CF.ADDNX
Syntax
CF.ADDNX key item
- Available in:
- Redis Stack / Bloom 1.0.0
- Time complexity:
- O(k + i), where k is the number of sub-filters and i is maxIterations
Adds an item to a cuckoo filter if the item does not exist.
This command is similar to the combination of CF.EXISTS and CF.ADD. It does not add an item into the filter if its fingerprint already exists.
- This command is slower than
CF.ADDbecause it first checks whether the item exists. - Since
CF.EXISTScan result in false positive,CF.ADDNXmay not add an item because it is supposedly already exist, which may be wrong.
Required arguments
key
is key name for a cuckoo filter to add items to.
If key does not exist - a new cuckoo filter is created.
item
is an item to add.
Return value
Returns one of these replies:
- Integer reply, where
0means that the item's fingerprint already exist in the filter, and1means that the item has been successfully added to the filter. - [] on error (invalid arguments, wrong key type, etc.) and also when the filter is full.
Examples
redis> CF.ADDNX cf item
(integer) 1
redis> CF.ADDNX cf item
(integer) 0