Node BitView

NodeJS Buffer interface provides a way to manipulate bytes, but what if we needed to manipulate bits?

This library was created to address the gap of a built-in bit interface.

Installation

npm install bitview --save

Initializing a view

new BitView(Length)
new BitView(buffer)
new BitView(buffer, byteOffset, length);
Buffer.from(arg)

Parameters:

length: length in bits
buffer: use an existing buffer
arg: Another interface to create a new BitView instance
arg could be an array of bits [1,0,1] or a string '1010' or a buffer.
byteOffset: default 0, starting offset of the bitview.

Methods

.flip(pos)

flips the value of the bit at location pos

.get(pos)

Returns the value of the bit at location pos  (0 or 1)

.set(pos,v)

Sets the value of a bit at location pos to v

.toString()

  Returns a string representation of the BitView.

.toBuffer()

Returns the buffer used by the view.

Properties

.length

Returns length in bits.

Usage:

const BitView = require("bitview")
 
const view= new BitView(10);
 
view.set(0,true);
console.log(view.get(0)); // true
view.flip(0)
console.log(view.get(0)); // false
 
const view2=BitView.from('101010');
console.log(view2.get(2)); // true
 
const view3=BitView.from([1, 0, 1]);
console.log(view3.get(1)); // false
console.log(view3.get(2)); // true

Implementation

BitView uses bitwise operations to manipulate each bit in a buffer (Low Complexity)