lib,src: port isIPv4() to js

Removes a few lines of C++ code while making `isIPv4()` about 3x faster.
`isIPv6()` and `isIP()` for the IPv6 case stay about the same.

I removed the homegrown `isIPv4()` in lib/dns.js that utilized a lookup
table.  It is in fact a little faster than the new `isIPv4()` function
but:

1. The difference is only measurable at around 10M iterations, and
2. The function is a "probably IPv4" heuristic, not a proper validator.

PR-URL: https://github.com/nodejs/node/pull/18398
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Jan Krems <jan.krems@gmail.com>
Reviewed-By: Joyee Cheung <joyeec9h3@gmail.com>
Reviewed-By: Richard Lau <riclau@uk.ibm.com>

1 files changed, 0 insertions, 12 deletions

diff --git a/src/cares_wrap.cc b/src/cares_wrap.cc
index 165a8cda20..191e3c92dc 100644
--- a/src/cares_wrap.cc
+++ b/src/cares_wrap.cc
@@ -1886,16 +1886,6 @@ int ParseIP(const char* ip, ParseIPResult* result = nullptr) {
   return 0;
 }
 
-void IsIP(const FunctionCallbackInfo<Value>& args) {
-  node::Utf8Value ip(args.GetIsolate(), args[0]);
-  args.GetReturnValue().Set(ParseIP(*ip));
-}
-
-void IsIPv4(const FunctionCallbackInfo<Value>& args) {
-  node::Utf8Value ip(args.GetIsolate(), args[0]);
-  args.GetReturnValue().Set(4 == ParseIP(*ip));
-}
-
 void IsIPv6(const FunctionCallbackInfo<Value>& args) {
   node::Utf8Value ip(args.GetIsolate(), args[0]);
   args.GetReturnValue().Set(6 == ParseIP(*ip));
@@ -2138,8 +2128,6 @@ void Initialize(Local<Object> target,
 
   env->SetMethod(target, "getaddrinfo", GetAddrInfo);
   env->SetMethod(target, "getnameinfo", GetNameInfo);
-  env->SetMethod(target, "isIP", IsIP);
-  env->SetMethod(target, "isIPv4", IsIPv4);
   env->SetMethod(target, "isIPv6", IsIPv6);
   env->SetMethod(target, "canonicalizeIP", CanonicalizeIP);