#include <signal.h>
+void SlotToKeyAdd(robj *key);
+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.
+ */
+
+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) {
if (server.ds_enabled &&
cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG)
{
- /* There is a save in progress for this object!
- * Wait for it to get out. */
- waitEmptyIOJobsQueue();
- processAllPendingIOJobs();
- redisAssert(!(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;
* 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)) {
- if (cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG) {
- /* There is a save in progress for this object!
- * Wait for it to get out. */
- waitEmptyIOJobsQueue();
- processAllPendingIOJobs();
- redisAssert((cacheScheduleIOGetFlags(db,key) & REDIS_IO_SAVEINPROG) == 0);
+ 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;
}
- redisLog(REDIS_DEBUG,"Force loading key %s via lookup",
- key->ptr);
+ /* 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);
+ dbAdd(db,key,val);
if (expire != -1) setExpire(db,key,expire);
server.stat_keyspace_hits++;
return val;
+ } else {
+ cacheSetKeyDoesNotExist(db,key);
}
}
server.stat_keyspace_misses++;
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.ds_enabled) cacheSetKeyMayExist(db,key);
+ 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 (server.ds_enabled) cacheSetKeyMayExist(db,key);
}
-/* 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) {
/* 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 */
+/* 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;
}
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 {
addReplyStatus(c,type);
}
-void saveCommand(redisClient *c) {
- if (server.bgsavechildpid != -1) {
- addReplyError(c,"Background save already in progress");
- return;
- }
- if (rdbSave(server.dbfilename) == REDIS_OK) {
- addReply(c,shared.ok);
- } else {
- addReply(c,shared.err);
- }
-}
-
-void bgsaveCommand(redisClient *c) {
- if (server.bgsavechildpid != -1) {
- addReplyError(c,"Background save already in progress");
- return;
- }
- if (rdbSaveBackground(server.dbfilename) == REDIS_OK) {
- addReplyStatus(c,"Background saving started");
- } else {
- addReply(c,shared.err);
- }
-}
-
void shutdownCommand(redisClient *c) {
if (prepareForShutdown() == REDIS_OK)
exit(0);
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]);
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;
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 */
int expireIfNeeded(redisDb *db, robj *key) {
time_t when = getExpire(db,key);
+ 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.
return time(NULL) > when;
}
- if (when < 0) return 0;
-
/* Return when this key has not expired */
if (time(NULL) <= when) return 0;
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));
}
}
}
+
+/* -----------------------------------------------------------------------------
+ * API to get key arguments from commands
+ * ---------------------------------------------------------------------------*/
+
+int *getKeysUsingCommandTable(struct redisCommand *cmd,robj **argv, int argc, int *numkeys) {
+ int j, i = 0, last, *keys;
+ REDIS_NOTUSED(argv);
+
+ if (cmd->firstkey == 0) {
+ *numkeys = 0;
+ return NULL;
+ }
+ last = cmd->lastkey;
+ if (last < 0) last = argc+last;
+ keys = zmalloc(sizeof(int)*((last - cmd->firstkey)+1));
+ for (j = cmd->firstkey; j <= last; j += cmd->keystep) {
+ redisAssert(j < argc);
+ keys[i++] = j;
+ }
+ *numkeys = i;
+ return keys;
+}
+
+int *getKeysFromCommand(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
+ if (cmd->getkeys_proc) {
+ return cmd->getkeys_proc(cmd,argv,argc,numkeys,flags);
+ } else {
+ return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
+ }
+}
+
+void getKeysFreeResult(int *result) {
+ zfree(result);
+}
+
+int *noPreloadGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
+ if (flags & REDIS_GETKEYS_PRELOAD) {
+ *numkeys = 0;
+ return NULL;
+ } else {
+ return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
+ }
+}
+
+int *renameGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
+ if (flags & REDIS_GETKEYS_PRELOAD) {
+ int *keys = zmalloc(sizeof(int));
+ *numkeys = 1;
+ keys[0] = 1;
+ return keys;
+ } else {
+ return getKeysUsingCommandTable(cmd,argv,argc,numkeys);
+ }
+}
+
+int *zunionInterGetKeys(struct redisCommand *cmd,robj **argv, int argc, int *numkeys, int flags) {
+ int i, num, *keys;
+ REDIS_NOTUSED(cmd);
+ REDIS_NOTUSED(flags);
+
+ num = atoi(argv[2]->ptr);
+ /* Sanity check. Don't return any key if the command is going to
+ * reply with syntax error. */
+ if (num > (argc-3)) {
+ *numkeys = 0;
+ return NULL;
+ }
+ keys = zmalloc(sizeof(int)*num);
+ for (i = 0; i < num; i++) keys[i] = 3+i;
+ *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;
+}
projects / redis.git / blobdiff