@fictivekin/growable-uint8-array

growable-uint8-array

GrowableUint8Array is simple wrapper around Uint8Array that manages resizing the buffer when appending new data.

Adds a new method extend which can be used to append data to an array. GrowableUint8Array will manage the underlying buffer, automatically allocating a larger Uint8Array when necessary using a simple exponential growth algorithm.

getElement(n) and setElement(n, value) can be used to get and set the value, respectively, at a specific index. When setting, index values less than zero or greater than the length of the array are silently ignored.

All TypedArray prototype methods are delegated to the underlying Uint8Array. If the prototype method returns an instance of Uint8Array it will be wrapped in a GrowableUint8Array.

Use growableUint8Array.unwrap() to return a Uint8Array view of the underlying data, with proper bounds. By default this will not copy the data, for performance reasons. Pass true as the first argument to unwrap to return a copy of the data.

Usage

import GrowableUint8Array from '@fictivekin/growable-uint8-array';

const arr = new GrowableUint8Array(new Uint8Array([1, 2, 3]));
console.log(arr.length); // 3
arr.extend([4, 5, 6]);   // GrowableUint8Array [ 1, 2, 3, 4, 5, 6 ]
console.log(arr.length); // 6
arr.map((x) => x * 2);   // GrowableUint8Array [ 2, 4, 6, 8, 10, 12 ]
console.log(arr);        // GrowableUint8Array [ 1, 2, 3, 4, 5, 6 ]
arr.unwrap()             // Uint8Array [ 1, 2, 3, 4, 5, 6 ]

Array-like access

If your environment supports ES6 proxies, you can use arr.accessProxy() to get a proxy object which allows for Array-like attribute access.

import GrowableUint8Array from '@fictivekin/growable-uint8-array';

const proxy = new GrowableUint8Array(new Uint8Array([1, 2, 42])).accessProxy();
proxy[2];          // 42
proxy[0] = 7;      // 7
proxy.extend([3, 2, 1]);

proxy.unwrap()    // Uint8Array [ 7, 2, 42, 3, 2, 1 ]

Install

npm install @fictivekin/growable-uint8-array

Contribute

Clone repo, then install dev dependencies: npm install --only=dev

Run tests

npm run test

Build

npm run build