https://github.com/mirage/ke

Fast implementation of queue in OCaml
https://github.com/mirage/ke

gadt ocaml queue

Last synced: 3 months ago
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Fast implementation of queue in OCaml

• Host: GitHub
• URL: https://github.com/mirage/ke
• Owner: mirage
• License: mit
• Created: 2018-12-11T15:42:30.000Z (almost 6 years ago)
• Default Branch: main
• Last Pushed: 2024-02-26T07:35:15.000Z (9 months ago)
• Last Synced: 2024-05-09T23:25:53.059Z (6 months ago)
• Topics: gadt, ocaml, queue
• Language: HTML
• Homepage:
• Size: 242 KB
• Stars: 50
• Watchers: 22
• Forks: 6
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • Changelog: CHANGES.md
  • License: LICENSE.md

Awesome Lists containing this project

• awesome-list - ke
• awesome-ocaml - Ke - Fast implementation of queue (FIFO) in OCaml. (Algorithms and Data Structures)

README

        
Ke - Fast implementation of Queue in OCaml

==========================================

![travis-ci](https://travis-ci.org/mirage/ke.svg?banch=master)

Queue or FIFO is one of the most famous data-structure used in several

algorithms. `Ke` provides some implementations of it in a functional or

imperative way.

It is a little library with a benchmark

([`bechamel`](https://github.com/dinosaure/bechamel.git) or `core_bench`),

a fuzzer and tests.

We provide a functional interface `Fke` or an imperative interface `Rke`.

From what we know, `Ke.Rke` is faster than `Queue` from the

standard library or the `base` package. The type of data that it can store

is limited (only supports the types supported by [`Bigarray.kind`](https://v2.ocaml.org/releases/5.1/api/Bigarray.html#TYPEkind))

, but this is enough for a lot of algorithms. The fast

operations are: put some elements faster than a sequence of `Queue.push`, and

get some elements faster than a sequence of `Queue.pop`.

We provide extended implementations (`Rke.Weighted` and `Fke.Weighted`) with

a limit on the number of elements stored. The purpose is to limit memory

consumption of the queue when we use it in some contexts (like _encoder_).

Again, as a part of the MirageOS project, `Ke` does not rely on C stubs,

`Obj.magic` and so on.

Author: Romain Calascibetta 

Documentation: https://mirage.github.io/ke/

Implementation notes

====================

The functional implementation `Fke` comes from Okazaki's queue

implementation with GADT to discard impossible cases.

`Rke`, `Rke.Weighted` and `Fke.Weighted` are limited by kind and follow Xen's

implementation of the shared memory ring-buffer. The length of the internal buffer

is always a power of two - that means for a large number of elements

this kind of queue may not fit your requirements.

A fuzzer was made to compare the standard `Queue` (as an oracle) with `Rke` and

`Fke`. We construct a set of actions (`push` and `pop`) and ensure (by GADT) to

never `pop` an empty queue.