bloom

bloom filter - 布隆过滤器，使用的时候需要转化成[]byte格式进行哈希

This implementation accepts keys for setting and testing as []byte. Thus, to add a string item, "Love":

n := uint(1000)
filter := bloom.New(20*n, 5) // load of 20, 5 keys
filter.Add([]byte("Love"))

Similarly, to test if "Love" is in bloom:

if filter.Test([]byte("Love"))

For numeric data, I recommend that you look into the encoding/binary library. But, for example, to add a uint32 to the filter:

i := uint32(100)
n1 := make([]byte, 4)
binary.BigEndian.PutUint32(n1, i)
filter.Add(n1)

Finally, there is a method to estimate the false positive rate of a particular bloom filter for a set of size n:

if filter.EstimateFalsePositiveRate(1000) > 0.001

Given the particular hashing scheme, it's best to be empirical about this. Note that estimating the FP rate will clear the Bloom filter.

Installation

go get -u github.com/ducksoso/bloom