bps.js/lib/utils.js

BPS patching utility

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.defaultLog = defaultLog;
exports.encodeNumber = encodeNumber;
exports.decodeNumber = decodeNumber;
exports.toIntBE = toIntBE;
exports.formatHex = formatHex;
var BPS_START = exports.BPS_START = Buffer.from('BPS1');
var BPS_FOOTER_LENGTH = exports.BPS_FOOTER_LENGTH = 12;

var SOURCE_READ = exports.SOURCE_READ = 0;
var TARGET_READ = exports.TARGET_READ = 1;
var SOURCE_COPY = exports.SOURCE_COPY = 2;
var TARGET_COPY = exports.TARGET_COPY = 3;

/* eslint-disable no-console */
function defaultLog(message) {
  if (console) {
    if (console.debug) {
      console.debug(message);
    } else if (console.log) {
      console.log(message);
    }
  }
}
/* eslint-enable no-console */

function encodeNumber(value) {
  var data = value;
  var encoded = [];
  while (true) {
    // eslint-disable-line no-constant-condition
    var x = data & 0x7f;
    data >>= 7;
    if (!data) {
      encoded.push(0x80 | x);
      break;
    }
    encoded.push(x);
    data--;
  }
  return Buffer.from(encoded);
}

function decodeNumber(data) {
  var offset = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 0;

  var index = offset;
  var value = 0;
  var shift = 1;

  while (true) {
    // eslint-disable-line no-constant-condition
    var x = data[index];
    index += 1;
    value += (x & 0x7f) * shift;
    if (x & 0x80) {
      break;
    }
    shift <<= 7;
    value += shift;
  }

  return [value, index];
}

function toIntBE(buffer) {
  var value = 0;
  for (var i = 0; i < buffer.length; i++) {
    value = value << 8 | buffer.readUInt8(i);
  }
  return value >>> 0;
}

function formatHex(v) {
  var byteLength = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : 1;

  var value = Buffer.isBuffer(v) ? toIntBE(v) : v;
  return '0x' + value.toString(16).padStart(2 * byteLength, '0');
}