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 "0.100"
  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"    /* LZF compression library */
  60 #include "pqsort.h" /* Partial qsort for SORT+LIMIT */
  61
  62 /* Error codes */
  63 #define REDIS_OK                0
  64 #define REDIS_ERR               -1
  65
  66 /* Static server configuration */
  67 #define REDIS_SERVERPORT        6379    /* TCP port */
  68 #define REDIS_MAXIDLETIME       (60*5)  /* default client timeout */
  69 #define REDIS_IOBUF_LEN         1024
  70 #define REDIS_LOADBUF_LEN       1024
  71 #define REDIS_STATIC_ARGS       4
  72 #define REDIS_DEFAULT_DBNUM     16
  73 #define REDIS_CONFIGLINE_MAX    1024
  74 #define REDIS_OBJFREELIST_MAX   1000000 /* Max number of objects to cache */
  75 #define REDIS_MAX_SYNC_TIME     60      /* Slave can't take more to sync */
  76 #define REDIS_EXPIRELOOKUPS_PER_CRON    100 /* try to expire 100 keys/second */
  77
  78 /* Hash table parameters */
  79 #define REDIS_HT_MINFILL        10      /* Minimal hash table fill 10% */
  80 #define REDIS_HT_MINSLOTS       16384   /* Never resize the HT under this */
  81
  82 /* Command flags */
  83 #define REDIS_CMD_BULK          1
  84 #define REDIS_CMD_INLINE        2
  85
  86 /* Object types */
  87 #define REDIS_STRING 0
  88 #define REDIS_LIST 1
  89 #define REDIS_SET 2
  90 #define REDIS_HASH 3
  91
  92 /* Object types only used for dumping to disk */
  93 #define REDIS_EXPIRETIME 253
  94 #define REDIS_SELECTDB 254
  95 #define REDIS_EOF 255
  96
  97 /* Defines related to the dump file format. To store 32 bits lengths for short
  98  * keys requires a lot of space, so we check the most significant 2 bits of
  99  * the first byte to interpreter the length:
 100  *
 101  * 00|000000 => if the two MSB are 00 the len is the 6 bits of this byte
 102  * 01|000000 00000000 =>  01, the len is 14 byes, 6 bits + 8 bits of next byte
 103  * 10|000000 [32 bit integer] => if it's 01, a full 32 bit len will follow
 104  * 11|000000 this means: specially encoded object will follow. The six bits
 105  *           number specify the kind of object that follows.
 106  *           See the REDIS_RDB_ENC_* defines.
 107  *
 108  * Lenghts up to 63 are stored using a single byte, most DB keys, and may
 109  * values, will fit inside. */
 110 #define REDIS_RDB_6BITLEN 0
 111 #define REDIS_RDB_14BITLEN 1
 112 #define REDIS_RDB_32BITLEN 2
 113 #define REDIS_RDB_ENCVAL 3
 114 #define REDIS_RDB_LENERR UINT_MAX
 115
 116 /* When a length of a string object stored on disk has the first two bits
 117  * set, the remaining two bits specify a special encoding for the object
 118  * accordingly to the following defines: */
 119 #define REDIS_RDB_ENC_INT8 0        /* 8 bit signed integer */
 120 #define REDIS_RDB_ENC_INT16 1       /* 16 bit signed integer */
 121 #define REDIS_RDB_ENC_INT32 2       /* 32 bit signed integer */
 122 #define REDIS_RDB_ENC_LZF 3         /* string compressed with FASTLZ */
 123
 124 /* Client flags */
 125 #define REDIS_CLOSE 1       /* This client connection should be closed ASAP */
 126 #define REDIS_SLAVE 2       /* This client is a slave server */
 127 #define REDIS_MASTER 4      /* This client is a master server */
 128 #define REDIS_MONITOR 8      /* This client is a slave monitor, see MONITOR */
 129
 130 /* Slave replication state - slave side */
 131 #define REDIS_REPL_NONE 0   /* No active replication */
 132 #define REDIS_REPL_CONNECT 1    /* Must connect to master */
 133 #define REDIS_REPL_CONNECTED 2  /* Connected to master */
 134
 135 /* Slave replication state - from the point of view of master
 136  * Note that in SEND_BULK and ONLINE state the slave receives new updates
 137  * in its output queue. In the WAIT_BGSAVE state instead the server is waiting
 138  * to start the next background saving in order to send updates to it. */
 139 #define REDIS_REPL_WAIT_BGSAVE_START 3 /* master waits bgsave to start feeding it */
 140 #define REDIS_REPL_WAIT_BGSAVE_END 4 /* master waits bgsave to start bulk DB transmission */
 141 #define REDIS_REPL_SEND_BULK 5 /* master is sending the bulk DB */
 142 #define REDIS_REPL_ONLINE 6 /* bulk DB already transmitted, receive updates */
 143
 144 /* List related stuff */
 145 #define REDIS_HEAD 0
 146 #define REDIS_TAIL 1
 147
 148 /* Sort operations */
 149 #define REDIS_SORT_GET 0
 150 #define REDIS_SORT_DEL 1
 151 #define REDIS_SORT_INCR 2
 152 #define REDIS_SORT_DECR 3
 153 #define REDIS_SORT_ASC 4
 154 #define REDIS_SORT_DESC 5
 155 #define REDIS_SORTKEY_MAX 1024
 156
 157 /* Log levels */
 158 #define REDIS_DEBUG 0
 159 #define REDIS_NOTICE 1
 160 #define REDIS_WARNING 2
 161
 162 /* Anti-warning macro... */
 163 #define REDIS_NOTUSED(V) ((void) V)
 164
 165 /*================================= Data types ============================== */
 166
 167 /* A redis object, that is a type able to hold a string / list / set */
 168 typedef struct redisObject {
 169     void *ptr;
 170     int type;
 171     int refcount;
 172 } robj;
 173
 174 typedef struct redisDb {
 175     dict *dict;
 176     dict *expires;
 177     int id;
 178 } redisDb;
 179
 180 /* With multiplexing we need to take per-clinet state.
 181  * Clients are taken in a liked list. */
 182 typedef struct redisClient {
 183     int fd;
 184     redisDb *db;
 185     int dictid;
 186     sds querybuf;
 187     robj **argv;
 188     int argc;
 189     int bulklen;            /* bulk read len. -1 if not in bulk read mode */
 190     list *reply;
 191     int sentlen;
 192     time_t lastinteraction; /* time of the last interaction, used for timeout */
 193     int flags;              /* REDIS_CLOSE | REDIS_SLAVE | REDIS_MONITOR */
 194     int slaveseldb;         /* slave selected db, if this client is a slave */
 195     int authenticated;      /* when requirepass is non-NULL */
 196     int replstate;          /* replication state if this is a slave */
 197     int repldbfd;           /* replication DB file descriptor */
 198     long repldboff;          /* replication DB file offset */
 199     off_t repldbsize;       /* replication DB file size */
 200 } redisClient;
 201
 202 struct saveparam {
 203     time_t seconds;
 204     int changes;
 205 };
 206
 207 /* Global server state structure */
 208 struct redisServer {
 209     int port;
 210     int fd;
 211     redisDb *db;
 212     dict *sharingpool;
 213     unsigned int sharingpoolsize;
 214     long long dirty;            /* changes to DB from the last save */
 215     list *clients;
 216     list *slaves, *monitors;
 217     char neterr[ANET_ERR_LEN];
 218     aeEventLoop *el;
 219     int cronloops;              /* number of times the cron function run */
 220     list *objfreelist;          /* A list of freed objects to avoid malloc() */
 221     time_t lastsave;            /* Unix time of last save succeeede */
 222     size_t usedmemory;             /* Used memory in megabytes */
 223     /* Fields used only for stats */
 224     time_t stat_starttime;         /* server start time */
 225     long long stat_numcommands;    /* number of processed commands */
 226     long long stat_numconnections; /* number of connections received */
 227     /* Configuration */
 228     int verbosity;
 229     int glueoutputbuf;
 230     int maxidletime;
 231     int dbnum;
 232     int daemonize;
 233     char *pidfile;
 234     int bgsaveinprogress;
 235     struct saveparam *saveparams;
 236     int saveparamslen;
 237     char *logfile;
 238     char *bindaddr;
 239     char *dbfilename;
 240     char *requirepass;
 241     int shareobjects;
 242     /* Replication related */
 243     int isslave;
 244     char *masterhost;
 245     int masterport;
 246     redisClient *master;    /* client that is master for this slave */
 247     int replstate;
 248     /* Sort parameters - qsort_r() is only available under BSD so we
 249      * have to take this state global, in order to pass it to sortCompare() */
 250     int sort_desc;
 251     int sort_alpha;
 252     int sort_bypattern;
 253 };
 254
 255 typedef void redisCommandProc(redisClient *c);
 256 struct redisCommand {
 257     char *name;
 258     redisCommandProc *proc;
 259     int arity;
 260     int flags;
 261 };
 262
 263 typedef struct _redisSortObject {
 264     robj *obj;
 265     union {
 266         double score;
 267         robj *cmpobj;
 268     } u;
 269 } redisSortObject;
 270
 271 typedef struct _redisSortOperation {
 272     int type;
 273     robj *pattern;
 274 } redisSortOperation;
 275
 276 struct sharedObjectsStruct {
 277     robj *crlf, *ok, *err, *emptybulk, *czero, *cone, *pong, *space,
 278     *colon, *nullbulk, *nullmultibulk,
 279     *emptymultibulk, *wrongtypeerr, *nokeyerr, *syntaxerr, *sameobjecterr,
 280     *outofrangeerr, *plus,
 281     *select0, *select1, *select2, *select3, *select4,
 282     *select5, *select6, *select7, *select8, *select9;
 283 } shared;
 284
 285 /*================================ Prototypes =============================== */
 286
 287 static void freeStringObject(robj *o);
 288 static void freeListObject(robj *o);
 289 static void freeSetObject(robj *o);
 290 static void decrRefCount(void *o);
 291 static robj *createObject(int type, void *ptr);
 292 static void freeClient(redisClient *c);
 293 static int rdbLoad(char *filename);
 294 static void addReply(redisClient *c, robj *obj);
 295 static void addReplySds(redisClient *c, sds s);
 296 static void incrRefCount(robj *o);
 297 static int rdbSaveBackground(char *filename);
 298 static robj *createStringObject(char *ptr, size_t len);
 299 static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc);
 300 static int syncWithMaster(void);
 301 static robj *tryObjectSharing(robj *o);
 302 static int removeExpire(redisDb *db, robj *key);
 303 static int expireIfNeeded(redisDb *db, robj *key);
 304 static int deleteIfVolatile(redisDb *db, robj *key);
 305 static int deleteKey(redisDb *db, robj *key);
 306 static time_t getExpire(redisDb *db, robj *key);
 307 static int setExpire(redisDb *db, robj *key, time_t when);
 308 static void updateSalvesWaitingBgsave(int bgsaveerr);
 309
 310 static void authCommand(redisClient *c);
 311 static void pingCommand(redisClient *c);
 312 static void echoCommand(redisClient *c);
 313 static void setCommand(redisClient *c);
 314 static void setnxCommand(redisClient *c);
 315 static void getCommand(redisClient *c);
 316 static void delCommand(redisClient *c);
 317 static void existsCommand(redisClient *c);
 318 static void incrCommand(redisClient *c);
 319 static void decrCommand(redisClient *c);
 320 static void incrbyCommand(redisClient *c);
 321 static void decrbyCommand(redisClient *c);
 322 static void selectCommand(redisClient *c);
 323 static void randomkeyCommand(redisClient *c);
 324 static void keysCommand(redisClient *c);
 325 static void dbsizeCommand(redisClient *c);
 326 static void lastsaveCommand(redisClient *c);
 327 static void saveCommand(redisClient *c);
 328 static void bgsaveCommand(redisClient *c);
 329 static void shutdownCommand(redisClient *c);
 330 static void moveCommand(redisClient *c);
 331 static void renameCommand(redisClient *c);
 332 static void renamenxCommand(redisClient *c);
 333 static void lpushCommand(redisClient *c);
 334 static void rpushCommand(redisClient *c);
 335 static void lpopCommand(redisClient *c);
 336 static void rpopCommand(redisClient *c);
 337 static void llenCommand(redisClient *c);
 338 static void lindexCommand(redisClient *c);
 339 static void lrangeCommand(redisClient *c);
 340 static void ltrimCommand(redisClient *c);
 341 static void typeCommand(redisClient *c);
 342 static void lsetCommand(redisClient *c);
 343 static void saddCommand(redisClient *c);
 344 static void sremCommand(redisClient *c);
 345 static void smoveCommand(redisClient *c);
 346 static void sismemberCommand(redisClient *c);
 347 static void scardCommand(redisClient *c);
 348 static void sinterCommand(redisClient *c);
 349 static void sinterstoreCommand(redisClient *c);
 350 static void sunionCommand(redisClient *c);
 351 static void sunionstoreCommand(redisClient *c);
 352 static void sdiffCommand(redisClient *c);
 353 static void sdiffstoreCommand(redisClient *c);
 354 static void syncCommand(redisClient *c);
 355 static void flushdbCommand(redisClient *c);
 356 static void flushallCommand(redisClient *c);
 357 static void sortCommand(redisClient *c);
 358 static void lremCommand(redisClient *c);
 359 static void infoCommand(redisClient *c);
 360 static void mgetCommand(redisClient *c);
 361 static void monitorCommand(redisClient *c);
 362 static void expireCommand(redisClient *c);
 363 static void getSetCommand(redisClient *c);
 364 static void ttlCommand(redisClient *c);
 365
 366 /*================================= Globals ================================= */
 367
 368 /* Global vars */
 369 static struct redisServer server; /* server global state */
 370 static struct redisCommand cmdTable[] = {
 371     {"get",getCommand,2,REDIS_CMD_INLINE},
 372     {"set",setCommand,3,REDIS_CMD_BULK},
 373     {"setnx",setnxCommand,3,REDIS_CMD_BULK},
 374     {"del",delCommand,-2,REDIS_CMD_INLINE},
 375     {"exists",existsCommand,2,REDIS_CMD_INLINE},
 376     {"incr",incrCommand,2,REDIS_CMD_INLINE},
 377     {"decr",decrCommand,2,REDIS_CMD_INLINE},
 378     {"mget",mgetCommand,-2,REDIS_CMD_INLINE},
 379     {"rpush",rpushCommand,3,REDIS_CMD_BULK},
 380     {"lpush",lpushCommand,3,REDIS_CMD_BULK},
 381     {"rpop",rpopCommand,2,REDIS_CMD_INLINE},
 382     {"lpop",lpopCommand,2,REDIS_CMD_INLINE},
 383     {"llen",llenCommand,2,REDIS_CMD_INLINE},
 384     {"lindex",lindexCommand,3,REDIS_CMD_INLINE},
 385     {"lset",lsetCommand,4,REDIS_CMD_BULK},
 386     {"lrange",lrangeCommand,4,REDIS_CMD_INLINE},
 387     {"ltrim",ltrimCommand,4,REDIS_CMD_INLINE},
 388     {"lrem",lremCommand,4,REDIS_CMD_BULK},
 389     {"sadd",saddCommand,3,REDIS_CMD_BULK},
 390     {"srem",sremCommand,3,REDIS_CMD_BULK},
 391     {"smove",smoveCommand,4,REDIS_CMD_BULK},
 392     {"sismember",sismemberCommand,3,REDIS_CMD_BULK},
 393     {"scard",scardCommand,2,REDIS_CMD_INLINE},
 394     {"sinter",sinterCommand,-2,REDIS_CMD_INLINE},
 395     {"sinterstore",sinterstoreCommand,-3,REDIS_CMD_INLINE},
 396     {"sunion",sunionCommand,-2,REDIS_CMD_INLINE},
 397     {"sunionstore",sunionstoreCommand,-3,REDIS_CMD_INLINE},
 398     {"sdiff",sdiffCommand,-2,REDIS_CMD_INLINE},
 399     {"sdiffstore",sdiffstoreCommand,-3,REDIS_CMD_INLINE},
 400     {"smembers",sinterCommand,2,REDIS_CMD_INLINE},
 401     {"incrby",incrbyCommand,3,REDIS_CMD_INLINE},
 402     {"decrby",decrbyCommand,3,REDIS_CMD_INLINE},
 403     {"getset",getSetCommand,3,REDIS_CMD_BULK},
 404     {"randomkey",randomkeyCommand,1,REDIS_CMD_INLINE},
 405     {"select",selectCommand,2,REDIS_CMD_INLINE},
 406     {"move",moveCommand,3,REDIS_CMD_INLINE},
 407     {"rename",renameCommand,3,REDIS_CMD_INLINE},
 408     {"renamenx",renamenxCommand,3,REDIS_CMD_INLINE},
 409     {"keys",keysCommand,2,REDIS_CMD_INLINE},
 410     {"dbsize",dbsizeCommand,1,REDIS_CMD_INLINE},
 411     {"auth",authCommand,2,REDIS_CMD_INLINE},
 412     {"ping",pingCommand,1,REDIS_CMD_INLINE},
 413     {"echo",echoCommand,2,REDIS_CMD_BULK},
 414     {"save",saveCommand,1,REDIS_CMD_INLINE},
 415     {"bgsave",bgsaveCommand,1,REDIS_CMD_INLINE},
 416     {"shutdown",shutdownCommand,1,REDIS_CMD_INLINE},
 417     {"lastsave",lastsaveCommand,1,REDIS_CMD_INLINE},
 418     {"type",typeCommand,2,REDIS_CMD_INLINE},
 419     {"sync",syncCommand,1,REDIS_CMD_INLINE},
 420     {"flushdb",flushdbCommand,1,REDIS_CMD_INLINE},
 421     {"flushall",flushallCommand,1,REDIS_CMD_INLINE},
 422     {"sort",sortCommand,-2,REDIS_CMD_INLINE},
 423     {"info",infoCommand,1,REDIS_CMD_INLINE},
 424     {"monitor",monitorCommand,1,REDIS_CMD_INLINE},
 425     {"expire",expireCommand,3,REDIS_CMD_INLINE},
 426     {"ttl",ttlCommand,2,REDIS_CMD_INLINE},
 427     {NULL,NULL,0,0}
 428 };
 429
 430 /*============================ Utility functions ============================ */
 431
 432 /* Glob-style pattern matching. */
 433 int stringmatchlen(const char *pattern, int patternLen,
 434         const char *string, int stringLen, int nocase)
 435 {
 436     while(patternLen) {
 437         switch(pattern[0]) {
 438         case '*':
 439             while (pattern[1] == '*') {
 440                 pattern++;
 441                 patternLen--;
 442             }
 443             if (patternLen == 1)
 444                 return 1; /* match */
 445             while(stringLen) {
 446                 if (stringmatchlen(pattern+1, patternLen-1,
 447                             string, stringLen, nocase))
 448                     return 1; /* match */
 449                 string++;
 450                 stringLen--;
 451             }
 452             return 0; /* no match */
 453             break;
 454         case '?':
 455             if (stringLen == 0)
 456                 return 0; /* no match */
 457             string++;
 458             stringLen--;
 459             break;
 460         case '[':
 461         {
 462             int not, match;
 463
 464             pattern++;
 465             patternLen--;
 466             not = pattern[0] == '^';
 467             if (not) {
 468                 pattern++;
 469                 patternLen--;
 470             }
 471             match = 0;
 472             while(1) {
 473                 if (pattern[0] == '\\') {
 474                     pattern++;
 475                     patternLen--;
 476                     if (pattern[0] == string[0])
 477                         match = 1;
 478                 } else if (pattern[0] == ']') {
 479                     break;
 480                 } else if (patternLen == 0) {
 481                     pattern--;
 482                     patternLen++;
 483                     break;
 484                 } else if (pattern[1] == '-' && patternLen >= 3) {
 485                     int start = pattern[0];
 486                     int end = pattern[2];
 487                     int c = string[0];
 488                     if (start > end) {
 489                         int t = start;
 490                         start = end;
 491                         end = t;
 492                     }
 493                     if (nocase) {
 494                         start = tolower(start);
 495                         end = tolower(end);
 496                         c = tolower(c);
 497                     }
 498                     pattern += 2;
 499                     patternLen -= 2;
 500                     if (c >= start && c <= end)
 501                         match = 1;
 502                 } else {
 503                     if (!nocase) {
 504                         if (pattern[0] == string[0])
 505                             match = 1;
 506                     } else {
 507                         if (tolower((int)pattern[0]) == tolower((int)string[0]))
 508                             match = 1;
 509                     }
 510                 }
 511                 pattern++;
 512                 patternLen--;
 513             }
 514             if (not)
 515                 match = !match;
 516             if (!match)
 517                 return 0; /* no match */
 518             string++;
 519             stringLen--;
 520             break;
 521         }
 522         case '\\':
 523             if (patternLen >= 2) {
 524                 pattern++;
 525                 patternLen--;
 526             }
 527             /* fall through */
 528         default:
 529             if (!nocase) {
 530                 if (pattern[0] != string[0])
 531                     return 0; /* no match */
 532             } else {
 533                 if (tolower((int)pattern[0]) != tolower((int)string[0]))
 534                     return 0; /* no match */
 535             }
 536             string++;
 537             stringLen--;
 538             break;
 539         }
 540         pattern++;
 541         patternLen--;
 542         if (stringLen == 0) {
 543             while(*pattern == '*') {
 544                 pattern++;
 545                 patternLen--;
 546             }
 547             break;
 548         }
 549     }
 550     if (patternLen == 0 && stringLen == 0)
 551         return 1;
 552     return 0;
 553 }
 554
 555 void redisLog(int level, const char *fmt, ...)
 556 {
 557     va_list ap;
 558     FILE *fp;
 559
 560     fp = (server.logfile == NULL) ? stdout : fopen(server.logfile,"a");
 561     if (!fp) return;
 562
 563     va_start(ap, fmt);
 564     if (level >= server.verbosity) {
 565         char *c = ".-*";
 566         char buf[64];
 567         time_t now;
 568
 569         now = time(NULL);
 570         strftime(buf,64,"%d %b %H:%M:%S",gmtime(&now));
 571         fprintf(fp,"%s %c ",buf,c[level]);
 572         vfprintf(fp, fmt, ap);
 573         fprintf(fp,"\n");
 574         fflush(fp);
 575     }
 576     va_end(ap);
 577
 578     if (server.logfile) fclose(fp);
 579 }
 580
 581 /*====================== Hash table type implementation  ==================== */
 582
 583 /* This is an hash table type that uses the SDS dynamic strings libary as
 584  * keys and radis objects as values (objects can hold SDS strings,
 585  * lists, sets). */
 586
 587 static int sdsDictKeyCompare(void *privdata, const void *key1,
 588         const void *key2)
 589 {
 590     int l1,l2;
 591     DICT_NOTUSED(privdata);
 592
 593     l1 = sdslen((sds)key1);
 594     l2 = sdslen((sds)key2);
 595     if (l1 != l2) return 0;
 596     return memcmp(key1, key2, l1) == 0;
 597 }
 598
 599 static void dictRedisObjectDestructor(void *privdata, void *val)
 600 {
 601     DICT_NOTUSED(privdata);
 602
 603     decrRefCount(val);
 604 }
 605
 606 static int dictSdsKeyCompare(void *privdata, const void *key1,
 607         const void *key2)
 608 {
 609     const robj *o1 = key1, *o2 = key2;
 610     return sdsDictKeyCompare(privdata,o1->ptr,o2->ptr);
 611 }
 612
 613 static unsigned int dictSdsHash(const void *key) {
 614     const robj *o = key;
 615     return dictGenHashFunction(o->ptr, sdslen((sds)o->ptr));
 616 }
 617
 618 static dictType setDictType = {
 619     dictSdsHash,               /* hash function */
 620     NULL,                      /* key dup */
 621     NULL,                      /* val dup */
 622     dictSdsKeyCompare,         /* key compare */
 623     dictRedisObjectDestructor, /* key destructor */
 624     NULL                       /* val destructor */
 625 };
 626
 627 static dictType hashDictType = {
 628     dictSdsHash,                /* hash function */
 629     NULL,                       /* key dup */
 630     NULL,                       /* val dup */
 631     dictSdsKeyCompare,          /* key compare */
 632     dictRedisObjectDestructor,  /* key destructor */
 633     dictRedisObjectDestructor   /* val destructor */
 634 };
 635
 636 /* ========================= Random utility functions ======================= */
 637
 638 /* Redis generally does not try to recover from out of memory conditions
 639  * when allocating objects or strings, it is not clear if it will be possible
 640  * to report this condition to the client since the networking layer itself
 641  * is based on heap allocation for send buffers, so we simply abort.
 642  * At least the code will be simpler to read... */
 643 static void oom(const char *msg) {
 644     fprintf(stderr, "%s: Out of memory\n",msg);
 645     fflush(stderr);
 646     sleep(1);
 647     abort();
 648 }
 649
 650 /* ====================== Redis server networking stuff ===================== */
 651 void closeTimedoutClients(void) {
 652     redisClient *c;
 653     listNode *ln;
 654     time_t now = time(NULL);
 655
 656     listRewind(server.clients);
 657     while ((ln = listYield(server.clients)) != NULL) {
 658         c = listNodeValue(ln);
 659         if (!(c->flags & REDIS_SLAVE) &&    /* no timeout for slaves */
 660              (now - c->lastinteraction > server.maxidletime)) {
 661             redisLog(REDIS_DEBUG,"Closing idle client");
 662             freeClient(c);
 663         }
 664     }
 665 }
 666
 667 /* If the percentage of used slots in the HT reaches REDIS_HT_MINFILL
 668  * we resize the hash table to save memory */
 669 void tryResizeHashTables(void) {
 670     int j;
 671
 672     for (j = 0; j < server.dbnum; j++) {
 673         long long size, used;
 674
 675         size = dictSlots(server.db[j].dict);
 676         used = dictSize(server.db[j].dict);
 677         if (size && used && size > REDIS_HT_MINSLOTS &&
 678             (used*100/size < REDIS_HT_MINFILL)) {
 679             redisLog(REDIS_NOTICE,"The hash table %d is too sparse, resize it...",j);
 680             dictResize(server.db[j].dict);
 681             redisLog(REDIS_NOTICE,"Hash table %d resized.",j);
 682         }
 683     }
 684 }
 685
 686 int serverCron(struct aeEventLoop *eventLoop, long long id, void *clientData) {
 687     int j, loops = server.cronloops++;
 688     REDIS_NOTUSED(eventLoop);
 689     REDIS_NOTUSED(id);
 690     REDIS_NOTUSED(clientData);
 691
 692     /* Update the global state with the amount of used memory */
 693     server.usedmemory = zmalloc_used_memory();
 694
 695     /* Show some info about non-empty databases */
 696     for (j = 0; j < server.dbnum; j++) {
 697         long long size, used, vkeys;
 698
 699         size = dictSlots(server.db[j].dict);
 700         used = dictSize(server.db[j].dict);
 701         vkeys = dictSize(server.db[j].expires);
 702         if (!(loops % 5) && used > 0) {
 703             redisLog(REDIS_DEBUG,"DB %d: %d keys (%d volatile) in %d slots HT.",j,used,vkeys,size);
 704             /* dictPrintStats(server.dict); */
 705         }
 706     }
 707
 708     /* We don't want to resize the hash tables while a bacground saving
 709      * is in progress: the saving child is created using fork() that is
 710      * implemented with a copy-on-write semantic in most modern systems, so
 711      * if we resize the HT while there is the saving child at work actually
 712      * a lot of memory movements in the parent will cause a lot of pages
 713      * copied. */
 714     if (!server.bgsaveinprogress) tryResizeHashTables();
 715
 716     /* Show information about connected clients */
 717     if (!(loops % 5)) {
 718         redisLog(REDIS_DEBUG,"%d clients connected (%d slaves), %zu bytes in use",
 719             listLength(server.clients)-listLength(server.slaves),
 720             listLength(server.slaves),
 721             server.usedmemory,
 722             dictSize(server.sharingpool));
 723     }
 724
 725     /* Close connections of timedout clients */
 726     if (server.maxidletime && !(loops % 10))
 727         closeTimedoutClients();
 728
 729     /* Check if a background saving in progress terminated */
 730     if (server.bgsaveinprogress) {
 731         int statloc;
 732         /* XXX: TODO handle the case of the saving child killed */
 733         if (wait4(-1,&statloc,WNOHANG,NULL)) {
 734             int exitcode = WEXITSTATUS(statloc);
 735             if (exitcode == 0) {
 736                 redisLog(REDIS_NOTICE,
 737                     "Background saving terminated with success");
 738                 server.dirty = 0;
 739                 server.lastsave = time(NULL);
 740             } else {
 741                 redisLog(REDIS_WARNING,
 742                     "Background saving error");
 743             }
 744             server.bgsaveinprogress = 0;
 745             updateSalvesWaitingBgsave(exitcode == 0 ? REDIS_OK : REDIS_ERR);
 746         }
 747     } else {
 748         /* If there is not a background saving in progress check if
 749          * we have to save now */
 750          time_t now = time(NULL);
 751          for (j = 0; j < server.saveparamslen; j++) {
 752             struct saveparam *sp = server.saveparams+j;
 753
 754             if (server.dirty >= sp->changes &&
 755                 now-server.lastsave > sp->seconds) {
 756                 redisLog(REDIS_NOTICE,"%d changes in %d seconds. Saving...",
 757                     sp->changes, sp->seconds);
 758                 rdbSaveBackground(server.dbfilename);
 759                 break;
 760             }
 761          }
 762     }
 763
 764     /* Try to expire a few timed out keys */
 765     for (j = 0; j < server.dbnum; j++) {
 766         redisDb *db = server.db+j;
 767         int num = dictSize(db->expires);
 768
 769         if (num) {
 770             time_t now = time(NULL);
 771
 772             if (num > REDIS_EXPIRELOOKUPS_PER_CRON)
 773                 num = REDIS_EXPIRELOOKUPS_PER_CRON;
 774             while (num--) {
 775                 dictEntry *de;
 776                 time_t t;
 777
 778                 if ((de = dictGetRandomKey(db->expires)) == NULL) break;
 779                 t = (time_t) dictGetEntryVal(de);
 780                 if (now > t) {
 781                     deleteKey(db,dictGetEntryKey(de));
 782                 }
 783             }
 784         }
 785     }
 786
 787     /* Check if we should connect to a MASTER */
 788     if (server.replstate == REDIS_REPL_CONNECT) {
 789         redisLog(REDIS_NOTICE,"Connecting to MASTER...");
 790         if (syncWithMaster() == REDIS_OK) {
 791             redisLog(REDIS_NOTICE,"MASTER <-> SLAVE sync succeeded");
 792         }
 793     }
 794     return 1000;
 795 }
 796
 797 static void createSharedObjects(void) {
 798     shared.crlf = createObject(REDIS_STRING,sdsnew("\r\n"));
 799     shared.ok = createObject(REDIS_STRING,sdsnew("+OK\r\n"));
 800     shared.err = createObject(REDIS_STRING,sdsnew("-ERR\r\n"));
 801     shared.emptybulk = createObject(REDIS_STRING,sdsnew("$0\r\n\r\n"));
 802     shared.czero = createObject(REDIS_STRING,sdsnew(":0\r\n"));
 803     shared.cone = createObject(REDIS_STRING,sdsnew(":1\r\n"));
 804     shared.nullbulk = createObject(REDIS_STRING,sdsnew("$-1\r\n"));
 805     shared.nullmultibulk = createObject(REDIS_STRING,sdsnew("*-1\r\n"));
 806     shared.emptymultibulk = createObject(REDIS_STRING,sdsnew("*0\r\n"));
 807     /* no such key */
 808     shared.pong = createObject(REDIS_STRING,sdsnew("+PONG\r\n"));
 809     shared.wrongtypeerr = createObject(REDIS_STRING,sdsnew(
 810         "-ERR Operation against a key holding the wrong kind of value\r\n"));
 811     shared.nokeyerr = createObject(REDIS_STRING,sdsnew(
 812         "-ERR no such key\r\n"));
 813     shared.syntaxerr = createObject(REDIS_STRING,sdsnew(
 814         "-ERR syntax error\r\n"));
 815     shared.sameobjecterr = createObject(REDIS_STRING,sdsnew(
 816         "-ERR source and destination objects are the same\r\n"));
 817     shared.outofrangeerr = createObject(REDIS_STRING,sdsnew(
 818         "-ERR index out of range\r\n"));
 819     shared.space = createObject(REDIS_STRING,sdsnew(" "));
 820     shared.colon = createObject(REDIS_STRING,sdsnew(":"));
 821     shared.plus = createObject(REDIS_STRING,sdsnew("+"));
 822     shared.select0 = createStringObject("select 0\r\n",10);
 823     shared.select1 = createStringObject("select 1\r\n",10);
 824     shared.select2 = createStringObject("select 2\r\n",10);
 825     shared.select3 = createStringObject("select 3\r\n",10);
 826     shared.select4 = createStringObject("select 4\r\n",10);
 827     shared.select5 = createStringObject("select 5\r\n",10);
 828     shared.select6 = createStringObject("select 6\r\n",10);
 829     shared.select7 = createStringObject("select 7\r\n",10);
 830     shared.select8 = createStringObject("select 8\r\n",10);
 831     shared.select9 = createStringObject("select 9\r\n",10);
 832 }
 833
 834 static void appendServerSaveParams(time_t seconds, int changes) {
 835     server.saveparams = zrealloc(server.saveparams,sizeof(struct saveparam)*(server.saveparamslen+1));
 836     if (server.saveparams == NULL) oom("appendServerSaveParams");
 837     server.saveparams[server.saveparamslen].seconds = seconds;
 838     server.saveparams[server.saveparamslen].changes = changes;
 839     server.saveparamslen++;
 840 }
 841
 842 static void ResetServerSaveParams() {
 843     zfree(server.saveparams);
 844     server.saveparams = NULL;
 845     server.saveparamslen = 0;
 846 }
 847
 848 static void initServerConfig() {
 849     server.dbnum = REDIS_DEFAULT_DBNUM;
 850     server.port = REDIS_SERVERPORT;
 851     server.verbosity = REDIS_DEBUG;
 852     server.maxidletime = REDIS_MAXIDLETIME;
 853     server.saveparams = NULL;
 854     server.logfile = NULL; /* NULL = log on standard output */
 855     server.bindaddr = NULL;
 856     server.glueoutputbuf = 1;
 857     server.daemonize = 0;
 858     server.pidfile = "/var/run/redis.pid";
 859     server.dbfilename = "dump.rdb";
 860     server.requirepass = NULL;
 861     server.shareobjects = 0;
 862     ResetServerSaveParams();
 863
 864     appendServerSaveParams(60*60,1);  /* save after 1 hour and 1 change */
 865     appendServerSaveParams(300,100);  /* save after 5 minutes and 100 changes */
 866     appendServerSaveParams(60,10000); /* save after 1 minute and 10000 changes */
 867     /* Replication related */
 868     server.isslave = 0;
 869     server.masterhost = NULL;
 870     server.masterport = 6379;
 871     server.master = NULL;
 872     server.replstate = REDIS_REPL_NONE;
 873 }
 874
 875 static void initServer() {
 876     int j;
 877
 878     signal(SIGHUP, SIG_IGN);
 879     signal(SIGPIPE, SIG_IGN);
 880
 881     server.clients = listCreate();
 882     server.slaves = listCreate();
 883     server.monitors = listCreate();
 884     server.objfreelist = listCreate();
 885     createSharedObjects();
 886     server.el = aeCreateEventLoop();
 887     server.db = zmalloc(sizeof(redisDb)*server.dbnum);
 888     server.sharingpool = dictCreate(&setDictType,NULL);
 889     server.sharingpoolsize = 1024;
 890     if (!server.db || !server.clients || !server.slaves || !server.monitors || !server.el || !server.objfreelist)
 891         oom("server initialization"); /* Fatal OOM */
 892     server.fd = anetTcpServer(server.neterr, server.port, server.bindaddr);
 893     if (server.fd == -1) {
 894         redisLog(REDIS_WARNING, "Opening TCP port: %s", server.neterr);
 895         exit(1);
 896     }
 897     for (j = 0; j < server.dbnum; j++) {
 898         server.db[j].dict = dictCreate(&hashDictType,NULL);
 899         server.db[j].expires = dictCreate(&setDictType,NULL);
 900         server.db[j].id = j;
 901     }
 902     server.cronloops = 0;
 903     server.bgsaveinprogress = 0;
 904     server.lastsave = time(NULL);
 905     server.dirty = 0;
 906     server.usedmemory = 0;
 907     server.stat_numcommands = 0;
 908     server.stat_numconnections = 0;
 909     server.stat_starttime = time(NULL);
 910     aeCreateTimeEvent(server.el, 1000, serverCron, NULL, NULL);
 911 }
 912
 913 /* Empty the whole database */
 914 static long long emptyDb() {
 915     int j;
 916     long long removed = 0;
 917
 918     for (j = 0; j < server.dbnum; j++) {
 919         removed += dictSize(server.db[j].dict);
 920         dictEmpty(server.db[j].dict);
 921         dictEmpty(server.db[j].expires);
 922     }
 923     return removed;
 924 }
 925
 926 static int yesnotoi(char *s) {
 927     if (!strcasecmp(s,"yes")) return 1;
 928     else if (!strcasecmp(s,"no")) return 0;
 929     else return -1;
 930 }
 931
 932 /* I agree, this is a very rudimental way to load a configuration...
 933    will improve later if the config gets more complex */
 934 static void loadServerConfig(char *filename) {
 935     FILE *fp = fopen(filename,"r");
 936     char buf[REDIS_CONFIGLINE_MAX+1], *err = NULL;
 937     int linenum = 0;
 938     sds line = NULL;
 939
 940     if (!fp) {
 941         redisLog(REDIS_WARNING,"Fatal error, can't open config file");
 942         exit(1);
 943     }
 944     while(fgets(buf,REDIS_CONFIGLINE_MAX+1,fp) != NULL) {
 945         sds *argv;
 946         int argc, j;
 947
 948         linenum++;
 949         line = sdsnew(buf);
 950         line = sdstrim(line," \t\r\n");
 951
 952         /* Skip comments and blank lines*/
 953         if (line[0] == '#' || line[0] == '\0') {
 954             sdsfree(line);
 955             continue;
 956         }
 957
 958         /* Split into arguments */
 959         argv = sdssplitlen(line,sdslen(line)," ",1,&argc);
 960         sdstolower(argv[0]);
 961
 962         /* Execute config directives */
 963         if (!strcasecmp(argv[0],"timeout") && argc == 2) {
 964             server.maxidletime = atoi(argv[1]);
 965             if (server.maxidletime < 0) {
 966                 err = "Invalid timeout value"; goto loaderr;
 967             }
 968         } else if (!strcasecmp(argv[0],"port") && argc == 2) {
 969             server.port = atoi(argv[1]);
 970             if (server.port < 1 || server.port > 65535) {
 971                 err = "Invalid port"; goto loaderr;
 972             }
 973         } else if (!strcasecmp(argv[0],"bind") && argc == 2) {
 974             server.bindaddr = zstrdup(argv[1]);
 975         } else if (!strcasecmp(argv[0],"save") && argc == 3) {
 976             int seconds = atoi(argv[1]);
 977             int changes = atoi(argv[2]);
 978             if (seconds < 1 || changes < 0) {
 979                 err = "Invalid save parameters"; goto loaderr;
 980             }
 981             appendServerSaveParams(seconds,changes);
 982         } else if (!strcasecmp(argv[0],"dir") && argc == 2) {
 983             if (chdir(argv[1]) == -1) {
 984                 redisLog(REDIS_WARNING,"Can't chdir to '%s': %s",
 985                     argv[1], strerror(errno));
 986                 exit(1);
 987             }
 988         } else if (!strcasecmp(argv[0],"loglevel") && argc == 2) {
 989             if (!strcasecmp(argv[1],"debug")) server.verbosity = REDIS_DEBUG;
 990             else if (!strcasecmp(argv[1],"notice")) server.verbosity = REDIS_NOTICE;
 991             else if (!strcasecmp(argv[1],"warning")) server.verbosity = REDIS_WARNING;
 992             else {
 993                 err = "Invalid log level. Must be one of debug, notice, warning";
 994                 goto loaderr;
 995             }
 996         } else if (!strcasecmp(argv[0],"logfile") && argc == 2) {
 997             FILE *fp;
 998
 999             server.logfile = zstrdup(argv[1]);
1000             if (!strcasecmp(server.logfile,"stdout")) {
1001                 zfree(server.logfile);
1002                 server.logfile = NULL;
1003             }
1004             if (server.logfile) {
1005                 /* Test if we are able to open the file. The server will not
1006                  * be able to abort just for this problem later... */
1007                 fp = fopen(server.logfile,"a");
1008                 if (fp == NULL) {
1009                     err = sdscatprintf(sdsempty(),
1010                         "Can't open the log file: %s", strerror(errno));
1011                     goto loaderr;
1012                 }
1013                 fclose(fp);
1014             }
1015         } else if (!strcasecmp(argv[0],"databases") && argc == 2) {
1016             server.dbnum = atoi(argv[1]);
1017             if (server.dbnum < 1) {
1018                 err = "Invalid number of databases"; goto loaderr;
1019             }
1020         } else if (!strcasecmp(argv[0],"slaveof") && argc == 3) {
1021             server.masterhost = sdsnew(argv[1]);
1022             server.masterport = atoi(argv[2]);
1023             server.replstate = REDIS_REPL_CONNECT;
1024         } else if (!strcasecmp(argv[0],"glueoutputbuf") && argc == 2) {
1025             if ((server.glueoutputbuf = yesnotoi(argv[1])) == -1) {
1026                 err = "argument must be 'yes' or 'no'"; goto loaderr;
1027             }
1028         } else if (!strcasecmp(argv[0],"shareobjects") && argc == 2) {
1029             if ((server.shareobjects = yesnotoi(argv[1])) == -1) {
1030                 err = "argument must be 'yes' or 'no'"; goto loaderr;
1031             }
1032         } else if (!strcasecmp(argv[0],"daemonize") && argc == 2) {
1033             if ((server.daemonize = yesnotoi(argv[1])) == -1) {
1034                 err = "argument must be 'yes' or 'no'"; goto loaderr;
1035             }
1036         } else if (!strcasecmp(argv[0],"requirepass") && argc == 2) {
1037           server.requirepass = zstrdup(argv[1]);
1038         } else if (!strcasecmp(argv[0],"pidfile") && argc == 2) {
1039           server.pidfile = zstrdup(argv[1]);
1040         } else if (!strcasecmp(argv[0],"dbfilename") && argc == 2) {
1041           server.dbfilename = zstrdup(argv[1]);
1042         } else {
1043             err = "Bad directive or wrong number of arguments"; goto loaderr;
1044         }
1045         for (j = 0; j < argc; j++)
1046             sdsfree(argv[j]);
1047         zfree(argv);
1048         sdsfree(line);
1049     }
1050     fclose(fp);
1051     return;
1052
1053 loaderr:
1054     fprintf(stderr, "\n*** FATAL CONFIG FILE ERROR ***\n");
1055     fprintf(stderr, "Reading the configuration file, at line %d\n", linenum);
1056     fprintf(stderr, ">>> '%s'\n", line);
1057     fprintf(stderr, "%s\n", err);
1058     exit(1);
1059 }
1060
1061 static void freeClientArgv(redisClient *c) {
1062     int j;
1063
1064     for (j = 0; j < c->argc; j++)
1065         decrRefCount(c->argv[j]);
1066     c->argc = 0;
1067 }
1068
1069 static void freeClient(redisClient *c) {
1070     listNode *ln;
1071
1072     aeDeleteFileEvent(server.el,c->fd,AE_READABLE);
1073     aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);
1074     sdsfree(c->querybuf);
1075     listRelease(c->reply);
1076     freeClientArgv(c);
1077     close(c->fd);
1078     ln = listSearchKey(server.clients,c);
1079     assert(ln != NULL);
1080     listDelNode(server.clients,ln);
1081     if (c->flags & REDIS_SLAVE) {
1082         if (c->replstate == REDIS_REPL_SEND_BULK && c->repldbfd != -1)
1083             close(c->repldbfd);
1084         list *l = (c->flags & REDIS_MONITOR) ? server.monitors : server.slaves;
1085         ln = listSearchKey(l,c);
1086         assert(ln != NULL);
1087         listDelNode(l,ln);
1088     }
1089     if (c->flags & REDIS_MASTER) {
1090         server.master = NULL;
1091         server.replstate = REDIS_REPL_CONNECT;
1092     }
1093     zfree(c->argv);
1094     zfree(c);
1095 }
1096
1097 static void glueReplyBuffersIfNeeded(redisClient *c) {
1098     int totlen = 0;
1099     listNode *ln;
1100     robj *o;
1101
1102     listRewind(c->reply);
1103     while((ln = listYield(c->reply))) {
1104         o = ln->value;
1105         totlen += sdslen(o->ptr);
1106         /* This optimization makes more sense if we don't have to copy
1107          * too much data */
1108         if (totlen > 1024) return;
1109     }
1110     if (totlen > 0) {
1111         char buf[1024];
1112         int copylen = 0;
1113
1114         listRewind(c->reply);
1115         while((ln = listYield(c->reply))) {
1116             o = ln->value;
1117             memcpy(buf+copylen,o->ptr,sdslen(o->ptr));
1118             copylen += sdslen(o->ptr);
1119             listDelNode(c->reply,ln);
1120         }
1121         /* Now the output buffer is empty, add the new single element */
1122         addReplySds(c,sdsnewlen(buf,totlen));
1123     }
1124 }
1125
1126 static void sendReplyToClient(aeEventLoop *el, int fd, void *privdata, int mask) {
1127     redisClient *c = privdata;
1128     int nwritten = 0, totwritten = 0, objlen;
1129     robj *o;
1130     REDIS_NOTUSED(el);
1131     REDIS_NOTUSED(mask);
1132
1133     if (server.glueoutputbuf && listLength(c->reply) > 1)
1134         glueReplyBuffersIfNeeded(c);
1135     while(listLength(c->reply)) {
1136         o = listNodeValue(listFirst(c->reply));
1137         objlen = sdslen(o->ptr);
1138
1139         if (objlen == 0) {
1140             listDelNode(c->reply,listFirst(c->reply));
1141             continue;
1142         }
1143
1144         if (c->flags & REDIS_MASTER) {
1145             nwritten = objlen - c->sentlen;
1146         } else {
1147             nwritten = write(fd, ((char*)o->ptr)+c->sentlen, objlen - c->sentlen);
1148             if (nwritten <= 0) break;
1149         }
1150         c->sentlen += nwritten;
1151         totwritten += nwritten;
1152         /* If we fully sent the object on head go to the next one */
1153         if (c->sentlen == objlen) {
1154             listDelNode(c->reply,listFirst(c->reply));
1155             c->sentlen = 0;
1156         }
1157     }
1158     if (nwritten == -1) {
1159         if (errno == EAGAIN) {
1160             nwritten = 0;
1161         } else {
1162             redisLog(REDIS_DEBUG,
1163                 "Error writing to client: %s", strerror(errno));
1164             freeClient(c);
1165             return;
1166         }
1167     }
1168     if (totwritten > 0) c->lastinteraction = time(NULL);
1169     if (listLength(c->reply) == 0) {
1170         c->sentlen = 0;
1171         aeDeleteFileEvent(server.el,c->fd,AE_WRITABLE);
1172     }
1173 }
1174
1175 static struct redisCommand *lookupCommand(char *name) {
1176     int j = 0;
1177     while(cmdTable[j].name != NULL) {
1178         if (!strcasecmp(name,cmdTable[j].name)) return &cmdTable[j];
1179         j++;
1180     }
1181     return NULL;
1182 }
1183
1184 /* resetClient prepare the client to process the next command */
1185 static void resetClient(redisClient *c) {
1186     freeClientArgv(c);
1187     c->bulklen = -1;
1188 }
1189
1190 /* If this function gets called we already read a whole
1191  * command, argments are in the client argv/argc fields.
1192  * processCommand() execute the command or prepare the
1193  * server for a bulk read from the client.
1194  *
1195  * If 1 is returned the client is still alive and valid and
1196  * and other operations can be performed by the caller. Otherwise
1197  * if 0 is returned the client was destroied (i.e. after QUIT). */
1198 static int processCommand(redisClient *c) {
1199     struct redisCommand *cmd;
1200     long long dirty;
1201
1202     /* The QUIT command is handled as a special case. Normal command
1203      * procs are unable to close the client connection safely */
1204     if (!strcasecmp(c->argv[0]->ptr,"quit")) {
1205         freeClient(c);
1206         return 0;
1207     }
1208     cmd = lookupCommand(c->argv[0]->ptr);
1209     if (!cmd) {
1210         addReplySds(c,sdsnew("-ERR unknown command\r\n"));
1211         resetClient(c);
1212         return 1;
1213     } else if ((cmd->arity > 0 && cmd->arity != c->argc) ||
1214                (c->argc < -cmd->arity)) {
1215         addReplySds(c,sdsnew("-ERR wrong number of arguments\r\n"));
1216         resetClient(c);
1217         return 1;
1218     } else if (cmd->flags & REDIS_CMD_BULK && c->bulklen == -1) {
1219         int bulklen = atoi(c->argv[c->argc-1]->ptr);
1220
1221         decrRefCount(c->argv[c->argc-1]);
1222         if (bulklen < 0 || bulklen > 1024*1024*1024) {
1223             c->argc--;
1224             addReplySds(c,sdsnew("-ERR invalid bulk write count\r\n"));
1225             resetClient(c);
1226             return 1;
1227         }
1228         c->argc--;
1229         c->bulklen = bulklen+2; /* add two bytes for CR+LF */
1230         /* It is possible that the bulk read is already in the
1231          * buffer. Check this condition and handle it accordingly */
1232         if ((signed)sdslen(c->querybuf) >= c->bulklen) {
1233             c->argv[c->argc] = createStringObject(c->querybuf,c->bulklen-2);
1234             c->argc++;
1235             c->querybuf = sdsrange(c->querybuf,c->bulklen,-1);
1236         } else {
1237             return 1;
1238         }
1239     }
1240     /* Let's try to share objects on the command arguments vector */
1241     if (server.shareobjects) {
1242         int j;
1243         for(j = 1; j < c->argc; j++)
1244             c->argv[j] = tryObjectSharing(c->argv[j]);
1245     }
1246     /* Check if the user is authenticated */
1247     if (server.requirepass && !c->authenticated && cmd->proc != authCommand) {
1248         addReplySds(c,sdsnew("-ERR operation not permitted\r\n"));
1249         resetClient(c);
1250         return 1;
1251     }
1252
1253     /* Exec the command */
1254     dirty = server.dirty;
1255     cmd->proc(c);
1256     if (server.dirty-dirty != 0 && listLength(server.slaves))
1257         replicationFeedSlaves(server.slaves,cmd,c->db->id,c->argv,c->argc);
1258     if (listLength(server.monitors))
1259         replicationFeedSlaves(server.monitors,cmd,c->db->id,c->argv,c->argc);
1260     server.stat_numcommands++;
1261
1262     /* Prepare the client for the next command */
1263     if (c->flags & REDIS_CLOSE) {
1264         freeClient(c);
1265         return 0;
1266     }
1267     resetClient(c);
1268     return 1;
1269 }
1270
1271 static void replicationFeedSlaves(list *slaves, struct redisCommand *cmd, int dictid, robj **argv, int argc) {
1272     listNode *ln;
1273     int outc = 0, j;
1274     robj **outv;
1275     /* (args*2)+1 is enough room for args, spaces, newlines */
1276     robj *static_outv[REDIS_STATIC_ARGS*2+1];
1277
1278     if (argc <= REDIS_STATIC_ARGS) {
1279         outv = static_outv;
1280     } else {
1281         outv = zmalloc(sizeof(robj*)*(argc*2+1));
1282         if (!outv) oom("replicationFeedSlaves");
1283     }
1284
1285     for (j = 0; j < argc; j++) {
1286         if (j != 0) outv[outc++] = shared.space;
1287         if ((cmd->flags & REDIS_CMD_BULK) && j == argc-1) {
1288             robj *lenobj;
1289
1290             lenobj = createObject(REDIS_STRING,
1291                 sdscatprintf(sdsempty(),"%d\r\n",sdslen(argv[j]->ptr)));
1292             lenobj->refcount = 0;
1293             outv[outc++] = lenobj;
1294         }
1295         outv[outc++] = argv[j];
1296     }
1297     outv[outc++] = shared.crlf;
1298
1299     /* Increment all the refcounts at start and decrement at end in order to
1300      * be sure to free objects if there is no slave in a replication state
1301      * able to be feed with commands */
1302     for (j = 0; j < outc; j++) incrRefCount(outv[j]);
1303     listRewind(slaves);
1304     while((ln = listYield(slaves))) {
1305         redisClient *slave = ln->value;
1306
1307         /* Don't feed slaves that are still waiting for BGSAVE to start */
1308         if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START) continue;
1309
1310         /* Feed all the other slaves, MONITORs and so on */
1311         if (slave->slaveseldb != dictid) {
1312             robj *selectcmd;
1313
1314             switch(dictid) {
1315             case 0: selectcmd = shared.select0; break;
1316             case 1: selectcmd = shared.select1; break;
1317             case 2: selectcmd = shared.select2; break;
1318             case 3: selectcmd = shared.select3; break;
1319             case 4: selectcmd = shared.select4; break;
1320             case 5: selectcmd = shared.select5; break;
1321             case 6: selectcmd = shared.select6; break;
1322             case 7: selectcmd = shared.select7; break;
1323             case 8: selectcmd = shared.select8; break;
1324             case 9: selectcmd = shared.select9; break;
1325             default:
1326                 selectcmd = createObject(REDIS_STRING,
1327                     sdscatprintf(sdsempty(),"select %d\r\n",dictid));
1328                 selectcmd->refcount = 0;
1329                 break;
1330             }
1331             addReply(slave,selectcmd);
1332             slave->slaveseldb = dictid;
1333         }
1334         for (j = 0; j < outc; j++) addReply(slave,outv[j]);
1335     }
1336     for (j = 0; j < outc; j++) decrRefCount(outv[j]);
1337     if (outv != static_outv) zfree(outv);
1338 }
1339
1340 static void readQueryFromClient(aeEventLoop *el, int fd, void *privdata, int mask) {
1341     redisClient *c = (redisClient*) privdata;
1342     char buf[REDIS_IOBUF_LEN];
1343     int nread;
1344     REDIS_NOTUSED(el);
1345     REDIS_NOTUSED(mask);
1346
1347     nread = read(fd, buf, REDIS_IOBUF_LEN);
1348     if (nread == -1) {
1349         if (errno == EAGAIN) {
1350             nread = 0;
1351         } else {
1352             redisLog(REDIS_DEBUG, "Reading from client: %s",strerror(errno));
1353             freeClient(c);
1354             return;
1355         }
1356     } else if (nread == 0) {
1357         redisLog(REDIS_DEBUG, "Client closed connection");
1358         freeClient(c);
1359         return;
1360     }
1361     if (nread) {
1362         c->querybuf = sdscatlen(c->querybuf, buf, nread);
1363         c->lastinteraction = time(NULL);
1364     } else {
1365         return;
1366     }
1367
1368 again:
1369     if (c->bulklen == -1) {
1370         /* Read the first line of the query */
1371         char *p = strchr(c->querybuf,'\n');
1372         size_t querylen;
1373         if (p) {
1374             sds query, *argv;
1375             int argc, j;
1376
1377             query = c->querybuf;
1378             c->querybuf = sdsempty();
1379             querylen = 1+(p-(query));
1380             if (sdslen(query) > querylen) {
1381                 /* leave data after the first line of the query in the buffer */
1382                 c->querybuf = sdscatlen(c->querybuf,query+querylen,sdslen(query)-querylen);
1383             }
1384             *p = '\0'; /* remove "\n" */
1385             if (*(p-1) == '\r') *(p-1) = '\0'; /* and "\r" if any */
1386             sdsupdatelen(query);
1387
1388             /* Now we can split the query in arguments */
1389             if (sdslen(query) == 0) {
1390                 /* Ignore empty query */
1391                 sdsfree(query);
1392                 return;
1393             }
1394             argv = sdssplitlen(query,sdslen(query)," ",1,&argc);
1395             if (argv == NULL) oom("sdssplitlen");
1396             sdsfree(query);
1397
1398             if (c->argv) zfree(c->argv);
1399             c->argv = zmalloc(sizeof(robj*)*argc);
1400             if (c->argv == NULL) oom("allocating arguments list for client");
1401
1402             for (j = 0; j < argc; j++) {
1403                 if (sdslen(argv[j])) {
1404                     c->argv[c->argc] = createObject(REDIS_STRING,argv[j]);
1405                     c->argc++;
1406                 } else {
1407                     sdsfree(argv[j]);
1408                 }
1409             }
1410             zfree(argv);
1411             /* Execute the command. If the client is still valid
1412              * after processCommand() return and there is something
1413              * on the query buffer try to process the next command. */
1414             if (processCommand(c) && sdslen(c->querybuf)) goto again;
1415             return;
1416         } else if (sdslen(c->querybuf) >= 1024) {
1417             redisLog(REDIS_DEBUG, "Client protocol error");
1418             freeClient(c);
1419             return;
1420         }
1421     } else {
1422         /* Bulk read handling. Note that if we are at this point
1423            the client already sent a command terminated with a newline,
1424            we are reading the bulk data that is actually the last
1425            argument of the command. */
1426         int qbl = sdslen(c->querybuf);
1427
1428         if (c->bulklen <= qbl) {
1429             /* Copy everything but the final CRLF as final argument */
1430             c->argv[c->argc] = createStringObject(c->querybuf,c->bulklen-2);
1431             c->argc++;
1432             c->querybuf = sdsrange(c->querybuf,c->bulklen,-1);
1433             processCommand(c);
1434             return;
1435         }
1436     }
1437 }
1438
1439 static int selectDb(redisClient *c, int id) {
1440     if (id < 0 || id >= server.dbnum)
1441         return REDIS_ERR;
1442     c->db = &server.db[id];
1443     return REDIS_OK;
1444 }
1445
1446 static void *dupClientReplyValue(void *o) {
1447     incrRefCount((robj*)o);
1448     return 0;
1449 }
1450
1451 static redisClient *createClient(int fd) {
1452     redisClient *c = zmalloc(sizeof(*c));
1453
1454     anetNonBlock(NULL,fd);
1455     anetTcpNoDelay(NULL,fd);
1456     if (!c) return NULL;
1457     selectDb(c,0);
1458     c->fd = fd;
1459     c->querybuf = sdsempty();
1460     c->argc = 0;
1461     c->argv = NULL;
1462     c->bulklen = -1;
1463     c->sentlen = 0;
1464     c->flags = 0;
1465     c->lastinteraction = time(NULL);
1466     c->authenticated = 0;
1467     c->replstate = REDIS_REPL_NONE;
1468     if ((c->reply = listCreate()) == NULL) oom("listCreate");
1469     listSetFreeMethod(c->reply,decrRefCount);
1470     listSetDupMethod(c->reply,dupClientReplyValue);
1471     if (aeCreateFileEvent(server.el, c->fd, AE_READABLE,
1472         readQueryFromClient, c, NULL) == AE_ERR) {
1473         freeClient(c);
1474         return NULL;
1475     }
1476     if (!listAddNodeTail(server.clients,c)) oom("listAddNodeTail");
1477     return c;
1478 }
1479
1480 static void addReply(redisClient *c, robj *obj) {
1481     if (listLength(c->reply) == 0 &&
1482         (c->replstate == REDIS_REPL_NONE ||
1483          c->replstate == REDIS_REPL_ONLINE) &&
1484         aeCreateFileEvent(server.el, c->fd, AE_WRITABLE,
1485         sendReplyToClient, c, NULL) == AE_ERR) return;
1486     if (!listAddNodeTail(c->reply,obj)) oom("listAddNodeTail");
1487     incrRefCount(obj);
1488 }
1489
1490 static void addReplySds(redisClient *c, sds s) {
1491     robj *o = createObject(REDIS_STRING,s);
1492     addReply(c,o);
1493     decrRefCount(o);
1494 }
1495
1496 static void acceptHandler(aeEventLoop *el, int fd, void *privdata, int mask) {
1497     int cport, cfd;
1498     char cip[128];
1499     REDIS_NOTUSED(el);
1500     REDIS_NOTUSED(mask);
1501     REDIS_NOTUSED(privdata);
1502
1503     cfd = anetAccept(server.neterr, fd, cip, &cport);
1504     if (cfd == AE_ERR) {
1505         redisLog(REDIS_DEBUG,"Accepting client connection: %s", server.neterr);
1506         return;
1507     }
1508     redisLog(REDIS_DEBUG,"Accepted %s:%d", cip, cport);
1509     if (createClient(cfd) == NULL) {
1510         redisLog(REDIS_WARNING,"Error allocating resoures for the client");
1511         close(cfd); /* May be already closed, just ingore errors */
1512         return;
1513     }
1514     server.stat_numconnections++;
1515 }
1516
1517 /* ======================= Redis objects implementation ===================== */
1518
1519 static robj *createObject(int type, void *ptr) {
1520     robj *o;
1521
1522     if (listLength(server.objfreelist)) {
1523         listNode *head = listFirst(server.objfreelist);
1524         o = listNodeValue(head);
1525         listDelNode(server.objfreelist,head);
1526     } else {
1527         o = zmalloc(sizeof(*o));
1528     }
1529     if (!o) oom("createObject");
1530     o->type = type;
1531     o->ptr = ptr;
1532     o->refcount = 1;
1533     return o;
1534 }
1535
1536 static robj *createStringObject(char *ptr, size_t len) {
1537     return createObject(REDIS_STRING,sdsnewlen(ptr,len));
1538 }
1539
1540 static robj *createListObject(void) {
1541     list *l = listCreate();
1542
1543     if (!l) oom("listCreate");
1544     listSetFreeMethod(l,decrRefCount);
1545     return createObject(REDIS_LIST,l);
1546 }
1547
1548 static robj *createSetObject(void) {
1549     dict *d = dictCreate(&setDictType,NULL);
1550     if (!d) oom("dictCreate");
1551     return createObject(REDIS_SET,d);
1552 }
1553
1554 static void freeStringObject(robj *o) {
1555     sdsfree(o->ptr);
1556 }
1557
1558 static void freeListObject(robj *o) {
1559     listRelease((list*) o->ptr);
1560 }
1561
1562 static void freeSetObject(robj *o) {
1563     dictRelease((dict*) o->ptr);
1564 }
1565
1566 static void freeHashObject(robj *o) {
1567     dictRelease((dict*) o->ptr);
1568 }
1569
1570 static void incrRefCount(robj *o) {
1571     o->refcount++;
1572 #ifdef DEBUG_REFCOUNT
1573     if (o->type == REDIS_STRING)
1574         printf("Increment '%s'(%p), now is: %d\n",o->ptr,o,o->refcount);
1575 #endif
1576 }
1577
1578 static void decrRefCount(void *obj) {
1579     robj *o = obj;
1580
1581 #ifdef DEBUG_REFCOUNT
1582     if (o->type == REDIS_STRING)
1583         printf("Decrement '%s'(%p), now is: %d\n",o->ptr,o,o->refcount-1);
1584 #endif
1585     if (--(o->refcount) == 0) {
1586         switch(o->type) {
1587         case REDIS_STRING: freeStringObject(o); break;
1588         case REDIS_LIST: freeListObject(o); break;
1589         case REDIS_SET: freeSetObject(o); break;
1590         case REDIS_HASH: freeHashObject(o); break;
1591         default: assert(0 != 0); break;
1592         }
1593         if (listLength(server.objfreelist) > REDIS_OBJFREELIST_MAX ||
1594             !listAddNodeHead(server.objfreelist,o))
1595             zfree(o);
1596     }
1597 }
1598
1599 /* Try to share an object against the shared objects pool */
1600 static robj *tryObjectSharing(robj *o) {
1601     struct dictEntry *de;
1602     unsigned long c;
1603
1604     if (o == NULL || server.shareobjects == 0) return o;
1605
1606     assert(o->type == REDIS_STRING);
1607     de = dictFind(server.sharingpool,o);
1608     if (de) {
1609         robj *shared = dictGetEntryKey(de);
1610
1611         c = ((unsigned long) dictGetEntryVal(de))+1;
1612         dictGetEntryVal(de) = (void*) c;
1613         incrRefCount(shared);
1614         decrRefCount(o);
1615         return shared;
1616     } else {
1617         /* Here we are using a stream algorihtm: Every time an object is
1618          * shared we increment its count, everytime there is a miss we
1619          * recrement the counter of a random object. If this object reaches
1620          * zero we remove the object and put the current object instead. */
1621         if (dictSize(server.sharingpool) >=
1622                 server.sharingpoolsize) {
1623             de = dictGetRandomKey(server.sharingpool);
1624             assert(de != NULL);
1625             c = ((unsigned long) dictGetEntryVal(de))-1;
1626             dictGetEntryVal(de) = (void*) c;
1627             if (c == 0) {
1628                 dictDelete(server.sharingpool,de->key);
1629             }
1630         } else {
1631             c = 0; /* If the pool is empty we want to add this object */
1632         }
1633         if (c == 0) {
1634             int retval;
1635
1636             retval = dictAdd(server.sharingpool,o,(void*)1);
1637             assert(retval == DICT_OK);
1638             incrRefCount(o);
1639         }
1640         return o;
1641     }
1642 }
1643
1644 static robj *lookupKey(redisDb *db, robj *key) {
1645     dictEntry *de = dictFind(db->dict,key);
1646     return de ? dictGetEntryVal(de) : NULL;
1647 }
1648
1649 static robj *lookupKeyRead(redisDb *db, robj *key) {
1650     expireIfNeeded(db,key);
1651     return lookupKey(db,key);
1652 }
1653
1654 static robj *lookupKeyWrite(redisDb *db, robj *key) {
1655     deleteIfVolatile(db,key);
1656     return lookupKey(db,key);
1657 }
1658
1659 static int deleteKey(redisDb *db, robj *key) {
1660     int retval;
1661
1662     /* We need to protect key from destruction: after the first dictDelete()
1663      * it may happen that 'key' is no longer valid if we don't increment
1664      * it's count. This may happen when we get the object reference directly
1665      * from the hash table with dictRandomKey() or dict iterators */
1666     incrRefCount(key);
1667     if (dictSize(db->expires)) dictDelete(db->expires,key);
1668     retval = dictDelete(db->dict,key);
1669     decrRefCount(key);
1670
1671     return retval == DICT_OK;
1672 }
1673
1674 /*============================ DB saving/loading ============================ */
1675
1676 static int rdbSaveType(FILE *fp, unsigned char type) {
1677     if (fwrite(&type,1,1,fp) == 0) return -1;
1678     return 0;
1679 }
1680
1681 static int rdbSaveTime(FILE *fp, time_t t) {
1682     int32_t t32 = (int32_t) t;
1683     if (fwrite(&t32,4,1,fp) == 0) return -1;
1684     return 0;
1685 }
1686
1687 /* check rdbLoadLen() comments for more info */
1688 static int rdbSaveLen(FILE *fp, uint32_t len) {
1689     unsigned char buf[2];
1690
1691     if (len < (1<<6)) {
1692         /* Save a 6 bit len */
1693         buf[0] = (len&0xFF)|(REDIS_RDB_6BITLEN<<6);
1694         if (fwrite(buf,1,1,fp) == 0) return -1;
1695     } else if (len < (1<<14)) {
1696         /* Save a 14 bit len */
1697         buf[0] = ((len>>8)&0xFF)|(REDIS_RDB_14BITLEN<<6);
1698         buf[1] = len&0xFF;
1699         if (fwrite(buf,2,1,fp) == 0) return -1;
1700     } else {
1701         /* Save a 32 bit len */
1702         buf[0] = (REDIS_RDB_32BITLEN<<6);
1703         if (fwrite(buf,1,1,fp) == 0) return -1;
1704         len = htonl(len);
1705         if (fwrite(&len,4,1,fp) == 0) return -1;
1706     }
1707     return 0;
1708 }
1709
1710 /* String objects in the form "2391" "-100" without any space and with a
1711  * range of values that can fit in an 8, 16 or 32 bit signed value can be
1712  * encoded as integers to save space */
1713 int rdbTryIntegerEncoding(sds s, unsigned char *enc) {
1714     long long value;
1715     char *endptr, buf[32];
1716
1717     /* Check if it's possible to encode this value as a number */
1718     value = strtoll(s, &endptr, 10);
1719     if (endptr[0] != '\0') return 0;
1720     snprintf(buf,32,"%lld",value);
1721
1722     /* If the number converted back into a string is not identical
1723      * then it's not possible to encode the string as integer */
1724     if (strlen(buf) != sdslen(s) || memcmp(buf,s,sdslen(s))) return 0;
1725
1726     /* Finally check if it fits in our ranges */
1727     if (value >= -(1<<7) && value <= (1<<7)-1) {
1728         enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT8;
1729         enc[1] = value&0xFF;
1730         return 2;
1731     } else if (value >= -(1<<15) && value <= (1<<15)-1) {
1732         enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT16;
1733         enc[1] = value&0xFF;
1734         enc[2] = (value>>8)&0xFF;
1735         return 3;
1736     } else if (value >= -((long long)1<<31) && value <= ((long long)1<<31)-1) {
1737         enc[0] = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_INT32;
1738         enc[1] = value&0xFF;
1739         enc[2] = (value>>8)&0xFF;
1740         enc[3] = (value>>16)&0xFF;
1741         enc[4] = (value>>24)&0xFF;
1742         return 5;
1743     } else {
1744         return 0;
1745     }
1746 }
1747
1748 static int rdbSaveLzfStringObject(FILE *fp, robj *obj) {
1749     unsigned int comprlen, outlen;
1750     unsigned char byte;
1751     void *out;
1752
1753     /* We require at least four bytes compression for this to be worth it */
1754     outlen = sdslen(obj->ptr)-4;
1755     if (outlen <= 0) return 0;
1756     if ((out = zmalloc(outlen+1)) == NULL) return 0;
1757     comprlen = lzf_compress(obj->ptr, sdslen(obj->ptr), out, outlen);
1758     if (comprlen == 0) {
1759         zfree(out);
1760         return 0;
1761     }
1762     /* Data compressed! Let's save it on disk */
1763     byte = (REDIS_RDB_ENCVAL<<6)|REDIS_RDB_ENC_LZF;
1764     if (fwrite(&byte,1,1,fp) == 0) goto writeerr;
1765     if (rdbSaveLen(fp,comprlen) == -1) goto writeerr;
1766     if (rdbSaveLen(fp,sdslen(obj->ptr)) == -1) goto writeerr;
1767     if (fwrite(out,comprlen,1,fp) == 0) goto writeerr;
1768     zfree(out);
1769     return comprlen;
1770
1771 writeerr:
1772     zfree(out);
1773     return -1;
1774 }
1775
1776 /* Save a string objet as [len][data] on disk. If the object is a string
1777  * representation of an integer value we try to safe it in a special form */
1778 static int rdbSaveStringObject(FILE *fp, robj *obj) {
1779     size_t len = sdslen(obj->ptr);
1780     int enclen;
1781
1782     /* Try integer encoding */
1783     if (len <= 11) {
1784         unsigned char buf[5];
1785         if ((enclen = rdbTryIntegerEncoding(obj->ptr,buf)) > 0) {
1786             if (fwrite(buf,enclen,1,fp) == 0) return -1;
1787             return 0;
1788         }
1789     }
1790
1791     /* Try LZF compression - under 20 bytes it's unable to compress even
1792      * aaaaaaaaaaaaaaaaaa so skip it */
1793     if (1 && len > 20) {
1794         int retval;
1795
1796         retval = rdbSaveLzfStringObject(fp,obj);
1797         if (retval == -1) return -1;
1798         if (retval > 0) return 0;
1799         /* retval == 0 means data can't be compressed, save the old way */
1800     }
1801
1802     /* Store verbatim */
1803     if (rdbSaveLen(fp,len) == -1) return -1;
1804     if (len && fwrite(obj->ptr,len,1,fp) == 0) return -1;
1805     return 0;
1806 }
1807
1808 /* Save the DB on disk. Return REDIS_ERR on error, REDIS_OK on success */
1809 static int rdbSave(char *filename) {
1810     dictIterator *di = NULL;
1811     dictEntry *de;
1812     FILE *fp;
1813     char tmpfile[256];
1814     int j;
1815     time_t now = time(NULL);
1816
1817     snprintf(tmpfile,256,"temp-%d.%ld.rdb",(int)time(NULL),(long int)random());
1818     fp = fopen(tmpfile,"w");
1819     if (!fp) {
1820         redisLog(REDIS_WARNING, "Failed saving the DB: %s", strerror(errno));
1821         return REDIS_ERR;
1822     }
1823     if (fwrite("REDIS0001",9,1,fp) == 0) goto werr;
1824     for (j = 0; j < server.dbnum; j++) {
1825         redisDb *db = server.db+j;
1826         dict *d = db->dict;
1827         if (dictSize(d) == 0) continue;
1828         di = dictGetIterator(d);
1829         if (!di) {
1830             fclose(fp);
1831             return REDIS_ERR;
1832         }
1833
1834         /* Write the SELECT DB opcode */
1835         if (rdbSaveType(fp,REDIS_SELECTDB) == -1) goto werr;
1836         if (rdbSaveLen(fp,j) == -1) goto werr;
1837
1838         /* Iterate this DB writing every entry */
1839         while((de = dictNext(di)) != NULL) {
1840             robj *key = dictGetEntryKey(de);
1841             robj *o = dictGetEntryVal(de);
1842             time_t expiretime = getExpire(db,key);
1843
1844             /* Save the expire time */
1845             if (expiretime != -1) {
1846                 /* If this key is already expired skip it */
1847                 if (expiretime < now) continue;
1848                 if (rdbSaveType(fp,REDIS_EXPIRETIME) == -1) goto werr;
1849                 if (rdbSaveTime(fp,expiretime) == -1) goto werr;
1850             }
1851             /* Save the key and associated value */
1852             if (rdbSaveType(fp,o->type) == -1) goto werr;
1853             if (rdbSaveStringObject(fp,key) == -1) goto werr;
1854             if (o->type == REDIS_STRING) {
1855                 /* Save a string value */
1856                 if (rdbSaveStringObject(fp,o) == -1) goto werr;
1857             } else if (o->type == REDIS_LIST) {
1858                 /* Save a list value */
1859                 list *list = o->ptr;
1860                 listNode *ln;
1861
1862                 listRewind(list);
1863                 if (rdbSaveLen(fp,listLength(list)) == -1) goto werr;
1864                 while((ln = listYield(list))) {
1865                     robj *eleobj = listNodeValue(ln);
1866
1867                     if (rdbSaveStringObject(fp,eleobj) == -1) goto werr;
1868                 }
1869             } else if (o->type == REDIS_SET) {
1870                 /* Save a set value */
1871                 dict *set = o->ptr;
1872                 dictIterator *di = dictGetIterator(set);
1873                 dictEntry *de;
1874
1875                 if (!set) oom("dictGetIteraotr");
1876                 if (rdbSaveLen(fp,dictSize(set)) == -1) goto werr;
1877                 while((de = dictNext(di)) != NULL) {
1878                     robj *eleobj = dictGetEntryKey(de);
1879
1880                     if (rdbSaveStringObject(fp,eleobj) == -1) goto werr;
1881                 }
1882                 dictReleaseIterator(di);
1883             } else {
1884                 assert(0 != 0);
1885             }
1886         }
1887         dictReleaseIterator(di);
1888     }
1889     /* EOF opcode */
1890     if (rdbSaveType(fp,REDIS_EOF) == -1) goto werr;
1891
1892     /* Make sure data will not remain on the OS's output buffers */
1893     fflush(fp);
1894     fsync(fileno(fp));
1895     fclose(fp);
1896
1897     /* Use RENAME to make sure the DB file is changed atomically only
1898      * if the generate DB file is ok. */
1899     if (rename(tmpfile,filename) == -1) {
1900         redisLog(REDIS_WARNING,"Error moving temp DB file on the final destionation: %s", strerror(errno));
1901         unlink(tmpfile);
1902         return REDIS_ERR;
1903     }
1904     redisLog(REDIS_NOTICE,"DB saved on disk");
1905     server.dirty = 0;
1906     server.lastsave = time(NULL);
1907     return REDIS_OK;
1908
1909 werr:
1910     fclose(fp);
1911     unlink(tmpfile);
1912     redisLog(REDIS_WARNING,"Write error saving DB on disk: %s", strerror(errno));
1913     if (di) dictReleaseIterator(di);
1914     return REDIS_ERR;
1915 }
1916
1917 static int rdbSaveBackground(char *filename) {
1918     pid_t childpid;
1919
1920     if (server.bgsaveinprogress) return REDIS_ERR;
1921     if ((childpid = fork()) == 0) {
1922         /* Child */
1923         close(server.fd);
1924         if (rdbSave(filename) == REDIS_OK) {
1925             exit(0);
1926         } else {
1927             exit(1);
1928         }
1929     } else {
1930         /* Parent */
1931         if (childpid == -1) {
1932             redisLog(REDIS_WARNING,"Can't save in background: fork: %s",
1933                 strerror(errno));
1934             return REDIS_ERR;
1935         }
1936         redisLog(REDIS_NOTICE,"Background saving started by pid %d",childpid);
1937         server.bgsaveinprogress = 1;
1938         return REDIS_OK;
1939     }
1940     return REDIS_OK; /* unreached */
1941 }
1942
1943 static int rdbLoadType(FILE *fp) {
1944     unsigned char type;
1945     if (fread(&type,1,1,fp) == 0) return -1;
1946     return type;
1947 }
1948
1949 static time_t rdbLoadTime(FILE *fp) {
1950     int32_t t32;
1951     if (fread(&t32,4,1,fp) == 0) return -1;
1952     return (time_t) t32;
1953 }
1954
1955 /* Load an encoded length from the DB, see the REDIS_RDB_* defines on the top
1956  * of this file for a description of how this are stored on disk.
1957  *
1958  * isencoded is set to 1 if the readed length is not actually a length but
1959  * an "encoding type", check the above comments for more info */
1960 static uint32_t rdbLoadLen(FILE *fp, int rdbver, int *isencoded) {
1961     unsigned char buf[2];
1962     uint32_t len;
1963
1964     if (isencoded) *isencoded = 0;
1965     if (rdbver == 0) {
1966         if (fread(&len,4,1,fp) == 0) return REDIS_RDB_LENERR;
1967         return ntohl(len);
1968     } else {
1969         int type;
1970
1971         if (fread(buf,1,1,fp) == 0) return REDIS_RDB_LENERR;
1972         type = (buf[0]&0xC0)>>6;
1973         if (type == REDIS_RDB_6BITLEN) {
1974             /* Read a 6 bit len */
1975             return buf[0]&0x3F;
1976         } else if (type == REDIS_RDB_ENCVAL) {
1977             /* Read a 6 bit len encoding type */
1978             if (isencoded) *isencoded = 1;
1979             return buf[0]&0x3F;
1980         } else if (type == REDIS_RDB_14BITLEN) {
1981             /* Read a 14 bit len */
1982             if (fread(buf+1,1,1,fp) == 0) return REDIS_RDB_LENERR;
1983             return ((buf[0]&0x3F)<<8)|buf[1];
1984         } else {
1985             /* Read a 32 bit len */
1986             if (fread(&len,4,1,fp) == 0) return REDIS_RDB_LENERR;
1987             return ntohl(len);
1988         }
1989     }
1990 }
1991
1992 static robj *rdbLoadIntegerObject(FILE *fp, int enctype) {
1993     unsigned char enc[4];
1994     long long val;
1995
1996     if (enctype == REDIS_RDB_ENC_INT8) {
1997         if (fread(enc,1,1,fp) == 0) return NULL;
1998         val = (signed char)enc[0];
1999     } else if (enctype == REDIS_RDB_ENC_INT16) {
2000         uint16_t v;
2001         if (fread(enc,2,1,fp) == 0) return NULL;
2002         v = enc[0]|(enc[1]<<8);
2003         val = (int16_t)v;
2004     } else if (enctype == REDIS_RDB_ENC_INT32) {
2005         uint32_t v;
2006         if (fread(enc,4,1,fp) == 0) return NULL;
2007         v = enc[0]|(enc[1]<<8)|(enc[2]<<16)|(enc[3]<<24);
2008         val = (int32_t)v;
2009     } else {
2010         val = 0; /* anti-warning */
2011         assert(0!=0);
2012     }
2013     return createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",val));
2014 }
2015
2016 static robj *rdbLoadLzfStringObject(FILE*fp, int rdbver) {
2017     unsigned int len, clen;
2018     unsigned char *c = NULL;
2019     sds val = NULL;
2020
2021     if ((clen = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR) return NULL;
2022     if ((len = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR) return NULL;
2023     if ((c = zmalloc(clen)) == NULL) goto err;
2024     if ((val = sdsnewlen(NULL,len)) == NULL) goto err;
2025     if (fread(c,clen,1,fp) == 0) goto err;
2026     if (lzf_decompress(c,clen,val,len) == 0) goto err;
2027     zfree(c);
2028     return createObject(REDIS_STRING,val);
2029 err:
2030     zfree(c);
2031     sdsfree(val);
2032     return NULL;
2033 }
2034
2035 static robj *rdbLoadStringObject(FILE*fp, int rdbver) {
2036     int isencoded;
2037     uint32_t len;
2038     sds val;
2039
2040     len = rdbLoadLen(fp,rdbver,&isencoded);
2041     if (isencoded) {
2042         switch(len) {
2043         case REDIS_RDB_ENC_INT8:
2044         case REDIS_RDB_ENC_INT16:
2045         case REDIS_RDB_ENC_INT32:
2046             return tryObjectSharing(rdbLoadIntegerObject(fp,len));
2047         case REDIS_RDB_ENC_LZF:
2048             return tryObjectSharing(rdbLoadLzfStringObject(fp,rdbver));
2049         default:
2050             assert(0!=0);
2051         }
2052     }
2053
2054     if (len == REDIS_RDB_LENERR) return NULL;
2055     val = sdsnewlen(NULL,len);
2056     if (len && fread(val,len,1,fp) == 0) {
2057         sdsfree(val);
2058         return NULL;
2059     }
2060     return tryObjectSharing(createObject(REDIS_STRING,val));
2061 }
2062
2063 static int rdbLoad(char *filename) {
2064     FILE *fp;
2065     robj *keyobj = NULL;
2066     uint32_t dbid;
2067     int type, retval, rdbver;
2068     dict *d = server.db[0].dict;
2069     redisDb *db = server.db+0;
2070     char buf[1024];
2071     time_t expiretime = -1, now = time(NULL);
2072
2073     fp = fopen(filename,"r");
2074     if (!fp) return REDIS_ERR;
2075     if (fread(buf,9,1,fp) == 0) goto eoferr;
2076     buf[9] = '\0';
2077     if (memcmp(buf,"REDIS",5) != 0) {
2078         fclose(fp);
2079         redisLog(REDIS_WARNING,"Wrong signature trying to load DB from file");
2080         return REDIS_ERR;
2081     }
2082     rdbver = atoi(buf+5);
2083     if (rdbver > 1) {
2084         fclose(fp);
2085         redisLog(REDIS_WARNING,"Can't handle RDB format version %d",rdbver);
2086         return REDIS_ERR;
2087     }
2088     while(1) {
2089         robj *o;
2090
2091         /* Read type. */
2092         if ((type = rdbLoadType(fp)) == -1) goto eoferr;
2093         if (type == REDIS_EXPIRETIME) {
2094             if ((expiretime = rdbLoadTime(fp)) == -1) goto eoferr;
2095             /* We read the time so we need to read the object type again */
2096             if ((type = rdbLoadType(fp)) == -1) goto eoferr;
2097         }
2098         if (type == REDIS_EOF) break;
2099         /* Handle SELECT DB opcode as a special case */
2100         if (type == REDIS_SELECTDB) {
2101             if ((dbid = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR)
2102                 goto eoferr;
2103             if (dbid >= (unsigned)server.dbnum) {
2104                 redisLog(REDIS_WARNING,"FATAL: Data file was created with a Redis server configured to handle more than %d databases. Exiting\n", server.dbnum);
2105                 exit(1);
2106             }
2107             db = server.db+dbid;
2108             d = db->dict;
2109             continue;
2110         }
2111         /* Read key */
2112         if ((keyobj = rdbLoadStringObject(fp,rdbver)) == NULL) goto eoferr;
2113
2114         if (type == REDIS_STRING) {
2115             /* Read string value */
2116             if ((o = rdbLoadStringObject(fp,rdbver)) == NULL) goto eoferr;
2117         } else if (type == REDIS_LIST || type == REDIS_SET) {
2118             /* Read list/set value */
2119             uint32_t listlen;
2120
2121             if ((listlen = rdbLoadLen(fp,rdbver,NULL)) == REDIS_RDB_LENERR)
2122                 goto eoferr;
2123             o = (type == REDIS_LIST) ? createListObject() : createSetObject();
2124             /* Load every single element of the list/set */
2125             while(listlen--) {
2126                 robj *ele;
2127
2128                 if ((ele = rdbLoadStringObject(fp,rdbver)) == NULL) goto eoferr;
2129                 if (type == REDIS_LIST) {
2130                     if (!listAddNodeTail((list*)o->ptr,ele))
2131                         oom("listAddNodeTail");
2132                 } else {
2133                     if (dictAdd((dict*)o->ptr,ele,NULL) == DICT_ERR)
2134                         oom("dictAdd");
2135                 }
2136             }
2137         } else {
2138             assert(0 != 0);
2139         }
2140         /* Add the new object in the hash table */
2141         retval = dictAdd(d,keyobj,o);
2142         if (retval == DICT_ERR) {
2143             redisLog(REDIS_WARNING,"Loading DB, duplicated key (%s) found! Unrecoverable error, exiting now.", keyobj->ptr);
2144             exit(1);
2145         }
2146         /* Set the expire time if needed */
2147         if (expiretime != -1) {
2148             setExpire(db,keyobj,expiretime);
2149             /* Delete this key if already expired */
2150             if (expiretime < now) deleteKey(db,keyobj);
2151             expiretime = -1;
2152         }
2153         keyobj = o = NULL;
2154     }
2155     fclose(fp);
2156     return REDIS_OK;
2157
2158 eoferr: /* unexpected end of file is handled here with a fatal exit */
2159     if (keyobj) decrRefCount(keyobj);
2160     redisLog(REDIS_WARNING,"Short read or OOM loading DB. Unrecoverable error, exiting now.");
2161     exit(1);
2162     return REDIS_ERR; /* Just to avoid warning */
2163 }
2164
2165 /*================================== Commands =============================== */
2166
2167 static void authCommand(redisClient *c) {
2168     if (!server.requirepass || !strcmp(c->argv[1]->ptr, server.requirepass)) {
2169       c->authenticated = 1;
2170       addReply(c,shared.ok);
2171     } else {
2172       c->authenticated = 0;
2173       addReply(c,shared.err);
2174     }
2175 }
2176
2177 static void pingCommand(redisClient *c) {
2178     addReply(c,shared.pong);
2179 }
2180
2181 static void echoCommand(redisClient *c) {
2182     addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",
2183         (int)sdslen(c->argv[1]->ptr)));
2184     addReply(c,c->argv[1]);
2185     addReply(c,shared.crlf);
2186 }
2187
2188 /*=================================== Strings =============================== */
2189
2190 static void setGenericCommand(redisClient *c, int nx) {
2191     int retval;
2192
2193     retval = dictAdd(c->db->dict,c->argv[1],c->argv[2]);
2194     if (retval == DICT_ERR) {
2195         if (!nx) {
2196             dictReplace(c->db->dict,c->argv[1],c->argv[2]);
2197             incrRefCount(c->argv[2]);
2198         } else {
2199             addReply(c,shared.czero);
2200             return;
2201         }
2202     } else {
2203         incrRefCount(c->argv[1]);
2204         incrRefCount(c->argv[2]);
2205     }
2206     server.dirty++;
2207     removeExpire(c->db,c->argv[1]);
2208     addReply(c, nx ? shared.cone : shared.ok);
2209 }
2210
2211 static void setCommand(redisClient *c) {
2212     setGenericCommand(c,0);
2213 }
2214
2215 static void setnxCommand(redisClient *c) {
2216     setGenericCommand(c,1);
2217 }
2218
2219 static void getCommand(redisClient *c) {
2220     robj *o = lookupKeyRead(c->db,c->argv[1]);
2221
2222     if (o == NULL) {
2223         addReply(c,shared.nullbulk);
2224     } else {
2225         if (o->type != REDIS_STRING) {
2226             addReply(c,shared.wrongtypeerr);
2227         } else {
2228             addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(o->ptr)));
2229             addReply(c,o);
2230             addReply(c,shared.crlf);
2231         }
2232     }
2233 }
2234
2235 static void getSetCommand(redisClient *c) {
2236     getCommand(c);
2237     if (dictAdd(c->db->dict,c->argv[1],c->argv[2]) == DICT_ERR) {
2238         dictReplace(c->db->dict,c->argv[1],c->argv[2]);
2239     } else {
2240         incrRefCount(c->argv[1]);
2241     }
2242     incrRefCount(c->argv[2]);
2243     server.dirty++;
2244     removeExpire(c->db,c->argv[1]);
2245 }
2246
2247 static void mgetCommand(redisClient *c) {
2248     int j;
2249
2250     addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",c->argc-1));
2251     for (j = 1; j < c->argc; j++) {
2252         robj *o = lookupKeyRead(c->db,c->argv[j]);
2253         if (o == NULL) {
2254             addReply(c,shared.nullbulk);
2255         } else {
2256             if (o->type != REDIS_STRING) {
2257                 addReply(c,shared.nullbulk);
2258             } else {
2259                 addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(o->ptr)));
2260                 addReply(c,o);
2261                 addReply(c,shared.crlf);
2262             }
2263         }
2264     }
2265 }
2266
2267 static void incrDecrCommand(redisClient *c, long long incr) {
2268     long long value;
2269     int retval;
2270     robj *o;
2271
2272     o = lookupKeyWrite(c->db,c->argv[1]);
2273     if (o == NULL) {
2274         value = 0;
2275     } else {
2276         if (o->type != REDIS_STRING) {
2277             value = 0;
2278         } else {
2279             char *eptr;
2280
2281             value = strtoll(o->ptr, &eptr, 10);
2282         }
2283     }
2284
2285     value += incr;
2286     o = createObject(REDIS_STRING,sdscatprintf(sdsempty(),"%lld",value));
2287     retval = dictAdd(c->db->dict,c->argv[1],o);
2288     if (retval == DICT_ERR) {
2289         dictReplace(c->db->dict,c->argv[1],o);
2290         removeExpire(c->db,c->argv[1]);
2291     } else {
2292         incrRefCount(c->argv[1]);
2293     }
2294     server.dirty++;
2295     addReply(c,shared.colon);
2296     addReply(c,o);
2297     addReply(c,shared.crlf);
2298 }
2299
2300 static void incrCommand(redisClient *c) {
2301     incrDecrCommand(c,1);
2302 }
2303
2304 static void decrCommand(redisClient *c) {
2305     incrDecrCommand(c,-1);
2306 }
2307
2308 static void incrbyCommand(redisClient *c) {
2309     long long incr = strtoll(c->argv[2]->ptr, NULL, 10);
2310     incrDecrCommand(c,incr);
2311 }
2312
2313 static void decrbyCommand(redisClient *c) {
2314     long long incr = strtoll(c->argv[2]->ptr, NULL, 10);
2315     incrDecrCommand(c,-incr);
2316 }
2317
2318 /* ========================= Type agnostic commands ========================= */
2319
2320 static void delCommand(redisClient *c) {
2321     int deleted = 0, j;
2322
2323     for (j = 1; j < c->argc; j++) {
2324         if (deleteKey(c->db,c->argv[j])) {
2325             server.dirty++;
2326             deleted++;
2327         }
2328     }
2329     switch(deleted) {
2330     case 0:
2331         addReply(c,shared.czero);
2332         break;
2333     case 1:
2334         addReply(c,shared.cone);
2335         break;
2336     default:
2337         addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",deleted));
2338         break;
2339     }
2340 }
2341
2342 static void existsCommand(redisClient *c) {
2343     addReply(c,lookupKeyRead(c->db,c->argv[1]) ? shared.cone : shared.czero);
2344 }
2345
2346 static void selectCommand(redisClient *c) {
2347     int id = atoi(c->argv[1]->ptr);
2348
2349     if (selectDb(c,id) == REDIS_ERR) {
2350         addReplySds(c,sdsnew("-ERR invalid DB index\r\n"));
2351     } else {
2352         addReply(c,shared.ok);
2353     }
2354 }
2355
2356 static void randomkeyCommand(redisClient *c) {
2357     dictEntry *de;
2358
2359     while(1) {
2360         de = dictGetRandomKey(c->db->dict);
2361         if (!de || expireIfNeeded(c->db,dictGetEntryKey(de)) == 0) break;
2362     }
2363     if (de == NULL) {
2364         addReply(c,shared.plus);
2365         addReply(c,shared.crlf);
2366     } else {
2367         addReply(c,shared.plus);
2368         addReply(c,dictGetEntryKey(de));
2369         addReply(c,shared.crlf);
2370     }
2371 }
2372
2373 static void keysCommand(redisClient *c) {
2374     dictIterator *di;
2375     dictEntry *de;
2376     sds pattern = c->argv[1]->ptr;
2377     int plen = sdslen(pattern);
2378     int numkeys = 0, keyslen = 0;
2379     robj *lenobj = createObject(REDIS_STRING,NULL);
2380
2381     di = dictGetIterator(c->db->dict);
2382     if (!di) oom("dictGetIterator");
2383     addReply(c,lenobj);
2384     decrRefCount(lenobj);
2385     while((de = dictNext(di)) != NULL) {
2386         robj *keyobj = dictGetEntryKey(de);
2387
2388         sds key = keyobj->ptr;
2389         if ((pattern[0] == '*' && pattern[1] == '\0') ||
2390             stringmatchlen(pattern,plen,key,sdslen(key),0)) {
2391             if (expireIfNeeded(c->db,keyobj) == 0) {
2392                 if (numkeys != 0)
2393                     addReply(c,shared.space);
2394                 addReply(c,keyobj);
2395                 numkeys++;
2396                 keyslen += sdslen(key);
2397             }
2398         }
2399     }
2400     dictReleaseIterator(di);
2401     lenobj->ptr = sdscatprintf(sdsempty(),"$%lu\r\n",keyslen+(numkeys ? (numkeys-1) : 0));
2402     addReply(c,shared.crlf);
2403 }
2404
2405 static void dbsizeCommand(redisClient *c) {
2406     addReplySds(c,
2407         sdscatprintf(sdsempty(),":%lu\r\n",dictSize(c->db->dict)));
2408 }
2409
2410 static void lastsaveCommand(redisClient *c) {
2411     addReplySds(c,
2412         sdscatprintf(sdsempty(),":%lu\r\n",server.lastsave));
2413 }
2414
2415 static void typeCommand(redisClient *c) {
2416     robj *o;
2417     char *type;
2418
2419     o = lookupKeyRead(c->db,c->argv[1]);
2420     if (o == NULL) {
2421         type = "+none";
2422     } else {
2423         switch(o->type) {
2424         case REDIS_STRING: type = "+string"; break;
2425         case REDIS_LIST: type = "+list"; break;
2426         case REDIS_SET: type = "+set"; break;
2427         default: type = "unknown"; break;
2428         }
2429     }
2430     addReplySds(c,sdsnew(type));
2431     addReply(c,shared.crlf);
2432 }
2433
2434 static void saveCommand(redisClient *c) {
2435     if (server.bgsaveinprogress) {
2436         addReplySds(c,sdsnew("-ERR background save in progress\r\n"));
2437         return;
2438     }
2439     if (rdbSave(server.dbfilename) == REDIS_OK) {
2440         addReply(c,shared.ok);
2441     } else {
2442         addReply(c,shared.err);
2443     }
2444 }
2445
2446 static void bgsaveCommand(redisClient *c) {
2447     if (server.bgsaveinprogress) {
2448         addReplySds(c,sdsnew("-ERR background save already in progress\r\n"));
2449         return;
2450     }
2451     if (rdbSaveBackground(server.dbfilename) == REDIS_OK) {
2452         addReply(c,shared.ok);
2453     } else {
2454         addReply(c,shared.err);
2455     }
2456 }
2457
2458 static void shutdownCommand(redisClient *c) {
2459     redisLog(REDIS_WARNING,"User requested shutdown, saving DB...");
2460     /* XXX: TODO kill the child if there is a bgsave in progress */
2461     if (rdbSave(server.dbfilename) == REDIS_OK) {
2462         if (server.daemonize) {
2463             unlink(server.pidfile);
2464         }
2465         redisLog(REDIS_WARNING,"%zu bytes used at exit",zmalloc_used_memory());
2466         redisLog(REDIS_WARNING,"Server exit now, bye bye...");
2467         exit(1);
2468     } else {
2469         redisLog(REDIS_WARNING,"Error trying to save the DB, can't exit");
2470         addReplySds(c,sdsnew("-ERR can't quit, problems saving the DB\r\n"));
2471     }
2472 }
2473
2474 static void renameGenericCommand(redisClient *c, int nx) {
2475     robj *o;
2476
2477     /* To use the same key as src and dst is probably an error */
2478     if (sdscmp(c->argv[1]->ptr,c->argv[2]->ptr) == 0) {
2479         addReply(c,shared.sameobjecterr);
2480         return;
2481     }
2482
2483     o = lookupKeyWrite(c->db,c->argv[1]);
2484     if (o == NULL) {
2485         addReply(c,shared.nokeyerr);
2486         return;
2487     }
2488     incrRefCount(o);
2489     deleteIfVolatile(c->db,c->argv[2]);
2490     if (dictAdd(c->db->dict,c->argv[2],o) == DICT_ERR) {
2491         if (nx) {
2492             decrRefCount(o);
2493             addReply(c,shared.czero);
2494             return;
2495         }
2496         dictReplace(c->db->dict,c->argv[2],o);
2497     } else {
2498         incrRefCount(c->argv[2]);
2499     }
2500     deleteKey(c->db,c->argv[1]);
2501     server.dirty++;
2502     addReply(c,nx ? shared.cone : shared.ok);
2503 }
2504
2505 static void renameCommand(redisClient *c) {
2506     renameGenericCommand(c,0);
2507 }
2508
2509 static void renamenxCommand(redisClient *c) {
2510     renameGenericCommand(c,1);
2511 }
2512
2513 static void moveCommand(redisClient *c) {
2514     robj *o;
2515     redisDb *src, *dst;
2516     int srcid;
2517
2518     /* Obtain source and target DB pointers */
2519     src = c->db;
2520     srcid = c->db->id;
2521     if (selectDb(c,atoi(c->argv[2]->ptr)) == REDIS_ERR) {
2522         addReply(c,shared.outofrangeerr);
2523         return;
2524     }
2525     dst = c->db;
2526     selectDb(c,srcid); /* Back to the source DB */
2527
2528     /* If the user is moving using as target the same
2529      * DB as the source DB it is probably an error. */
2530     if (src == dst) {
2531         addReply(c,shared.sameobjecterr);
2532         return;
2533     }
2534
2535     /* Check if the element exists and get a reference */
2536     o = lookupKeyWrite(c->db,c->argv[1]);
2537     if (!o) {
2538         addReply(c,shared.czero);
2539         return;
2540     }
2541
2542     /* Try to add the element to the target DB */
2543     deleteIfVolatile(dst,c->argv[1]);
2544     if (dictAdd(dst->dict,c->argv[1],o) == DICT_ERR) {
2545         addReply(c,shared.czero);
2546         return;
2547     }
2548     incrRefCount(c->argv[1]);
2549     incrRefCount(o);
2550
2551     /* OK! key moved, free the entry in the source DB */
2552     deleteKey(src,c->argv[1]);
2553     server.dirty++;
2554     addReply(c,shared.cone);
2555 }
2556
2557 /* =================================== Lists ================================ */
2558 static void pushGenericCommand(redisClient *c, int where) {
2559     robj *lobj;
2560     list *list;
2561
2562     lobj = lookupKeyWrite(c->db,c->argv[1]);
2563     if (lobj == NULL) {
2564         lobj = createListObject();
2565         list = lobj->ptr;
2566         if (where == REDIS_HEAD) {
2567             if (!listAddNodeHead(list,c->argv[2])) oom("listAddNodeHead");
2568         } else {
2569             if (!listAddNodeTail(list,c->argv[2])) oom("listAddNodeTail");
2570         }
2571         dictAdd(c->db->dict,c->argv[1],lobj);
2572         incrRefCount(c->argv[1]);
2573         incrRefCount(c->argv[2]);
2574     } else {
2575         if (lobj->type != REDIS_LIST) {
2576             addReply(c,shared.wrongtypeerr);
2577             return;
2578         }
2579         list = lobj->ptr;
2580         if (where == REDIS_HEAD) {
2581             if (!listAddNodeHead(list,c->argv[2])) oom("listAddNodeHead");
2582         } else {
2583             if (!listAddNodeTail(list,c->argv[2])) oom("listAddNodeTail");
2584         }
2585         incrRefCount(c->argv[2]);
2586     }
2587     server.dirty++;
2588     addReply(c,shared.ok);
2589 }
2590
2591 static void lpushCommand(redisClient *c) {
2592     pushGenericCommand(c,REDIS_HEAD);
2593 }
2594
2595 static void rpushCommand(redisClient *c) {
2596     pushGenericCommand(c,REDIS_TAIL);
2597 }
2598
2599 static void llenCommand(redisClient *c) {
2600     robj *o;
2601     list *l;
2602
2603     o = lookupKeyRead(c->db,c->argv[1]);
2604     if (o == NULL) {
2605         addReply(c,shared.czero);
2606         return;
2607     } else {
2608         if (o->type != REDIS_LIST) {
2609             addReply(c,shared.wrongtypeerr);
2610         } else {
2611             l = o->ptr;
2612             addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",listLength(l)));
2613         }
2614     }
2615 }
2616
2617 static void lindexCommand(redisClient *c) {
2618     robj *o;
2619     int index = atoi(c->argv[2]->ptr);
2620
2621     o = lookupKeyRead(c->db,c->argv[1]);
2622     if (o == NULL) {
2623         addReply(c,shared.nullbulk);
2624     } else {
2625         if (o->type != REDIS_LIST) {
2626             addReply(c,shared.wrongtypeerr);
2627         } else {
2628             list *list = o->ptr;
2629             listNode *ln;
2630
2631             ln = listIndex(list, index);
2632             if (ln == NULL) {
2633                 addReply(c,shared.nullbulk);
2634             } else {
2635                 robj *ele = listNodeValue(ln);
2636                 addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(ele->ptr)));
2637                 addReply(c,ele);
2638                 addReply(c,shared.crlf);
2639             }
2640         }
2641     }
2642 }
2643
2644 static void lsetCommand(redisClient *c) {
2645     robj *o;
2646     int index = atoi(c->argv[2]->ptr);
2647
2648     o = lookupKeyWrite(c->db,c->argv[1]);
2649     if (o == NULL) {
2650         addReply(c,shared.nokeyerr);
2651     } else {
2652         if (o->type != REDIS_LIST) {
2653             addReply(c,shared.wrongtypeerr);
2654         } else {
2655             list *list = o->ptr;
2656             listNode *ln;
2657
2658             ln = listIndex(list, index);
2659             if (ln == NULL) {
2660                 addReply(c,shared.outofrangeerr);
2661             } else {
2662                 robj *ele = listNodeValue(ln);
2663
2664                 decrRefCount(ele);
2665                 listNodeValue(ln) = c->argv[3];
2666                 incrRefCount(c->argv[3]);
2667                 addReply(c,shared.ok);
2668                 server.dirty++;
2669             }
2670         }
2671     }
2672 }
2673
2674 static void popGenericCommand(redisClient *c, int where) {
2675     robj *o;
2676
2677     o = lookupKeyWrite(c->db,c->argv[1]);
2678     if (o == NULL) {
2679         addReply(c,shared.nullbulk);
2680     } else {
2681         if (o->type != REDIS_LIST) {
2682             addReply(c,shared.wrongtypeerr);
2683         } else {
2684             list *list = o->ptr;
2685             listNode *ln;
2686
2687             if (where == REDIS_HEAD)
2688                 ln = listFirst(list);
2689             else
2690                 ln = listLast(list);
2691
2692             if (ln == NULL) {
2693                 addReply(c,shared.nullbulk);
2694             } else {
2695                 robj *ele = listNodeValue(ln);
2696                 addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(ele->ptr)));
2697                 addReply(c,ele);
2698                 addReply(c,shared.crlf);
2699                 listDelNode(list,ln);
2700                 server.dirty++;
2701             }
2702         }
2703     }
2704 }
2705
2706 static void lpopCommand(redisClient *c) {
2707     popGenericCommand(c,REDIS_HEAD);
2708 }
2709
2710 static void rpopCommand(redisClient *c) {
2711     popGenericCommand(c,REDIS_TAIL);
2712 }
2713
2714 static void lrangeCommand(redisClient *c) {
2715     robj *o;
2716     int start = atoi(c->argv[2]->ptr);
2717     int end = atoi(c->argv[3]->ptr);
2718
2719     o = lookupKeyRead(c->db,c->argv[1]);
2720     if (o == NULL) {
2721         addReply(c,shared.nullmultibulk);
2722     } else {
2723         if (o->type != REDIS_LIST) {
2724             addReply(c,shared.wrongtypeerr);
2725         } else {
2726             list *list = o->ptr;
2727             listNode *ln;
2728             int llen = listLength(list);
2729             int rangelen, j;
2730             robj *ele;
2731
2732             /* convert negative indexes */
2733             if (start < 0) start = llen+start;
2734             if (end < 0) end = llen+end;
2735             if (start < 0) start = 0;
2736             if (end < 0) end = 0;
2737
2738             /* indexes sanity checks */
2739             if (start > end || start >= llen) {
2740                 /* Out of range start or start > end result in empty list */
2741                 addReply(c,shared.emptymultibulk);
2742                 return;
2743             }
2744             if (end >= llen) end = llen-1;
2745             rangelen = (end-start)+1;
2746
2747             /* Return the result in form of a multi-bulk reply */
2748             ln = listIndex(list, start);
2749             addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",rangelen));
2750             for (j = 0; j < rangelen; j++) {
2751                 ele = listNodeValue(ln);
2752                 addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",(int)sdslen(ele->ptr)));
2753                 addReply(c,ele);
2754                 addReply(c,shared.crlf);
2755                 ln = ln->next;
2756             }
2757         }
2758     }
2759 }
2760
2761 static void ltrimCommand(redisClient *c) {
2762     robj *o;
2763     int start = atoi(c->argv[2]->ptr);
2764     int end = atoi(c->argv[3]->ptr);
2765
2766     o = lookupKeyWrite(c->db,c->argv[1]);
2767     if (o == NULL) {
2768         addReply(c,shared.nokeyerr);
2769     } else {
2770         if (o->type != REDIS_LIST) {
2771             addReply(c,shared.wrongtypeerr);
2772         } else {
2773             list *list = o->ptr;
2774             listNode *ln;
2775             int llen = listLength(list);
2776             int j, ltrim, rtrim;
2777
2778             /* convert negative indexes */
2779             if (start < 0) start = llen+start;
2780             if (end < 0) end = llen+end;
2781             if (start < 0) start = 0;
2782             if (end < 0) end = 0;
2783
2784             /* indexes sanity checks */
2785             if (start > end || start >= llen) {
2786                 /* Out of range start or start > end result in empty list */
2787                 ltrim = llen;
2788                 rtrim = 0;
2789             } else {
2790                 if (end >= llen) end = llen-1;
2791                 ltrim = start;
2792                 rtrim = llen-end-1;
2793             }
2794
2795             /* Remove list elements to perform the trim */
2796             for (j = 0; j < ltrim; j++) {
2797                 ln = listFirst(list);
2798                 listDelNode(list,ln);
2799             }
2800             for (j = 0; j < rtrim; j++) {
2801                 ln = listLast(list);
2802                 listDelNode(list,ln);
2803             }
2804             addReply(c,shared.ok);
2805             server.dirty++;
2806         }
2807     }
2808 }
2809
2810 static void lremCommand(redisClient *c) {
2811     robj *o;
2812
2813     o = lookupKeyWrite(c->db,c->argv[1]);
2814     if (o == NULL) {
2815         addReply(c,shared.nokeyerr);
2816     } else {
2817         if (o->type != REDIS_LIST) {
2818             addReply(c,shared.wrongtypeerr);
2819         } else {
2820             list *list = o->ptr;
2821             listNode *ln, *next;
2822             int toremove = atoi(c->argv[2]->ptr);
2823             int removed = 0;
2824             int fromtail = 0;
2825
2826             if (toremove < 0) {
2827                 toremove = -toremove;
2828                 fromtail = 1;
2829             }
2830             ln = fromtail ? list->tail : list->head;
2831             while (ln) {
2832                 robj *ele = listNodeValue(ln);
2833
2834                 next = fromtail ? ln->prev : ln->next;
2835                 if (sdscmp(ele->ptr,c->argv[3]->ptr) == 0) {
2836                     listDelNode(list,ln);
2837                     server.dirty++;
2838                     removed++;
2839                     if (toremove && removed == toremove) break;
2840                 }
2841                 ln = next;
2842             }
2843             addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",removed));
2844         }
2845     }
2846 }
2847
2848 /* ==================================== Sets ================================ */
2849
2850 static void saddCommand(redisClient *c) {
2851     robj *set;
2852
2853     set = lookupKeyWrite(c->db,c->argv[1]);
2854     if (set == NULL) {
2855         set = createSetObject();
2856         dictAdd(c->db->dict,c->argv[1],set);
2857         incrRefCount(c->argv[1]);
2858     } else {
2859         if (set->type != REDIS_SET) {
2860             addReply(c,shared.wrongtypeerr);
2861             return;
2862         }
2863     }
2864     if (dictAdd(set->ptr,c->argv[2],NULL) == DICT_OK) {
2865         incrRefCount(c->argv[2]);
2866         server.dirty++;
2867         addReply(c,shared.cone);
2868     } else {
2869         addReply(c,shared.czero);
2870     }
2871 }
2872
2873 static void sremCommand(redisClient *c) {
2874     robj *set;
2875
2876     set = lookupKeyWrite(c->db,c->argv[1]);
2877     if (set == NULL) {
2878         addReply(c,shared.czero);
2879     } else {
2880         if (set->type != REDIS_SET) {
2881             addReply(c,shared.wrongtypeerr);
2882             return;
2883         }
2884         if (dictDelete(set->ptr,c->argv[2]) == DICT_OK) {
2885             server.dirty++;
2886             addReply(c,shared.cone);
2887         } else {
2888             addReply(c,shared.czero);
2889         }
2890     }
2891 }
2892
2893 static void smoveCommand(redisClient *c) {
2894     robj *srcset, *dstset;
2895
2896     srcset = lookupKeyWrite(c->db,c->argv[1]);
2897     dstset = lookupKeyWrite(c->db,c->argv[2]);
2898
2899     /* If the source key does not exist return 0, if it's of the wrong type
2900      * raise an error */
2901     if (srcset == NULL || srcset->type != REDIS_SET) {
2902         addReply(c, srcset ? shared.wrongtypeerr : shared.czero);
2903         return;
2904     }
2905     /* Error if the destination key is not a set as well */
2906     if (dstset && dstset->type != REDIS_SET) {
2907         addReply(c,shared.wrongtypeerr);
2908         return;
2909     }
2910     /* Remove the element from the source set */
2911     if (dictDelete(srcset->ptr,c->argv[3]) == DICT_ERR) {
2912         /* Key not found in the src set! return zero */
2913         addReply(c,shared.czero);
2914         return;
2915     }
2916     server.dirty++;
2917     /* Add the element to the destination set */
2918     if (!dstset) {
2919         dstset = createSetObject();
2920         dictAdd(c->db->dict,c->argv[2],dstset);
2921         incrRefCount(c->argv[2]);
2922     }
2923     if (dictAdd(dstset->ptr,c->argv[3],NULL) == DICT_OK)
2924         incrRefCount(c->argv[3]);
2925     addReply(c,shared.cone);
2926 }
2927
2928 static void sismemberCommand(redisClient *c) {
2929     robj *set;
2930
2931     set = lookupKeyRead(c->db,c->argv[1]);
2932     if (set == NULL) {
2933         addReply(c,shared.czero);
2934     } else {
2935         if (set->type != REDIS_SET) {
2936             addReply(c,shared.wrongtypeerr);
2937             return;
2938         }
2939         if (dictFind(set->ptr,c->argv[2]))
2940             addReply(c,shared.cone);
2941         else
2942             addReply(c,shared.czero);
2943     }
2944 }
2945
2946 static void scardCommand(redisClient *c) {
2947     robj *o;
2948     dict *s;
2949
2950     o = lookupKeyRead(c->db,c->argv[1]);
2951     if (o == NULL) {
2952         addReply(c,shared.czero);
2953         return;
2954     } else {
2955         if (o->type != REDIS_SET) {
2956             addReply(c,shared.wrongtypeerr);
2957         } else {
2958             s = o->ptr;
2959             addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",
2960                 dictSize(s)));
2961         }
2962     }
2963 }
2964
2965 static int qsortCompareSetsByCardinality(const void *s1, const void *s2) {
2966     dict **d1 = (void*) s1, **d2 = (void*) s2;
2967
2968     return dictSize(*d1)-dictSize(*d2);
2969 }
2970
2971 static void sinterGenericCommand(redisClient *c, robj **setskeys, int setsnum, robj *dstkey) {
2972     dict **dv = zmalloc(sizeof(dict*)*setsnum);
2973     dictIterator *di;
2974     dictEntry *de;
2975     robj *lenobj = NULL, *dstset = NULL;
2976     int j, cardinality = 0;
2977
2978     if (!dv) oom("sinterGenericCommand");
2979     for (j = 0; j < setsnum; j++) {
2980         robj *setobj;
2981
2982         setobj = dstkey ?
2983                     lookupKeyWrite(c->db,setskeys[j]) :
2984                     lookupKeyRead(c->db,setskeys[j]);
2985         if (!setobj) {
2986             zfree(dv);
2987             if (dstkey) {
2988                 deleteKey(c->db,dstkey);
2989                 addReply(c,shared.ok);
2990             } else {
2991                 addReply(c,shared.nullmultibulk);
2992             }
2993             return;
2994         }
2995         if (setobj->type != REDIS_SET) {
2996             zfree(dv);
2997             addReply(c,shared.wrongtypeerr);
2998             return;
2999         }
3000         dv[j] = setobj->ptr;
3001     }
3002     /* Sort sets from the smallest to largest, this will improve our
3003      * algorithm's performace */
3004     qsort(dv,setsnum,sizeof(dict*),qsortCompareSetsByCardinality);
3005
3006     /* The first thing we should output is the total number of elements...
3007      * since this is a multi-bulk write, but at this stage we don't know
3008      * the intersection set size, so we use a trick, append an empty object
3009      * to the output list and save the pointer to later modify it with the
3010      * right length */
3011     if (!dstkey) {
3012         lenobj = createObject(REDIS_STRING,NULL);
3013         addReply(c,lenobj);
3014         decrRefCount(lenobj);
3015     } else {
3016         /* If we have a target key where to store the resulting set
3017          * create this key with an empty set inside */
3018         dstset = createSetObject();
3019     }
3020
3021     /* Iterate all the elements of the first (smallest) set, and test
3022      * the element against all the other sets, if at least one set does
3023      * not include the element it is discarded */
3024     di = dictGetIterator(dv[0]);
3025     if (!di) oom("dictGetIterator");
3026
3027     while((de = dictNext(di)) != NULL) {
3028         robj *ele;
3029
3030         for (j = 1; j < setsnum; j++)
3031             if (dictFind(dv[j],dictGetEntryKey(de)) == NULL) break;
3032         if (j != setsnum)
3033             continue; /* at least one set does not contain the member */
3034         ele = dictGetEntryKey(de);
3035         if (!dstkey) {
3036             addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",sdslen(ele->ptr)));
3037             addReply(c,ele);
3038             addReply(c,shared.crlf);
3039             cardinality++;
3040         } else {
3041             dictAdd(dstset->ptr,ele,NULL);
3042             incrRefCount(ele);
3043         }
3044     }
3045     dictReleaseIterator(di);
3046
3047     if (dstkey) {
3048         /* Store the resulting set into the target */
3049         deleteKey(c->db,dstkey);
3050         dictAdd(c->db->dict,dstkey,dstset);
3051         incrRefCount(dstkey);
3052     }
3053
3054     if (!dstkey) {
3055         lenobj->ptr = sdscatprintf(sdsempty(),"*%d\r\n",cardinality);
3056     } else {
3057         addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",
3058             dictSize((dict*)dstset->ptr)));
3059         server.dirty++;
3060     }
3061     zfree(dv);
3062 }
3063
3064 static void sinterCommand(redisClient *c) {
3065     sinterGenericCommand(c,c->argv+1,c->argc-1,NULL);
3066 }
3067
3068 static void sinterstoreCommand(redisClient *c) {
3069     sinterGenericCommand(c,c->argv+2,c->argc-2,c->argv[1]);
3070 }
3071
3072 #define REDIS_OP_UNION 0
3073 #define REDIS_OP_DIFF 1
3074
3075 static void sunionDiffGenericCommand(redisClient *c, robj **setskeys, int setsnum, robj *dstkey, int op) {
3076     dict **dv = zmalloc(sizeof(dict*)*setsnum);
3077     dictIterator *di;
3078     dictEntry *de;
3079     robj *dstset = NULL;
3080     int j, cardinality = 0;
3081
3082     if (!dv) oom("sunionDiffGenericCommand");
3083     for (j = 0; j < setsnum; j++) {
3084         robj *setobj;
3085
3086         setobj = dstkey ?
3087                     lookupKeyWrite(c->db,setskeys[j]) :
3088                     lookupKeyRead(c->db,setskeys[j]);
3089         if (!setobj) {
3090             dv[j] = NULL;
3091             continue;
3092         }
3093         if (setobj->type != REDIS_SET) {
3094             zfree(dv);
3095             addReply(c,shared.wrongtypeerr);
3096             return;
3097         }
3098         dv[j] = setobj->ptr;
3099     }
3100
3101     /* We need a temp set object to store our union. If the dstkey
3102      * is not NULL (that is, we are inside an SUNIONSTORE operation) then
3103      * this set object will be the resulting object to set into the target key*/
3104     dstset = createSetObject();
3105
3106     /* Iterate all the elements of all the sets, add every element a single
3107      * time to the result set */
3108     for (j = 0; j < setsnum; j++) {
3109         if (op == REDIS_OP_DIFF && j == 0 && !dv[j]) break; /* result set is empty */
3110         if (!dv[j]) continue; /* non existing keys are like empty sets */
3111
3112         di = dictGetIterator(dv[j]);
3113         if (!di) oom("dictGetIterator");
3114
3115         while((de = dictNext(di)) != NULL) {
3116             robj *ele;
3117
3118             /* dictAdd will not add the same element multiple times */
3119             ele = dictGetEntryKey(de);
3120             if (op == REDIS_OP_UNION || j == 0) {
3121                 if (dictAdd(dstset->ptr,ele,NULL) == DICT_OK) {
3122                     incrRefCount(ele);
3123                     cardinality++;
3124                 }
3125             } else if (op == REDIS_OP_DIFF) {
3126                 if (dictDelete(dstset->ptr,ele) == DICT_OK) {
3127                     cardinality--;
3128                 }
3129             }
3130         }
3131         dictReleaseIterator(di);
3132
3133         if (op == REDIS_OP_DIFF && cardinality == 0) break; /* result set is empty */
3134     }
3135
3136     /* Output the content of the resulting set, if not in STORE mode */
3137     if (!dstkey) {
3138         addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",cardinality));
3139         di = dictGetIterator(dstset->ptr);
3140         if (!di) oom("dictGetIterator");
3141         while((de = dictNext(di)) != NULL) {
3142             robj *ele;
3143
3144             ele = dictGetEntryKey(de);
3145             addReplySds(c,sdscatprintf(sdsempty(),
3146                     "$%d\r\n",sdslen(ele->ptr)));
3147             addReply(c,ele);
3148             addReply(c,shared.crlf);
3149         }
3150         dictReleaseIterator(di);
3151     } else {
3152         /* If we have a target key where to store the resulting set
3153          * create this key with the result set inside */
3154         deleteKey(c->db,dstkey);
3155         dictAdd(c->db->dict,dstkey,dstset);
3156         incrRefCount(dstkey);
3157     }
3158
3159     /* Cleanup */
3160     if (!dstkey) {
3161         decrRefCount(dstset);
3162     } else {
3163         addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",
3164             dictSize((dict*)dstset->ptr)));
3165         server.dirty++;
3166     }
3167     zfree(dv);
3168 }
3169
3170 static void sunionCommand(redisClient *c) {
3171     sunionDiffGenericCommand(c,c->argv+1,c->argc-1,NULL,REDIS_OP_UNION);
3172 }
3173
3174 static void sunionstoreCommand(redisClient *c) {
3175     sunionDiffGenericCommand(c,c->argv+2,c->argc-2,c->argv[1],REDIS_OP_UNION);
3176 }
3177
3178 static void sdiffCommand(redisClient *c) {
3179     sunionDiffGenericCommand(c,c->argv+1,c->argc-1,NULL,REDIS_OP_DIFF);
3180 }
3181
3182 static void sdiffstoreCommand(redisClient *c) {
3183     sunionDiffGenericCommand(c,c->argv+2,c->argc-2,c->argv[1],REDIS_OP_DIFF);
3184 }
3185
3186 static void flushdbCommand(redisClient *c) {
3187     server.dirty += dictSize(c->db->dict);
3188     dictEmpty(c->db->dict);
3189     dictEmpty(c->db->expires);
3190     addReply(c,shared.ok);
3191 }
3192
3193 static void flushallCommand(redisClient *c) {
3194     server.dirty += emptyDb();
3195     addReply(c,shared.ok);
3196     rdbSave(server.dbfilename);
3197     server.dirty++;
3198 }
3199
3200 redisSortOperation *createSortOperation(int type, robj *pattern) {
3201     redisSortOperation *so = zmalloc(sizeof(*so));
3202     if (!so) oom("createSortOperation");
3203     so->type = type;
3204     so->pattern = pattern;
3205     return so;
3206 }
3207
3208 /* Return the value associated to the key with a name obtained
3209  * substituting the first occurence of '*' in 'pattern' with 'subst' */
3210 robj *lookupKeyByPattern(redisDb *db, robj *pattern, robj *subst) {
3211     char *p;
3212     sds spat, ssub;
3213     robj keyobj;
3214     int prefixlen, sublen, postfixlen;
3215     /* Expoit the internal sds representation to create a sds string allocated on the stack in order to make this function faster */
3216     struct {
3217         long len;
3218         long free;
3219         char buf[REDIS_SORTKEY_MAX+1];
3220     } keyname;
3221
3222     spat = pattern->ptr;
3223     ssub = subst->ptr;
3224     if (sdslen(spat)+sdslen(ssub)-1 > REDIS_SORTKEY_MAX) return NULL;
3225     p = strchr(spat,'*');
3226     if (!p) return NULL;
3227
3228     prefixlen = p-spat;
3229     sublen = sdslen(ssub);
3230     postfixlen = sdslen(spat)-(prefixlen+1);
3231     memcpy(keyname.buf,spat,prefixlen);
3232     memcpy(keyname.buf+prefixlen,ssub,sublen);
3233     memcpy(keyname.buf+prefixlen+sublen,p+1,postfixlen);
3234     keyname.buf[prefixlen+sublen+postfixlen] = '\0';
3235     keyname.len = prefixlen+sublen+postfixlen;
3236
3237     keyobj.refcount = 1;
3238     keyobj.type = REDIS_STRING;
3239     keyobj.ptr = ((char*)&keyname)+(sizeof(long)*2);
3240
3241     /* printf("lookup '%s' => %p\n", keyname.buf,de); */
3242     return lookupKeyRead(db,&keyobj);
3243 }
3244
3245 /* sortCompare() is used by qsort in sortCommand(). Given that qsort_r with
3246  * the additional parameter is not standard but a BSD-specific we have to
3247  * pass sorting parameters via the global 'server' structure */
3248 static int sortCompare(const void *s1, const void *s2) {
3249     const redisSortObject *so1 = s1, *so2 = s2;
3250     int cmp;
3251
3252     if (!server.sort_alpha) {
3253         /* Numeric sorting. Here it's trivial as we precomputed scores */
3254         if (so1->u.score > so2->u.score) {
3255             cmp = 1;
3256         } else if (so1->u.score < so2->u.score) {
3257             cmp = -1;
3258         } else {
3259             cmp = 0;
3260         }
3261     } else {
3262         /* Alphanumeric sorting */
3263         if (server.sort_bypattern) {
3264             if (!so1->u.cmpobj || !so2->u.cmpobj) {
3265                 /* At least one compare object is NULL */
3266                 if (so1->u.cmpobj == so2->u.cmpobj)
3267                     cmp = 0;
3268                 else if (so1->u.cmpobj == NULL)
3269                     cmp = -1;
3270                 else
3271                     cmp = 1;
3272             } else {
3273                 /* We have both the objects, use strcoll */
3274                 cmp = strcoll(so1->u.cmpobj->ptr,so2->u.cmpobj->ptr);
3275             }
3276         } else {
3277             /* Compare elements directly */
3278             cmp = strcoll(so1->obj->ptr,so2->obj->ptr);
3279         }
3280     }
3281     return server.sort_desc ? -cmp : cmp;
3282 }
3283
3284 /* The SORT command is the most complex command in Redis. Warning: this code
3285  * is optimized for speed and a bit less for readability */
3286 static void sortCommand(redisClient *c) {
3287     list *operations;
3288     int outputlen = 0;
3289     int desc = 0, alpha = 0;
3290     int limit_start = 0, limit_count = -1, start, end;
3291     int j, dontsort = 0, vectorlen;
3292     int getop = 0; /* GET operation counter */
3293     robj *sortval, *sortby = NULL;
3294     redisSortObject *vector; /* Resulting vector to sort */
3295
3296     /* Lookup the key to sort. It must be of the right types */
3297     sortval = lookupKeyRead(c->db,c->argv[1]);
3298     if (sortval == NULL) {
3299         addReply(c,shared.nokeyerr);
3300         return;
3301     }
3302     if (sortval->type != REDIS_SET && sortval->type != REDIS_LIST) {
3303         addReply(c,shared.wrongtypeerr);
3304         return;
3305     }
3306
3307     /* Create a list of operations to perform for every sorted element.
3308      * Operations can be GET/DEL/INCR/DECR */
3309     operations = listCreate();
3310     listSetFreeMethod(operations,zfree);
3311     j = 2;
3312
3313     /* Now we need to protect sortval incrementing its count, in the future
3314      * SORT may have options able to overwrite/delete keys during the sorting
3315      * and the sorted key itself may get destroied */
3316     incrRefCount(sortval);
3317
3318     /* The SORT command has an SQL-alike syntax, parse it */
3319     while(j < c->argc) {
3320         int leftargs = c->argc-j-1;
3321         if (!strcasecmp(c->argv[j]->ptr,"asc")) {
3322             desc = 0;
3323         } else if (!strcasecmp(c->argv[j]->ptr,"desc")) {
3324             desc = 1;
3325         } else if (!strcasecmp(c->argv[j]->ptr,"alpha")) {
3326             alpha = 1;
3327         } else if (!strcasecmp(c->argv[j]->ptr,"limit") && leftargs >= 2) {
3328             limit_start = atoi(c->argv[j+1]->ptr);
3329             limit_count = atoi(c->argv[j+2]->ptr);
3330             j+=2;
3331         } else if (!strcasecmp(c->argv[j]->ptr,"by") && leftargs >= 1) {
3332             sortby = c->argv[j+1];
3333             /* If the BY pattern does not contain '*', i.e. it is constant,
3334              * we don't need to sort nor to lookup the weight keys. */
3335             if (strchr(c->argv[j+1]->ptr,'*') == NULL) dontsort = 1;
3336             j++;
3337         } else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
3338             listAddNodeTail(operations,createSortOperation(
3339                 REDIS_SORT_GET,c->argv[j+1]));
3340             getop++;
3341             j++;
3342         } else if (!strcasecmp(c->argv[j]->ptr,"del") && leftargs >= 1) {
3343             listAddNodeTail(operations,createSortOperation(
3344                 REDIS_SORT_DEL,c->argv[j+1]));
3345             j++;
3346         } else if (!strcasecmp(c->argv[j]->ptr,"incr") && leftargs >= 1) {
3347             listAddNodeTail(operations,createSortOperation(
3348                 REDIS_SORT_INCR,c->argv[j+1]));
3349             j++;
3350         } else if (!strcasecmp(c->argv[j]->ptr,"get") && leftargs >= 1) {
3351             listAddNodeTail(operations,createSortOperation(
3352                 REDIS_SORT_DECR,c->argv[j+1]));
3353             j++;
3354         } else {
3355             decrRefCount(sortval);
3356             listRelease(operations);
3357             addReply(c,shared.syntaxerr);
3358             return;
3359         }
3360         j++;
3361     }
3362
3363     /* Load the sorting vector with all the objects to sort */
3364     vectorlen = (sortval->type == REDIS_LIST) ?
3365         listLength((list*)sortval->ptr) :
3366         dictSize((dict*)sortval->ptr);
3367     vector = zmalloc(sizeof(redisSortObject)*vectorlen);
3368     if (!vector) oom("allocating objects vector for SORT");
3369     j = 0;
3370     if (sortval->type == REDIS_LIST) {
3371         list *list = sortval->ptr;
3372         listNode *ln;
3373
3374         listRewind(list);
3375         while((ln = listYield(list))) {
3376             robj *ele = ln->value;
3377             vector[j].obj = ele;
3378             vector[j].u.score = 0;
3379             vector[j].u.cmpobj = NULL;
3380             j++;
3381         }
3382     } else {
3383         dict *set = sortval->ptr;
3384         dictIterator *di;
3385         dictEntry *setele;
3386
3387         di = dictGetIterator(set);
3388         if (!di) oom("dictGetIterator");
3389         while((setele = dictNext(di)) != NULL) {
3390             vector[j].obj = dictGetEntryKey(setele);
3391             vector[j].u.score = 0;
3392             vector[j].u.cmpobj = NULL;
3393             j++;
3394         }
3395         dictReleaseIterator(di);
3396     }
3397     assert(j == vectorlen);
3398
3399     /* Now it's time to load the right scores in the sorting vector */
3400     if (dontsort == 0) {
3401         for (j = 0; j < vectorlen; j++) {
3402             if (sortby) {
3403                 robj *byval;
3404
3405                 byval = lookupKeyByPattern(c->db,sortby,vector[j].obj);
3406                 if (!byval || byval->type != REDIS_STRING) continue;
3407                 if (alpha) {
3408                     vector[j].u.cmpobj = byval;
3409                     incrRefCount(byval);
3410                 } else {
3411                     vector[j].u.score = strtod(byval->ptr,NULL);
3412                 }
3413             } else {
3414                 if (!alpha) vector[j].u.score = strtod(vector[j].obj->ptr,NULL);
3415             }
3416         }
3417     }
3418
3419     /* We are ready to sort the vector... perform a bit of sanity check
3420      * on the LIMIT option too. We'll use a partial version of quicksort. */
3421     start = (limit_start < 0) ? 0 : limit_start;
3422     end = (limit_count < 0) ? vectorlen-1 : start+limit_count-1;
3423     if (start >= vectorlen) {
3424         start = vectorlen-1;
3425         end = vectorlen-2;
3426     }
3427     if (end >= vectorlen) end = vectorlen-1;
3428
3429     if (dontsort == 0) {
3430         server.sort_desc = desc;
3431         server.sort_alpha = alpha;
3432         server.sort_bypattern = sortby ? 1 : 0;
3433         if (sortby && (start != 0 || end != vectorlen-1))
3434             pqsort(vector,vectorlen,sizeof(redisSortObject),sortCompare, start,end);
3435         else
3436             qsort(vector,vectorlen,sizeof(redisSortObject),sortCompare);
3437     }
3438
3439     /* Send command output to the output buffer, performing the specified
3440      * GET/DEL/INCR/DECR operations if any. */
3441     outputlen = getop ? getop*(end-start+1) : end-start+1;
3442     addReplySds(c,sdscatprintf(sdsempty(),"*%d\r\n",outputlen));
3443     for (j = start; j <= end; j++) {
3444         listNode *ln;
3445         if (!getop) {
3446             addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",
3447                 sdslen(vector[j].obj->ptr)));
3448             addReply(c,vector[j].obj);
3449             addReply(c,shared.crlf);
3450         }
3451         listRewind(operations);
3452         while((ln = listYield(operations))) {
3453             redisSortOperation *sop = ln->value;
3454             robj *val = lookupKeyByPattern(c->db,sop->pattern,
3455                 vector[j].obj);
3456
3457             if (sop->type == REDIS_SORT_GET) {
3458                 if (!val || val->type != REDIS_STRING) {
3459                     addReply(c,shared.nullbulk);
3460                 } else {
3461                     addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",
3462                         sdslen(val->ptr)));
3463                     addReply(c,val);
3464                     addReply(c,shared.crlf);
3465                 }
3466             } else if (sop->type == REDIS_SORT_DEL) {
3467                 /* TODO */
3468             }
3469         }
3470     }
3471
3472     /* Cleanup */
3473     decrRefCount(sortval);
3474     listRelease(operations);
3475     for (j = 0; j < vectorlen; j++) {
3476         if (sortby && alpha && vector[j].u.cmpobj)
3477             decrRefCount(vector[j].u.cmpobj);
3478     }
3479     zfree(vector);
3480 }
3481
3482 static void infoCommand(redisClient *c) {
3483     sds info;
3484     time_t uptime = time(NULL)-server.stat_starttime;
3485
3486     info = sdscatprintf(sdsempty(),
3487         "redis_version:%s\r\n"
3488         "connected_clients:%d\r\n"
3489         "connected_slaves:%d\r\n"
3490         "used_memory:%zu\r\n"
3491         "changes_since_last_save:%lld\r\n"
3492         "bgsave_in_progress:%d\r\n"
3493         "last_save_time:%d\r\n"
3494         "total_connections_received:%lld\r\n"
3495         "total_commands_processed:%lld\r\n"
3496         "uptime_in_seconds:%d\r\n"
3497         "uptime_in_days:%d\r\n"
3498         ,REDIS_VERSION,
3499         listLength(server.clients)-listLength(server.slaves),
3500         listLength(server.slaves),
3501         server.usedmemory,
3502         server.dirty,
3503         server.bgsaveinprogress,
3504         server.lastsave,
3505         server.stat_numconnections,
3506         server.stat_numcommands,
3507         uptime,
3508         uptime/(3600*24)
3509     );
3510     addReplySds(c,sdscatprintf(sdsempty(),"$%d\r\n",sdslen(info)));
3511     addReplySds(c,info);
3512     addReply(c,shared.crlf);
3513 }
3514
3515 static void monitorCommand(redisClient *c) {
3516     /* ignore MONITOR if aleady slave or in monitor mode */
3517     if (c->flags & REDIS_SLAVE) return;
3518
3519     c->flags |= (REDIS_SLAVE|REDIS_MONITOR);
3520     c->slaveseldb = 0;
3521     if (!listAddNodeTail(server.monitors,c)) oom("listAddNodeTail");
3522     addReply(c,shared.ok);
3523 }
3524
3525 /* ================================= Expire ================================= */
3526 static int removeExpire(redisDb *db, robj *key) {
3527     if (dictDelete(db->expires,key) == DICT_OK) {
3528         return 1;
3529     } else {
3530         return 0;
3531     }
3532 }
3533
3534 static int setExpire(redisDb *db, robj *key, time_t when) {
3535     if (dictAdd(db->expires,key,(void*)when) == DICT_ERR) {
3536         return 0;
3537     } else {
3538         incrRefCount(key);
3539         return 1;
3540     }
3541 }
3542
3543 /* Return the expire time of the specified key, or -1 if no expire
3544  * is associated with this key (i.e. the key is non volatile) */
3545 static time_t getExpire(redisDb *db, robj *key) {
3546     dictEntry *de;
3547
3548     /* No expire? return ASAP */
3549     if (dictSize(db->expires) == 0 ||
3550        (de = dictFind(db->expires,key)) == NULL) return -1;
3551
3552     return (time_t) dictGetEntryVal(de);
3553 }
3554
3555 static int expireIfNeeded(redisDb *db, robj *key) {
3556     time_t when;
3557     dictEntry *de;
3558
3559     /* No expire? return ASAP */
3560     if (dictSize(db->expires) == 0 ||
3561        (de = dictFind(db->expires,key)) == NULL) return 0;
3562
3563     /* Lookup the expire */
3564     when = (time_t) dictGetEntryVal(de);
3565     if (time(NULL) <= when) return 0;
3566
3567     /* Delete the key */
3568     dictDelete(db->expires,key);
3569     return dictDelete(db->dict,key) == DICT_OK;
3570 }
3571
3572 static int deleteIfVolatile(redisDb *db, robj *key) {
3573     dictEntry *de;
3574
3575     /* No expire? return ASAP */
3576     if (dictSize(db->expires) == 0 ||
3577        (de = dictFind(db->expires,key)) == NULL) return 0;
3578
3579     /* Delete the key */
3580     server.dirty++;
3581     dictDelete(db->expires,key);
3582     return dictDelete(db->dict,key) == DICT_OK;
3583 }
3584
3585 static void expireCommand(redisClient *c) {
3586     dictEntry *de;
3587     int seconds = atoi(c->argv[2]->ptr);
3588
3589     de = dictFind(c->db->dict,c->argv[1]);
3590     if (de == NULL) {
3591         addReply(c,shared.czero);
3592         return;
3593     }
3594     if (seconds <= 0) {
3595         addReply(c, shared.czero);
3596         return;
3597     } else {
3598         time_t when = time(NULL)+seconds;
3599         if (setExpire(c->db,c->argv[1],when))
3600             addReply(c,shared.cone);
3601         else
3602             addReply(c,shared.czero);
3603         return;
3604     }
3605 }
3606
3607 static void ttlCommand(redisClient *c) {
3608     time_t expire;
3609     int ttl = -1;
3610
3611     expire = getExpire(c->db,c->argv[1]);
3612     if (expire != -1) {
3613         ttl = (int) (expire-time(NULL));
3614         if (ttl < 0) ttl = -1;
3615     }
3616     addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",ttl));
3617 }
3618
3619 /* =============================== Replication  ============================= */
3620
3621 static int syncWrite(int fd, char *ptr, ssize_t size, int timeout) {
3622     ssize_t nwritten, ret = size;
3623     time_t start = time(NULL);
3624
3625     timeout++;
3626     while(size) {
3627         if (aeWait(fd,AE_WRITABLE,1000) & AE_WRITABLE) {
3628             nwritten = write(fd,ptr,size);
3629             if (nwritten == -1) return -1;
3630             ptr += nwritten;
3631             size -= nwritten;
3632         }
3633         if ((time(NULL)-start) > timeout) {
3634             errno = ETIMEDOUT;
3635             return -1;
3636         }
3637     }
3638     return ret;
3639 }
3640
3641 static int syncRead(int fd, char *ptr, ssize_t size, int timeout) {
3642     ssize_t nread, totread = 0;
3643     time_t start = time(NULL);
3644
3645     timeout++;
3646     while(size) {
3647         if (aeWait(fd,AE_READABLE,1000) & AE_READABLE) {
3648             nread = read(fd,ptr,size);
3649             if (nread == -1) return -1;
3650             ptr += nread;
3651             size -= nread;
3652             totread += nread;
3653         }
3654         if ((time(NULL)-start) > timeout) {
3655             errno = ETIMEDOUT;
3656             return -1;
3657         }
3658     }
3659     return totread;
3660 }
3661
3662 static int syncReadLine(int fd, char *ptr, ssize_t size, int timeout) {
3663     ssize_t nread = 0;
3664
3665     size--;
3666     while(size) {
3667         char c;
3668
3669         if (syncRead(fd,&c,1,timeout) == -1) return -1;
3670         if (c == '\n') {
3671             *ptr = '\0';
3672             if (nread && *(ptr-1) == '\r') *(ptr-1) = '\0';
3673             return nread;
3674         } else {
3675             *ptr++ = c;
3676             *ptr = '\0';
3677             nread++;
3678         }
3679     }
3680     return nread;
3681 }
3682
3683 static void syncCommand(redisClient *c) {
3684     /* ignore SYNC if aleady slave or in monitor mode */
3685     if (c->flags & REDIS_SLAVE) return;
3686
3687     /* SYNC can't be issued when the server has pending data to send to
3688      * the client about already issued commands. We need a fresh reply
3689      * buffer registering the differences between the BGSAVE and the current
3690      * dataset, so that we can copy to other slaves if needed. */
3691     if (listLength(c->reply) != 0) {
3692         addReplySds(c,sdsnew("-ERR SYNC is invalid with pending input\r\n"));
3693         return;
3694     }
3695
3696     redisLog(REDIS_NOTICE,"Slave ask for synchronization");
3697     /* Here we need to check if there is a background saving operation
3698      * in progress, or if it is required to start one */
3699     if (server.bgsaveinprogress) {
3700         /* Ok a background save is in progress. Let's check if it is a good
3701          * one for replication, i.e. if there is another slave that is
3702          * registering differences since the server forked to save */
3703         redisClient *slave;
3704         listNode *ln;
3705
3706         listRewind(server.slaves);
3707         while((ln = listYield(server.slaves))) {
3708             slave = ln->value;
3709             if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_END) break;
3710         }
3711         if (ln) {
3712             /* Perfect, the server is already registering differences for
3713              * another slave. Set the right state, and copy the buffer. */
3714             listRelease(c->reply);
3715             c->reply = listDup(slave->reply);
3716             if (!c->reply) oom("listDup copying slave reply list");
3717             c->replstate = REDIS_REPL_WAIT_BGSAVE_END;
3718             redisLog(REDIS_NOTICE,"Waiting for end of BGSAVE for SYNC");
3719         } else {
3720             /* No way, we need to wait for the next BGSAVE in order to
3721              * register differences */
3722             c->replstate = REDIS_REPL_WAIT_BGSAVE_START;
3723             redisLog(REDIS_NOTICE,"Waiting for next BGSAVE for SYNC");
3724         }
3725     } else {
3726         /* Ok we don't have a BGSAVE in progress, let's start one */
3727         redisLog(REDIS_NOTICE,"Starting BGSAVE for SYNC");
3728         if (rdbSaveBackground(server.dbfilename) != REDIS_OK) {
3729             redisLog(REDIS_NOTICE,"Replication failed, can't BGSAVE");
3730             addReplySds(c,sdsnew("-ERR Unalbe to perform background save\r\n"));
3731             return;
3732         }
3733         c->replstate = REDIS_REPL_WAIT_BGSAVE_END;
3734     }
3735     c->repldbfd = -1;
3736     c->flags |= REDIS_SLAVE;
3737     c->slaveseldb = 0;
3738     if (!listAddNodeTail(server.slaves,c)) oom("listAddNodeTail");
3739     return;
3740 }
3741
3742 static void sendBulkToSlave(aeEventLoop *el, int fd, void *privdata, int mask) {
3743     redisClient *slave = privdata;
3744     REDIS_NOTUSED(el);
3745     REDIS_NOTUSED(mask);
3746     char buf[REDIS_IOBUF_LEN];
3747     ssize_t nwritten, buflen;
3748
3749     if (slave->repldboff == 0) {
3750         /* Write the bulk write count before to transfer the DB. In theory here
3751          * we don't know how much room there is in the output buffer of the
3752          * socket, but in pratice SO_SNDLOWAT (the minimum count for output
3753          * operations) will never be smaller than the few bytes we need. */
3754         sds bulkcount;
3755
3756         bulkcount = sdscatprintf(sdsempty(),"$%lld\r\n",(unsigned long long)
3757             slave->repldbsize);
3758         if (write(fd,bulkcount,sdslen(bulkcount)) != (signed)sdslen(bulkcount))
3759         {
3760             sdsfree(bulkcount);
3761             freeClient(slave);
3762             return;
3763         }
3764         sdsfree(bulkcount);
3765     }
3766     lseek(slave->repldbfd,slave->repldboff,SEEK_SET);
3767     buflen = read(slave->repldbfd,buf,REDIS_IOBUF_LEN);
3768     if (buflen <= 0) {
3769         redisLog(REDIS_WARNING,"Read error sending DB to slave: %s",
3770             (buflen == 0) ? "premature EOF" : strerror(errno));
3771         freeClient(slave);
3772         return;
3773     }
3774     if ((nwritten = write(fd,buf,buflen)) == -1) {
3775         redisLog(REDIS_DEBUG,"Write error sending DB to slave: %s",
3776             strerror(errno));
3777         freeClient(slave);
3778         return;
3779     }
3780     slave->repldboff += nwritten;
3781     if (slave->repldboff == slave->repldbsize) {
3782         close(slave->repldbfd);
3783         slave->repldbfd = -1;
3784         aeDeleteFileEvent(server.el,slave->fd,AE_WRITABLE);
3785         slave->replstate = REDIS_REPL_ONLINE;
3786         if (aeCreateFileEvent(server.el, slave->fd, AE_WRITABLE,
3787             sendReplyToClient, slave, NULL) == AE_ERR) {
3788             freeClient(slave);
3789             return;
3790         }
3791         addReplySds(slave,sdsempty());
3792         redisLog(REDIS_NOTICE,"Synchronization with slave succeeded");
3793     }
3794 }
3795
3796 static void updateSalvesWaitingBgsave(int bgsaveerr) {
3797     listNode *ln;
3798     int startbgsave = 0;
3799
3800     listRewind(server.slaves);
3801     while((ln = listYield(server.slaves))) {
3802         redisClient *slave = ln->value;
3803
3804         if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START) {
3805             startbgsave = 1;
3806             slave->replstate = REDIS_REPL_WAIT_BGSAVE_END;
3807         } else if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_END) {
3808             struct stat buf;
3809
3810             if (bgsaveerr != REDIS_OK) {
3811                 freeClient(slave);
3812                 redisLog(REDIS_WARNING,"SYNC failed. BGSAVE child returned an error");
3813                 continue;
3814             }
3815             if ((slave->repldbfd = open(server.dbfilename,O_RDONLY)) == -1 ||
3816                 fstat(slave->repldbfd,&buf) == -1) {
3817                 freeClient(slave);
3818                 redisLog(REDIS_WARNING,"SYNC failed. Can't open/stat DB after BGSAVE: %s", strerror(errno));
3819                 continue;
3820             }
3821             slave->repldboff = 0;
3822             slave->repldbsize = buf.st_size;
3823             slave->replstate = REDIS_REPL_SEND_BULK;
3824             aeDeleteFileEvent(server.el,slave->fd,AE_WRITABLE);
3825             if (aeCreateFileEvent(server.el, slave->fd, AE_WRITABLE, sendBulkToSlave, slave, NULL) == AE_ERR) {
3826                 freeClient(slave);
3827                 continue;
3828             }
3829         }
3830     }
3831     if (startbgsave) {
3832         if (rdbSaveBackground(server.dbfilename) != REDIS_OK) {
3833             listRewind(server.slaves);
3834             redisLog(REDIS_WARNING,"SYNC failed. BGSAVE failed");
3835             while((ln = listYield(server.slaves))) {
3836                 redisClient *slave = ln->value;
3837
3838                 if (slave->replstate == REDIS_REPL_WAIT_BGSAVE_START)
3839                     freeClient(slave);
3840             }
3841         }
3842     }
3843 }
3844
3845 static int syncWithMaster(void) {
3846     char buf[1024], tmpfile[256];
3847     int dumpsize;
3848     int fd = anetTcpConnect(NULL,server.masterhost,server.masterport);
3849     int dfd;
3850
3851     if (fd == -1) {
3852         redisLog(REDIS_WARNING,"Unable to connect to MASTER: %s",
3853             strerror(errno));
3854         return REDIS_ERR;
3855     }
3856     /* Issue the SYNC command */
3857     if (syncWrite(fd,"SYNC \r\n",7,5) == -1) {
3858         close(fd);
3859         redisLog(REDIS_WARNING,"I/O error writing to MASTER: %s",
3860             strerror(errno));
3861         return REDIS_ERR;
3862     }
3863     /* Read the bulk write count */
3864     if (syncReadLine(fd,buf,1024,5) == -1) {
3865         close(fd);
3866         redisLog(REDIS_WARNING,"I/O error reading bulk count from MASTER: %s",
3867             strerror(errno));
3868         return REDIS_ERR;
3869     }
3870     dumpsize = atoi(buf+1);
3871     redisLog(REDIS_NOTICE,"Receiving %d bytes data dump from MASTER",dumpsize);
3872     /* Read the bulk write data on a temp file */
3873     snprintf(tmpfile,256,"temp-%d.%ld.rdb",(int)time(NULL),(long int)random());
3874     dfd = open(tmpfile,O_CREAT|O_WRONLY,0644);
3875     if (dfd == -1) {
3876         close(fd);
3877         redisLog(REDIS_WARNING,"Opening the temp file needed for MASTER <-> SLAVE synchronization: %s",strerror(errno));
3878         return REDIS_ERR;
3879     }
3880     while(dumpsize) {
3881         int nread, nwritten;
3882
3883         nread = read(fd,buf,(dumpsize < 1024)?dumpsize:1024);
3884         if (nread == -1) {
3885             redisLog(REDIS_WARNING,"I/O error trying to sync with MASTER: %s",
3886                 strerror(errno));
3887             close(fd);
3888             close(dfd);
3889             return REDIS_ERR;
3890         }
3891         nwritten = write(dfd,buf,nread);
3892         if (nwritten == -1) {
3893             redisLog(REDIS_WARNING,"Write error writing to the DB dump file needed for MASTER <-> SLAVE synchrnonization: %s", strerror(errno));
3894             close(fd);
3895             close(dfd);
3896             return REDIS_ERR;
3897         }
3898         dumpsize -= nread;
3899     }
3900     close(dfd);
3901     if (rename(tmpfile,server.dbfilename) == -1) {
3902         redisLog(REDIS_WARNING,"Failed trying to rename the temp DB into dump.rdb in MASTER <-> SLAVE synchronization: %s", strerror(errno));
3903         unlink(tmpfile);
3904         close(fd);
3905         return REDIS_ERR;
3906     }
3907     emptyDb();
3908     if (rdbLoad(server.dbfilename) != REDIS_OK) {
3909         redisLog(REDIS_WARNING,"Failed trying to load the MASTER synchronization DB from disk");
3910         close(fd);
3911         return REDIS_ERR;
3912     }
3913     server.master = createClient(fd);
3914     server.master->flags |= REDIS_MASTER;
3915     server.replstate = REDIS_REPL_CONNECTED;
3916     return REDIS_OK;
3917 }
3918
3919 /* =================================== Main! ================================ */
3920
3921 #ifdef __linux__
3922 int linuxOvercommitMemoryValue(void) {
3923     FILE *fp = fopen("/proc/sys/vm/overcommit_memory","r");
3924     char buf[64];
3925
3926     if (!fp) return -1;
3927     if (fgets(buf,64,fp) == NULL) {
3928         fclose(fp);
3929         return -1;
3930     }
3931     fclose(fp);
3932
3933     return atoi(buf);
3934 }
3935
3936 void linuxOvercommitMemoryWarning(void) {
3937     if (linuxOvercommitMemoryValue() == 0) {
3938         redisLog(REDIS_WARNING,"WARNING overcommit_memory is set to 0! Background save may fail under low condition memory. To fix this issue add 'echo 1 > /proc/sys/vm/overcommit_memory' in your init scripts.");
3939     }
3940 }
3941 #endif /* __linux__ */
3942
3943 static void daemonize(void) {
3944     int fd;
3945     FILE *fp;
3946
3947     if (fork() != 0) exit(0); /* parent exits */
3948     setsid(); /* create a new session */
3949
3950     /* Every output goes to /dev/null. If Redis is daemonized but
3951      * the 'logfile' is set to 'stdout' in the configuration file
3952      * it will not log at all. */
3953     if ((fd = open("/dev/null", O_RDWR, 0)) != -1) {
3954         dup2(fd, STDIN_FILENO);
3955         dup2(fd, STDOUT_FILENO);
3956         dup2(fd, STDERR_FILENO);
3957         if (fd > STDERR_FILENO) close(fd);
3958     }
3959     /* Try to write the pid file */
3960     fp = fopen(server.pidfile,"w");
3961     if (fp) {
3962         fprintf(fp,"%d\n",getpid());
3963         fclose(fp);
3964     }
3965 }
3966
3967 int main(int argc, char **argv) {
3968 #ifdef __linux__
3969     linuxOvercommitMemoryWarning();
3970 #endif
3971
3972     initServerConfig();
3973     if (argc == 2) {
3974         ResetServerSaveParams();
3975         loadServerConfig(argv[1]);
3976     } else if (argc > 2) {
3977         fprintf(stderr,"Usage: ./redis-server [/path/to/redis.conf]\n");
3978         exit(1);
3979     }
3980     initServer();
3981     if (server.daemonize) daemonize();
3982     redisLog(REDIS_NOTICE,"Server started, Redis version " REDIS_VERSION);
3983     if (rdbLoad(server.dbfilename) == REDIS_OK)
3984         redisLog(REDIS_NOTICE,"DB loaded from disk");
3985     if (aeCreateFileEvent(server.el, server.fd, AE_READABLE,
3986         acceptHandler, NULL, NULL) == AE_ERR) oom("creating file event");
3987     redisLog(REDIS_NOTICE,"The server is now ready to accept connections on port %d", server.port);
3988     aeMain(server.el);
3989     aeDeleteEventLoop(server.el);
3990     return 0;
3991 }