* 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.
+ */
+
+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) {
robj *val = dictGetEntryVal(de);
- if (server.vm_enabled) {
- if (val->storage == REDIS_VM_MEMORY ||
- val->storage == REDIS_VM_SWAPPING)
- {
- /* If we were swapping the object out, cancel the operation */
- if (val->storage == REDIS_VM_SWAPPING)
- vmCancelThreadedIOJob(val);
- /* Update the access time for the aging algorithm. */
- val->lru = server.lruclock;
- } else {
- int notify = (val->storage == REDIS_VM_LOADING);
+ /* Update the access time for the aging algorithm.
+ * Don't do it if we have a saving child, as this will trigger
+ * 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;
+ }
- /* Our value was swapped on disk. Bring it at home. */
- redisAssert(val->type == REDIS_VMPOINTER);
- val = vmLoadObject(val);
- dictGetEntryVal(de) = val;
+ /* 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);
+ }
- /* Clients blocked by the VM subsystem may be waiting for
- * this key... */
- if (notify) handleClientsBlockedOnSwappedKey(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);
}
}
- return val;
- } else {
+ server.stat_keyspace_misses++;
return NULL;
}
}
}
robj *lookupKeyWrite(redisDb *db, robj *key) {
- deleteIfVolatile(db,key);
- touchWatchedKey(db,key);
+ expireIfNeeded(db,key);
return lookupKey(db,key);
}
} else {
sds copy = sdsdup(key->ptr);
dictAdd(db->dict, copy, val);
+ if (server.ds_enabled) cacheSetKeyMayExist(db,key);
return REDIS_OK;
}
}
*
* On update (key already existed) 0 is returned. Otherwise 1. */
int dbReplace(redisDb *db, robj *key, robj *val) {
- if (dictFind(db->dict,key->ptr) == NULL) {
+ robj *oldval;
+ int retval;
+
+ if ((oldval = dictFetchValue(db->dict,key->ptr)) == NULL) {
sds copy = sdsdup(key->ptr);
dictAdd(db->dict, copy, val);
- return 1;
+ retval = 1;
} else {
dictReplace(db->dict, key->ptr, val);
- return 0;
+ retval = 0;
}
+ if (server.ds_enabled) cacheSetKeyMayExist(db,key);
+ return retval;
}
int dbExists(redisDb *db, robj *key) {
/* 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;
}
-/* Empty the whole database */
+/* 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;
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;
}
return REDIS_OK;
}
+/*-----------------------------------------------------------------------------
+ * Hooks for key space changes.
+ *
+ * Every time a key in the database is modified the function
+ * signalModifiedKey() is called.
+ *
+ * Every time a DB is flushed the function signalFlushDb() is called.
+ *----------------------------------------------------------------------------*/
+
+void signalModifiedKey(redisDb *db, robj *key) {
+ touchWatchedKey(db,key);
+ if (server.ds_enabled)
+ cacheScheduleIO(db,key,REDIS_IO_SAVE);
+}
+
+void signalFlushedDb(int dbid) {
+ touchWatchedKeysOnFlush(dbid);
+}
+
/*-----------------------------------------------------------------------------
* Type agnostic commands operating on the key space
*----------------------------------------------------------------------------*/
void flushdbCommand(redisClient *c) {
server.dirty += dictSize(c->db->dict);
- touchWatchedKeysOnFlush(c->db->id);
+ signalFlushedDb(c->db->id);
dictEmpty(c->db->dict);
dictEmpty(c->db->expires);
+ if (server.ds_enabled) dsFlushDb(c->db->id);
addReply(c,shared.ok);
}
void flushallCommand(redisClient *c) {
- touchWatchedKeysOnFlush(-1);
+ signalFlushedDb(-1);
server.dirty += emptyDb();
addReply(c,shared.ok);
if (server.bgsavechildpid != -1) {
kill(server.bgsavechildpid,SIGKILL);
rdbRemoveTempFile(server.bgsavechildpid);
}
- rdbSave(server.dbfilename);
+ if (server.ds_enabled)
+ dsFlushDb(-1);
+ else
+ rdbSave(server.dbfilename);
server.dirty++;
}
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])) {
- touchWatchedKey(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);
int id = atoi(c->argv[1]->ptr);
if (selectDb(c,id) == REDIS_ERR) {
- addReplySds(c,sdsnew("-ERR invalid DB index\r\n"));
+ addReplyError(c,"invalid DB index");
} else {
addReply(c,shared.ok);
}
dictIterator *di;
dictEntry *de;
sds pattern = c->argv[1]->ptr;
- int plen = sdslen(pattern);
+ int plen = sdslen(pattern), allkeys;
unsigned long numkeys = 0;
- robj *lenobj = createObject(REDIS_STRING,NULL);
+ void *replylen = addDeferredMultiBulkLength(c);
di = dictGetIterator(c->db->dict);
- addReply(c,lenobj);
- decrRefCount(lenobj);
+ allkeys = (pattern[0] == '*' && pattern[1] == '\0');
while((de = dictNext(di)) != NULL) {
sds key = dictGetEntryKey(de);
robj *keyobj;
- if ((pattern[0] == '*' && pattern[1] == '\0') ||
- stringmatchlen(pattern,plen,key,sdslen(key),0)) {
+ if (allkeys || stringmatchlen(pattern,plen,key,sdslen(key),0)) {
keyobj = createStringObject(key,sdslen(key));
if (expireIfNeeded(c->db,keyobj) == 0) {
addReplyBulk(c,keyobj);
}
}
dictReleaseIterator(di);
- lenobj->ptr = sdscatprintf(sdsempty(),"*%lu\r\n",numkeys);
+ setDeferredMultiBulkLength(c,replylen,numkeys);
}
void dbsizeCommand(redisClient *c) {
- addReplySds(c,
- sdscatprintf(sdsempty(),":%lu\r\n",dictSize(c->db->dict)));
+ addReplyLongLong(c,dictSize(c->db->dict));
}
void lastsaveCommand(redisClient *c) {
- addReplySds(c,
- sdscatprintf(sdsempty(),":%lu\r\n",server.lastsave));
+ addReplyLongLong(c,server.lastsave);
}
void typeCommand(redisClient *c) {
o = lookupKeyRead(c->db,c->argv[1]);
if (o == NULL) {
- type = "+none";
+ type = "none";
} else {
switch(o->type) {
- case REDIS_STRING: type = "+string"; break;
- case REDIS_LIST: type = "+list"; break;
- case REDIS_SET: type = "+set"; break;
- case REDIS_ZSET: type = "+zset"; break;
- case REDIS_HASH: type = "+hash"; break;
- default: type = "+unknown"; break;
+ case REDIS_STRING: type = "string"; break;
+ case REDIS_LIST: type = "list"; break;
+ case REDIS_SET: type = "set"; break;
+ case REDIS_ZSET: type = "zset"; break;
+ case REDIS_HASH: type = "hash"; break;
+ default: type = "unknown"; break;
}
}
- addReplySds(c,sdsnew(type));
- addReply(c,shared.crlf);
-}
-
-void saveCommand(redisClient *c) {
- if (server.bgsavechildpid != -1) {
- addReplySds(c,sdsnew("-ERR background save in progress\r\n"));
- return;
- }
- if (rdbSave(server.dbfilename) == REDIS_OK) {
- addReply(c,shared.ok);
- } else {
- addReply(c,shared.err);
- }
-}
-
-void bgsaveCommand(redisClient *c) {
- if (server.bgsavechildpid != -1) {
- addReplySds(c,sdsnew("-ERR background save already in progress\r\n"));
- return;
- }
- if (rdbSaveBackground(server.dbfilename) == REDIS_OK) {
- char *status = "+Background saving started\r\n";
- addReplySds(c,sdsnew(status));
- } else {
- addReply(c,shared.err);
- }
+ addReplyStatus(c,type);
}
void shutdownCommand(redisClient *c) {
if (prepareForShutdown() == REDIS_OK)
exit(0);
- addReplySds(c, sdsnew("-ERR Errors trying to SHUTDOWN. Check logs.\r\n"));
+ addReplyError(c,"Errors trying to SHUTDOWN. Check logs.");
}
void renameGenericCommand(redisClient *c, int nx) {
return;
incrRefCount(o);
- deleteIfVolatile(c->db,c->argv[2]);
if (dbAdd(c->db,c->argv[2],o) == REDIS_ERR) {
if (nx) {
decrRefCount(o);
dbReplace(c->db,c->argv[2],o);
}
dbDelete(c->db,c->argv[1]);
- touchWatchedKey(c->db,c->argv[2]);
+ signalModifiedKey(c->db,c->argv[1]);
+ signalModifiedKey(c->db,c->argv[2]);
server.dirty++;
addReply(c,nx ? shared.cone : shared.ok);
}
}
/* Try to add the element to the target DB */
- deleteIfVolatile(dst,c->argv[1]);
if (dbAdd(dst,c->argv[1],o) == REDIS_ERR) {
addReply(c,shared.czero);
return;
/* An expire may only be removed if there is a corresponding entry in the
* main dict. Otherwise, the key will never be freed. */
redisAssert(dictFind(db->dict,key->ptr) != NULL);
- if (dictDelete(db->expires,key->ptr) == DICT_OK) {
- return 1;
- } else {
- return 0;
- }
+ return dictDelete(db->expires,key->ptr) == DICT_OK;
}
-int setExpire(redisDb *db, robj *key, time_t when) {
+void setExpire(redisDb *db, robj *key, time_t when) {
dictEntry *de;
/* Reuse the sds from the main dict in the expire dict */
- redisAssert((de = dictFind(db->dict,key->ptr)) != NULL);
- if (dictAdd(db->expires,dictGetEntryKey(de),(void*)when) == DICT_ERR) {
- return 0;
- } else {
- return 1;
- }
+ de = dictFind(db->dict,key->ptr);
+ redisAssert(de != NULL);
+ dictReplace(db->expires,dictGetEntryKey(de),(void*)when);
}
/* Return the expire time of the specified key, or -1 if no expire
return (time_t) dictGetEntryVal(de);
}
+/* Propagate expires into slaves and the AOF file.
+ * When a key expires in the master, a DEL operation for this key is sent
+ * to all the slaves and the AOF file if enabled.
+ *
+ * This way the key expiry is centralized in one place, and since both
+ * AOF and the master->slave link guarantee operation ordering, everything
+ * will be consistent even if we allow write operations against expiring
+ * keys. */
+void propagateExpire(redisDb *db, robj *key) {
+ robj *argv[2];
+
+ argv[0] = createStringObject("DEL",3);
+ argv[1] = key;
+ incrRefCount(key);
+
+ if (server.appendonly)
+ feedAppendOnlyFile(server.delCommand,db->id,argv,2);
+ if (listLength(server.slaves))
+ replicationFeedSlaves(server.slaves,db->id,argv,2);
+
+ decrRefCount(argv[0]);
+ decrRefCount(argv[1]);
+}
+
int expireIfNeeded(redisDb *db, robj *key) {
time_t when = getExpire(db,key);
- if (when < 0) return 0;
+
+ if (when < 0) return 0; /* No expire for this key */
+
+ /* 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.
+ *
+ * Still we try to return the right information to the caller,
+ * 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 when this key has not expired */
if (time(NULL) <= when) return 0;
/* Delete the key */
server.stat_expiredkeys++;
- server.dirty++;
- return dbDelete(db,key);
-}
-
-int deleteIfVolatile(redisDb *db, robj *key) {
- if (getExpire(db,key) < 0) return 0;
-
- /* Delete the key */
- server.stat_expiredkeys++;
- server.dirty++;
+ propagateExpire(db,key);
return dbDelete(db,key);
}
void expireGenericCommand(redisClient *c, robj *key, robj *param, long offset) {
dictEntry *de;
- time_t seconds;
+ long seconds;
if (getLongFromObjectOrReply(c, param, &seconds, NULL) != REDIS_OK) return;
if (seconds <= 0) {
if (dbDelete(c->db,key)) server.dirty++;
addReply(c, shared.cone);
+ signalModifiedKey(c->db,key);
return;
} else {
time_t when = time(NULL)+seconds;
- if (setExpire(c->db,key,when)) {
- addReply(c,shared.cone);
- server.dirty++;
- } else {
- addReply(c,shared.czero);
- }
+ setExpire(c->db,key,when);
+ addReply(c,shared.cone);
+ signalModifiedKey(c->db,key);
+ server.dirty++;
return;
}
}
}
void ttlCommand(redisClient *c) {
- time_t expire;
- int ttl = -1;
+ time_t expire, ttl = -1;
expire = getExpire(c->db,c->argv[1]);
if (expire != -1) {
- ttl = (int) (expire-time(NULL));
+ ttl = (expire-time(NULL));
if (ttl < 0) ttl = -1;
}
- addReplySds(c,sdscatprintf(sdsempty(),":%d\r\n",ttl));
+ addReplyLongLong(c,(long long)ttl);
}
+void persistCommand(redisClient *c) {
+ dictEntry *de;
+ de = dictFind(c->db->dict,c->argv[1]->ptr);
+ if (de == NULL) {
+ addReply(c,shared.czero);
+ } else {
+ if (removeExpire(c->db,c->argv[1])) {
+ addReply(c,shared.cone);
+ server.dirty++;
+ } else {
+ addReply(c,shared.czero);
+ }
+ }
+}
projects / redis.git / blobdiff