void lsetCommand(redisClient *c) {
int slotnum = keyHashSlot(c->argv[1]->ptr, sdslen(c->argv[1]->ptr));
robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nokeyerr,slotnum);
if (o == NULL || checkType(c,o,REDIS_LIST)) return;
long index;
robj *value = (c->argv[3] = tryObjectEncoding(c->argv[3]));
if ((getLongFromObjectOrReply(c, c->argv[2], &index, NULL) != REDIS_OK))
return;
listTypeTryConversion(o,value);
if (o->encoding == REDIS_ENCODING_ZIPLIST) {
unsigned char *p, *zl = o->ptr;
p = ziplistIndex(zl,index);
if (p == NULL) {
addReply(c,shared.outofrangeerr);
} else {
o->ptr = ziplistDelete(o->ptr,&p);
value = getDecodedObject(value);
o->ptr = ziplistInsert(o->ptr,p,value->ptr,sdslen(value->ptr));
decrRefCount(value);
addReply(c,shared.ok);
signalModifiedKey(c->db,c->argv[1],slotnum);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"lset",c->argv[1],c->db->id);
server.dirty++;
}
} else if (o->encoding == REDIS_ENCODING_LINKEDLIST) {
listNode *ln = listIndex(o->ptr,index);
if (ln == NULL) {
addReply(c,shared.outofrangeerr);
} else {
decrRefCount((robj*)listNodeValue(ln));
listNodeValue(ln) = value;
incrRefCount(value);
addReply(c,shared.ok);
signalModifiedKey(c->db,c->argv[1],slotnum);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,"lset",c->argv[1],c->db->id);
server.dirty++;
}
} else {
redisPanic("Unknown list encoding");
}
}
/* If the specified key has clients blocked waiting for list pushes, this
* function will put the key reference into the server.ready_keys list.
* Note that db->ready_keys is a hash table that allows us to avoid putting
* the same key again and again in the list in case of multiple pushes
* made by a script or in the context of MULTI/EXEC.
*
* The list will be finally processed by handleClientsBlockedOnLists() */
void signalListAsReady(redisDb *_db, robj *key) {
redisDb *db = &_db[keyHashSlot(key->ptr, sdslen(key->ptr))];
readyList *rl;
/* No clients blocking for this key? No need to queue it. */
if (dictFind(db->blocking_keys,key) == NULL) return;
/* Key was already signaled? No need to queue it again. */
if (dictFind(db->ready_keys,key) != NULL) return;
/* Ok, we need to queue this key into server.ready_keys. */
rl = zmalloc(sizeof(*rl));
rl->key = key;
rl->db = _db;
incrRefCount(key);
listAddNodeTail(server.ready_keys,rl);
/* We also add the key in the db->ready_keys dictionary in order
* to avoid adding it multiple times into a list with a simple O(1)
* check. */
incrRefCount(key);
redisAssert(dictAdd(db->ready_keys,key,NULL) == DICT_OK);
}
void popGenericCommand(redisClient *c, int where) {
int slotnum = keyHashSlot(c->argv[1]->ptr, sdslen(c->argv[1]->ptr));
robj *o = lookupKeyWriteOrReply(c,c->argv[1],shared.nullbulk,slotnum);
if (o == NULL || checkType(c,o,REDIS_LIST)) return;
robj *value = listTypePop(o,where);
if (value == NULL) {
addReply(c,shared.nullbulk);
} else {
char *event = (where == REDIS_HEAD) ? "lpop" : "rpop";
addReplyBulk(c,value);
decrRefCount(value);
notifyKeyspaceEvent(REDIS_NOTIFY_LIST,event,c->argv[1],c->db->id);
if (listTypeLength(o) == 0) {
notifyKeyspaceEvent(REDIS_NOTIFY_GENERIC,"del",
c->argv[1],c->db->id);
dbDelete(c->db,c->argv[1],slotnum);
}
signalModifiedKey(c->db,c->argv[1],slotnum);
server.dirty++;
}
}
void SlotToKeyDel(robj *key) {
unsigned int hashslot = keyHashSlot(key->ptr,sdslen(key->ptr));
zslDelete(server.cluster.slots_to_keys,hashslot,key);
}
/* 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);
}
/* This function should be called by Redis every time a single command,
* a MULTI/EXEC block, or a Lua script, terminated its execution after
* being called by a client.
*
* All the keys with at least one client blocked that received at least
* one new element via some PUSH operation are accumulated into
* the server.ready_keys list. This function will run the list and will
* serve clients accordingly. Note that the function will iterate again and
* again as a result of serving BRPOPLPUSH we can have new blocking clients
* to serve because of the PUSH side of BRPOPLPUSH. */
void handleClientsBlockedOnLists(void) {
while(listLength(server.ready_keys) != 0) {
list *l;
/* Point server.ready_keys to a fresh list and save the current one
* locally. This way as we run the old list we are free to call
* signalListAsReady() that may push new elements in server.ready_keys
* when handling clients blocked into BRPOPLPUSH. */
l = server.ready_keys;
server.ready_keys = listCreate();
while(listLength(l) != 0) {
listNode *ln = listFirst(l);
readyList *rl = ln->value;
int slotnum = keyHashSlot(rl->key->ptr, sdslen(rl->key->ptr));
redisDb *db = &(rl->db)[slotnum];
/* First of all remove this key from db->ready_keys so that
* we can safely call signalListAsReady() against this key. */
dictDelete(db->ready_keys,rl->key);
/* If the key exists and it's a list, serve blocked clients
* with data. */
robj *o = lookupKeyWrite(rl->db,rl->key,slotnum);
if (o != NULL && o->type == REDIS_LIST) {
dictEntry *de;
/* We serve clients in the same order they blocked for
* this key, from the first blocked to the last. */
de = dictFind(db->blocking_keys,rl->key);
if (de) {
list *clients = dictGetVal(de);
int numclients = listLength(clients);
while(numclients--) {
listNode *clientnode = listFirst(clients);
redisClient *receiver = clientnode->value;
robj *dstkey = receiver->bpop.target;
int where = (receiver->lastcmd &&
receiver->lastcmd->proc == blpopCommand) ?
REDIS_HEAD : REDIS_TAIL;
robj *value = listTypePop(o,where);
if (value) {
/* Protect receiver->bpop.target, that will be
* freed by the next unblockClient()
* call. */
if (dstkey) incrRefCount(dstkey);
unblockClient(receiver);
if (serveClientBlockedOnList(receiver,
rl->key,dstkey,rl->db,value,
where) == REDIS_ERR)
{
/* If we failed serving the client we need
* to also undo the POP operation. */
listTypePush(o,value,where);
}
if (dstkey) decrRefCount(dstkey);
decrRefCount(value);
} else {
break;
}
}
}
if (listTypeLength(o) == 0) dbDelete(rl->db,rl->key,slotnum);
/* We don't call signalModifiedKey() as it was already called
* when an element was pushed on the list. */
}
/* Free this item. */
decrRefCount(rl->key);
zfree(rl);
listDelNode(l,ln);
}
listRelease(l); /* We have the new list on place at this point. */
}
}
/* 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));
sds sdskey = sdsdup(key->ptr);
zslInsert(server.cluster->slots_to_keys,hashslot,sdskey);
}
