SwiftRoaring

Swift wrapper for CRoaring (a C/C++ implementation at https://github.com/RoaringBitmap/CRoaring)

Roaring bitmaps are used by several important systems:

Apache Lucene and derivative systems such as Solr and Elastic,
Metamarkets' Druid,
Apache Spark,
Netflix Atlas,
LinkedIn Pinot,
OpenSearchServer,
Cloud Torrent,
Whoosh,
Pilosa,
Microsoft Visual Studio Team Services (VSTS),
eBay's Apache Kylin.

Roaring bitmaps are found to work well in many important applications:

Use Roaring for bitmap compression whenever possible. Do not use other bitmap compression methods (Wang et al., SIGMOD 2017)

Dependencies

Swift 4.0 or higher

Usage using Swift Package Manager

Create a directory where you will create your application:

mkdir foo
cd foo
swift package init --type executable

Then edit Package.swift so that it reads something like this:

import PackageDescription

let package = Package(
    name: "foo",
    dependencies: [
   .package(url: "https://github.com/RoaringBitmap/SwiftRoaring",  from: "0.0.1")
    ],
    targets: [
        .target(
            name: "foo",
            dependencies: ["SwiftRoaring"]),
    ]
)

Edit main.swift (in Sources) so that it looks something like this :

import SwiftRoaring;

....

Example

Here is a simplified but complete example:

import SwiftRoaring

//Create a new Roaring Bitmap
let bitmap = RoaringBitmap()

//Example: Add Range
bitmap.addRange(min: 0, max: 500)

//Example: copy
let cpy = bitmap.copy()

//Example: Operators
let and = bitmap && cpy

//Example: Iterate
for i in bitmap {
    print(i)
}

//See documentation for more functionalities!

Development

You can build using Swift Package Manager as follows:

swift build  --configuration release

To find where the library is built, type the following in your shell:

 echo $(swift build   --configuration release  --show-bin-path)

You can run tests using Swift Package Manager as follows:

swift test

Interactive use

$ swift build  --configuration release
$ swift repl -I .build/release -L .build/release -lSwiftRoaringDynamic
  1> import SwiftRoaring
  2> let bitmap = RoaringBitmap()
  3> bitmap.add(1)
  4> for i in bitmap {
       print(i)
     }

Mailing list/discussion group

https://groups.google.com/forum/#!forum/roaring-bitmaps

Compatibility with Java RoaringBitmap library

You can read bitmaps in Go, Java, C, C++ that have been serialized in Java, C, C++.

References

Daniel Lemire, Owen Kaser, Nathan Kurz, Luca Deri, Chris O'Hara, François Saint-Jacques, Gregory Ssi-Yan-Kai, Software: Practice and Experience Volume 48, Issue 4 April 2018 Pages 867-895 arXiv:1709.07821
Samy Chambi, Daniel Lemire, Owen Kaser, Robert Godin, Better bitmap performance with Roaring bitmaps, Software: Practice and Experience Volume 46, Issue 5, pages 709–719, May 2016 http://arxiv.org/abs/1402.6407 This paper used data from http://lemire.me/data/realroaring2014.html
Daniel Lemire, Gregory Ssi-Yan-Kai, Owen Kaser, Consistently faster and smaller compressed bitmaps with Roaring, Software: Practice and Experience Volume 46, Issue 11, pages 1547-1569, November 2016 http://arxiv.org/abs/1603.06549