Filter

This is a library for implementing Bloom and Cuckoo filters in Swift. The library provides two filters BloomFilter and CuckooFilter which can be used to filter data, reduce database access, crawlers, etc.

CuckooFilter is under development, details are in cuckoo_filter branch

Installation

The library can be added as dependency via swift package manager or Cocoapods .

SPM

// swift-tools-version: 5.7
// The swift-tools-version declares the minimum version of Swift required to build this package.

import PackageDescription

let package = Package(
    name: "YourPackage",
    products: [
        .library(name: "YourPackage", targets: ["YourPackage"]),
    ],
    dependencies: [
        .package(url: "https://github.com/panicfrog/Filters.git", from: "0.0.2"),
    ],
    targets: [
        .target(
            name: "YourPackage",
            dependencies: ["Filter"]),
    ]
)

Xcode

File -> Add packages https://github.com/panicfrog/Filters.git

Cocoapods

pod 'Filters', '~> 0.0.2'

Usage

// create bloom filter with `BloomFilterBuilder`
let bloom = BloomFilterBuilder.default
        .with(maxElements: max)   // the maximum number of elements expected to be added
        .with(hasher: Xxhasher()) // default is Murmurhash3_x86_32
        .with(safety: true)       // thread safety
        .build()
// add item to filter
bloom.add("hello")
// determine whether item is comtained in the bloom filter
bloom.contains("hello")

you can also use mmap to mapping bloom's bitmap to a file

// create bloom filter with `BloomFilterBuilder`, that can mapping bitmap to file using mmap
let url = URL(string: "<path your want to mapping>")!
let bloom = BloomFilterBuilder.default
  .with(maxElements: max)
  .with { m in
    try! MmapBitmap(m, path: url)
  }.build()
// add item to filter
bloom.add("item1")
// determine whether item is comtained in the bloom filter
bloom.contains("item1")

API

You can clone the warehouse code, and then use Swift-DocC to produce the api documentation for local preview, and the online documentation is coming soon ...

swift package --disable-sandbox preview-documentation --target Filter

License

This library is licensed under the MIT License. See the LICENSE file for more details.