Fast TS/JS implementation of a circular buffer (aka ring queue, cyclic list, etc.) Extremely well tested.
npm install circular_buffer_js
npm install --save-dev circular_buffer_js
`
* Documentation
* Main functional documentation
* Build history
Typescript implementation of a circular buffer, and JS compiles to a es6
module minified, es6 commonjs minified, es6 iife minified, and es6 iife full.
1. Well tested.
* 100% coverage, 100% property coverage.
1. Tiny.
* The es6 minified module build is currently 1.4k.
1. Dependency-free.
* Only dev-time deps like typescript are involved.
API
You should consider viewing the
real documentation,
but:
`typescript
// yields a buffer of fixed size size
const cb = new circular_buffer(size),
cb2 = circular_buffer.from([1,2,3]);
cb.push(item); // inserts item at end of cb, then returns item
cb.shove(item); // inserts item at end of cb; remove if needed, returns removed
cb.pop(); // removes and returns first element
cb.at(location); // shows the element at 0-indexed offset location
cb.pos(location); // shows the element at run-indexed offset location
cb.offset(); // shows the delta from 0-indexed to head
cb.indexOf(item); // returns the index of the first item, or -1
cb.find(pred); // return the the first match or undefined
cb.every(pred); // tests if every queue element satisfies the predicate
cb.some(pred); // tests if at least one element satisfies the predicate
cb.fill(item); // maxes length and sets every element to item
cb.clear(); // empties the container
cb.reverse(); // reverses the container
cb.resize(size,pE); // change to new size, truncating if required; pE to prefer end
cb.toArray(); // return an array of the current contents of the queue
cb.first; // returns the first value in the queue; throws when empty
cb.last; // returns the last value in the queue; throws when empty
cb.isFull; // returns true if no space left; false otherwise
cb.isEmpty; // returns true if no space remains; false otherwise
cb.available; // returns the number of spaces remaining currently
cb.capacity; // returns the total size allocated
cb.length; // returns the amount of space currently used
`
What is this?
This is a circular buffer (or cycle buffer, ring queue, etc.) It was written
because a library I wanted to use had a native buggy implementation, so I
provided something more trustworthy.
A circular buffer is a fixed size buffer that allows you to push and pop
forever, as a first in first out queue-like structure. Circular buffers are
more efficient than queues, but can overflow.
$3
`javascript
import { circular_buffer } from 'circular_buffer_js';
const cb = new circular_buffer(3); // [ , , ]
cb.push(1); // ok: [1, , ]
cb.push(2); // ok: [1,2, ]
cb.push(3); // ok: [1,2,3]
cb.at(0); // 1
cb.first; // 1
cb.last; // 3
cb.push(4); // throws - full! ; [1,2,3]
cb.pop(); // 1: [2,3, ]
cb.at(0); // 2: [2,3, ]
cb.push(4); // ok: [2,3,4]
cb.push(5); // throws - full! ; [2,3,4]
cb.pop(); // 2: [3,4, ]
cb.pop(); // 3: [4, , ]
cb.pop(); // 4: [ , , ]
cb.pop(); // throws - empty! ; [ , , ]
`
$3
It's typescript, so you can also
`typescript
import { circular_buffer } from 'circular_buffer_js';
const cb = new circular_buffer(3);
`
$3
And there's a CommonJS build, so you can
`javascript
const cbuf = require('circular_buffer_js'),
circular_buffer = new cbuf.circular_buffer;
`
$3
There're also two iife builds - both regular and minified - so that you can
use this in older browsers, or from CDN.
`html
``