CF.INSERTNX

CF.INSERTNX key [CAPACITY capacity] [NOCREATE] ITEMS item [item ...]

Available in:

Redis Stack / Bloom 1.0.0

Time complexity:

O(n * (k + i)), where n is the number of items, k is the number of sub-filters and i is maxIterations

Adds one or more items to a cuckoo filter if they did not exist previously, allowing the filter to be created with a custom capacity if it does not exist yet.

This command is similar to CF.ADDNX, except that more than one item can be added and capacity can be specified.

Notes:

• This command is slower than CF.INSERT because it first checks whether each item exists.
• Since CF.EXISTS can result in false positive, CF.INSERTNX may not add an item because it is supposedly already exist, which may be wrong.

Required arguments

Optional arguments

Return value

Returns one of these replies:

• Array reply of Integer reply, where 0 means that the item's fingerprint already exists in the filter, 1 means that the item has been successfully added to the filter, and -1 means that the item was not added because the filter is full.
• [] on error (invalid arguments, wrong key type, etc.) and also when NOCREATE is specified and key does not exist.

Complexity

O(n + i), where n is the number of sub-filters and i is maxIterations. Adding items requires up to 2 memory accesses per sub-filter. But as the filter fills up, both locations for an item might be full. The filter attempts to Cuckoo swap items up to maxIterations times.

Examples

redis> CF.INSERTNX cf CAPACITY 1000 ITEMS item1 item2 
1) (integer) 1
2) (integer) 1

redis> CF.INSERTNX cf CAPACITY 1000 ITEMS item1 item2 item3
1) (integer) 0
2) (integer) 0
3) (integer) 1

redis> CF.INSERTNX cf_new CAPACITY 1000 NOCREATE ITEMS item1 item2 
(error) ERR not found