chat/modules/ArrayBufferUtils.jsm
author Clemens <clemens@gorilla-computing.de>
Mon, 12 Mar 2018 17:44:46 +0100
changeset 30466 9b22a733b765b9a50133661fdccba4e01c3d91de
parent 24030 17e3470d8d8d489e589b3c8a36c5e3b89a73068d
child 35696 e5737872508567abf8b0444f43eb4ee4ce211c75
permissions -rw-r--r--
Bug 321434 - Location does not appear in multiday view event box. r/a=philipp MozReview-Commit-ID: 4BbeOscF0ec

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

/*
 * JavaScript ArrayBuffers are missing a variety of useful methods which are
 * provided by this module.
 */

this.EXPORTED_SYMBOLS = ["copyBytes", "ArrayBufferToBytes",
  "BytesToArrayBuffer", "StringToBytes", "StringToArrayBuffer",
  "ArrayBufferToString", "ArrayBufferToHexString"];

/*
 * aTarget / aSource are ArrayBuffers.
 *
 * Note that this is very similar to ArrayBuffer.slice except that it allows
 * for an offset in the target as well as the source.
 */
function copyBytes(aTarget, aSource, aTargetOffset = 0, aSourceOffset = 0,
                   aLength = aSource.byteLength) {
  // The rest just gets the data copied into it.
  let view = new Uint8Array(aTarget, aTargetOffset);
  view.set(new Uint8Array(aSource, aSourceOffset, aLength));
}

function ArrayBufferToBytes(aBuf) {
  return [...new Uint8Array(aBuf)];
}

function BytesToArrayBuffer(aBytes = []) {
  let buf = new ArrayBuffer(aBytes.length);
  let view = new Uint8Array(buf);
  view.set(aBytes);
  return buf;
}

function StringToBytes(aString) {
  let bytes = [];
  for (let i in aString) {
    bytes.push(aString.charCodeAt(i));
  }
  return bytes;
}

function StringToArrayBuffer(aString) {
  return BytesToArrayBuffer(StringToBytes(aString));
}

function ArrayBufferToString(aData) {
  return Array.from(new Uint8Array(aData)).map(b => String.fromCharCode(b)).join("");
}

function ArrayBufferToHexString(aData) {
  return "0x" + Array.from(new Uint8Array(aData)).map(b => ("0" + b.toString(16)).slice(-2)).join(" ");
}