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1 /*
2 * Copyright (c) 2009-2012, Salvatore Sanfilippo <antirez at gmail dot com>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions are met:
7 *
8 * * Redistributions of source code must retain the above copyright notice,
9 * this list of conditions and the following disclaimer.
10 * * Redistributions in binary form must reproduce the above copyright
11 * notice, this list of conditions and the following disclaimer in the
12 * documentation and/or other materials provided with the distribution.
13 * * Neither the name of Redis nor the names of its contributors may be used
14 * to endorse or promote products derived from this software without
15 * specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27 * POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include "redis.h"
31
32 #include <signal.h>
33 #include <ctype.h>
34
35 void SlotToKeyAdd(robj *key);
36 void SlotToKeyDel(robj *key);
37
38 /*-----------------------------------------------------------------------------
39 * C-level DB API
40 *----------------------------------------------------------------------------*/
41
42 robj *lookupKey(redisDb *db, robj *key) {
43 dictEntry *de = dictFind(db->dict,key->ptr);
44 if (de) {
45 robj *val = dictGetVal(de);
46
47 /* Update the access time for the aging algorithm.
48 * Don't do it if we have a saving child, as this will trigger
49 * a copy on write madness. */
50 if (server.rdb_child_pid == -1 && server.aof_child_pid == -1)
51 val->lru = server.lruclock;
52 return val;
53 } else {
54 return NULL;
55 }
56 }
57
58 robj *lookupKeyRead(redisDb *db, robj *key) {
59 robj *val;
60
61 expireIfNeeded(db,key);
62 val = lookupKey(db,key);
63 if (val == NULL)
64 server.stat_keyspace_misses++;
65 else
66 server.stat_keyspace_hits++;
67 return val;
68 }
69
70 robj *lookupKeyWrite(redisDb *db, robj *key) {
71 expireIfNeeded(db,key);
72 return lookupKey(db,key);
73 }
74
75 robj *lookupKeyReadOrReply(redisClient *c, robj *key, robj *reply) {
76 robj *o = lookupKeyRead(c->db, key);
77 if (!o) addReply(c,reply);
78 return o;
79 }
80
81 robj *lookupKeyWriteOrReply(redisClient *c, robj *key, robj *reply) {
82 robj *o = lookupKeyWrite(c->db, key);
83 if (!o) addReply(c,reply);
84 return o;
85 }
86
87 /* Add the key to the DB. It's up to the caller to increment the reference
88 * counte of the value if needed.
89 *
90 * The program is aborted if the key already exists. */
91 void dbAdd(redisDb *db, robj *key, robj *val) {
92 sds copy = sdsdup(key->ptr);
93 int retval = dictAdd(db->dict, copy, val);
94
95 redisAssertWithInfo(NULL,key,retval == REDIS_OK);
96 if (server.cluster_enabled) SlotToKeyAdd(key);
97 }
98
99 /* Overwrite an existing key with a new value. Incrementing the reference
100 * count of the new value is up to the caller.
101 * This function does not modify the expire time of the existing key.
102 *
103 * The program is aborted if the key was not already present. */
104 void dbOverwrite(redisDb *db, robj *key, robj *val) {
105 struct dictEntry *de = dictFind(db->dict,key->ptr);
106
107 redisAssertWithInfo(NULL,key,de != NULL);
108 dictReplace(db->dict, key->ptr, val);
109 }
110
111 /* High level Set operation. This function can be used in order to set
112 * a key, whatever it was existing or not, to a new object.
113 *
114 * 1) The ref count of the value object is incremented.
115 * 2) clients WATCHing for the destination key notified.
116 * 3) The expire time of the key is reset (the key is made persistent). */
117 void setKey(redisDb *db, robj *key, robj *val) {
118 if (lookupKeyWrite(db,key) == NULL) {
119 dbAdd(db,key,val);
120 } else {
121 dbOverwrite(db,key,val);
122 }
123 incrRefCount(val);
124 removeExpire(db,key);
125 signalModifiedKey(db,key);
126 }
127
128 int dbExists(redisDb *db, robj *key) {
129 return dictFind(db->dict,key->ptr) != NULL;
130 }
131
132 /* Return a random key, in form of a Redis object.
133 * If there are no keys, NULL is returned.
134 *
135 * The function makes sure to return keys not already expired. */
136 robj *dbRandomKey(redisDb *db) {
137 struct dictEntry *de;
138
139 while(1) {
140 sds key;
141 robj *keyobj;
142
143 de = dictGetRandomKey(db->dict);
144 if (de == NULL) return NULL;
145
146 key = dictGetKey(de);
147 keyobj = createStringObject(key,sdslen(key));
148 if (dictFind(db->expires,key)) {
149 if (expireIfNeeded(db,keyobj)) {
150 decrRefCount(keyobj);
151 continue; /* search for another key. This expired. */
152 }
153 }
154 return keyobj;
155 }
156 }
157
158 /* Delete a key, value, and associated expiration entry if any, from the DB */
159 int dbDelete(redisDb *db, robj *key) {
160 /* Deleting an entry from the expires dict will not free the sds of
161 * the key, because it is shared with the main dictionary. */
162 if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr);
163 if (dictDelete(db->dict,key->ptr) == DICT_OK) {
164 if (server.cluster_enabled) SlotToKeyDel(key);
165 return 1;
166 } else {
167 return 0;
168 }
169 }
170
171 long long emptyDb() {
172 int j;
173 long long removed = 0;
174
175 for (j = 0; j < server.dbnum; j++) {
176 removed += dictSize(server.db[j].dict);
177 dictEmpty(server.db[j].dict);
178 dictEmpty(server.db[j].expires);
179 }
180 return removed;
181 }
182
183 int selectDb(redisClient *c, int id) {
184 if (id < 0 || id >= server.dbnum)
185 return REDIS_ERR;
186 c->db = &server.db[id];
187 return REDIS_OK;
188 }
189
190 /*-----------------------------------------------------------------------------
191 * Hooks for key space changes.
192 *
193 * Every time a key in the database is modified the function
194 * signalModifiedKey() is called.
195 *
196 * Every time a DB is flushed the function signalFlushDb() is called.
197 *----------------------------------------------------------------------------*/
198
199 void signalModifiedKey(redisDb *db, robj *key) {
200 touchWatchedKey(db,key);
201 }
202
203 void signalFlushedDb(int dbid) {
204 touchWatchedKeysOnFlush(dbid);
205 }
206
207 /*-----------------------------------------------------------------------------
208 * Type agnostic commands operating on the key space
209 *----------------------------------------------------------------------------*/
210
211 void flushdbCommand(redisClient *c) {
212 server.dirty += dictSize(c->db->dict);
213 signalFlushedDb(c->db->id);
214 dictEmpty(c->db->dict);
215 dictEmpty(c->db->expires);
216 addReply(c,shared.ok);
217 }
218
219 void flushallCommand(redisClient *c) {
220 signalFlushedDb(-1);
221 server.dirty += emptyDb();
222 addReply(c,shared.ok);
223 if (server.rdb_child_pid != -1) {
224 kill(server.rdb_child_pid,SIGKILL);
225 rdbRemoveTempFile(server.rdb_child_pid);
226 }
227 if (server.saveparamslen > 0) {
228 /* Normally rdbSave() will reset dirty, but we don't want this here
229 * as otherwise FLUSHALL will not be replicated nor put into the AOF. */
230 int saved_dirty = server.dirty;
231 rdbSave(server.rdb_filename);
232 server.dirty = saved_dirty;
233 }
234 server.dirty++;
235 }
236
237 void delCommand(redisClient *c) {
238 int deleted = 0, j;
239
240 for (j = 1; j < c->argc; j++) {
241 if (dbDelete(c->db,c->argv[j])) {
242 signalModifiedKey(c->db,c->argv[j]);
243 server.dirty++;
244 deleted++;
245 }
246 }
247 addReplyLongLong(c,deleted);
248 }
249
250 void existsCommand(redisClient *c) {
251 expireIfNeeded(c->db,c->argv[1]);
252 if (dbExists(c->db,c->argv[1])) {
253 addReply(c, shared.cone);
254 } else {
255 addReply(c, shared.czero);
256 }
257 }
258
259 void selectCommand(redisClient *c) {
260 long id;
261
262 if (getLongFromObjectOrReply(c, c->argv[1], &id,
263 "invalid DB index") != REDIS_OK)
264 return;
265
266 if (server.cluster_enabled && id != 0) {
267 addReplyError(c,"SELECT is not allowed in cluster mode");
268 return;
269 }
270 if (selectDb(c,id) == REDIS_ERR) {
271 addReplyError(c,"invalid DB index");
272 } else {
273 addReply(c,shared.ok);
274 }
275 }
276
277 void randomkeyCommand(redisClient *c) {
278 robj *key;
279
280 if ((key = dbRandomKey(c->db)) == NULL) {
281 addReply(c,shared.nullbulk);
282 return;
283 }
284
285 addReplyBulk(c,key);
286 decrRefCount(key);
287 }
288
289 void keysCommand(redisClient *c) {
290 dictIterator *di;
291 dictEntry *de;
292 sds pattern = c->argv[1]->ptr;
293 int plen = sdslen(pattern), allkeys;
294 unsigned long numkeys = 0;
295 void *replylen = addDeferredMultiBulkLength(c);
296
297 di = dictGetSafeIterator(c->db->dict);
298 allkeys = (pattern[0] == '*' && pattern[1] == '\0');
299 while((de = dictNext(di)) != NULL) {
300 sds key = dictGetKey(de);
301 robj *keyobj;
302
303 if (allkeys || stringmatchlen(pattern,plen,key,sdslen(key),0)) {
304 keyobj = createStringObject(key,sdslen(key));
305 if (expireIfNeeded(c->db,keyobj) == 0) {
306 addReplyBulk(c,keyobj);
307 numkeys++;
308 }
309 decrRefCount(keyobj);
310 }
311 }
312 dictReleaseIterator(di);
313 setDeferredMultiBulkLength(c,replylen,numkeys);
314 }
315
316 void dbsizeCommand(redisClient *c) {
317 addReplyLongLong(c,dictSize(c->db->dict));
318 }
319
320 void lastsaveCommand(redisClient *c) {
321 addReplyLongLong(c,server.lastsave);
322 }
323
324 void typeCommand(redisClient *c) {
325 robj *o;
326 char *type;
327
328 o = lookupKeyRead(c->db,c->argv[1]);
329 if (o == NULL) {
330 type = "none";
331 } else {
332 switch(o->type) {
333 case REDIS_STRING: type = "string"; break;
334 case REDIS_LIST: type = "list"; break;
335 case REDIS_SET: type = "set"; break;
336 case REDIS_ZSET: type = "zset"; break;
337 case REDIS_HASH: type = "hash"; break;
338 default: type = "unknown"; break;
339 }
340 }
341 addReplyStatus(c,type);
342 }
343
344 void shutdownCommand(redisClient *c) {
345 int flags = 0;
346
347 if (c->argc > 2) {
348 addReply(c,shared.syntaxerr);
349 return;
350 } else if (c->argc == 2) {
351 if (!strcasecmp(c->argv[1]->ptr,"nosave")) {
352 flags |= REDIS_SHUTDOWN_NOSAVE;
353 } else if (!strcasecmp(c->argv[1]->ptr,"save")) {
354 flags |= REDIS_SHUTDOWN_SAVE;
355 } else {
356 addReply(c,shared.syntaxerr);
357 return;
358 }
359 }
360 if (prepareForShutdown(flags) == REDIS_OK) exit(0);
361 addReplyError(c,"Errors trying to SHUTDOWN. Check logs.");
362 }
363
364 void renameGenericCommand(redisClient *c, int nx) {
365 robj *o;
366 long long expire;
367
368 /* To use the same key as src and dst is probably an error */
369 if (sdscmp(c->argv[1]->ptr,c->argv[2]->ptr) == 0) {
370 addReply(c,shared.sameobjecterr);
371 return;
372 }
373
374 if ((o = lookupKeyWriteOrReply(c,c->argv[1],shared.nokeyerr)) == NULL)
375 return;
376
377 incrRefCount(o);
378 expire = getExpire(c->db,c->argv[1]);
379 if (lookupKeyWrite(c->db,c->argv[2]) != NULL) {
380 if (nx) {
381 decrRefCount(o);
382 addReply(c,shared.czero);
383 return;
384 }
385 /* Overwrite: delete the old key before creating the new one with the same name. */
386 dbDelete(c->db,c->argv[2]);
387 }
388 dbAdd(c->db,c->argv[2],o);
389 if (expire != -1) setExpire(c->db,c->argv[2],expire);
390 dbDelete(c->db,c->argv[1]);
391 signalModifiedKey(c->db,c->argv[1]);
392 signalModifiedKey(c->db,c->argv[2]);
393 server.dirty++;
394 addReply(c,nx ? shared.cone : shared.ok);
395 }
396
397 void renameCommand(redisClient *c) {
398 renameGenericCommand(c,0);
399 }
400
401 void renamenxCommand(redisClient *c) {
402 renameGenericCommand(c,1);
403 }
404
405 void moveCommand(redisClient *c) {
406 robj *o;
407 redisDb *src, *dst;
408 int srcid;
409
410 if (server.cluster_enabled) {
411 addReplyError(c,"MOVE is not allowed in cluster mode");
412 return;
413 }
414
415 /* Obtain source and target DB pointers */
416 src = c->db;
417 srcid = c->db->id;
418 if (selectDb(c,atoi(c->argv[2]->ptr)) == REDIS_ERR) {
419 addReply(c,shared.outofrangeerr);
420 return;
421 }
422 dst = c->db;
423 selectDb(c,srcid); /* Back to the source DB */
424
425 /* If the user is moving using as target the same
426 * DB as the source DB it is probably an error. */
427 if (src == dst) {
428 addReply(c,shared.sameobjecterr);
429 return;
430 }
431
432 /* Check if the element exists and get a reference */
433 o = lookupKeyWrite(c->db,c->argv[1]);
434 if (!o) {
435 addReply(c,shared.czero);
436 return;
437 }
438
439 /* Return zero if the key already exists in the target DB */
440 if (lookupKeyWrite(dst,c->argv[1]) != NULL) {
441 addReply(c,shared.czero);
442 return;
443 }
444 dbAdd(dst,c->argv[1],o);
445 incrRefCount(o);
446
447 /* OK! key moved, free the entry in the source DB */
448 dbDelete(src,c->argv[1]);
449 server.dirty++;
450 addReply(c,shared.cone);
451 }
452
453 /*-----------------------------------------------------------------------------
454 * Expires API
455 *----------------------------------------------------------------------------*/
456
457 int removeExpire(redisDb *db, robj *key) {
458 /* An expire may only be removed if there is a corresponding entry in the
459 * main dict. Otherwise, the key will never be freed. */
460 redisAssertWithInfo(NULL,key,dictFind(db->dict,key->ptr) != NULL);
461 return dictDelete(db->expires,key->ptr) == DICT_OK;
462 }
463
464 void setExpire(redisDb *db, robj *key, long long when) {
465 dictEntry *kde, *de;
466
467 /* Reuse the sds from the main dict in the expire dict */
468 kde = dictFind(db->dict,key->ptr);
469 redisAssertWithInfo(NULL,key,kde != NULL);
470 de = dictReplaceRaw(db->expires,dictGetKey(kde));
471 dictSetSignedIntegerVal(de,when);
472 }
473
474 /* Return the expire time of the specified key, or -1 if no expire
475 * is associated with this key (i.e. the key is non volatile) */
476 long long getExpire(redisDb *db, robj *key) {
477 dictEntry *de;
478
479 /* No expire? return ASAP */
480 if (dictSize(db->expires) == 0 ||
481 (de = dictFind(db->expires,key->ptr)) == NULL) return -1;
482
483 /* The entry was found in the expire dict, this means it should also
484 * be present in the main dict (safety check). */
485 redisAssertWithInfo(NULL,key,dictFind(db->dict,key->ptr) != NULL);
486 return dictGetSignedIntegerVal(de);
487 }
488
489 /* Propagate expires into slaves and the AOF file.
490 * When a key expires in the master, a DEL operation for this key is sent
491 * to all the slaves and the AOF file if enabled.
492 *
493 * This way the key expiry is centralized in one place, and since both
494 * AOF and the master->slave link guarantee operation ordering, everything
495 * will be consistent even if we allow write operations against expiring
496 * keys. */
497 void propagateExpire(redisDb *db, robj *key) {
498 robj *argv[2];
499
500 argv[0] = shared.del;
501 argv[1] = key;
502 incrRefCount(argv[0]);
503 incrRefCount(argv[1]);
504
505 if (server.aof_state != REDIS_AOF_OFF)
506 feedAppendOnlyFile(server.delCommand,db->id,argv,2);
507 if (listLength(server.slaves))
508 replicationFeedSlaves(server.slaves,db->id,argv,2);
509
510 decrRefCount(argv[0]);
511 decrRefCount(argv[1]);
512 }
513
514 int expireIfNeeded(redisDb *db, robj *key) {
515 long long when = getExpire(db,key);
516
517 if (when < 0) return 0; /* No expire for this key */
518
519 /* Don't expire anything while loading. It will be done later. */
520 if (server.loading) return 0;
521
522 /* If we are running in the context of a slave, return ASAP:
523 * the slave key expiration is controlled by the master that will
524 * send us synthesized DEL operations for expired keys.
525 *
526 * Still we try to return the right information to the caller,
527 * that is, 0 if we think the key should be still valid, 1 if
528 * we think the key is expired at this time. */
529 if (server.masterhost != NULL) {
530 return mstime() > when;
531 }
532
533 /* Return when this key has not expired */
534 if (mstime() <= when) return 0;
535
536 /* Delete the key */
537 server.stat_expiredkeys++;
538 propagateExpire(db,key);
539 return dbDelete(db,key);
540 }
541
542 /*-----------------------------------------------------------------------------
543 * Expires Commands
544 *----------------------------------------------------------------------------*/
545
546 /* This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT
547 * and PEXPIREAT. Because the commad second argument may be relative or absolute
548 * the "basetime" argument is used to signal what the base time is (either 0
549 * for *AT variants of the command, or the current time for relative expires).
550 *
551 * unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for
552 * the argv[2] parameter. The basetime is always specified in milliesconds. */
553 void expireGenericCommand(redisClient *c, long long basetime, int unit) {
554 dictEntry *de;
555 robj *key = c->argv[1], *param = c->argv[2];
556 long long when; /* unix time in milliseconds when the key will expire. */
557
558 if (getLongLongFromObjectOrReply(c, param, &when, NULL) != REDIS_OK)
559 return;
560
561 if (unit == UNIT_SECONDS) when *= 1000;
562 when += basetime;
563
564 de = dictFind(c->db->dict,key->ptr);
565 if (de == NULL) {
566 addReply(c,shared.czero);
567 return;
568 }
569 /* EXPIRE with negative TTL, or EXPIREAT with a timestamp into the past
570 * should never be executed as a DEL when load the AOF or in the context
571 * of a slave instance.
572 *
573 * Instead we take the other branch of the IF statement setting an expire
574 * (possibly in the past) and wait for an explicit DEL from the master. */
575 if (when <= mstime() && !server.loading && !server.masterhost) {
576 robj *aux;
577
578 redisAssertWithInfo(c,key,dbDelete(c->db,key));
579 server.dirty++;
580
581 /* Replicate/AOF this as an explicit DEL. */
582 aux = createStringObject("DEL",3);
583 rewriteClientCommandVector(c,2,aux,key);
584 decrRefCount(aux);
585 signalModifiedKey(c->db,key);
586 addReply(c, shared.cone);
587 return;
588 } else {
589 setExpire(c->db,key,when);
590 addReply(c,shared.cone);
591 signalModifiedKey(c->db,key);
592 server.dirty++;
593 return;
594 }
595 }
596
597 void expireCommand(redisClient *c) {
598 expireGenericCommand(c,mstime(),UNIT_SECONDS);
599 }
600
601 void expireatCommand(redisClient *c) {
602 expireGenericCommand(c,0,UNIT_SECONDS);
603 }
604
605 void pexpireCommand(redisClient *c) {
606 expireGenericCommand(c,mstime(),UNIT_MILLISECONDS);
607 }
608
609 void pexpireatCommand(redisClient *c) {
610 expireGenericCommand(c,0,UNIT_MILLISECONDS);
611 }
612
613 void ttlGenericCommand(redisClient *c, int output_ms) {
614 long long expire, ttl = -1;
615
616 expire = getExpire(c->db,c->argv[1]);
617 if (expire != -1) {
618 ttl = expire-mstime();
619 if (ttl < 0) ttl = -1;
620 }
621 if (ttl == -1) {
622 addReplyLongLong(c,-1);
623 } else {
624 addReplyLongLong(c,output_ms ? ttl : ((ttl+500)/1000));
625 }
626 }
627
628 void ttlCommand(redisClient *c) {
629 ttlGenericCommand(c, 0);
630 }
631
632 void pttlCommand(redisClient *c) {
633 ttlGenericCommand(c, 1);
634 }
635
636 void persistCommand(redisClient *c) {
637 dictEntry *de;
638
639 de = dictFind(c->db->dict,c->argv[1]->ptr);
640 if (de == NULL) {
641 addReply(c,shared.czero);
642 } else {
643 if (removeExpire(c->db,c->argv[1])) {
644 addReply(c,shared.cone);
645 server.dirty++;
646 } else {
647 addReply(c,shared.czero);
648 }
649 }
650 }
651
652 /* -----------------------------------------------------------------------------
653 * API to get key arguments from commands
654 * ---------------------------------------------------------------------------*/
655
656 int *getKeysUsingCommandTable(struct redisCommand *cmd,robj **argv, int argc, int *numkeys) {
657 int j, i = 0, last, *keys;
658 REDIS_NOTUSED(argv);
659
660 if (cmd->firstkey == 0) {
661 *numkeys = 0;
662 return NULL;
663 }
664 last = cmd->lastkey;
665 if (last < 0) last = argc+last;
666 keys = zmalloc(sizeof(int)*((last - cmd->firstkey)+1));
667 for (j = cmd->firstkey; j <= last; j += cmd->keystep) {
668 redisAssert(j < argc);
669 keys[i++] = j;
670 }
671 *numkeys = i;
672 return keys;
673 }
674
675 int *getKeysFromCommand(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
676 if (cmd->getkeys_proc) {
677 return cmd->getkeys_proc(cmd,argv,argc,numkeys,flags);
678 } else {
679 return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
680 }
681 }
682
683 void getKeysFreeResult(int *result) {
684 zfree(result);
685 }
686
687 int *noPreloadGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
688 if (flags & REDIS_GETKEYS_PRELOAD) {
689 *numkeys = 0;
690 return NULL;
691 } else {
692 return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
693 }
694 }
695
696 int *renameGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
697 if (flags & REDIS_GETKEYS_PRELOAD) {
698 int *keys = zmalloc(sizeof(int));
699 *numkeys = 1;
700 keys[0] = 1;
701 return keys;
702 } else {
703 return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
704 }
705 }
706
707 int *zunionInterGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
708 int i, num, *keys;
709 REDIS_NOTUSED(cmd);
710 REDIS_NOTUSED(flags);
711
712 num = atoi(argv[2]->ptr);
713 /* Sanity check. Don't return any key if the command is going to
714 * reply with syntax error. */
715 if (num > (argc-3)) {
716 *numkeys = 0;
717 return NULL;
718 }
719 keys = zmalloc(sizeof(int)*num);
720 for (i = 0; i < num; i++) keys[i] = 3+i;
721 *numkeys = num;
722 return keys;
723 }
724
725 /* Slot to Key API. This is used by Redis Cluster in order to obtain in
726 * a fast way a key that belongs to a specified hash slot. This is useful
727 * while rehashing the cluster. */
728 void SlotToKeyAdd(robj *key) {
729 unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
730
731 zslInsert(server.cluster.slots_to_keys,hashslot,key);
732 incrRefCount(key);
733 }
734
735 void SlotToKeyDel(robj *key) {
736 unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
737
738 zslDelete(server.cluster.slots_to_keys,hashslot,key);
739 }
740
741 unsigned int GetKeysInSlot(unsigned int hashslot, robj **keys, unsigned int count) {
742 zskiplistNode *n;
743 zrangespec range;
744 int j = 0;
745
746 range.min = range.max = hashslot;
747 range.minex = range.maxex = 0;
748
749 n = zslFirstInRange(server.cluster.slots_to_keys, range);
750 while(n && n->score == hashslot && count--) {
751 keys[j++] = n->obj;
752 n = n->level[0].forward;
753 }
754 return j;
755 }