chat-server/qq-imsvr/node_modules/arraybuffer.slice/index.js

/**
 * An abstraction for slicing an arraybuffer even when
 * ArrayBuffer.prototype.slice is not supported
 *
 * @api public
 */

module.exports = function(arraybuffer, start, end) {
  var bytes = arraybuffer.byteLength;
  start = start || 0;
  end = end || bytes;

  if (arraybuffer.slice) { return arraybuffer.slice(start, end); }

  if (start < 0) { start += bytes; }
  if (end < 0) { end += bytes; }
  if (end > bytes) { end = bytes; }

  if (start >= bytes || start >= end || bytes === 0) {
    return new ArrayBuffer(0);
  }

  var abv = new Uint8Array(arraybuffer);
  var result = new Uint8Array(end - start);
  for (var i = start, ii = 0; i < end; i++, ii++) {
    result[ii] = abv[i];
  }
  return result.buffer;
};