = 0; j < argc; j++)
1014             sdsfree(argv[j]);
1015         zfree(argv);
1016         sdsfree(line);
1017     }
1018     fclose(fp);
1019     return;
1020
1021 loaderr:
1022     fprintf(stderr, "\n*** FATAL CONFIG FILE ERROR ***\n");
1023     fprintf(stderr, "Reading the configuration file, at line %d\n", linenum);
1024     fprintf(stderr, ">>> '%s'\n", line);
1025     fprintf(stderr, "%s\n", err);
1026     exit(1);
1027 }
1028
1029 static void freeClientArgv(redisClient *c) {
1030     int j;
1031
1032     for (j = 0; j < c->argc; j++)
1033         decrRefCount(c->argv[j]);
1034     c->argc = 0;
1035 }
1036
1037 static void freeClient(redisClient *c) {
1038     listNode *ln;
1039
1040     aeDeleteFileEvent(server.el,c->fd,AE_READABLE);
1041     aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);
1042     sdsfree(c->querybuf);
1043     listRelease(c->reply);
1044     freeClientArgv(c);
1045     close(c->fd);
1046     ln = listSearchKey(server.clients,c);
1047     assert(ln != NULL);
1048     listDelNode(server.clients,ln);
1049     if (c->flags & REDIS_SLAVE) {
1050         if (c->replstate == REDIS_REPL_SEND_BULK && c->repldbfd != -1)
1051             close(c->repldbfd);
1052         list *l = (c->flags & REDIS_MONITOR) ? server.monitors : server.slaves;
1053         ln = listSearchKey(l,c);
1054         assert(ln != NULL);
1055         listDelNode(l,ln);
1056     }
1057     if (c->flags & REDIS_MASTER) {
1058         server.master = NULL;
1059         server.replstate = REDIS_REPL_CONNECT;
1060     }
1061     zfree(c);
1062 }
1063
1064 static void glueReplyBuffersIfNeeded(redisClient *c) {
1065     int totlen = 0;
1066     listNode *ln;
1067     robj *o;
1068
1069     listRewind(c->reply);
1070     while((ln = listYield(c->reply))) {
1071         o = ln->value;
1072         totlen += sdslen(o->ptr);
1073         /* This optimization makes more sense if we don't have to copy
1074          * too much data */
1075         if (totlen > 1024) return;
1076     }
1077     if (totlen > 0) {
1078         char buf[1024];
1079         int copylen = 0;
1080
1081         listRewind(c->reply);
1082         while((ln = listYield(c->reply))) {
1083             o = ln->value;
1084             memcpy(buf+copylen,o->ptr,sdslen(o->ptr));
1085             copylen += sdslen(o->ptr);
1086             listDelNode(c->reply,ln);
1087         }
1088         /* Now the output buffer is empty, add the new single element */
1089         addReplySds(c,sdsnewlen(buf,totlen));
1090     }
1091 }
1092
1093 static void sendReplyToClient(aeEventLoop *el, int fd, void *privdata, int mask) {
1094     redisClient *c = privdata;
1095     int nwritten = 0, totwritten = 0, objlen;
1096     robj *o;
1097     REDIS_NOTUSED(el);
1098     REDIS_NOTUSED(mask);
1099
1100     if (server.glueoutputbuf && listLength(c->reply) > 1)
1101         glueReplyBuffersIfNeeded(c);
1102     while(listLength(c->reply)) {
1103         o = listNodeValue(listFirst(c->reply));
1104         objlen = sdslen(o->ptr);
1105
1106         if (objlen == 0) {
1107             listDelNode(c->reply,listFirst(c->reply));
1108             continue;
1109         }
1110
1111         if (c->flags & REDIS_MASTER) {
1112             nwritten = objlen - c->sentlen;
1113         } else {
1114             nwritten = write(fd, ((char*)o->ptr)+c->sentlen, objlen - c->sentlen);
1115             if (nwritten <= 0) break;
1116         }
1117         c->sentlen += nwritten;
1118         totwritten += nwritten;
1119         /* If we fully sent the object on head go to the next one */
1120         if (c->sentlen == objlen) {
1121             listDelNode(c->reply,listFirst(c->reply));
1122             c->sentlen = 0;
1123         }
1124     }
1125     if (nwritten == -1) {
1126         if (errno == EAGAIN) {
1127             nwritten = 0;
1128         } else {
1129             redisLog(REDIS_DEBUG,
1130                 "Error writing to client: %s", strerror(errno));
1131             freeClient(c);
1132             return;
1133         }
1134     }
1135     if (totwritten > 0) c->lastinteraction = time(NULL);
1136     if (listLength(c->reply) == 0) {
1137         c->sentlen = 0;
1138         aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);
1139     }
1140 }
1141
1142 static struct redisCommand *lookupCommand(char *name) {
1143     int j = 0;
1144     while(cmdTable[j].name != NULL) {
1145         if (!strcasecmp(name,cmdTable[j].name)) return &cmdTable[j];
1146         j++;
1147     }
1148     return NULL;
1149 }
1150
1151 /* resetClient prepare the client to process the next command */
1152 static void resetClient(redisClient *c) {
1153     freeClientArgv(c);
1154     c->bulklen = -1;
1155 }
1156
1157 /* If this function gets called we already read a whole
1158  * command, argments are in the client argv/argc fields.
1159  * processCommand() execute the command or prepare the
1160  * server for a bulk read from the client.
1161  *
1162  * If 1 is returned the client is still alive and valid and
1163  * and other operations can be performed by the caller. Otherwise
1164  * if 0 is returned the client was destroied (i.e. after QUIT). */
1165 static int processCommand(redisClient *c) {
1166     struct redisCommand *cmd;
1167     long long dirty;
1168
1169     /* The QUIT command is handled as a special case. Normal command
1170      * procs are unable to close the client connection safely */
1171     if (!strcasecmp(c->argv[0]->ptr,"quit")) {
1172         freeClient(c);
1173         return 0;
1174     }
1175     cmd = lookupCommand(c->argv[0]->ptr);
1176     if (!cmd) {
1177         addReplySds(c,sdsnew("-ERR unknown command\r\n"));
1178         resetClient(c);
1179         return 1;
1180     } else if ((cmd->arity > 0 && cmd->arity != c->argc) ||
1181                (c->argc < -cmd->arity)) {
1182         addReplySds(c,sdsnew("-ERR wrong number of arguments\r\n"));
1183         resetClient(c);
1184         return 1;
1185     } else if (cmd->flags & REDIS_CMD_BULK && c->bulklen == -1) {
1186         int bulklen = atoi(c->argv[c->argc-1]->ptr);
1187
1188         decrRefCount(c->argv[c->argc-1]);
1189         if (bulklen < 0 || bulklen > 1024*1024*1024) {
1190             c->argc--;
1191             addReplySds(c,sdsnew("-ERR invalid bulk write count\r\n"));
1192             resetClient(c);
1193             return 1;
1194         }
1195         c->argc--;
1196         c->bulklen = bulklen+2; /* add two bytes for CR+LF */
1197         /* It is possible that the bulk read is already in the
1198          * buffer. Check this condition and handle it accordingly */
1199         if ((signed)sdslen(c->querybuf) >= c->bulklen) {
1200             c->argv[c->argc] = createStringObject(c->querybuf,c->bulklen-2);
1201             c->argc++;
1202             c->querybuf = sdsrange(c->querybuf,c->bulklen,-1);
1203         } else {
1204             return 1;
1205         }
1206     }
1207     /* Let's try to share objects on the command arguments vector */
1208     if (server.shareobjects) {
1209         int j;
1210         for(j = 1; j < c->argc; j++)
1211             c->argv[j] = tryObjectSharing(c->argv[j]);
1212     }
1213     /* Check if the user is authenticated */
1214     if (server.requirepass && !c->authenticated && cmd->proc != authCommand) {
1215         addReplySds(c,sdsnew("-ERR operation not permitted\r\n"));
1216         resetClient(c);
1217         return 1;
1218     }
1219
1220     /* Exec the command */
1221     dirty = server.dirty;
1222     cmd->proc(c);
1223     if (server.dirty-dirty != 0 && listLength(server.slaves))
1224         replicationFeedSlaves(server.slaves,cmd,c->db->id,c->argv,c->argc);
1225     if (listLength(server.monitors))
1226         replicationFeedSlaves(server.monitors,cmd,c->db->id,c->argv,c->argc);
1227     server.stat_numcommands++;
1228
1229     /* Prepare the client for the next command */
1230     if (c->flags & REDIS_CLOSE) {
1231         freeClient(c);
1232         return 0;
1233     }
1234     resetClient(c);
1235     return 1;
1236 }
1237
1238 static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc) {
1239     listNode *ln;
1240     robj *outv[REDIS_MAX_ARGS*4]; /* enough room for args, spaces, newlines */
1241     int outc = 0, j;
1242
1243     for (j = 0; j < argc; j++) {
1244         if (j != 0) outv[outc++] = shared.space;
1245         if ((cmd->flags & REDIS_CMD_BULK) && j == argc-1) {
1246             robj *lenobj;
1247
1248             lenobj = createObject(REDIS_STRING,
1249                 sdscatprintf(sdsempty(),"%d\r\n",sdslen(argv[j]->ptr)));
1250             lenobj->refcount = 0;
1251             outv[outc++] = lenobj;
1252         }
1253         outv[outc++] = argv[j];
1254     }
1255     outv[outc++] = shared.crlf;
1256
1257     /* Increment all the refcounts at start and decrement at end in order to
1258      * be sure to free objects if there is no slave in a replication state
1259      * able to be feed with commands */
1260     for (j = 0; j < outc; j++) incrRefCount(outv[j]);
1261     listRewind(slaves);
1262     while((ln = listYield(slaves))) {
1263         redisClient *slave = ln->value;
1264
1265         /* Don't feed slaves that are still waiting for BGSAVE to start */
1266         if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START) continue;
1267
1268         /* Feed all the other slaves, MONITORs and so on */
1269         if (slave->slaveseldb != dictid) {
1270             robj *selectcmd;
1271
1272             switch(dictid) {
1273             case 0: selectcmd = shared.select0; break;
1274             case 1: selectcmd = shared.select1; break;
1275             case 2: selectcmd = shared.select2; break;
1276             case 3: selectcmd = shared.select3; break;
1277             case 4: selectcmd = shared.select4; break;
1278             case 5: selectcmd = shared.select5; break;
1279             case 6: selectcmd = shared.select6; break;
1280             case 7: selectcmd = shared.select7; break;
1281             case 8: selectcmd = shared.select8; break;
1282             case 9: selectcmd = shared.select9; break;
1283             default:
1284                 selectcmd = createObject(REDIS_STRING,
1285                     sdscatprintf(sdsempty(),"select %d\r\n",dictid));
1286                 selectcmd->refcount = 0;
1287                 break;
1288             }
1289             addReply(slave,selectcmd);
1290             slave->slaveseldb = dictid;
1291         }
1292         for (j = 0; j < outc; j++) addReply(slave,outv[j]);
1293     }
1294     for (j = 0; j < outc; j++) decrRefCount(outv[j]);
1295 }
1296
1297 static void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask) {
1298     redisClient *c = (redisClient*) privdata;
1299     char buf[REDIS_IOBUF_LEN];
1300     int nread;
1301     REDIS_NOTUSED(el);
1302     REDIS_NOTUSED(mask);
1303
1304     nread = read(fd, buf, REDIS_IOBUF_LEN);
1305     if (nread == -1) {
1306         if (errno == EAGAIN) {
1307             nread = 0;
1308         } else {
1309             redisLog(REDIS_DEBUG, "Reading from client: %s",strerror(errno));
1310             freeClient(c);
1311             return;
1312         }
1313     } else if (nread == 0) {
1314         redisLog(REDIS_DEBUG, "Client closed connection");
1315         freeClient(c);
1316         return;
1317     }
1318     if (nread) {
1319         c->querybuf = sdscatlen(c->querybuf, buf, nread);
1320         c->lastinteraction = time(NULL);
1321     } else {
1322         return;
1323     }
1324
1325 again:
1326     if (c->bulklen == -1) {
1327         /* Read the first line of the query */
1328         char *p = strchr(c->querybuf,'\n');
1329         size_t querylen;
1330         if (p) {
1331             sds query, *argv;
1332             int argc, j;
1333
1334             query = c->querybuf;
1335             c->querybuf = sdsempty();
1336             querylen = 1+(p-(query));
1337             if (sdslen(query) > querylen) {
1338                 /* leave data after the first line of the query in the buffer */
1339                 c->querybuf = sdscatlen(c->querybuf,query+querylen,sdslen(query)-querylen);
1340             }
1341             *p = '\0'; /* remove "\n" */
1342             if (*(p-1) == '\r') *(p-1) = '\0'; /* and "\r" if any */
1343             sdsupdatelen(query);
1344
1345             /* Now we can split the query in arguments */
1346             if (sdslen(query) == 0) {
1347                 /* Ignore empty query */
1348                 sdsfree(query);
1349                 return;
1350             }
1351             argv = sdssplitlen(query,sdslen(query)," ",1,&argc);
1352             sdsfree(query);
1353             if (argv == NULL) oom("sdssplitlen");
1354             for (j = 0; j < argc && j < REDIS_MAX_ARGS; j++) {
1355                 if (sdslen(argv[j])) {
1356                     c->argv[c->argc] = createObject(REDIS_STRING,argv[j]);
1357                     c->argc++;
1358                 } else {
1359                     sdsfree(argv[j]);
1360                 }
1361             }
1362             zfree(argv);
1363             /* Execute the command. If the client is still valid
1364              * after processCommand() return and there is something
1365              * on the query buffer try to process the next command. */
1366             if (processCommand(c) && sdslen(c->querybuf)) goto again;
1367             return;
1368         } else if (sdslen(c->querybuf) >= 1024) {
1369             redisLog(REDIS_DEBUG, "Client protocol error");
1370             freeClient(c);
1371             return;
1372         }
1373     } else {
1374         /* Bulk read handling. Note that if we are at this point
1375            the client already sent a command terminated with a newline,
1376            we are reading the bulk data that is actually the last
1377            argument of the command. */
1378         int qbl = sdslen(c->querybuf);
1379
1380         if (c->bulklen <= qbl) {
1381             /* Copy everything but the final CRLF as final argument */
1382             c->argv[c->argc] = createStringObject(c->querybuf,c->bulklen-2);
1383             c->argc++;
1384             c->querybuf = sdsrange(c->querybuf,c->bulklen,-1);
1385             processCommand(c);
1386             return;
1387         }
1388     }
1389 }
1390
1391 static int selectDb(redisClient *c, int id) {
1392     if (id < 0 || id >= server.dbnum)
1393         return REDIS_ERR;
1394     c->db = &server.db[id];
1395     return REDIS_OK;
1396 }
1397
1398 static void *dupClientReplyValue(void *o) {
1399     incrRefCount((robj*)o);
1400     return 0;
1401 }
1402
1403 static redisClient *createClient(int fd) {
1404     redisClient *c = zmalloc(sizeof(*c));
1405
1406     anetNonBlock(NULL,fd);
1407     anetTcpNoDelay(NULL,fd);
1408     if (!c) return NULL;
1409     selectDb(c,0);
1410     c->fd = fd;
1411     c->querybuf = sdsempty();
1412     c->argc = 0;
1413     c->bulklen = -1;
1414     c->sentlen = 0;
1415     c->flags = 0;
1416     c->lastinteraction = time(NULL);
1417     c->authenticated = 0;
1418     c->replstate = REDIS_REPL_NONE;
1419     if ((c->reply = listCreate()) == NULL) oom("listCreate");
1420     listSetFreeMethod(c->reply,decrRefCount);
1421     listSetDupMethod(c->reply,dupClientReplyValue);
1422     if (aeCreateFileEvent(server.el, c->fd, AE_READABLE,
1423         readQueryFromClient, c, NULL) == AE_ERR) {
1424         freeClient(c);
1425         return NULL;
1426     }
1427     if (!listAddNodeTail(server.clients,c)) oom("listAddNodeTail");
1428     return c;
1429 }
1430
1431 static void addReply(redisClient *c, robj *obj) {
1432     if (listLength(c->reply) == 0 &&
1433         (c->replstate == REDIS_REPL_NONE ||
1434          c->replstate == REDIS_REPL_ONLINE) &&
1435         aeCreateFileEvent(server.el, c->fd, AE_WRITABLE,
1436         sendReplyToClient, c, NULL) == AE_ERR) return;
1437     if (!listAddNodeTail(c->reply,obj)) oom("listAddNodeTail");
1438     incrRefCount(obj);
1439 }
1440
1441 static void addReplySds(redisClient *c, sds s) {
1442     robj *o = createObject(REDIS_STRING,s);
1443     addReply(c,o);
1444     decrRefCount(o);
1445 }
1446
1447 static void acceptHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
1448     int cport, cfd;
1449     char cip[128];
1450     REDIS_NOTUSED(el);
1451     REDIS_NOTUSED(mask);
1452     REDIS_NOTUSED(privdata);
1453
1454     cfd = anetAccept(server.neterr, fd, cip, &cport);
1455     if (cfd == AE_ERR) {
1456         redisLog(REDIS_DEBUG,"Accepting client connection: %s", server.neterr);
1457         return;
1458     }
1459     redisLog(REDIS_DEBUG,"Accepted %s:%d", cip, cport);
1460     if (createClient(cfd) == NULL) {
1461         redisLog(REDIS_WARNING,"Error allocating resoures for the client");
1462         close(cfd); /* May be already closed, just ingore errors */
1463         return;
1464     }
1465     server.stat_numconnections++;
1466 }
1467
1468 /* ======================= Redis objects implementation ===================== */
1469
1470 static robj *createObject(int type, void *ptr) {
1471     robj *o;
1472
1473     if (listLength(server.objfreelist)) {
1474         listNode *head = listFirst(server.objfreelist);
1475         o = listNodeValue(head);
1476         listDelNode(server.objfreelist,head);
1477     } else {
1478         o = zmalloc(sizeof(*o));
1479     }
1480     if (!o) oom("createObject");
1481     o->type = type;
1482     o->ptr = ptr;
1483     o->refcount = 1;
1484     return o;
1485 }
1486
1487 static robj *createStringObject(char *ptr, size_t len) {
1488     return createObject(REDIS_STRING,sdsnewlen(ptr,len));
1489 }
1490
1491 static robj *createListObject(void) {
1492     list *l = listCreate();
1493
1494     if (!l) oom("listCreate");
1495     listSetFreeMethod(l,decrRefCount);
1496     return createObject(REDIS_LIST,l);
1497 }
1498
1499 static robj *createSetObject(void) {
1500     dict *d = dictCreate(&setDictType,NULL);
1501     if (!d) oom("dictCreate");
1502     return createObject(REDIS_SET,d);
1503 }
1504
1505 static void freeStringObject(robj *o) {
1506     sdsfree(o->ptr);
1507 }
1508
1509 static void freeListObject(robj *o) {
1510     listRelease((list*) o->ptr);
1511 }
1512
1513 static void freeSetObject(robj *o) {
1514     dictRelease((dict*) o->ptr);
1515 }
1516
1517 static void freeHashObject(robj *o) {
1518     dictRelease((dict*) o->ptr);
1519 }
1520
1521 static void incrRefCount(robj *o) {
1522     o->refcount++;
1523 #ifdef DEBUG_REFCOUNT
1524     if (o->type == REDIS_STRING)
1525         printf("Increment '%s'(%p), now is: %d\n",o->ptr,o,o->refcount);
1526 #endif
1527 }
1528
1529 static void decrRefCount(void *obj) {
1530     robj *o = obj;
1531
1532 #ifdef DEBUG_REFCOUNT
1533     if (o->type == REDIS_STRING)
1534         printf("Decrement '%s'(%p), now is: %d\n",o->ptr,o,o->refcount-1);
1535 #endif
1536     if (--(o->refcount) == 0) {
1537         switch(o->type) {
1538         case REDIS_STRING: freeStringObject(o); break;
1539         case REDIS_LIST: freeListObject(o); break;
1540         case REDIS_SET: freeSetObject(o); break;
1541         case REDIS_HASH: freeHashObject(o); break;
1542         default: assert(0 != 0); break;
1543         }
1544         if (listLength(server.objfreelist) > REDIS_OBJFREELIST_MAX ||
1545             !listAddNodeHead(server.objfreelist,o))
1546             zfree(o);
1547     }
1548 }
1549
1550 /* Try to share an object against the shared objects pool */
1551 static robj *tryObjectSharing(robj *o) {
1552     struct dictEntry *de;
1553     unsigned long c;
1554
1555     if (o == NULL || server.shareobjects == 0) return o;
1556
1557     assert(o->type == REDIS_STRING);
1558     de = dictFind(server.sharingpool,o);
1559     if (de) {
1560         robj *shared = dictGetEntryKey(de);
1561
1562         c = ((unsigned long) dictGetEntryVal(de))+1;
1563         dictGetEntryVal(de) = (void*) c;
1564         incrRefCount(shared);
1565         decrRefCount(o);
1566         return shared;
1567     } else {
1568         /* Here we are using a stream algorihtm: Every time an object is
1569          * shared we increment its count, everytime there is a miss we
1570          * recrement the counter of a random object. If this object reaches
1571          * zero we remove the object and put the current object instead. */
1572         if (dictSize(server.sharingpool) >=
1573                 server.sharingpoolsize) {
1574             de = dictGetRandomKey(server.sharingpool);
1575             assert(de != NULL);
1576             c = ((unsigned long) dictGetEntryVal(de))-1;
1577             dictGetEntryVal(de) = (void*) c;
1578             if (c == 0) {
1579                 dictDelete(server.sharingpool,de->key);
1580             }
1581         } else {
1582             c = 0; /* If the pool is empty we want to add this object */
1583         }
1584         if (c == 0) {
1585             int retval;
1586
1587             retval = dictAdd(server.sharingpool,o,(void*)1);
1588             assert(retval == DICT_OK);
1589             incrRefCount(o);
1590         }
1591         return o;
1592     }
1593 }
1594
1595 static robj *lookupKey(redisDb *db, robj *key) {
1596     dictEntry *de = dictFind(db->dict,key);
1597     return de ? dictGetEntryVal(de) : NULL;
1598 }
1599
1600 static robj *lookupKeyRead(redisDb *db, robj *key) {
1601     expireIfNeeded(db,key);
1602     return lookupKey(db,key);
1603 }
1604
1605 static robj *lookupKeyWrite(redisDb *db, robj *key) {
1606     deleteIfVolatile(db,key);
1607     return lookupKey(db,key);
1608 }
1609
1610 static int deleteKey(redisDb *db, robj *key) {
1611     int retval;
1612
1613     /* We need to protect key from destruction: after the first dictDelete()
1614      * it may happen that 'key' is no longer valid if we don't increment
1615      * it's count. This may happen when we get the object reference directly
1616      * from the hash table with dictRandomKey() or dict iterators */
1617     incrRefCount(key);
1618     if (dictSize(db->expires)) dictDelete(db->expires,key);
1619     retval = dictDelete(db->dict,key);
1620     decrRefCount(key);
1621
1622     return retval == DICT_OK;
1623 }
1624
1625 /*============================ DB saving/loading ============================ */
1626
1627 static int rdbSaveType(FILE *fp, unsigned char type) {
1628     if (fwrite(&type,1,1,fp) == 0) return -1;
1629     return 0;
1630 }
1631
1632 static int rdbSaveTime(FILE *fp, time_t t) {
1633     int32_t t32 = (int32_t) t;
1634     if (fwrite(&t32,4,1,fp) == 0) return -1;
1635     return 0;
1636 }
1637
1638 /* check rdbLoadLen() comments for more info */
1639 static int rdbSaveLen(FILE *fp, uint32_t len) {
1640     unsigned char buf[2];
1641
1642     if (len < (1<<6)) {
1643         /* Save a 6 bit len */
1644         buf[0] = (len&0xFF)|(REDIS_RDB_6BITLEN<<6);
1645         if (fwrite(buf,1,1,fp) == 0) return -1;
1646     } else if (len < (1<<14)) {
1647         /* Save a 14 bit len */
1648         buf[0] = ((len>>8)&0xFF)|(REDIS_RDB_14BITLEN<<6);
1649         buf[1] = len&0xFF;
1650         if (fwrite(buf,2,1,fp) == 0) return -1;
1651     } else {
1652         /* Save a 32 bit len */
1653         buf[0] = (REDIS_RDB_32BITLEN<<6);
1654         if (fwrite(buf,1,1,fp) == 0) return -1;
1655         len = htonl(len);
1656         if (fwrite(&len,4,1,fp) == 0) return -1;
1657     }
1658     return 0;
1659 }
1660
1661 /* String objects in the form "2391" "-100" without any space and with a
1662  * range of values that can fit in an 8, 16 or 32 bit signed value can be
1663  * encoded as integers to save space */
1664 int rdbTryIntegerEncoding(sds s, unsigned char *enc) {
1665     long long value;
1666     char *endptr, buf[32];
1667
1668     /* Check if it's possible to encode this value as a number */
1669     value = strtoll(s, &endptr, 10);
1670     if (endptr[0] != '\0') return 0;
1671     snprintf(buf,32,"%lld",value);
1672
1673     /* If the number converted back into a string is not identical
1674      * then it's not possible to encode the string as integer */
1675     if (strlen(buf) != sdslen(s) || memcmp(buf,s,sdslen(s))) return 0;
1676
1677     /* Finally check if it fits in our ranges */
1678     if (value >= -(1<<7) && value <= (1<<7)-1) {
1679         enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT8;
1680         enc[1] = value&0xFF;
1681         return 2;
1682     } else if (value >= -(1<<15) && value <= (1<<15)-1) {
1683         enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT16;
1684         enc[1] = value&0xFF;
1685         enc[2] = (value>>8)&0xFF;
1686         return 3;
1687     } else if (value >= -((long long)1<<31) && value <= ((long long)1<<31)-1) {
1688         enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT32;
1689         enc[1] = value&0xFF;
1690         enc[2] = (value>>8)&0xFF;
1691         enc[3] = (value>>16)&0xFF;
1692         enc[4] = (value>>24)&0xFF;
1693         return 5;
1694     } else {
1695         return 0;
1696     }
1697 }
1698
1699 static int rdbSaveLzfStringObject(FILE *fp, robj *obj) {
1700     unsigned int comprlen, outlen;
1701     unsigned char byte;
1702     void *out;
1703
1704     /* We require at least four bytes compression for this to be worth it */
1705     outlen = sdslen(obj->ptr)-4;
1706     if (outlen <= 0) return 0;
1707     if ((out = zmalloc(outlen)) == NULL) return 0;
1708     comprlen = lzf_compress(obj->ptr, sdslen(obj->ptr), out, outlen);
1709     if (comprlen == 0) {
1710         zfree(out);
1711         return 0;
1712     }
1713     /* Data compressed! Let's save it on disk */
1714     byte = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_LZF;
1715     if (fwrite(&byte,1,1,fp) == 0) goto writeerr;
1716     if (rdbSaveLen(fp,comprlen) == -1) goto writeerr;
1717     if (rdbSaveLen(fp,sdslen(obj->ptr)) == -1) goto writeerr;
1718     if (fwrite(out,comprlen,1,fp) == 0) goto writeerr;
1719     zfree(out);
1720     return comprlen;
1721
1722 writeerr:
1723     zfree(out);
1724     return -1;
1725 }
1726
1727 /* Save a string objet as [len][data] on disk. If the object is a string
1728  * representation of an integer value we try to safe it in a special form */
1729 static int rdbSaveStringObject(FILE *fp, robj *obj) {
1730     size_t len = sdslen(obj->ptr);
1731     int enclen;
1732
1733     /* Try integer encoding */
1734     if (len <= 11) {
1735         unsigned char buf[5];
1736         if ((enclen = rdbTryIntegerEncoding(obj->ptr,buf)) > 0) {
1737             if (fwrite(buf,enclen,1,fp) == 0) return -1;
1738             return 0;
1739         }
1740     }
1741
1742     /* Try LZF compression - under 20 bytes it's unable to compress even
1743      * aaaaaaaaaaaaaaaaaa so skip it */
1744     if (len > 20) {
1745         int retval;
1746
1747         retval = rdbSaveLzfStringObject(fp,obj);
1748         if (retval == -1) return -1;
1749         if (retval > 0) return 0;
1750         /* retval == 0 means data can't be compressed, save the old way */
1751     }
1752
1753     /* Store verbatim */
1754     if (rdbSaveLen(fp,len) == -1) return -1;
1755     if (len && fwrite(obj->ptr,len,1,fp) == 0) return -1;
1756     return 0;
1757 }
1758
1759 /* Save the DB on disk. Return REDIS_ERR on error, REDIS_OK on success */
1760 static int rdbSave(char *filename) {
1761     dictIterator *di = NULL;
1762     dictEntry *de;
1763     FILE *fp;
1764     char tmpfile[256];
1765     int j;
1766     time_t now = time(NULL);
1767
1768     snprintf(tmpfile,256,"temp-%d.%ld.rdb",(int)time(NULL),(long int)random());
1769     fp = fopen(tmpfile,"w");
1770     if (!fp) {
1771         redisLog(REDIS_WARNING, "Failed saving the DB: %s", strerror(errno));
1772         return REDIS_ERR;
1773     }
1774     if (fwrite("REDIS0001",9,1,fp) == 0) goto werr;
1775     for (j = 0; j < server.dbnum; j++) {
1776         redisDb *db = server.db+j;
1777         dict *d = db->dict;
1778         if (dictSize(d) == 0) continue;
1779         di = dictGetIterator(d);
1780         if (!di) {
1781             fclose(fp);
1782             return REDIS_ERR;
1783         }
1784
1785         /* Write the SELECT DB opcode */
1786         if (rdbSaveType(fp,REDIS_SELECTDB) == -1) goto werr;
1787         if (rdbSaveLen(fp,j) == -1) goto werr;
1788
1789         /* Iterate this DB writing every entry */
1790         while((de = dictNext(di)) != NULL) {
1791             robj *key = dictGetEntryKey(de);
1792             robj *o = dictGetEntryVal(de);
1793             time_t expiretime = getExpire(db,key);
1794
1795             /* Save the expire time */
1796             if (expiretime != -1) {
1797                 /* If this key is already expired skip it */
1798                 if (expiretime < now) continue;
1799                 if (rdbSaveType(fp,REDIS_EXPIRETIME) == -1) goto werr;
1800                 if (rdbSaveTime(fp,expiretime) == -1) goto werr;
1801             }
1802             /* Save the key and associated value */
1803             if (rdbSaveType(fp,o->type) == -1) goto werr;
1804             if (rdbSaveStringObject(fp,key) == -1) goto werr;
1805             if (o->type == REDIS_STRING) {
1806                 /* Save a string value */
1807                 if (rdbSaveStringObject(fp,o) == -1) goto werr;
1808             } else if (o->type == REDIS_LIST) {
1809                 /* Save a list value */
1810                 list *list = o->ptr;
1811                 listNode *ln;
1812
1813                 listRewind(list);
1814                 if (rdbSaveLen(fp,listLength(list)) == -1) goto werr;
1815                 while((ln = listYield(list))) {
1816                     robj *eleobj = listNodeValue(ln);
1817
1818                     if (rdbSaveStringObject(fp,eleobj) == -1) goto werr;
1819                 }
1820             } else if (o->type == REDIS_SET) {
1821                 /* Save a set value */
1822                 dict *set = o->ptr;
1823                 dictIterator *di = dictGetIterator(set);
1824                 dictEntry *de;
1825
1826                 if (!set) oom("dictGetIteraotr");
1827                 if (rdbSaveLen(fp,dictSize(set)) == -1) goto werr;
1828                 while((de = dictNext(di)) != NULL) {
1829                     robj *eleobj = dictGetEntryKey(de);
1830
1831                     if (rdbSaveStringObject(fp,eleobj) == -1) goto werr;
1832                 }
1833                 dictReleaseIterator(di);
1834             } else {
1835                 assert(0 != 0);
1836             }
1837         }
1838         dictReleaseIterator(di);
1839     }
1840     /* EOF opcode */
1841     if (rdbSaveType(fp,REDIS_EOF) == -1) goto werr;
1842
1843     /* Make sure data will not remain on the OS's output buffers */
1844     fflush(fp);
1845     fsync(fileno(fp));
1846     fclose(fp);
1847
1848     /* Use RENAME to make sure the DB file is changed atomically only
1849      * if the generate DB file is ok. */
1850     if (rename(tmpfile,filename) == -1) {
1851         redisLog(REDIS_WARNING,"Error moving temp DB file on the final destionation: %s", strerror(errno));
1852         unlink(tmpfile);
1853         return REDIS_ERR;
1854     }
1855     redisLog(REDIS_NOTICE,"DB saved on disk");
1856     server.dirty = 0;
1857     server.lastsave = time(NULL);
1858     return REDIS_OK;
1859
1860 werr:
1861     fclose(fp);
1862     unlink(tmpfile);
1863     redisLog(REDIS_WARNING,"Write error saving DB on disk: %s", strerror(errno));
1864     if (di) dictReleaseIterator(di);
1865     return REDIS_ERR;
1866 }
1867
1868 static int rdbSaveBackground(char *filename) {
1869     pid_t childpid;
1870
1871     if (server.bgsaveinprogress) return REDIS_ERR;
1872     if ((childpid = fork()) == 0) {
1873         /* Child */
1874         close(server.fd);
1875         if (rdbSave(filename) == REDIS_OK) {
1876             exit(0);
1877         } else {
1878             exit(1);
1879         }
1880     } else {
1881         /* Parent */
1882         redisLog(REDIS_NOTICE,"Background saving started by pid %d",childpid);
1883         server.bgsaveinprogress = 1;
1884         return REDIS_OK;
1885     }
1886     return REDIS_OK; /* unreached */
1887 }
1888
1889 static int rdbLoadType(FILE *fp) {
1890     unsigned char type;
1891     if (fread(&type,1,1,fp) == 0) return -1;
1892     return type;
1893 }
1894
1895 static time_t rdbLoadTime(FILE *fp) {
1896     int32_t t32;
1897     if (fread(&t32,4,1,fp) == 0) return -1;
1898     return (time_t) t32;
1899 }
1900
1901 /* Load an encoded length from the DB, see the REDIS_RDB_* defines on the top
1902  * of this file for a description of how this are stored on disk.
1903  *
1904  * isencoded is set to 1 if the readed length is not actually a length but
1905  * an "encoding type", check the above comments for more info */
1906 static uint32_t rdbLoadLen(FILE *fp, int rdbver, int *isencoded) {
1907     unsigned char buf[2];
1908     uint32_t len;
1909
1910     if (isencoded) *isencoded = 0;
1911     if (rdbver == 0) {
1912         if (fread(&len,4,1,fp) == 0) return REDIS_RDB_LENERR;
1913         return ntohl(len);
1914     } else {
1915         int type;
1916
1917         if (fread(buf,1,1,fp) == 0) return REDIS_RDB_LENERR;
1918         type = (buf[0]&0xC0)>>6;
1919         if (type == REDIS_RDB_6BITLEN) {
1920             /* Read a 6 bit len */
1921             return buf[0]&0x3F;
1922         } else if (type == REDIS_RDB_ENCVAL) {
1923             /* Read a 6 bit len encoding type */
1924             if (isencoded) *isencoded = 1;
1925             return buf[0]&0x3F;
1926         } else if (type == REDIS_RDB_14BITLEN) {
1927             /* Read a 14 bit len */
1928             if (fread(buf+1,1,1,fp) == 0) return REDIS_RDB_LENERR;
1929             return ((buf[0]&0x3F)<<8)|buf[1];
1930         } else {
1931             /* Read a 32 bit len */
1932             if (fread(&len,4,1,fp) == 0) return REDIS_RDB_LENERR;
1933             return ntohl(len);
1934         }
1935     }
1936 }
1937
1938 static robj *rdbLoadIntegerObject(FILE *fp, int enctype) {
1939     unsigned char enc[4];
1940     long long val;
1941
1942     if (enctype == REDIS_RDB_ENC_INT8) {
1943         if (fread(enc,1,1,fp) == 0) return NULL;
1944         val = (signed char)enc[0];
1945     } else if (enctype == REDIS_RDB_ENC_INT16) {
1946         uint16_t v;
1947         if (fread(enc,2,1,fp) == 0) return NULL;
1948         v = enc[0]|(enc[1]<<8);
1949         val = (int16_t)v;
1950     } else if (enctype == REDIS_RDB_ENC_INT32) {
1951         uint32_t v;
1952         if (fread(enc,4,1,fp) == 0) return NULL;
1953         v = enc[0]|(enc[1]<<8)|(enc[2]<<16)|(enc[3]<<24);
1954         val = (int32_t)v;
1955     } else {
1956         val = 0; /* anti-warning */
1957         assert(0!=0);
1958     }
1959     return createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",val));
1960 }
1961
1962 static robj *rdbLoadLzfStringObject(FILE*fp, int rdbver) {
1963     unsigned int len, clen;
1964     unsigned char *c = NULL;
1965     sds val = NULL;
1966
1967     if ((clen = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR) return NULL;
1968     if ((len = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR) return NULL;
1969     if ((c = zmalloc(clen)) == NULL) goto err;
1970     if ((val = sdsnewlen(NULL,len)) == NULL) goto err;
1971     if (fread(c,clen,1,fp) == 0) goto err;
1972     if (lzf_decompress(c,clen,val,len) == 0) goto err;
1973     return createObject(REDIS_STRING,val);
1974 err:
1975     zfree(c);
1976     sdsfree(val);
1977     return NULL;
1978 }
1979
1980 static robj *rdbLoadStringObject(FILE*fp, int rdbver) {
1981     int isencoded;
1982     uint32_t len;
1983     sds val;
1984
1985     len = rdbLoadLen(fp,rdbver,&isencoded);
1986     if (isencoded) {
1987         switch(len) {
1988         case REDIS_RDB_ENC_INT8:
1989         case REDIS_RDB_ENC_INT16:
1990         case REDIS_RDB_ENC_INT32:
1991             return tryObjectSharing(rdbLoadIntegerObject(fp,len));
1992         case REDIS_RDB_ENC_LZF:
1993             return tryObjectSharing(rdbLoadLzfStringObject(fp,rdbver));
1994         default:
1995             assert(0!=0);
1996         }
1997     }
1998
1999     if (len == REDIS_RDB_LENERR) return NULL;
2000     val = sdsnewlen(NULL,len);
2001     if (len && fread(val,len,1,fp) == 0) {
2002         sdsfree(val);
2003         return NULL;
2004     }
2005     return tryObjectSharing(createObject(REDIS_STRING,val));
2006 }
2007
2008 static int rdbLoad(char *filename) {
2009     FILE *fp;
2010     robj *keyobj = NULL;
2011     uint32_t dbid;
2012     int type, retval, rdbver;
2013     dict *d = server.db[0].dict;
2014     redisDb *db = server.db+0;
2015     char buf[1024];
2016     time_t expiretime = -1, now = time(NULL);
2017
2018     fp = fopen(filename,"r");
2019     if (!fp) return REDIS_ERR;
2020     if (fread(buf,9,1,fp) == 0) goto eoferr;
2021     buf[9] = '\0';
2022     if (memcmp(buf,"REDIS",5) != 0) {
2023         fclose(fp);
2024         redisLog(REDIS_WARNING,"Wrong signature trying to load DB from file");
2025         return REDIS_ERR;
2026     }
2027     rdbver = atoi(buf+5);
2028     if (rdbver > 1) {
2029         fclose(fp);
2030         redisLog(REDIS_WARNING,"Can't handle RDB format version %d",rdbver);
2031         return REDIS_ERR;
2032     }
2033     while(1) {
2034         robj *o;
2035
2036         /* Read type. */
2037         if ((type = rdbLoadType(fp)) == -1) goto eoferr;
2038         if (type == REDIS_EXPIRETIME) {
2039             if ((expiretime = rdbLoadTime(fp)) == -1) goto eoferr;
2040             /* We read the time so we need to read the object type again */
2041             if ((type = rdbLoadType(fp)) == -1) goto eoferr;
2042         }
2043         if (type == REDIS_EOF) break;
2044         /* Handle SELECT DB opcode as a special case */
2045         if (type == REDIS_SELECTDB) {
2046             if ((dbid = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR)
2047                 goto eoferr;
2048             if (dbid >= (unsigned)server.dbnum) {
2049                 redisLog(REDIS_WARNING,"FATAL: Data file was created with a Redis server configured to handle more than %d databases. Exiting\n", server.dbnum);
2050                 exit(1);
2051             }
2052             db = server.db+dbid;
2053             d = db->dict;
2054             continue;
2055         }
2056         /* Read key */
2057         if ((keyobj = rdbLoadStringObject(fp,rdbver)) == NULL) goto eoferr;
2058
2059         if (type == REDIS_STRING) {
2060             /* Read string value */
2061             if ((o = rdbLoadStringObject(fp,rdbver)) == NULL) goto eoferr;
2062         } else if (type == REDIS_LIST || type == REDIS_SET) {
2063             /* Read list/set value */
2064             uint32_t listlen;
2065
2066             if ((listlen = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR)
2067                 goto eoferr;
2068             o = (type == REDIS_LIST) ? createListObject() : createSetObject();
2069             /* Load every single element of the list/set */
2070             while(listlen--) {
2071                 robj *ele;
2072
2073                 if ((ele = rdbLoadStringObject(fp,rdbver)) == NULL) goto eoferr;
2074                 if (type == REDIS_LIST) {
2075                     if (!listAddNodeTail((list*)o->ptr,ele))
2076                         oom("listAddNodeTail");
2077                 } else {
2078                     if (dictAdd((dict*)o->ptr,ele,NULL) == DICT_ERR)
2079                         oom("dictAdd");
2080                 }
2081             }
2082         } else {
2083             assert(0 != 0);
2084         }
2085         /* Add the new object in the hash table */
2086         retval = dictAdd(d,keyobj,o);
2087         if (retval == DICT_ERR) {
2088             redisLog(REDIS_WARNING,"Loading DB, duplicated key (%s) found! Unrecoverable error, exiting now.", keyobj->ptr);
2089             exit(1);
2090         }
2091         /* Set the expire time if needed */
2092         if (expiretime != -1) {
2093             setExpire(db,keyobj,expiretime);
2094             /* Delete this key if already expired */
2095             if (expiretime < now) deleteKey(db,keyobj);
2096             expiretime = -1;
2097         }
2098         keyobj = o = NULL;
2099     }
2100     fclose(fp);
2101     return REDIS_OK;
2102
2103 eoferr: /* unexpected end of file is handled here with a fatal exit */
2104     if (keyobj) decrRefCount(keyobj);
2105     redisLog(REDIS_WARNING,"Short read or OOM loading DB. Unrecoverable error, exiting now.");
2106     exit(1);
2107     return REDIS_ERR; /* Just to avoid warning */
2108 }
2109
2110 /*================================== Commands =============================== */
2111
2112 static void authCommand(redisClient *c) {
2113     if (!server.requirepass || !strcmp(c->argv[1]->ptr, server.requirepass)) {
2114       c->authenticated = 1;
2115       addReply(c,shared.ok);
2116     } else {
2117       c->authenticated = 0;
2118       addReply(c,shared.err);
2119     }
2120 }
2121
2122 static void pingCommand(redisClient *c) {
2123     addReply(c,shared.pong);
2124 }
2125
2126 static void echoCommand(redisClient *c) {
2127     addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",
2128         (int)sdslen(c->argv[1]->ptr)));
2129     addReply(c,c->argv[1]);
2130     addReply(c,shared.crlf);
2131 }
2132
2133 /*=================================== Strings =============================== */
2134
2135 static void setGenericCommand(redisClient *c, int nx) {
2136     int retval;
2137
2138     retval = dictAdd(c->db->dict,c->argv[1],c->argv[2]);
2139     if (retval == DICT_ERR) {
2140         if (!nx) {
2141             dictReplace(c->db->dict,c->argv[1],c->argv[2]);
2142             incrRefCount(c->argv[2]);
2143         } else {
2144             addReply(c,shared.czero);
2145             return;
2146         }
2147     } else {
2148         incrRefCount(c->argv[1]);
2149         incrRefCount(c->argv[2]);
2150     }
2151     server.dirty++;
2152     removeExpire(c->db,c->argv[1]);
2153     addReply(c, nx ? shared.cone : shared.ok);
2154 }
2155
2156 static void setCommand(redisClient *c) {
2157     setGenericCommand(c,0);
2158 }
2159
2160 static void setnxCommand(redisClient *c) {
2161     setGenericCommand(c,1);
2162 }
2163
2164 static void getCommand(redisClient *c) {
2165     robj *o = lookupKeyRead(c->db,c->argv[1]);
2166
2167     if (o == NULL) {
2168         addReply(c,shared.nullbulk);
2169     } else {
2170         if (o->type != REDIS_STRING) {
2171             addReply(c,shared.wrongtypeerr);
2172         } else {
2173             addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(o->ptr)));
2174             addReply(c,o);
2175             addReply(c,shared.crlf);
2176         }
2177     }
2178 }
2179
2180 static void getSetCommand(redisClient *c) {
2181     getCommand(c);
2182     if (dictAdd(c->db->dict,c->argv[1],c->argv[2]) == DICT_ERR) {
2183         dictReplace(c->db->dict,c->argv[1],c->argv[2]);
2184     } else {
2185         incrRefCount(c->argv[1]);
2186     }
2187     incrRefCount(c->argv[2]);
2188     server.dirty++;
2189     removeExpire(c->db,c->argv[1]);
2190 }
2191
2192 static void mgetCommand(redisClient *c) {
2193     int j;
2194
2195     addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",c->argc-1));
2196     for (j = 1; j < c->argc; j++) {
2197         robj *o = lookupKeyRead(c->db,c->argv[j]);
2198         if (o == NULL) {
2199             addReply(c,shared.nullbulk);
2200         } else {
2201             if (o->type != REDIS_STRING) {
2202                 addReply(c,shared.nullbulk);
2203             } else {
2204                 addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(o->ptr)));
2205                 addReply(c,o);
2206                 addReply(c,shared.crlf);
2207             }
2208         }
2209     }
2210 }
2211
2212 static void incrDecrCommand(redisClient *c, long long incr) {
2213     long long value;
2214     int retval;
2215     robj *o;
2216
2217     o = lookupKeyWrite(c->db,c->argv[1]);
2218     if (o == NULL) {
2219         value = 0;
2220     } else {
2221         if (o->type != REDIS_STRING) {
2222             value = 0;
2223         } else {
2224             char *eptr;
2225
2226             value = strtoll(o->ptr, &eptr, 10);
2227         }
2228     }
2229
2230     value += incr;
2231     o = createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",value));
2232     retval = dictAdd(c->db->dict,c->argv[1],o);
2233     if (retval == DICT_ERR) {
2234         dictReplace(c->db->dict,c->argv[1],o);
2235         removeExpire(c->db,c->argv[1]);
2236     } else {
2237         incrRefCount(c->argv[1]);
2238     }
2239     server.dirty++;
2240     addReply(c,shared.colon);
2241     addReply(c,o);
2242     addReply(c,shared.crlf);
2243 }
2244
2245 static void incrCommand(redisClient *c) {
2246     incrDecrCommand(c,1);
2247 }
2248
2249 static void decrCommand(redisClient *c) {
2250     incrDecrCommand(c,-1);
2251 }
2252
2253 static void incrbyCommand(redisClient *c) {
2254     long long incr = strtoll(c->argv[2]->ptr, NULL, 10);
2255     incrDecrCommand(c,incr);
2256 }
2257
2258 static void decrbyCommand(redisClient *c) {
2259     long long incr = strtoll(c->argv[2]->ptr, NULL, 10);
2260     incrDecrCommand(c,-incr);
2261 }
2262
2263 /* ========================= Type agnostic commands ========================= */
2264
2265 static void delCommand(redisClient *c) {
2266     if (deleteKey(c->db,c->argv[1])) {
2267         server.dirty++;
2268         addReply(c,shared.cone);
2269     } else {
2270         addReply(c,shared.czero);
2271     }
2272 }
2273
2274 static void existsCommand(redisClient *c) {
2275     addReply(c,lookupKeyRead(c->db,c->argv[1]) ? shared.cone : shared.czero);
2276 }
2277
2278 static void selectCommand(redisClient *c) {
2279     int id = atoi(c->argv[1]->ptr);
2280
2281     if (selectDb(c,id) == REDIS_ERR) {
2282         addReplySds(c,sdsnew("-ERR invalid DB index\r\n"));
2283     } else {
2284         addReply(c,shared.ok);
2285     }
2286 }
2287
2288 static void randomkeyCommand(redisClient *c) {
2289     dictEntry *de;
2290
2291     while(1) {
2292         de = dictGetRandomKey(c->db->dict);
2293         if (!de || expireIfNeeded(c->db,dictGetEntryKey(de)) == 0) break;
2294     }
2295     if (de == NULL) {
2296         addReply(c,shared.plus);
2297         addReply(c,shared.crlf);
2298     } else {
2299         addReply(c,shared.plus);
2300         addReply(c,dictGetEntryKey(de));
2301         addReply(c,shared.crlf);
2302     }
2303 }
2304
2305 static void keysCommand(redisClient *c) {
2306     dictIterator *di;
2307     dictEntry *de;
2308     sds pattern = c->argv[1]->ptr;
2309     int plen = sdslen(pattern);
2310     int numkeys = 0, keyslen = 0;
2311     robj *lenobj = createObject(REDIS_STRING,NULL);
2312
2313     di = dictGetIterator(c->db->dict);
2314     if (!di) oom("dictGetIterator");
2315     addReply(c,lenobj);
2316     decrRefCount(lenobj);
2317     while((de = dictNext(di)) != NULL) {
2318         robj *keyobj = dictGetEntryKey(de);
2319
2320         sds key = keyobj->ptr;
2321         if ((pattern[0] == '*' && pattern[1] == '\0') ||
2322             stringmatchlen(pattern,plen,key,sdslen(key),0)) {
2323             if (expireIfNeeded(c->db,keyobj) == 0) {
2324                 if (numkeys != 0)
2325                     addReply(c,shared.space);
2326                 addReply(c,keyobj);
2327                 numkeys++;
2328                 keyslen += sdslen(key);
2329             }
2330         }
2331     }
2332     dictReleaseIterator(di);
2333     lenobj->ptr = sdscatprintf(sdsempty(),"$%lu\r\n",keyslen+(numkeys ? (numkeys-1) : 0));
2334     addReply(c,shared.crlf);
2335 }
2336
2337 static void dbsizeCommand(redisClient *c) {
2338     addReplySds(c,
2339         sdscatprintf(sdsempty(),":%lu\r\n",dictSize(c->db->dict)));
2340 }
2341
2342 static void lastsaveCommand(redisClient *c) {
2343     addReplySds(c,
2344         sdscatprintf(sdsempty(),":%lu\r\n",server.lastsave));
2345 }
2346
2347 static void typeCommand(redisClient *c) {
2348     robj *o;
2349     char *type;
2350
2351     o = lookupKeyRead(c->db,c->argv[1]);
2352     if (o == NULL) {
2353         type = "+none";
2354     } else {
2355         switch(o->type) {
2356         case REDIS_STRING: type = "+string"; break;
2357         case REDIS_LIST: type = "+list"; break;
2358         case REDIS_SET: type = "+set"; break;
2359         default: type = "unknown"; break;
2360         }
2361     }
2362     addReplySds(c,sdsnew(type));
2363     addReply(c,shared.crlf);
2364 }
2365
2366 static void saveCommand(redisClient *c) {
2367     if (server.bgsaveinprogress) {
2368         addReplySds(c,sdsnew("-ERR background save in progress\r\n"));
2369         return;
2370     }
2371     if (rdbSave(server.dbfilename) == REDIS_OK) {
2372         addReply(c,shared.ok);
2373     } else {
2374         addReply(c,shared.err);
2375     }
2376 }
2377
2378 static void bgsaveCommand(redisClient *c) {
2379     if (server.bgsaveinprogress) {
2380         addReplySds(c,sdsnew("-ERR background save already in progress\r\n"));
2381         return;
2382     }
2383     if (rdbSaveBackground(server.dbfilename) == REDIS_OK) {
2384         addReply(c,shared.ok);
2385     } else {
2386         addReply(c,shared.err);
2387     }
2388 }
2389
2390 static void shutdownCommand(redisClient *c) {
2391     redisLog(REDIS_WARNING,"User requested shutdown, saving DB...");
2392     /* XXX: TODO kill the child if there is a bgsave in progress */
2393     if (rdbSave(server.dbfilename) == REDIS_OK) {
2394         if (server.daemonize) {
2395             unlink(server.pidfile);
2396         }
2397         redisLog(REDIS_WARNING,"%zu bytes used at exit",zmalloc_used_memory());
2398         redisLog(REDIS_WARNING,"Server exit now, bye bye...");
2399         exit(1);
2400     } else {
2401         redisLog(REDIS_WARNING,"Error trying to save the DB, can't exit");
2402         addReplySds(c,sdsnew("-ERR can't quit, problems saving the DB\r\n"));
2403     }
2404 }
2405
2406 static void renameGenericCommand(redisClient *c, int nx) {
2407     robj *o;
2408
2409     /* To use the same key as src and dst is probably an error */
2410     if (sdscmp(c->argv[1]->ptr,c->argv[2]->ptr) == 0) {
2411         addReply(c,shared.sameobjecterr);
2412         return;
2413     }
2414
2415     o = lookupKeyWrite(c->db,c->argv[1]);
2416     if (o == NULL) {
2417         addReply(c,shared.nokeyerr);
2418         return;
2419     }
2420     incrRefCount(o);
2421     deleteIfVolatile(c->db,c->argv[2]);
2422     if (dictAdd(c->db->dict,c->argv[2],o) == DICT_ERR) {
2423         if (nx) {
2424             decrRefCount(o);
2425             addReply(c,shared.czero);
2426             return;
2427         }
2428         dictReplace(c->db->dict,c->argv[2],o);
2429     } else {
2430         incrRefCount(c->argv[2]);
2431     }
2432     deleteKey(c->db,c->argv[1]);
2433     server.dirty++;
2434     addReply(c,nx ? shared.cone : shared.ok);
2435 }
2436
2437 static void renameCommand(redisClient *c) {
2438     renameGenericCommand(c,0);
2439 }
2440
2441 static void renamenxCommand(redisClient *c) {
2442     renameGenericCommand(c,1);
2443 }
2444
2445 static void moveCommand(redisClient *c) {
2446     robj *o;
2447     redisDb *src, *dst;
2448     int srcid;
2449
2450     /* Obtain source and target DB pointers */
2451     src = c->db;
2452     srcid = c->db->id;
2453     if (selectDb(c,atoi(c->argv[2]->ptr)) == REDIS_ERR) {
2454         addReply(c,shared.outofrangeerr);
2455         return;
2456     }
2457     dst = c->db;
2458     selectDb(c,srcid); /* Back to the source DB */
2459
2460     /* If the user is moving using as target the same
2461      * DB as the source DB it is probably an error. */
2462     if (src == dst) {
2463         addReply(c,shared.sameobjecterr);
2464         return;
2465     }
2466
2467     /* Check if the element exists and get a reference */
2468     o = lookupKeyWrite(c->db,c->argv[1]);
2469     if (!o) {
2470         addReply(c,shared.czero);
2471         return;
2472     }
2473
2474     /* Try to add the element to the target DB */
2475     deleteIfVolatile(dst,c->argv[1]);
2476     if (dictAdd(dst->dict,c->argv[1],o) == DICT_ERR) {
2477         addReply(c,shared.czero);
2478         return;
2479     }
2480     incrRefCount(c->argv[1]);
2481     incrRefCount(o);
2482
2483     /* OK! key moved, free the entry in the source DB */
2484     deleteKey(src,c->argv[1]);
2485     server.dirty++;
2486     addReply(c,shared.cone);
2487 }
2488
2489 /* =================================== Lists ================================ */
2490 static void pushGenericCommand(redisClient *c, int where) {
2491     robj *lobj;
2492     list *list;
2493
2494     lobj = lookupKeyWrite(c->db,c->argv[1]);
2495     if (lobj == NULL) {
2496         lobj = createListObject();
2497         list = lobj->ptr;
2498         if (where == REDIS_HEAD) {
2499             if (!listAddNodeHead(list,c->argv[2])) oom("listAddNodeHead");
2500         } else {
2501             if (!listAddNodeTail(list,c->argv[2])) oom("listAddNodeTail");
2502         }
2503         dictAdd(c->db->dict,c->argv[1],lobj);
2504         incrRefCount(c->argv[1]);
2505         incrRefCount(c->argv[2]);
2506     } else {
2507         if (lobj->type != REDIS_LIST) {
2508             addReply(c,shared.wrongtypeerr);
2509             return;
2510         }
2511         list = lobj->ptr;
2512         if (where == REDIS_HEAD) {
2513             if (!listAddNodeHead(list,c->argv[2])) oom("listAddNodeHead");
2514         } else {
2515             if (!listAddNodeTail(list,c->argv[2])) oom("listAddNodeTail");
2516         }
2517         incrRefCount(c->argv[2]);
2518     }
2519     server.dirty++;
2520     addReply(c,shared.ok);
2521 }
2522
2523 static void lpushCommand(redisClient *c) {
2524     pushGenericCommand(c,REDIS_HEAD);
2525 }
2526
2527 static void rpushCommand(redisClient *c) {
2528     pushGenericCommand(c,REDIS_TAIL);
2529 }
2530
2531 static void llenCommand(redisClient *c) {
2532     robj *o;
2533     list *l;
2534
2535     o = lookupKeyRead(c->db,c->argv[1]);
2536     if (o == NULL) {
2537         addReply(c,shared.czero);
2538         return;
2539     } else {
2540         if (o->type != REDIS_LIST) {
2541             addReply(c,shared.wrongtypeerr);
2542         } else {
2543             l = o->ptr;
2544             addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",listLength(l)));
2545         }
2546     }
2547 }
2548
2549 static void lindexCommand(redisClient *c) {
2550     robj *o;
2551     int index = atoi(c->argv[2]->ptr);
2552
2553     o = lookupKeyRead(c->db,c->argv[1]);
2554     if (o == NULL) {
2555         addReply(c,shared.nullbulk);
2556     } else {
2557         if (o->type != REDIS_LIST) {
2558             addReply(c,shared.wrongtypeerr);
2559         } else {
2560             list *list = o->ptr;
2561             listNode *ln;
2562
2563             ln = listIndex(list, index);
2564             if (ln == NULL) {
2565                 addReply(c,shared.nullbulk);
2566             } else {
2567                 robj *ele = listNodeValue(ln);
2568                 addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(ele->ptr)));
2569                 addReply(c,ele);
2570                 addReply(c,shared.crlf);
2571             }
2572         }
2573     }
2574 }
2575
2576 static void lsetCommand(redisClient *c) {
2577     robj *o;
2578     int index = atoi(c->argv[2]->ptr);
2579
2580     o = lookupKeyWrite(c->db,c->argv[1]);
2581     if (o == NULL) {
2582         addReply(c,shared.nokeyerr);
2583     } else {
2584         if (o->type != REDIS_LIST) {
2585             addReply(c,shared.wrongtypeerr);
2586         } else {
2587             list *list = o->ptr;
2588             listNode *ln;
2589
2590             ln = listIndex(list, index);
2591             if (ln == NULL) {
2592                 addReply(c,shared.outofrangeerr);
2593             } else {
2594                 robj *ele = listNodeValue(ln);
2595
2596                 decrRefCount(ele);
2597                 listNodeValue(ln) = c->argv[3];
2598                 incrRefCount(c->argv[3]);
2599                 addReply(c,shared.ok);
2600                 server.dirty++;
2601             }
2602         }
2603     }
2604 }
2605
2606 static void popGenericCommand(redisClient *c, int where) {
2607     robj *o;
2608
2609     o = lookupKeyWrite(c->db,c->argv[1]);
2610     if (o == NULL) {
2611         addReply(c,shared.nullbulk);
2612     } else {
2613         if (o->type != REDIS_LIST) {
2614             addReply(c,shared.wrongtypeerr);
2615         } else {
2616             list *list = o->ptr;
2617             listNode *ln;
2618
2619             if (where == REDIS_HEAD)
2620                 ln = listFirst(list);
2621             else
2622                 ln = listLast(list);
2623
2624             if (ln == NULL) {
2625                 addReply(c,shared.nullbulk);
2626             } else {
2627                 robj *ele = listNodeValue(ln);
2628                 addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(ele->ptr)));
2629                 addReply(c,ele);
2630                 addReply(c,shared.crlf);
2631                 listDelNode(list,ln);
2632                 server.dirty++;
2633             }
2634         }
2635     }
2636 }
2637
2638 static void lpopCommand(redisClient *c) {
2639     popGenericCommand(c,REDIS_HEAD);
2640 }
2641
2642 static void rpopCommand(redisClient *c) {
2643     popGenericCommand(c,REDIS_TAIL);
2644 }
2645
2646 static void lrangeCommand(redisClient *c) {
2647     robj *o;
2648     int start = atoi(c->argv[2]->ptr);
2649     int end = atoi(c->argv[3]->ptr);
2650
2651     o = lookupKeyRead(c->db,c->argv[1]);
2652     if (o == NULL) {
2653         addReply(c,shared.nullmultibulk);
2654     } else {
2655         if (o->type != REDIS_LIST) {
2656             addReply(c,shared.wrongtypeerr);
2657         } else {
2658             list *list = o->ptr;
2659             listNode *ln;
2660             int llen = listLength(list);
2661             int rangelen, j;
2662             robj *ele;
2663
2664             /* convert negative indexes */
2665             if (start < 0) start = llen+start;
2666             if (end < 0) end = llen+end;
2667             if (start < 0) start = 0;
2668             if (end < 0) end = 0;
2669
2670             /* indexes sanity checks */
2671             if (start > end || start >= llen) {
2672                 /* Out of range start or start > end result in empty list */
2673                 addReply(c,shared.emptymultibulk);
2674                 return;
2675             }
2676             if (end >= llen) end = llen-1;
2677             rangelen = (end-start)+1;
2678
2679             /* Return the result in form of a multi-bulk reply */
2680             ln = listIndex(list, start);
2681             addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",rangelen));
2682             for (j = 0; j < rangelen; j++) {
2683                 ele = listNodeValue(ln);
2684                 addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(ele->ptr)));
2685                 addReply(c,ele);
2686                 addReply(c,shared.crlf);
2687                 ln = ln->next;
2688             }
2689         }
2690     }
2691 }
2692
2693 static void ltrimCommand(redisClient *c) {
2694     robj *o;
2695     int start = atoi(c->argv[2]->ptr);
2696     int end = atoi(c->argv[3]->ptr);
2697
2698     o = lookupKeyWrite(c->db,c->argv[1]);
2699     if (o == NULL) {
2700         addReply(c,shared.nokeyerr);
2701     } else {
2702         if (o->type != REDIS_LIST) {
2703             addReply(c,shared.wrongtypeerr);
2704         } else {
2705             list *list = o->ptr;
2706             listNode *ln;
2707             int llen = listLength(list);
2708             int j, ltrim, rtrim;
2709
2710             /* convert negative indexes */
2711             if (start < 0) start = llen+start;
2712             if (end < 0) end = llen+end;
2713             if (start < 0) start = 0;
2714             if (end < 0) end = 0;
2715
2716             /* indexes sanity checks */
2717             if (start > end || start >= llen) {
2718                 /* Out of range start or start > end result in empty list */
2719                 ltrim = llen;
2720                 rtrim = 0;
2721             } else {
2722                 if (end >= llen) end = llen-1;
2723                 ltrim = start;
2724                 rtrim = llen-end-1;
2725             }
2726
2727             /* Remove list elements to perform the trim */
2728             for (j = 0; j < ltrim; j++) {
2729                 ln = listFirst(list);
2730                 listDelNode(list,ln);
2731             }
2732             for (j = 0; j < rtrim; j++) {
2733                 ln = listLast(list);
2734                 listDelNode(list,ln);
2735             }
2736             addReply(c,shared.ok);
2737             server.dirty++;
2738         }
2739     }
2740 }
2741
2742 static void lremCommand(redisClient *c) {
2743     robj *o;
2744
2745     o = lookupKeyWrite(c->db,c->argv[1]);
2746     if (o == NULL) {
2747         addReply(c,shared.nokeyerr);
2748     } else {
2749         if (o->type != REDIS_LIST) {
2750             addReply(c,shared.wrongtypeerr);
2751         } else {
2752             list *list = o->ptr;
2753             listNode *ln, *next;
2754             int toremove = atoi(c->argv[2]->ptr);
2755             int removed = 0;
2756             int fromtail = 0;
2757
2758             if (toremove < 0) {
2759                 toremove = -toremove;
2760                 fromtail = 1;
2761             }
2762             ln = fromtail ? list->tail : list->head;
2763             while (ln) {
2764                 robj *ele = listNodeValue(ln);
2765
2766                 next = fromtail ? ln->prev : ln->next;
2767                 if (sdscmp(ele->ptr,c->argv[3]->ptr) == 0) {
2768                     listDelNode(list,ln);
2769                     server.dirty++;
2770                     removed++;
2771                     if (toremove && removed == toremove) break;
2772                 }
2773                 ln = next;
2774             }
2775             addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",removed));
2776         }
2777     }
2778 }
2779
2780 /* ==================================== Sets ================================ */
2781
2782 static void saddCommand(redisClient *c) {
2783     robj *set;
2784
2785     set = lookupKeyWrite(c->db,c->argv[1]);
2786     if (set == NULL) {
2787         set = createSetObject();
2788         dictAdd(c->db->dict,c->argv[1],set);
2789         incrRefCount(c->argv[1]);
2790     } else {
2791         if (set->type != REDIS_SET) {
2792             addReply(c,shared.wrongtypeerr);
2793             return;
2794         }
2795     }
2796     if (dictAdd(set->ptr,c->argv[2],NULL) == DICT_OK) {
2797         incrRefCount(c->argv[2]);
2798         server.dirty++;
2799         addReply(c,shared.cone);
2800     } else {
2801         addReply(c,shared.czero);
2802     }
2803 }
2804
2805 static void sremCommand(redisClient *c) {
2806     robj *set;
2807
2808     set = lookupKeyWrite(c->db,c->argv[1]);
2809     if (set == NULL) {
2810         addReply(c,shared.czero);
2811     } else {
2812         if (set->type != REDIS_SET) {
2813             addReply(c,shared.wrongtypeerr);
2814             return;
2815         }
2816         if (dictDelete(set->ptr,c->argv[2]) == DICT_OK) {
2817             server.dirty++;
2818             addReply(c,shared.cone);
2819         } else {
2820             addReply(c,shared.czero);
2821         }
2822     }
2823 }
2824
2825 static void smoveCommand(redisClient *c) {
2826     robj *srcset, *dstset;
2827
2828     srcset = lookupKeyWrite(c->db,c->argv[1]);
2829     dstset = lookupKeyWrite(c->db,c->argv[2]);
2830
2831     /* If the source key does not exist return 0, if it's of the wrong type
2832      * raise an error */
2833     if (srcset == NULL || srcset->type != REDIS_SET) {
2834         addReply(c, srcset ? shared.wrongtypeerr : shared.czero);
2835         return;
2836     }
2837     /* Error if the destination key is not a set as well */
2838     if (dstset && dstset->type != REDIS_SET) {
2839         addReply(c,shared.wrongtypeerr);
2840         return;
2841     }
2842     /* Remove the element from the source set */
2843     if (dictDelete(srcset->ptr,c->argv[3]) == DICT_ERR) {
2844         /* Key not found in the src set! return zero */
2845         addReply(c,shared.czero);
2846         return;
2847     }
2848     server.dirty++;
2849     /* Add the element to the destination set */
2850     if (!dstset) {
2851         dstset = createSetObject();
2852         dictAdd(c->db->dict,c->argv[2],dstset);
2853         incrRefCount(c->argv[2]);
2854     }
2855     if (dictAdd(dstset->ptr,c->argv[3],NULL) == DICT_OK)
2856         incrRefCount(c->argv[3]);
2857     addReply(c,shared.cone);
2858 }
2859
2860 static void sismemberCommand(redisClient *c) {
2861     robj *set;
2862
2863     set = lookupKeyRead(c->db,c->argv[1]);
2864     if (set == NULL) {
2865         addReply(c,shared.czero);
2866     } else {
2867         if (set->type != REDIS_SET) {
2868             addReply(c,shared.wrongtypeerr);
2869             return;
2870         }
2871         if (dictFind(set->ptr,c->argv[2]))
2872             addReply(c,shared.cone);
2873         else
2874             addReply(c,shared.czero);
2875     }
2876 }
2877
2878 static void scardCommand(redisClient *c) {
2879     robj *o;
2880     dict *s;
2881
2882     o = lookupKeyRead(c->db,c->argv[1]);
2883     if (o == NULL) {
2884         addReply(c,shared.czero);
2885         return;
2886     } else {
2887         if (o->type != REDIS_SET) {
2888             addReply(c,shared.wrongtypeerr);
2889         } else {
2890             s = o->ptr;
2891             addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",
2892                 dictSize(s)));
2893         }
2894     }
2895 }
2896
2897 static int qsortCompareSetsByCardinality(const void *s1, const void *s2) {
2898     dict **d1 = (void*) s1, **d2 = (void*) s2;
2899
2900     return dictSize(*d1)-dictSize(*d2);
2901 }
2902
2903 static void sinterGenericCommand(redisClient *c, robj **setskeys, int setsnum, robj *dstkey) {
2904     dict **dv = zmalloc(sizeof(dict*)*setsnum);
2905     dictIterator *di;
2906     dictEntry *de;
2907     robj *lenobj = NULL, *dstset = NULL;
2908     int j, cardinality = 0;
2909
2910     if (!dv) oom("sinterCommand");
2911     for (j = 0; j < setsnum; j++) {
2912         robj *setobj;
2913
2914         setobj = dstkey ?
2915                     lookupKeyWrite(c->db,setskeys[j]) :
2916                     lookupKeyRead(c->db,setskeys[j]);
2917         if (!setobj) {
2918             zfree(dv);
2919             if (dstkey) {
2920                 deleteKey(c->db,dstkey);
2921                 addReply(c,shared.ok);
2922             } else {
2923                 addReply(c,shared.nullmultibulk);
2924             }
2925             return;
2926         }
2927         if (setobj->type != REDIS_SET) {
2928             zfree(dv);
2929             addReply(c,shared.wrongtypeerr);
2930             return;
2931         }
2932         dv[j] = setobj->ptr;
2933     }
2934     /* Sort sets from the smallest to largest, this will improve our
2935      * algorithm's performace */
2936     qsort(dv,setsnum,sizeof(dict*),qsortCompareSetsByCardinality);
2937
2938     /* The first thing we should output is the total number of elements...
2939      * since this is a multi-bulk write, but at this stage we don't know
2940      * the intersection set size, so we use a trick, append an empty object
2941      * to the output list and save the pointer to later modify it with the
2942      * right length */
2943     if (!dstkey) {
2944         lenobj = createObject(REDIS_STRING,NULL);
2945         addReply(c,lenobj);
2946         decrRefCount(lenobj);
2947     } else {
2948         /* If we have a target key where to store the resulting set
2949          * create this key with an empty set inside */
2950         dstset = createSetObject();
2951         deleteKey(c->db,dstkey);
2952         dictAdd(c->db->dict,dstkey,dstset);
2953         incrRefCount(dstkey);
2954     }
2955
2956     /* Iterate all the elements of the first (smallest) set, and test
2957      * the element against all the other sets, if at least one set does
2958      * not include the element it is discarded */
2959     di = dictGetIterator(dv[0]);
2960     if (!di) oom("dictGetIterator");
2961
2962     while((de = dictNext(di)) != NULL) {
2963         robj *ele;
2964
2965         for (j = 1; j < setsnum; j++)
2966             if (dictFind(dv[j],dictGetEntryKey(de)) == NULL) break;
2967         if (j != setsnum)
2968             continue; /* at least one set does not contain the member */
2969         ele = dictGetEntryKey(de);
2970         if (!dstkey) {
2971             addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",sdslen(ele->ptr)));
2972             addReply(c,ele);
2973             addReply(c,shared.crlf);
2974             cardinality++;
2975         } else {
2976             dictAdd(dstset->ptr,ele,NULL);
2977             incrRefCount(ele);
2978         }
2979     }
2980     dictReleaseIterator(di);
2981
2982     if (!dstkey) {
2983         lenobj->ptr = sdscatprintf(sdsempty(),"*%d\r\n",cardinality);
2984     } else {
2985         addReply(c,shared.ok);
2986         server.dirty++;
2987     }
2988     zfree(dv);
2989 }
2990
2991 static void sinterCommand(redisClient *c) {
2992     sinterGenericCommand(c,c->argv+1,c->argc-1,NULL);
2993 }
2994
2995 static void sinterstoreCommand(redisClient *c) {
2996     sinterGenericCommand(c,c->argv+2,c->argc-2,c->argv[1]);
2997 }
2998
2999 static void sunionGenericCommand(redisClient *c, robj **setskeys, int setsnum, robj *dstkey) {
3000     dict **dv = zmalloc(sizeof(dict*)*setsnum);
3001     dictIterator *di;
3002     dictEntry *de;
3003     robj *lenobj = NULL, *dstset = NULL;
3004     int j, cardinality = 0;
3005
3006     if (!dv) oom("sunionCommand");
3007     for (j = 0; j < setsnum; j++) {
3008         robj *setobj;
3009
3010         setobj = dstkey ?
3011                     lookupKeyWrite(c->db,setskeys[j]) :
3012                     lookupKeyRead(c->db,setskeys[j]);
3013         if (!setobj) {
3014             dv[j] = NULL;
3015             continue;
3016         }
3017         if (setobj->type != REDIS_SET) {
3018             zfree(dv);
3019             addReply(c,shared.wrongtypeerr);
3020             return;
3021         }
3022         dv[j] = setobj->ptr;
3023     }
3024
3025     /* We need a temp set object to store our union. If the dstkey
3026      * is not NULL (that is, we are inside an SUNIONSTORE operation) then
3027      * this set object will be the resulting object to set into the target key*/
3028     dstset = createSetObject();
3029
3030     /* The first thing we should output is the total number of elements...
3031      * since this is a multi-bulk write, but at this stage we don't know
3032      * the intersection set size, so we use a trick, append an empty object
3033      * to the output list and save the pointer to later modify it with the
3034      * right length */
3035     if (!dstkey) {
3036         lenobj = createObject(REDIS_STRING,NULL);
3037         addReply(c,lenobj);
3038         decrRefCount(lenobj);
3039     } else {
3040         /* If we have a target key where to store the resulting set
3041          * create this key with an empty set inside */
3042         deleteKey(c->db,dstkey);
3043         dictAdd(c->db->dict,dstkey,dstset);
3044         incrRefCount(dstkey);
3045         server.dirty++;
3046     }
3047
3048     /* Iterate all the elements of all the sets, add every element a single
3049      * time to the result set */
3050     for (j = 0; j < setsnum; j++) {
3051         if (!dv[j]) continue; /* non existing keys are like empty sets */
3052
3053         di = dictGetIterator(dv[j]);
3054         if (!di) oom("dictGetIterator");
3055
3056         while((de = dictNext(di)) != NULL) {
3057             robj *ele;
3058
3059             /* dictAdd will not add the same element multiple times */
3060             ele = dictGetEntryKey(de);
3061             if (dictAdd(dstset->ptr,ele,NULL) == DICT_OK) {
3062                 incrRefCount(ele);
3063                 if (!dstkey) {
3064                     addReplySds(c,sdscatprintf(sdsempty(),
3065                             "$%d\r\n",sdslen(ele->ptr)));
3066                     addReply(c,ele);
3067                     addReply(c,shared.crlf);
3068                     cardinality++;
3069                 }
3070             }
3071         }
3072         dictReleaseIterator(di);
3073     }
3074
3075     if (!dstkey) {
3076         lenobj->ptr = sdscatprintf(sdsempty(),"*%d\r\n",cardinality);
3077         decrRefCount(dstset);
3078     } else {
3079         addReply(c,shared.ok);
3080         server.dirty++;
3081     }
3082     zfree(dv);
3083 }
3084
3085 static void sunionCommand(redisClient *c) {
3086     sunionGenericCommand(c,c->argv+1,c->argc-1,NULL);
3087 }
3088
3089 static void sunionstoreCommand(redisClient *c) {
3090     sunionGenericCommand(c,c->argv+2,c->argc-2,c->argv[1]);
3091 }
3092
3093 static void flushdbCommand(redisClient *c) {
3094     server.dirty += dictSize(c->db->dict);
3095     dictEmpty(c->db->dict);
3096     dictEmpty(c->db->expires);
3097     addReply(c,shared.ok);
3098 }
3099
3100 static void flushallCommand(redisClient *c) {
3101     server.dirty += emptyDb();
3102     addReply(c,shared.ok);
3103     rdbSave(server.dbfilename);
3104     server.dirty++;
3105 }
3106
3107 redisSortOperation *createSortOperation(int type, robj *pattern) {
3108     redisSortOperation *so = zmalloc(sizeof(*so));
3109     if (!so) oom("createSortOperation");
3110     so->type = type;
3111     so->pattern = pattern;
3112     return so;
3113 }
3114
3115 /* Return the value associated to the key with a name obtained
3116  * substituting the first occurence of '*' in 'pattern' with 'subst' */
3117 robj *lookupKeyByPattern(redisDb *db, robj *pattern, robj *subst) {
3118     char *p;
3119     sds spat, ssub;
3120     robj keyobj;
3121     int prefixlen, sublen, postfixlen;
3122     /* Expoit the internal sds representation to create a sds string allocated on the stack in order to make this function faster */
3123     struct {
3124         long len;
3125         long free;
3126         char buf[REDIS_SORTKEY_MAX+1];
3127     } keyname;
3128
3129     spat = pattern->ptr;
3130     ssub = subst->ptr;
3131     if (sdslen(spat)+sdslen(ssub)-1 > REDIS_SORTKEY_MAX) return NULL;
3132     p = strchr(spat,'*');
3133     if (!p) return NULL;
3134
3135     prefixlen = p-spat;
3136     sublen = sdslen(ssub);
3137     postfixlen = sdslen(spat)-(prefixlen+1);
3138     memcpy(keyname.buf,spat,prefixlen);
3139     memcpy(keyname.buf+prefixlen,ssub,sublen);
3140     memcpy(keyname.buf+prefixlen+sublen,p+1,postfixlen);
3141     keyname.buf[prefixlen+sublen+postfixlen] = '\0';
3142     keyname.len = prefixlen+sublen+postfixlen;
3143
3144     keyobj.refcount = 1;
3145     keyobj.type = REDIS_STRING;
3146     keyobj.ptr = ((char*)&keyname)+(sizeof(long)*2);
3147
3148     /* printf("lookup '%s' => %p\n", keyname.buf,de); */
3149     return lookupKeyRead(db,&keyobj);
3150 }
3151
3152 /* sortCompare() is used by qsort in sortCommand(). Given that qsort_r with
3153  * the additional parameter is not standard but a BSD-specific we have to
3154  * pass sorting parameters via the global 'server' structure */
3155 static int sortCompare(const void *s1, const void *s2) {
3156     const redisSortObject *so1 = s1, *so2 = s2;
3157     int cmp;
3158
3159     if (!server.sort_alpha) {
3160         /* Numeric sorting. Here it's trivial as we precomputed scores */
3161         if (so1->u.score > so2->u.score) {
3162             cmp = 1;
3163         } else if (so1->u.score < so2->u.score) {
3164             cmp = -1;
3165         } else {
3166             cmp = 0;
3167         }
3168     } else {
3169         /* Alphanumeric sorting */
3170         if (server.sort_bypattern) {
3171             if (!so1->u.cmpobj || !so2->u.cmpobj) {
3172                 /* At least one compare object is NULL */
3173                 if (so1->u.cmpobj == so2->u.cmpobj)
3174                     cmp = 0;
3175                 else if (so1->u.cmpobj == NULL)
3176                     cmp = -1;
3177                 else
3178                     cmp = 1;
3179             } else {
3180                 /* We have both the objects, use strcoll */
3181                 cmp = strcoll(so1->u.cmpobj->ptr,so2->u.cmpobj->ptr);
3182             }
3183         } else {
3184             /* Compare elements directly */
3185             cmp = strcoll(so1->obj->ptr,so2->obj->ptr);
3186         }
3187     }
3188     return server.sort_desc ? -cmp : cmp;
3189 }
3190
3191 /* The SORT command is the most complex command in Redis. Warning: this code
3192  * is optimized for speed and a bit less for readability */
3193 static void sortCommand(redisClient *c) {
3194     list *operations;
3195     int outputlen = 0;
3196     int desc = 0, alpha = 0;
3197     int limit_start = 0, limit_count = -1, start, end;
3198     int j, dontsort = 0, vectorlen;
3199     int getop = 0; /* GET operation counter */
3200     robj *sortval, *sortby = NULL;
3201     redisSortObject *vector; /* Resulting vector to sort */
3202
3203     /* Lookup the key to sort. It must be of the right types */
3204     sortval = lookupKeyRead(c->db,c->argv[1]);
3205     if (sortval == NULL) {
3206         addReply(c,shared.nokeyerr);
3207         return;
3208     }
3209     if (sortval->type != REDIS_SET && sortval->type != REDIS_LIST) {
3210         addReply(c,shared.wrongtypeerr);
3211         return;
3212     }
3213
3214     /* Create a list of operations to perform for every sorted element.
3215      * Operations can be GET/DEL/INCR/DECR */
3216     operations = listCreate();
3217     listSetFreeMethod(operations,zfree);
3218     j = 2;
3219
3220     /* Now we need to protect sortval incrementing its count, in the future
3221      * SORT may have options able to overwrite/delete keys during the sorting
3222      * and the sorted key itself may get destroied */
3223     incrRefCount(sortval);
3224
3225     /* The SORT command has an SQL-alike syntax, parse it */
3226     while(j < c->argc) {
3227         int leftargs = c->argc-j-1;
3228         if (!strcasecmp(c->argv[j]->ptr,"asc")) {
3229             desc = 0;
3230         } else if (!strcasecmp(c->argv[j]->ptr,"desc")) {
3231             desc = 1;
3232         } else if (!strcasecmp(c->argv[j]->ptr,"alpha")) {
3233             alpha = 1;
3234         } else if (!strcasecmp(c->argv[j]->ptr,"limit") && leftargs >= 2) {
3235             limit_start = atoi(c->argv[j+1]->ptr);
3236             limit_count = atoi(c->argv[j+2]->ptr);
3237             j+=2;
3238         } else if (!strcasecmp(c->argv[j]->ptr,"by") && leftargs >= 1) {
3239             sortby = c->argv[j+1];
3240             /* If the BY pattern does not contain '*', i.e. it is constant,
3241              * we don't need to sort nor to lookup the weight keys. */
3242             if (strchr(c->argv[j+1]->ptr,'*') == NULL) dontsort = 1;
3243             j++;
3244         } else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
3245             listAddNodeTail(operations,createSortOperation(
3246                 REDIS_SORT_GET,c->argv[j+1]));
3247             getop++;
3248             j++;
3249         } else if (!strcasecmp(c->argv[j]->ptr,"del") && leftargs >= 1) {
3250             listAddNodeTail(operations,createSortOperation(
3251                 REDIS_SORT_DEL,c->argv[j+1]));
3252             j++;
3253         } else if (!strcasecmp(c->argv[j]->ptr,"incr") && leftargs >= 1) {
3254             listAddNodeTail(operations,createSortOperation(
3255                 REDIS_SORT_INCR,c->argv[j+1]));
3256             j++;
3257         } else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
3258             listAddNodeTail(operations,createSortOperation(
3259                 REDIS_SORT_DECR,c->argv[j+1]));
3260             j++;
3261         } else {
3262             decrRefCount(sortval);
3263             listRelease(operations);
3264             addReply(c,shared.syntaxerr);
3265             return;
3266         }
3267         j++;
3268     }
3269
3270     /* Load the sorting vector with all the objects to sort */
3271     vectorlen = (sortval->type == REDIS_LIST) ?
3272         listLength((list*)sortval->ptr) :
3273         dictSize((dict*)sortval->ptr);
3274     vector = zmalloc(sizeof(redisSortObject)*vectorlen);
3275     if (!vector) oom("allocating objects vector for SORT");
3276     j = 0;
3277     if (sortval->type == REDIS_LIST) {
3278         list *list = sortval->ptr;
3279         listNode *ln;
3280
3281         listRewind(list);
3282         while((ln = listYield(list))) {
3283             robj *ele = ln->value;
3284             vector[j].obj = ele;
3285             vector[j].u.score = 0;
3286             vector[j].u.cmpobj = NULL;
3287             j++;
3288         }
3289     } else {
3290         dict *set = sortval->ptr;
3291         dictIterator *di;
3292         dictEntry *setele;
3293
3294         di = dictGetIterator(set);
3295         if (!di) oom("dictGetIterator");
3296         while((setele = dictNext(di)) != NULL) {
3297             vector[j].obj = dictGetEntryKey(setele);
3298             vector[j].u.score = 0;
3299             vector[j].u.cmpobj = NULL;
3300             j++;
3301         }
3302         dictReleaseIterator(di);
3303     }
3304     assert(j == vectorlen);
3305
3306     /* Now it's time to load the right scores in the sorting vector */
3307     if (dontsort == 0) {
3308         for (j = 0; j < vectorlen; j++) {
3309             if (sortby) {
3310                 robj *byval;
3311
3312                 byval = lookupKeyByPattern(c->db,sortby,vector[j].obj);
3313                 if (!byval || byval->type != REDIS_STRING) continue;
3314                 if (alpha) {
3315                     vector[j].u.cmpobj = byval;
3316                     incrRefCount(byval);
3317                 } else {
3318                     vector[j].u.score = strtod(byval->ptr,NULL);
3319                 }
3320             } else {
3321                 if (!alpha) vector[j].u.score = strtod(vector[j].obj->ptr,NULL);
3322             }
3323         }
3324     }
3325
3326     /* We are ready to sort the vector... perform a bit of sanity check
3327      * on the LIMIT option too. We'll use a partial version of quicksort. */
3328     start = (limit_start < 0) ? 0 : limit_start;
3329     end = (limit_count < 0) ? vectorlen-1 : start+limit_count-1;
3330     if (start >= vectorlen) {
3331         start = vectorlen-1;
3332         end = vectorlen-2;
3333     }
3334     if (end >= vectorlen) end = vectorlen-1;
3335
3336     if (dontsort == 0) {
3337         server.sort_desc = desc;
3338         server.sort_alpha = alpha;
3339         server.sort_bypattern = sortby ? 1 : 0;
3340         qsort(vector,vectorlen,sizeof(redisSortObject),sortCompare);
3341     }
3342
3343     /* Send command output to the output buffer, performing the specified
3344      * GET/DEL/INCR/DECR operations if any. */
3345     outputlen = getop ? getop*(end-start+1) : end-start+1;
3346     addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",outputlen));
3347     for (j = start; j <= end; j++) {
3348         listNode *ln;
3349         if (!getop) {
3350             addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",
3351                 sdslen(vector[j].obj->ptr)));
3352             addReply(c,vector[j].obj);
3353             addReply(c,shared.crlf);
3354         }
3355         listRewind(operations);
3356         while((ln = listYield(operations))) {
3357             redisSortOperation *sop = ln->value;
3358             robj *val = lookupKeyByPattern(c->db,sop->pattern,
3359                 vector[j].obj);
3360
3361             if (sop->type == REDIS_SORT_GET) {
3362                 if (!val || val->type != REDIS_STRING) {
3363                     addReply(c,shared.nullbulk);
3364                 } else {
3365                     addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",
3366                         sdslen(val->ptr)));
3367                     addReply(c,val);
3368                     addReply(c,shared.crlf);
3369                 }
3370             } else if (sop->type == REDIS_SORT_DEL) {
3371                 /* TODO */
3372             }
3373         }
3374     }
3375
3376     /* Cleanup */
3377     decrRefCount(sortval);
3378     listRelease(operations);
3379     for (j = 0; j < vectorlen; j++) {
3380         if (sortby && alpha && vector[j].u.cmpobj)
3381             decrRefCount(vector[j].u.cmpobj);
3382     }
3383     zfree(vector);
3384 }
3385
3386 static void infoCommand(redisClient *c) {
3387     sds info;
3388     time_t uptime = time(NULL)-server.stat_starttime;
3389
3390     info = sdscatprintf(sdsempty(),
3391         "redis_version:%s\r\n"
3392         "connected_clients:%d\r\n"
3393         "connected_slaves:%d\r\n"
3394         "used_memory:%zu\r\n"
3395         "changes_since_last_save:%lld\r\n"
3396         "bgsave_in_progress:%d\r\n"
3397         "last_save_time:%d\r\n"
3398         "total_connections_received:%lld\r\n"
3399         "total_commands_processed:%lld\r\n"
3400         "uptime_in_seconds:%d\r\n"
3401         "uptime_in_days:%d\r\n"
3402         ,REDIS_VERSION,
3403         listLength(server.clients)-listLength(server.slaves),
3404         listLength(server.slaves),
3405         server.usedmemory,
3406         server.dirty,
3407         server.bgsaveinprogress,
3408         server.lastsave,
3409         server.stat_numconnections,
3410         server.stat_numcommands,
3411         uptime,
3412         uptime/(3600*24)
3413     );
3414     addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",sdslen(info)));
3415     addReplySds(c,info);
3416     addReply(c,shared.crlf);
3417 }
3418
3419 static void monitorCommand(redisClient *c) {
3420     /* ignore MONITOR if aleady slave or in monitor mode */
3421     if (c->flags & REDIS_SLAVE) return;
3422
3423     c->flags |= (REDIS_SLAVE|REDIS_MONITOR);
3424     c->slaveseldb = 0;
3425     if (!listAddNodeTail(server.monitors,c)) oom("listAddNodeTail");
3426     addReply(c,shared.ok);
3427 }
3428
3429 /* ================================= Expire ================================= */
3430 static int removeExpire(redisDb *db, robj *key) {
3431     if (dictDelete(db->expires,key) == DICT_OK) {
3432         return 1;
3433     } else {
3434         return 0;
3435     }
3436 }
3437
3438 static int setExpire(redisDb *db, robj *key, time_t when) {
3439     if (dictAdd(db->expires,key,(void*)when) == DICT_ERR) {
3440         return 0;
3441     } else {
3442         incrRefCount(key);
3443         return 1;
3444     }
3445 }
3446
3447 /* Return the expire time of the specified key, or -1 if no expire
3448  * is associated with this key (i.e. the key is non volatile) */
3449 static time_t getExpire(redisDb *db, robj *key) {
3450     dictEntry *de;
3451
3452     /* No expire? return ASAP */
3453     if (dictSize(db->expires) == 0 ||
3454        (de = dictFind(db->expires,key)) == NULL) return -1;
3455
3456     return (time_t) dictGetEntryVal(de);
3457 }
3458
3459 static int expireIfNeeded(redisDb *db, robj *key) {
3460     time_t when;
3461     dictEntry *de;
3462
3463     /* No expire? return ASAP */
3464     if (dictSize(db->expires) == 0 ||
3465        (de = dictFind(db->expires,key)) == NULL) return 0;
3466
3467     /* Lookup the expire */
3468     when = (time_t) dictGetEntryVal(de);
3469     if (time(NULL) <= when) return 0;
3470
3471     /* Delete the key */
3472     dictDelete(db->expires,key);
3473     return dictDelete(db->dict,key) == DICT_OK;
3474 }
3475
3476 static int deleteIfVolatile(redisDb *db, robj *key) {
3477     dictEntry *de;
3478
3479     /* No expire? return ASAP */
3480     if (dictSize(db->expires) == 0 ||
3481        (de = dictFind(db->expires,key)) == NULL) return 0;
3482
3483     /* Delete the key */
3484     server.dirty++;
3485     dictDelete(db->expires,key);
3486     return dictDelete(db->dict,key) == DICT_OK;
3487 }
3488
3489 static void expireCommand(redisClient *c) {
3490     dictEntry *de;
3491     int seconds = atoi(c->argv[2]->ptr);
3492
3493     de = dictFind(c->db->dict,c->argv[1]);
3494     if (de == NULL) {
3495         addReply(c,shared.czero);
3496         return;
3497     }
3498     if (seconds <= 0) {
3499         addReply(c, shared.czero);
3500         return;
3501     } else {
3502         time_t when = time(NULL)+seconds;
3503         if (setExpire(c->db,c->argv[1],when))
3504             addReply(c,shared.cone);
3505         else
3506             addReply(c,shared.czero);
3507         return;
3508     }
3509 }
3510
3511 /* =============================== Replication  ============================= */
3512
3513 static int syncWrite(int fd, char *ptr, ssize_t size, int timeout) {
3514     ssize_t nwritten, ret = size;
3515     time_t start = time(NULL);
3516
3517     timeout++;
3518     while(size) {
3519         if (aeWait(fd,AE_WRITABLE,1000) & AE_WRITABLE) {
3520             nwritten = write(fd,ptr,size);
3521             if (nwritten == -1) return -1;
3522             ptr += nwritten;
3523             size -= nwritten;
3524         }
3525         if ((time(NULL)-start) > timeout) {
3526             errno = ETIMEDOUT;
3527             return -1;
3528         }
3529     }
3530     return ret;
3531 }
3532
3533 static int syncRead(int fd, char *ptr, ssize_t size, int timeout) {
3534     ssize_t nread, totread = 0;
3535     time_t start = time(NULL);
3536
3537     timeout++;
3538     while(size) {
3539         if (aeWait(fd,AE_READABLE,1000) & AE_READABLE) {
3540             nread = read(fd,ptr,size);
3541             if (nread == -1) return -1;
3542             ptr += nread;
3543             size -= nread;
3544             totread += nread;
3545         }
3546         if ((time(NULL)-start) > timeout) {
3547             errno = ETIMEDOUT;
3548             return -1;
3549         }
3550     }
3551     return totread;
3552 }
3553
3554 static int syncReadLine(int fd, char *ptr, ssize_t size, int timeout) {
3555     ssize_t nread = 0;
3556
3557     size--;
3558     while(size) {
3559         char c;
3560
3561         if (syncRead(fd,&c,1,timeout) == -1) return -1;
3562         if (c == '\n') {
3563             *ptr = '\0';
3564             if (nread && *(ptr-1) == '\r') *(ptr-1) = '\0';
3565             return nread;
3566         } else {
3567             *ptr++ = c;
3568             *ptr = '\0';
3569             nread++;
3570         }
3571     }
3572     return nread;
3573 }
3574
3575 static void syncCommand(redisClient *c) {
3576     /* ignore SYNC if aleady slave or in monitor mode */
3577     if (c->flags & REDIS_SLAVE) return;
3578
3579     /* SYNC can't be issued when the server has pending data to send to
3580      * the client about already issued commands. We need a fresh reply
3581      * buffer registering the differences between the BGSAVE and the current
3582      * dataset, so that we can copy to other slaves if needed. */
3583     if (listLength(c->reply) != 0) {
3584         addReplySds(c,sdsnew("-ERR SYNC is invalid with pending input\r\n"));
3585         return;
3586     }
3587
3588     redisLog(REDIS_NOTICE,"Slave ask for synchronization");
3589     /* Here we need to check if there is a background saving operation
3590      * in progress, or if it is required to start one */
3591     if (server.bgsaveinprogress) {
3592         /* Ok a background save is in progress. Let's check if it is a good
3593          * one for replication, i.e. if there is another slave that is
3594          * registering differences since the server forked to save */
3595         redisClient *slave;
3596         listNode *ln;
3597
3598         listRewind(server.slaves);
3599         while((ln = listYield(server.slaves))) {
3600             slave = ln->value;
3601             if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_END) break;
3602         }
3603         if (ln) {
3604             /* Perfect, the server is already registering differences for
3605              * another slave. Set the right state, and copy the buffer. */
3606             listRelease(c->reply);
3607             c->reply = listDup(slave->reply);
3608             if (!c->reply) oom("listDup copying slave reply list");
3609             c->replstate = REDIS_REPL_WAIT_BGSAVE_END;
3610             redisLog(REDIS_NOTICE,"Waiting for end of BGSAVE for SYNC");
3611         } else {
3612             /* No way, we need to wait for the next BGSAVE in order to
3613              * register differences */
3614             c->replstate = REDIS_REPL_WAIT_BGSAVE_START;
3615             redisLog(REDIS_NOTICE,"Waiting for next BGSAVE for SYNC");
3616         }
3617     } else {
3618         /* Ok we don't have a BGSAVE in progress, let's start one */
3619         redisLog(REDIS_NOTICE,"Starting BGSAVE for SYNC");
3620         if (rdbSaveBackground(server.dbfilename) != REDIS_OK) {
3621             redisLog(REDIS_NOTICE,"Replication failed, can't BGSAVE");
3622             addReplySds(c,sdsnew("-ERR Unalbe to perform background save\r\n"));
3623             return;
3624         }
3625         c->replstate = REDIS_REPL_WAIT_BGSAVE_END;
3626     }
3627     c->repldbfd = -1;
3628     c->flags |= REDIS_SLAVE;
3629     c->slaveseldb = 0;
3630     if (!listAddNodeTail(server.slaves,c)) oom("listAddNodeTail");
3631     return;
3632 }
3633
3634 static void sendBulkToSlave(aeEventLoop *el, int fd, void *privdata, int mask) {
3635     redisClient *slave = privdata;
3636     REDIS_NOTUSED(el);
3637     REDIS_NOTUSED(mask);
3638     char buf[REDIS_IOBUF_LEN];
3639     ssize_t nwritten, buflen;
3640
3641     if (slave->repldboff == 0) {
3642         /* Write the bulk write count before to transfer the DB. In theory here
3643          * we don't know how much room there is in the output buffer of the
3644          * socket, but in pratice SO_SNDLOWAT (the minimum count for output
3645          * operations) will never be smaller than the few bytes we need. */
3646         sds bulkcount;
3647
3648         bulkcount = sdscatprintf(sdsempty(),"$%lld\r\n",(unsigned long long)
3649             slave->repldbsize);
3650         if (write(fd,bulkcount,sdslen(bulkcount)) != (signed)sdslen(bulkcount))
3651         {
3652             sdsfree(bulkcount);
3653             freeClient(slave);
3654             return;
3655         }
3656         sdsfree(bulkcount);
3657     }
3658     lseek(slave->repldbfd,slave->repldboff,SEEK_SET);
3659     buflen = read(slave->repldbfd,buf,REDIS_IOBUF_LEN);
3660     if (buflen <= 0) {
3661         redisLog(REDIS_WARNING,"Read error sending DB to slave: %s",
3662             (buflen == 0) ? "premature EOF" : strerror(errno));
3663         freeClient(slave);
3664         return;
3665     }
3666     if ((nwritten = write(fd,buf,buflen)) == -1) {
3667         redisLog(REDIS_DEBUG,"Write error sending DB to slave: %s",
3668             strerror(errno));
3669         freeClient(slave);
3670         return;
3671     }
3672     slave->repldboff += nwritten;
3673     if (slave->repldboff == slave->repldbsize) {
3674         close(slave->repldbfd);
3675         slave->repldbfd = -1;
3676         aeDeleteFileEvent(server.el,slave->fd,AE_WRITABLE);
3677         slave->replstate = REDIS_REPL_ONLINE;
3678         if (aeCreateFileEvent(server.el, slave->fd, AE_WRITABLE,
3679             sendReplyToClient, slave, NULL) == AE_ERR) {
3680             freeClient(slave);
3681             return;
3682         }
3683         addReplySds(slave,sdsempty());
3684         redisLog(REDIS_NOTICE,"Synchronization with slave succeeded");
3685     }
3686 }
3687
3688 static void updateSalvesWaitingBgsave(int bgsaveerr) {
3689     listNode *ln;
3690     int startbgsave = 0;
3691
3692     listRewind(server.slaves);
3693     while((ln = listYield(server.slaves))) {
3694         redisClient *slave = ln->value;
3695
3696         if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START) {
3697             startbgsave = 1;
3698             slave->replstate = REDIS_REPL_WAIT_BGSAVE_END;
3699         } else if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_END) {
3700             struct stat buf;
3701
3702             if (bgsaveerr != REDIS_OK) {
3703                 freeClient(slave);
3704                 redisLog(REDIS_WARNING,"SYNC failed. BGSAVE child returned an error");
3705                 continue;
3706             }
3707             if ((slave->repldbfd = open(server.dbfilename,O_RDONLY)) == -1 ||
3708                 fstat(slave->repldbfd,&buf) == -1) {
3709                 freeClient(slave);
3710                 redisLog(REDIS_WARNING,"SYNC failed. Can't open/stat DB after BGSAVE: %s", strerror(errno));
3711                 continue;
3712             }
3713             slave->repldboff = 0;
3714             slave->repldbsize = buf.st_size;
3715             slave->replstate = REDIS_REPL_SEND_BULK;
3716             aeDeleteFileEvent(server.el,slave->fd,AE_WRITABLE);
3717             if (aeCreateFileEvent(server.el, slave->fd, AE_WRITABLE, sendBulkToSlave, slave, NULL) == AE_ERR) {
3718                 freeClient(slave);
3719                 continue;
3720             }
3721         }
3722     }
3723     if (startbgsave) {
3724         if (rdbSaveBackground(server.dbfilename) != REDIS_OK) {
3725             listRewind(server.slaves);
3726             redisLog(REDIS_WARNING,"SYNC failed. BGSAVE failed");
3727             while((ln = listYield(server.slaves))) {
3728                 redisClient *slave = ln->value;
3729
3730                 if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START)
3731                     freeClient(slave);
3732             }
3733         }
3734     }
3735 }
3736
3737 static int syncWithMaster(void) {
3738     char buf[1024], tmpfile[256];
3739     int dumpsize;
3740     int fd = anetTcpConnect(NULL,server.masterhost,server.masterport);
3741     int dfd;
3742
3743     if (fd == -1) {
3744         redisLog(REDIS_WARNING,"Unable to connect to MASTER: %s",
3745             strerror(errno));
3746         return REDIS_ERR;
3747     }
3748     /* Issue the SYNC command */
3749     if (syncWrite(fd,"SYNC \r\n",7,5) == -1) {
3750         close(fd);
3751         redisLog(REDIS_WARNING,"I/O error writing to MASTER: %s",
3752             strerror(errno));
3753         return REDIS_ERR;
3754     }
3755     /* Read the bulk write count */
3756     if (syncReadLine(fd,buf,1024,5) == -1) {
3757         close(fd);
3758         redisLog(REDIS_WARNING,"I/O error reading bulk count from MASTER: %s",
3759             strerror(errno));
3760         return REDIS_ERR;
3761     }
3762     dumpsize = atoi(buf+1);
3763     redisLog(REDIS_NOTICE,"Receiving %d bytes data dump from MASTER",dumpsize);
3764     /* Read the bulk write data on a temp file */
3765     snprintf(tmpfile,256,"temp-%d.%ld.rdb",(int)time(NULL),(long int)random());
3766     dfd = open(tmpfile,O_CREAT|O_WRONLY,0644);
3767     if (dfd == -1) {
3768         close(fd);
3769         redisLog(REDIS_WARNING,"Opening the temp file needed for MASTER <-> SLAVE synchronization: %s",strerror(errno));
3770         return REDIS_ERR;
3771     }
3772     while(dumpsize) {
3773         int nread, nwritten;
3774
3775         nread = read(fd,buf,(dumpsize < 1024)?dumpsize:1024);
3776         if (nread == -1) {
3777             redisLog(REDIS_WARNING,"I/O error trying to sync with MASTER: %s",
3778                 strerror(errno));
3779             close(fd);
3780             close(dfd);
3781             return REDIS_ERR;
3782         }
3783         nwritten = write(dfd,buf,nread);
3784         if (nwritten == -1) {
3785             redisLog(REDIS_WARNING,"Write error writing to the DB dump file needed for MASTER <-> SLAVE synchrnonization: %s", strerror(errno));
3786             close(fd);
3787             close(dfd);
3788             return REDIS_ERR;
3789         }
3790         dumpsize -= nread;
3791     }
3792     close(dfd);
3793     if (rename(tmpfile,server.dbfilename) == -1) {
3794         redisLog(REDIS_WARNING,"Failed trying to rename the temp DB into dump.rdb in MASTER <-> SLAVE synchronization: %s", strerror(errno));
3795         unlink(tmpfile);
3796         close(fd);
3797         return REDIS_ERR;
3798     }
3799     emptyDb();
3800     if (rdbLoad(server.dbfilename) != REDIS_OK) {
3801         redisLog(REDIS_WARNING,"Failed trying to load the MASTER synchronization DB from disk");
3802         close(fd);
3803         return REDIS_ERR;
3804     }
3805     server.master = createClient(fd);
3806     server.master->flags |= REDIS_MASTER;
3807     server.replstate = REDIS_REPL_CONNECTED;
3808     return REDIS_OK;
3809 }
3810
3811 /* =================================== Main! ================================ */
3812
3813 static void daemonize(void) {
3814     int fd;
3815     FILE *fp;
3816
3817     if (fork() != 0) exit(0); /* parent exits */
3818     setsid(); /* create a new session */
3819
3820     /* Every output goes to /dev/null. If Redis is daemonized but
3821      * the 'logfile' is set to 'stdout' in the configuration file
3822      * it will not log at all. */
3823     if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
3824         dup2(fd, STDIN_FILENO);
3825         dup2(fd, STDOUT_FILENO);
3826         dup2(fd, STDERR_FILENO);
3827         if (fd > STDERR_FILENO) close(fd);
3828     }
3829     /* Try to write the pid file */
3830     fp = fopen(server.pidfile,"w");
3831     if (fp) {
3832         fprintf(fp,"%d\n",getpid());
3833         fclose(fp);
3834     }
3835 }
3836
3837 int main(int argc, char **argv) {
3838     initServerConfig();
3839     if (argc == 2) {
3840         ResetServerSaveParams();
3841         loadServerConfig(argv[1]);
3842     } else if (argc > 2) {
3843         fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
3844         exit(1);
3845     }
3846     initServer();
3847     if (server.daemonize) daemonize();
3848     redisLog(REDIS_NOTICE,"Server started, Redis version " REDIS_VERSION);
3849     if (rdbLoad(server.dbfilename) == REDIS_OK)
3850         redisLog(REDIS_NOTICE,"DB loaded from disk");
3851     if (aeCreateFileEvent(server.el, server.fd, AE_READABLE,
3852         acceptHandler, NULL, NULL) == AE_ERR) oom("creating file event");
3853     redisLog(REDIS_NOTICE,"The server is now ready to accept connections on port %d", server.port);
3854     aeMain(server.el);
3855     aeDeleteEventLoop(server.el);
3856     return 0;
3857 }