perf: slide Buffer window 1 byte at a time;

- h/t @skuznetsov and @krthr - Closes #1 - See: https://forum.crystal-lang.org/t/a-tiny-1kb-fast-and-cryptographically-secure-uuid-v4-generator-for-crystal/1774
lukeed · Mar 1, 2020 · 40c5517 · 40c5517
1 parent ffc3244
commit 40c5517
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Showing 2 changed files with 4 additions and 2 deletions.
diff --git a/src/browser.js b/src/browser.js
@@ -12,13 +12,14 @@ export default function () {
 
 	var i=0, tmp, out='';
 	for (; i < 16; i++) {
-		tmp = BUFFER[IDX++];
+		tmp = BUFFER[i + IDX];
 		if (i==6) out += HEX[tmp & 15 | 64];
 		else if (i==8) out += HEX[tmp & 63 | 128];
 		else out += HEX[tmp];
 
 		if (i & 1 && i > 1 && i < 11) out += '-';
 	}
 
+	IDX++;
 	return out;
 }
diff --git a/src/node.js b/src/node.js
@@ -14,13 +14,14 @@ export default function () {
 
 	var i=0, tmp, out='';
 	for (; i < 16; i++) {
-		tmp = BUFFER[IDX++];
+		tmp = BUFFER[i + IDX];
 		if (i==6) out += HEX[tmp & 15 | 64];
 		else if (i==8) out += HEX[tmp & 63 | 128];
 		else out += HEX[tmp];
 
 		if (i & 1 && i > 1 && i < 11) out += '-';
 	}
 
+	IDX++;
 	return out;
 }