thingy-byte-utils/browser.js

Some utility functions for transforming bytes to other representations.

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

encoder = new TextEncoder("utf-8");

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

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

hexMap = slots.map(function(el, idx) {
  return idx.toString(16).padStart(2, '0');
});

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

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

frontHexMap = new Array(256);

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

backHexMap = new Array(256);

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

//###########################################################
// export bytesToBigInt = (byteBuffer) ->
//     byteBuffer = new Uint8Array(byteBuffer)
//     value = 0n
//     for byte,i in byteBuffer
//         value += bigIntMap[byte] << (8n * bigIntMap[i])
//     return value
export var bytesToBigInt = function(byteBuffer) {
  var byte, i, j, len, value;
  byteBuffer = new Uint8Array(byteBuffer);
  value = 0n;
  for (i = j = 0, len = byteBuffer.length; j < len; i = ++j) {
    byte = byteBuffer[i];
    value += BigInt(byte) << (8n * BigInt(i));
  }
  return value;
};

//###########################################################
export var bytesToUtf8 = function(byteBuffer) {
  return decoder.decode(byteBuffer);
};

export var utf8ToBytes = function(utf8) {
  // bytes = encoder.encode(utf8)
  // return bytes.buffer
  return encoder.encode(utf8);
};

//###########################################################
export var bytesToHex = function(byteBuffer) {
  var byte, byteArray, j, len, result;
  byteArray = new Uint8Array(byteBuffer);
  result = "";
  for (j = 0, len = byteArray.length; j < len; j++) {
    byte = byteArray[j];
    result += hexMap[byte];
  }
  return result;
};

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.buffer
  return result;
};