Fix GUID bytes ordering

src/common/guid-parse.js

@@ -0,0 +1,48 @@
+'use strict';
+
+// Maps for number <-> hex string conversion
+var _byteToHex = [];
+var _hexToByte = {};
+for (var i = 0; i < 256; i++) {
+  _byteToHex[i] = (i + 0x100).toString(16).substr(1);
+  _hexToByte[_byteToHex[i]] = i;
+}
+
+// **`parse()` - Parse a UUID into it's component bytes**
+function parse(s, buf, offset) {
+  const i = (buf && offset) || 0;
+  var ii = 0;
+
+  if (buf) buf.fill(0, i, i + 16);
+  buf = buf || new Buffer(16);
+  s.toLowerCase().replace(/[0-9a-f]{2}/g, function(oct) {
+    if (ii < 4) {
+      buf[i + (3 - ii++)] = _hexToByte[oct]
+    } else if (ii < 6) {
+      buf[i + 4 + (5 - ii++)] = _hexToByte[oct]
+    } else if (ii < 8) {
+      buf[i + 6 + (7 - ii++)] = _hexToByte[oct]
+    } else if (ii < 16) { // Don't overflow!
+      buf[i + ii++] = _hexToByte[oct];
+    }
+  });
+
+  return buf;
+}
+
+// **`unparse()` - Convert UUID byte array (ala parse()) into a string**
+function unparse(buf, offset) {
+  var i = offset || 0;
+  const bth = _byteToHex;
+  return  bth[buf[i+3]] + bth[buf[i+2]] +
+    bth[buf[i+1]] + bth[buf[i+0]] + '-' +
+    bth[buf[i+5]] + bth[buf[i+4]] + '-' +
+    bth[buf[i+7]] + bth[buf[i+6]] + '-' +
+    bth[buf[i+8]] + bth[buf[i+9]] + '-' +
+    bth[buf[i+10]] + bth[buf[i+11]] +
+    bth[buf[i+12]] + bth[buf[i+13]] +
+    bth[buf[i+14]] + bth[buf[i+15]];
+}
+
+exports.parse = parse;
+exports.unparse = unparse;