twos-complement-buffer

twos-complement-buffer

Copyright (c) 2018 Rafael da Silva Rocha.
https://github.com/rochars/twos-complement-buffer

twos-complement-buffer is a module to encode and decode two's complement integers to and from byte buffers.

• MIT licensed
• Use it out of the box in the browser
• Use it out of the box in Node.js
• Can be used with arrays and typed arrays
• Compatible with IE8+
• Include TypeScript declaration file
• Tested against Python's struct module
• Less than 2kb minified

Install

npm install twos-complement-buffer

Use

Node

If you installed via NPM or Yarn, import TwosComplementBuffer from twos-complement-buffer:

import TwosComplementBuffer from 'twos-complement-buffer';

// A byte buffer, array and Uint8Array can be used
let buffer = [];

// Create a UintBuffer to handle 32-bit numbers
let uintBufer = new UintBuffer(32);

// Pack a value
uintBufer.pack(buffer, -2045);

// Check the buffer
console.log(buffer);

Or require:

const TwosComplementBuffer = require('twos-complement-buffer');

Browser

Use twos-complement-buffer.umd.js in the /dist folder of this package:

<script src="twos-complement-buffer.umd.js"></script>
<script>
  import TwosComplementBuffer from 'twos-complement-buffer';

  // A byte buffer, array and Uint8Array can be used
  let buffer = [];

  // Create a UintBuffer to handle 32-bit numbers
  let uintBufer = new UintBuffer(32);

  // Pack a value
  uintBufer.pack(buffer, 3247);

  // Check the buffer
  console.log(buffer);
</script>

Or load it from the jsDelivr CDN:

<script src="https://cdn.jsdelivr.net/npm/twos-complement-buffer"></script>

Or load it from unpkg:

<script src="https://unpkg.com/twos-complement-buffer"></script>

API

/**
 * A class to write and read two's complement signed integers
 * to and from byte buffers.
 */
class TwosComplementBuffer {
  
  /**
   * @param {number} bits The number of bits used by the integer.
   */
  constructor(bits) {
    /**
     * The number of bits used by one number.
     * @type {number}
     */
    this.bits;
    /**
     * The number of bytes used by one number.
     * @type {number}
     */
    this.bytes;
  }

  /**
   * Write one two's complement signed integer to a byte buffer.
   * @param {!Uint8Array|!Array<number>} buffer An array of bytes.
   * @param {number} num The number.
   * @param {number=} index The index being written in the byte buffer.
   * @return {number} The next index to write on the byte buffer.
   * @throws {Error} If num is NaN.
   * @throws {Error} On overflow.
   */
  pack(buffer, num, index=0) {}
  
  /**
   * Read one two's complement signed integer from a byte buffer.
   * @param {!Uint8Array|!Array<number>} buffer An array of bytes.
   * @param {number=} index The index to read.
   * @return {number}
   * @throws {Error} On overflow.
   */
  unpack(buffer, index=0) {}
}

Contributing

twos-complement-buffer welcomes all contributions from anyone willing to work in good faith with other contributors and the community. No contribution is too small and all contributions are valued.

See CONTRIBUTING.md for details.

Style guide

twos-complement-buffer code should follow the Google JavaScript Style Guide:
https://google.github.io/styleguide/jsguide.html

Code of conduct

This project is bound by a code of conduct: The Contributor Covenant, version 1.4, also available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html

LICENSE

Copyright (c) 2018 Rafael da Silva Rocha.

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.