net: improve performance of isIPv4 and isIPv6

Author: Uzlopak

lib/internal/net.js

@@ -12,21 +12,21 @@ const errors = require('internal/errors');
 
 // IPv4 Segment
 const v4Seg = '(?:[0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])';
-const v4Str = `(${v4Seg}[.]){3}${v4Seg}`;
+const v4Str = `(?:${v4Seg}[.]){3}${v4Seg}`;
 const IPv4Reg = new RegExp(`^${v4Str}$`);
 
 // IPv6 Segment
 const v6Seg = '(?:[0-9a-fA-F]{1,4})';
-const IPv6Reg = new RegExp('^(' +
+const IPv6Reg = new RegExp('^(?:' +
   `(?:${v6Seg}:){7}(?:${v6Seg}|:)|` +
   `(?:${v6Seg}:){6}(?:${v4Str}|:${v6Seg}|:)|` +
-  `(?:${v6Seg}:){5}(?::${v4Str}|(:${v6Seg}){1,2}|:)|` +
-  `(?:${v6Seg}:){4}(?:(:${v6Seg}){0,1}:${v4Str}|(:${v6Seg}){1,3}|:)|` +
-  `(?:${v6Seg}:){3}(?:(:${v6Seg}){0,2}:${v4Str}|(:${v6Seg}){1,4}|:)|` +
-  `(?:${v6Seg}:){2}(?:(:${v6Seg}){0,3}:${v4Str}|(:${v6Seg}){1,5}|:)|` +
-  `(?:${v6Seg}:){1}(?:(:${v6Seg}){0,4}:${v4Str}|(:${v6Seg}){1,6}|:)|` +
-  `(?::((?::${v6Seg}){0,5}:${v4Str}|(?::${v6Seg}){1,7}|:))` +
-')(%[0-9a-zA-Z-.:]{1,})?$');
+  `(?:${v6Seg}:){5}(?::${v4Str}|(?::${v6Seg}){1,2}|:)|` +
+  `(?:${v6Seg}:){4}(?:(?::${v6Seg}){0,1}:${v4Str}|(?::${v6Seg}){1,3}|:)|` +
+  `(?:${v6Seg}:){3}(?:(?::${v6Seg}){0,2}:${v4Str}|(?::${v6Seg}){1,4}|:)|` +
+  `(?:${v6Seg}:){2}(?:(?::${v6Seg}){0,3}:${v4Str}|(?::${v6Seg}){1,5}|:)|` +
+  `(?:${v6Seg}:){1}(?:(?::${v6Seg}){0,4}:${v4Str}|(?::${v6Seg}){1,6}|:)|` +
+  `(?::(?:(?::${v6Seg}){0,5}:${v4Str}|(?::${v6Seg}){1,7}|:))` +
+')(?:%[0-9a-zA-Z-.:]{1,})?$');
 
 function isIPv4(s) {
   // TODO(aduh95): Replace RegExpPrototypeTest with RegExpPrototypeExec when it