Redis module that implements Bloom Filters using the redis module API. Needs Redis version >= 4.0.0.

make

redis-server --loadmodule /path/to/bloom_filter.so

make test

Initializes the Bloom Filter.

> bf.init key capacity error_rate seed

Last 3 parameters are optional.

• capacity is the number of expected different elements. Default is 1000000.
• error_rate the tolerated error_rate. Default is 0.01 (1%)
• seed initialization seed. Defaults to current time in microseconds.

Example:

> bf.init mykey 1000 0.05 1234
OK

Adds an element to the filter.

> bf.add key element

Example:

> bf.add mykey myelement
OK

Says if an element exists in the filter.

bf.exists key element

Example:

> bf.exists mykey myelement
(integer) 1
> bf.exists mykey notmyelement
(integer) 0

Merges key2 into key1.

bf.merge key1 key2

Keys must have same capacity, seed and error_rate. So they must have been initialized with all the parameters.

Example:

> bf.init myotherkey 1000 0.05 1234
OK
> bf.add myotherkey myotherelement
OK
> bf.merge mykey myotherkey
OK
> bf.exists mykey myotherelement
(integer) 1