eth_bloom: an Ethereum Bloom Filter

MOVED TO https://github.com/status-im/nim-eth

Introduction

A Nim implementation of the bloom filter used by Ethereum.

Description

Bloom filters are data structures that use hash functions to test whether an element is a member of a set. They work like other data structures but are probabilistic in nature: that is, they allow false positive matches but not false negative. Bloom filters use less storage space than other data structures.

Ethereum bloom filters are implemented with the Keccak-256 cryptographic hash function.

To see the bloom filter used in the context of Ethereum, please refer to the Ethereum Yellow Paper.

Installation

$ nimble install eth_bloom

Usage

import eth_bloom, stint
var f: BloomFilter
f.incl("test1")
assert("test1" in f)
assert("test2" notin f)
f.incl("test2")
assert("test2" in f)
assert(f.value.toHex == "80000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000010000000000000000000000000000000200000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000200000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000040000000000000000000000000000000000000000000000000000000000000000000")

License

Licensed and distributed under either of

• MIT license: LICENSE-MIT or http://opensource.org/licenses/MIT

or

• Apache License, Version 2.0, (LICENSE-APACHEv2 or http://www.apache.org/licenses/LICENSE-2.0)

at your option. This file may not be copied, modified, or distributed except according to those terms.