/xorfilter

Rust library implementing xor-filters

Primary LanguageRustApache License 2.0Apache-2.0

Rustdoc simple-build-test

Rust library implementing xor filters

Implementation of Xor Filters: Faster and Smaller Than Bloom and Cuckoo Filters in rust-lang, Journal of Experimental Algorithmics (to appear).

This package is a port from its golang implementation.

How to use xorfilter in my rust project ?

Add the following under project's Cargo.toml:

[dependencies]
xorfilter-rs = "0.2.0"

or

[dependencies]
xorfilter-rs = { git = "https://github.com/prataprc/xorfilter" }
use xorfilter::{xor8::Xor8Builder, BuildHasherDefault};

fn main() {
    let num_keys = 1000;
    let lookup = 10;
    let mut b = Xor8Builder::<BuildHasherDefault>::default();
    for i in 0..num_keys {
        if i % 2 == 0 {
            b.insert(&i);
        }
    }

    // build bitmap.
    let filter = b.build().unwrap();
    for key in 0..lookup {
        // there can be false positives, but no false negatives.
        println!("{key}: {}", filter.contains(&key));
    }
}

Open issues

  • Serialize / Deserialize Xor8 type.
  • Incrementally adding keys to a pre-built Xor8 instance.
  • Gather benchmark results for other implementations - Go, C, C++, Erlang, Java, Python.

Benchmarks

Following are the results for a set of 10-million u64 keys:

build 10M keys membership FPP Bits/Entry
Xor8-C 1.206 secs NA 0.389 % 9.84 bits
Xor8-rust 1.809 secs 61.716 ns 0.392 % 9.84 bits
Fuse8-C 0.508 secs NA 0.390 % 9.02 bits
Fuse8-rust 0.577 secs 42.657 ns 0.392 % 9.02 bits
Fuse16-C 0.515 secs NA 0.001 % 18.04 bits
Fuse16-rust 0.621 secs 54.657 ns 0.001 % 18.03 bits
  • Build time is measured in Seconds, for 10 million entries.
  • Membership is measured in Nanosec, for single lookup in a set of 10 million entries.
  • FPP = False Positive Probability measured in percentage

Useful links

Contribution

  • Simple workflow. Fork - Modify - Pull request.
  • Before creating a PR,
    • Run make build to confirm all versions of build is passing with 0 warnings and 0 errors.
    • Run check.sh with 0 warnings, 0 errors and all test-cases passing.
    • Run perf.sh with 0 warnings, 0 errors and all test-cases passing.
    • Install and run cargo spellcheck to remove common spelling mistakes.
  • Developer certificate of origin is preferred.