X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/4b61ca460c5d043b9d199a4e4991bfac5dde66c5..f1907057221cc1601a914c7626d896483999fb39:/src/db.c diff --git a/src/db.c b/src/db.c index fea2f12e..26af2f21 100644 --- a/src/db.c +++ b/src/db.c @@ -2,6 +2,9 @@ #include +void SlotToKeyAdd(robj *key); +void SlotToKeyDel(robj *key); + /*----------------------------------------------------------------------------- * C-level DB API *----------------------------------------------------------------------------*/ @@ -28,13 +31,6 @@ * the disk object. If it is in this state, we wait. */ -void lookupWaitBusyKey(redisDb *db, robj *key) { - /* FIXME: wait just for this key, not everything */ - waitEmptyIOJobsQueue(); - processAllPendingIOJobs(); - redisAssert((cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG) == 0); -} - robj *lookupKey(redisDb *db, robj *key) { dictEntry *de = dictFind(db->dict,key->ptr); if (de) { @@ -45,53 +41,9 @@ robj *lookupKey(redisDb *db, robj *key) { * a copy on write madness. */ if (server.bgsavechildpid == -1 && server.bgrewritechildpid == -1) val->lru = server.lruclock; - - if (server.ds_enabled && - cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG) - { - /* Need to wait for the key to get unbusy */ - redisLog(REDIS_DEBUG,"Lookup found a key in SAVEINPROG state. Waiting. (Key was in the cache)"); - lookupWaitBusyKey(db,key); - } server.stat_keyspace_hits++; return val; } else { - time_t expire; - robj *val; - - /* Key not found in the in memory hash table, but if disk store is - * enabled we may have this key on disk. If so load it in memory - * in a blocking way. */ - if (server.ds_enabled && cacheKeyMayExist(db,key)) { - long flags = cacheScheduleIOGetFlags(db,key); - - /* They key is not in cache, but it has a SAVE op in queue? - * The only possibility is that the key was deleted, since - * dirty keys are not evicted. */ - if (flags & REDIS_IO_SAVE) { - server.stat_keyspace_misses++; - return NULL; - } - - /* At this point we need to blocking load the key in memory. - * The first thing we do is waiting here if the key is busy. */ - if (flags & REDIS_IO_SAVEINPROG) { - redisLog(REDIS_DEBUG,"Lookup found a key in SAVEINPROG state. Waiting (while force loading)."); - lookupWaitBusyKey(db,key); - } - - redisLog(REDIS_DEBUG,"Force loading key %s via lookup", key->ptr); - val = dsGet(db,key,&expire); - if (val) { - int retval = dbAdd(db,key,val); - redisAssert(retval == REDIS_OK); - if (expire != -1) setExpire(db,key,expire); - server.stat_keyspace_hits++; - return val; - } else { - cacheSetKeyDoesNotExist(db,key); - } - } server.stat_keyspace_misses++; return NULL; } @@ -119,40 +71,45 @@ robj *lookupKeyWriteOrReply(redisClient *c, robj *key, robj *reply) { return o; } -/* Add the key to the DB. If the key already exists REDIS_ERR is returned, - * otherwise REDIS_OK is returned, and the caller should increment the - * refcount of 'val'. */ -int dbAdd(redisDb *db, robj *key, robj *val) { - /* Perform a lookup before adding the key, as we need to copy the - * key value. */ - if (dictFind(db->dict, key->ptr) != NULL) { - return REDIS_ERR; - } else { - sds copy = sdsdup(key->ptr); - dictAdd(db->dict, copy, val); - if (server.ds_enabled) cacheSetKeyMayExist(db,key); - return REDIS_OK; - } +/* Add the key to the DB. It's up to the caller to increment the reference + * counte of the value if needed. + * + * The program is aborted if the key already exists. */ +void dbAdd(redisDb *db, robj *key, robj *val) { + sds copy = sdsdup(key->ptr); + int retval = dictAdd(db->dict, copy, val); + + redisAssert(retval == REDIS_OK); + if (server.cluster_enabled) SlotToKeyAdd(key); + } + +/* Overwrite an existing key with a new value. Incrementing the reference + * count of the new value is up to the caller. + * This function does not modify the expire time of the existing key. + * + * The program is aborted if the key was not already present. */ +void dbOverwrite(redisDb *db, robj *key, robj *val) { + struct dictEntry *de = dictFind(db->dict,key->ptr); + + redisAssert(de != NULL); + dictReplace(db->dict, key->ptr, val); } -/* If the key does not exist, this is just like dbAdd(). Otherwise - * the value associated to the key is replaced with the new one. +/* High level Set operation. This function can be used in order to set + * a key, whatever it was existing or not, to a new object. * - * On update (key already existed) 0 is returned. Otherwise 1. */ -int dbReplace(redisDb *db, robj *key, robj *val) { - robj *oldval; - int retval; - - if ((oldval = dictFetchValue(db->dict,key->ptr)) == NULL) { - sds copy = sdsdup(key->ptr); - dictAdd(db->dict, copy, val); - retval = 1; + * 1) The ref count of the value object is incremented. + * 2) clients WATCHing for the destination key notified. + * 3) The expire time of the key is reset (the key is made persistent). */ +void setKey(redisDb *db, robj *key, robj *val) { + if (lookupKeyWrite(db,key) == NULL) { + dbAdd(db,key,val); } else { - dictReplace(db->dict, key->ptr, val); - retval = 0; + dbOverwrite(db,key,val); } - if (server.ds_enabled) cacheSetKeyMayExist(db,key); - return retval; + incrRefCount(val); + removeExpire(db,key); + touchWatchedKey(db,key); } int dbExists(redisDb *db, robj *key) { @@ -187,18 +144,15 @@ robj *dbRandomKey(redisDb *db) { /* Delete a key, value, and associated expiration entry if any, from the DB */ int dbDelete(redisDb *db, robj *key) { - /* If diskstore is enabled make sure to awake waiting clients for this key - * as it is not really useful to wait for a key already deleted to be - * loaded from disk. */ - if (server.ds_enabled) { - handleClientsBlockedOnSwappedKey(db,key); - cacheSetKeyDoesNotExist(db,key); - } - /* Deleting an entry from the expires dict will not free the sds of * the key, because it is shared with the main dictionary. */ if (dictSize(db->expires) > 0) dictDelete(db->expires,key->ptr); - return dictDelete(db->dict,key->ptr) == DICT_OK; + if (dictDelete(db->dict,key->ptr) == DICT_OK) { + if (server.cluster_enabled) SlotToKeyDel(key); + return 1; + } else { + return 0; + } } /* Empty the whole database. @@ -211,7 +165,6 @@ long long emptyDb() { removed += dictSize(server.db[j].dict); dictEmpty(server.db[j].dict); dictEmpty(server.db[j].expires); - if (server.ds_enabled) dictEmpty(server.db[j].io_negcache); } return removed; } @@ -234,8 +187,6 @@ int selectDb(redisClient *c, int id) { void signalModifiedKey(redisDb *db, robj *key) { touchWatchedKey(db,key); - if (server.ds_enabled) - cacheScheduleIO(db,key,REDIS_IO_SAVE); } void signalFlushedDb(int dbid) { @@ -251,7 +202,6 @@ void flushdbCommand(redisClient *c) { signalFlushedDb(c->db->id); dictEmpty(c->db->dict); dictEmpty(c->db->expires); - if (server.ds_enabled) dsFlushDb(c->db->id); addReply(c,shared.ok); } @@ -263,10 +213,7 @@ void flushallCommand(redisClient *c) { kill(server.bgsavechildpid,SIGKILL); rdbRemoveTempFile(server.bgsavechildpid); } - if (server.ds_enabled) - dsFlushDb(-1); - else - rdbSave(server.dbfilename); + rdbSave(server.dbfilename); server.dirty++; } @@ -274,22 +221,10 @@ void delCommand(redisClient *c) { int deleted = 0, j; for (j = 1; j < c->argc; j++) { - if (server.ds_enabled) { - lookupKeyRead(c->db,c->argv[j]); - /* FIXME: this can be optimized a lot, no real need to load - * a possibly huge value. */ - } if (dbDelete(c->db,c->argv[j])) { signalModifiedKey(c->db,c->argv[j]); server.dirty++; deleted++; - } else if (server.ds_enabled) { - if (cacheKeyMayExist(c->db,c->argv[j]) && - dsExists(c->db,c->argv[j])) - { - cacheScheduleIO(c->db,c->argv[j],REDIS_IO_SAVE); - deleted = 1; - } } } addReplyLongLong(c,deleted); @@ -307,6 +242,10 @@ void existsCommand(redisClient *c) { void selectCommand(redisClient *c) { int id = atoi(c->argv[1]->ptr); + if (server.cluster_enabled && id != 0) { + addReplyError(c,"SELECT is not allowed in cluster mode"); + return; + } if (selectDb(c,id) == REDIS_ERR) { addReplyError(c,"invalid DB index"); } else { @@ -400,13 +339,15 @@ void renameGenericCommand(redisClient *c, int nx) { return; incrRefCount(o); - if (dbAdd(c->db,c->argv[2],o) == REDIS_ERR) { + if (lookupKeyWrite(c->db,c->argv[2]) != NULL) { if (nx) { decrRefCount(o); addReply(c,shared.czero); return; } - dbReplace(c->db,c->argv[2],o); + dbOverwrite(c->db,c->argv[2],o); + } else { + dbAdd(c->db,c->argv[2],o); } dbDelete(c->db,c->argv[1]); signalModifiedKey(c->db,c->argv[1]); @@ -428,6 +369,11 @@ void moveCommand(redisClient *c) { redisDb *src, *dst; int srcid; + if (server.cluster_enabled) { + addReplyError(c,"MOVE is not allowed in cluster mode"); + return; + } + /* Obtain source and target DB pointers */ src = c->db; srcid = c->db->id; @@ -452,11 +398,12 @@ void moveCommand(redisClient *c) { return; } - /* Try to add the element to the target DB */ - if (dbAdd(dst,c->argv[1],o) == REDIS_ERR) { + /* Return zero if the key already exists in the target DB */ + if (lookupKeyWrite(dst,c->argv[1]) != NULL) { addReply(c,shared.czero); return; } + dbAdd(dst,c->argv[1],o); incrRefCount(o); /* OK! key moved, free the entry in the source DB */ @@ -529,6 +476,9 @@ int expireIfNeeded(redisDb *db, robj *key) { if (when < 0) return 0; /* No expire for this key */ + /* Don't expire anything while loading. It will be done later. */ + if (server.loading) return 0; + /* If we are running in the context of a slave, return ASAP: * the slave key expiration is controlled by the master that will * send us synthesized DEL operations for expired keys. @@ -566,10 +516,24 @@ void expireGenericCommand(redisClient *c, robj *key, robj *param, long offset) { addReply(c,shared.czero); return; } - if (seconds <= 0) { - if (dbDelete(c->db,key)) server.dirty++; - addReply(c, shared.cone); + /* EXPIRE with negative TTL, or EXPIREAT with a timestamp into the past + * should never be executed as a DEL when load the AOF or in the context + * of a slave instance. + * + * Instead we take the other branch of the IF statement setting an expire + * (possibly in the past) and wait for an explicit DEL from the master. */ + if (seconds <= 0 && !server.loading && !server.masterhost) { + robj *aux; + + redisAssert(dbDelete(c->db,key)); + server.dirty++; + + /* Replicate/AOF this as an explicit DEL. */ + aux = createStringObject("DEL",3); + rewriteClientCommandVector(c,2,aux,key); + decrRefCount(aux); signalModifiedKey(c->db,key); + addReply(c, shared.cone); return; } else { time_t when = time(NULL)+seconds; @@ -592,7 +556,6 @@ void expireatCommand(redisClient *c) { void ttlCommand(redisClient *c) { time_t expire, ttl = -1; - if (server.ds_enabled) lookupKeyRead(c->db,c->argv[1]); expire = getExpire(c->db,c->argv[1]); if (expire != -1) { ttl = (expire-time(NULL)); @@ -689,3 +652,35 @@ int *zunionInterGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *num *numkeys = num; return keys; } + +/* Slot to Key API. This is used by Redis Cluster in order to obtain in + * a fast way a key that belongs to a specified hash slot. This is useful + * while rehashing the cluster. */ +void SlotToKeyAdd(robj *key) { + unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr)); + + zslInsert(server.cluster.slots_to_keys,hashslot,key); + incrRefCount(key); +} + +void SlotToKeyDel(robj *key) { + unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr)); + + zslDelete(server.cluster.slots_to_keys,hashslot,key); +} + +unsigned int GetKeysInSlot(unsigned int hashslot, robj **keys, unsigned int count) { + zskiplistNode *n; + zrangespec range; + int j = 0; + + range.min = range.max = hashslot; + range.minex = range.maxex = 0; + + n = zslFirstInRange(server.cluster.slots_to_keys, range); + while(n && n->score == hashslot && count--) { + keys[j++] = n->obj; + n = n->level[0].forward; + } + return j; +}