X-Git-Url: https://git.saurik.com/redis.git/blobdiff_plain/d334281c802bc94e99475557ed341d356af0ab54..0d83011a11b42fe1b0d1bebb7b9a3318fd44f0e5:/src/db.c?ds=inline diff --git a/src/db.c b/src/db.c index f7d93e08..fff63f48 100644 --- a/src/db.c +++ b/src/db.c @@ -10,28 +10,6 @@ void SlotToKeyDel(robj *key); * C-level DB API *----------------------------------------------------------------------------*/ -/* Important notes on lookup and disk store. - * - * When disk store is enabled on lookup we can have different cases. - * - * a) The key is in memory: - * - If the key is not in IO_SAVEINPROG state we can access it. - * As if it's just IO_SAVE this means we have the key in the IO queue - * but can't be accessed by the IO thread (it requires to be - * translated into an IO Job by the cache cron function.) - * - If the key is in IO_SAVEINPROG we can't touch the key and have - * to blocking wait completion of operations. - * b) The key is not in memory: - * - If it's marked as non existing on disk as well (negative cache) - * we don't need to perform the disk access. - * - if the key MAY EXIST, but is not in memory, and it is marked as IO_SAVE - * then the key can only be a deleted one. As IO_SAVE keys are never - * evicted (dirty state), so the only possibility is that key was deleted. - * - if the key MAY EXIST we need to blocking load it. - * We check that the key is not in IO_SAVEINPROG state before accessing - * the disk object. If it is in this state, we wait. - */ - robj *lookupKey(redisDb *db, robj *key) { dictEntry *de = dictFind(db->dict,key->ptr); if (de) { @@ -42,17 +20,22 @@ robj *lookupKey(redisDb *db, robj *key) { * a copy on write madness. */ if (server.rdb_child_pid == -1 && server.aof_child_pid == -1) val->lru = server.lruclock; - server.stat_keyspace_hits++; return val; } else { - server.stat_keyspace_misses++; return NULL; } } robj *lookupKeyRead(redisDb *db, robj *key) { + robj *val; + expireIfNeeded(db,key); - return lookupKey(db,key); + val = lookupKey(db,key); + if (val == NULL) + server.stat_keyspace_misses++; + else + server.stat_keyspace_hits++; + return val; } robj *lookupKeyWrite(redisDb *db, robj *key) { @@ -110,7 +93,7 @@ void setKey(redisDb *db, robj *key, robj *val) { } incrRefCount(val); removeExpire(db,key); - touchWatchedKey(db,key); + signalModifiedKey(db,key); } int dbExists(redisDb *db, robj *key) { @@ -156,8 +139,6 @@ int dbDelete(redisDb *db, robj *key) { } } -/* Empty the whole database. - * If diskstore is enabled this function will just flush the in-memory cache. */ long long emptyDb() { int j; long long removed = 0; @@ -483,9 +464,10 @@ long long getExpire(redisDb *db, robj *key) { void propagateExpire(redisDb *db, robj *key) { robj *argv[2]; - argv[0] = createStringObject("DEL",3); + argv[0] = shared.del; argv[1] = key; - incrRefCount(key); + incrRefCount(argv[0]); + incrRefCount(argv[1]); if (server.aof_state != REDIS_AOF_OFF) feedAppendOnlyFile(server.delCommand,db->id,argv,2); @@ -512,7 +494,7 @@ int expireIfNeeded(redisDb *db, robj *key) { * that is, 0 if we think the key should be still valid, 1 if * we think the key is expired at this time. */ if (server.masterhost != NULL) { - return time(NULL) > when; + return mstime() > when; } /* Return when this key has not expired */ @@ -528,24 +510,23 @@ int expireIfNeeded(redisDb *db, robj *key) { * Expires Commands *----------------------------------------------------------------------------*/ -/* Given an string object return true if it contains exactly the "ms" - * or "MS" string. This is used in order to check if the last argument - * of EXPIRE, EXPIREAT or TTL is "ms" to switch into millisecond input/output */ -int stringObjectEqualsMs(robj *a) { - char *arg = a->ptr; - return tolower(arg[0]) == 'm' && tolower(arg[1]) == 's' && arg[2] == '\0'; -} - -void expireGenericCommand(redisClient *c, long long offset, int unit) { +/* This is the generic command implementation for EXPIRE, PEXPIRE, EXPIREAT + * and PEXPIREAT. Because the commad second argument may be relative or absolute + * the "basetime" argument is used to signal what the base time is (either 0 + * for *AT variants of the command, or the current time for relative expires). + * + * unit is either UNIT_SECONDS or UNIT_MILLISECONDS, and is only used for + * the argv[2] parameter. The basetime is always specified in milliesconds. */ +void expireGenericCommand(redisClient *c, long long basetime, int unit) { dictEntry *de; robj *key = c->argv[1], *param = c->argv[2]; - long long milliseconds; + long long when; /* unix time in milliseconds when the key will expire. */ - if (getLongLongFromObjectOrReply(c, param, &milliseconds, NULL) != REDIS_OK) + if (getLongLongFromObjectOrReply(c, param, &when, NULL) != REDIS_OK) return; - if (unit == UNIT_SECONDS) milliseconds *= 1000; - milliseconds -= offset; + if (unit == UNIT_SECONDS) when *= 1000; + when += basetime; de = dictFind(c->db->dict,key->ptr); if (de == NULL) { @@ -558,7 +539,7 @@ void expireGenericCommand(redisClient *c, long long offset, int unit) { * * 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 (milliseconds <= 0 && !server.loading && !server.masterhost) { + if (when <= mstime() && !server.loading && !server.masterhost) { robj *aux; redisAssertWithInfo(c,key,dbDelete(c->db,key)); @@ -572,7 +553,6 @@ void expireGenericCommand(redisClient *c, long long offset, int unit) { addReply(c, shared.cone); return; } else { - long long when = mstime()+milliseconds; setExpire(c->db,key,when); addReply(c,shared.cone); signalModifiedKey(c->db,key); @@ -582,19 +562,19 @@ void expireGenericCommand(redisClient *c, long long offset, int unit) { } void expireCommand(redisClient *c) { - expireGenericCommand(c,0,UNIT_SECONDS); + expireGenericCommand(c,mstime(),UNIT_SECONDS); } void expireatCommand(redisClient *c) { - expireGenericCommand(c,mstime(),UNIT_SECONDS); + expireGenericCommand(c,0,UNIT_SECONDS); } void pexpireCommand(redisClient *c) { - expireGenericCommand(c,0,UNIT_MILLISECONDS); + expireGenericCommand(c,mstime(),UNIT_MILLISECONDS); } void pexpireatCommand(redisClient *c) { - expireGenericCommand(c,mstime(),UNIT_MILLISECONDS); + expireGenericCommand(c,0,UNIT_MILLISECONDS); } void ttlGenericCommand(redisClient *c, int output_ms) {