thingy-byte-utils/index.js

Some utility functions for transforming bytes to other representations.

// Generated by CoffeeScript 2.7.0
//###########################################################
var backHexMap, bigIntMap, decoder, frontHexMap, hexChars, slots;

import {
  StringDecoder
} from "string_decoder";

decoder = new StringDecoder("utf-8");

slots = (new Array(256)).fill(0);

bigIntMap = slots.map(function(el, idx) {
  return BigInt(idx);
});

//###########################################################
hexChars = Array.from("0123456789abcdef");

frontHexMap = new Array(256);

// frontHexMap = {}
hexChars.forEach(function(el) {
  return frontHexMap[el] = 16 * parseInt(el, 16);
});

backHexMap = new Array(256);

// backHexMap = {}
hexChars.forEach(function(el) {
  return backHexMap[el] = parseInt(el, 16);
});

//###########################################################
export var bytesToBigInt = function(byteBuffer) {
  var byteArray, hex;
  byteArray = new Uint8Array(byteBuffer);
  hex = bytesToHex(byteArray.reverse());
  return BigInt("0x" + hex);
};

//###########################################################
export var bytesToUtf8 = function(byteBuffer) {
  var byteArray;
  byteArray = new Uint8Array(byteBuffer);
  return decoder.end(byteArray);
};

export var utf8ToBytes = function(utf8) {
  return new Uint8Array(Buffer.from(utf8, "utf8"));
};

//###########################################################
export var bytesToHex = function(byteBuffer) {
  return Buffer.from(byteBuffer).toString("hex");
};

export var hexToBytes = function(hex) {
  var i, j, ref, result;
  result = new Uint8Array(hex.length / 2);
  for (i = j = 0, ref = hex.length; j < ref; i = j += 2) {
    result[i / 2] = frontHexMap[hex[i]] + backHexMap[hex[i + 1]];
  }
  return result;
};