adriengibrat · July 5, 2016 23:34 · Jul 5, 2016
diff --git a/uuid.js b/uuid.js
@@ -0,0 +1,22 @@
+// see https://tools.ietf.org/html/rfc4122#section-4.4
+function uuid () {
+	var seeds = random(12)
+	// inspired by https://github.com/broofa/node-uuid/blob/v2.0.0/uuid.js#L362
+	seeds[5] = (seeds[5] & 0x0fff) | 0x4000 // version bits
+	seeds[7] = (seeds[7] & 0x3fff) | 0x8000 // clock_seq_hi_and_reserved bits
+
+	return 'xx-x-x-x-xxx'.replace(/x/g, function (x, index) { return hex(seeds[index]) })
+
+	function random (n) { // get n random 16-bit unsigned integers
+		var crypto = window.crypto || window.msCrypto
+		return crypto && window.Uint16Array ?
+			crypto.getRandomValues(new Uint16Array(n))
+			: Array.apply(null, Array(n)).map(() => Math.random() * 0xffff | 0)
+	}
+
+	function hex (integer) { // convert 16-bit integer to hexadecimal
+		return integer < 0x1000 ?
+			(integer + 0x10000).toString(16).substr(1) // keep leading zeros
+			: integer.toString(16)
+	}
+}