http: revise _http_server.js

* replace var with const
* eliminate unnecessary bytesParsed variable
http: remove bytesParsed var
PR-URL: #30279
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: Yorkie Liu <yorkiefixer@gmail.com>
Reviewed-By: Gireesh Punathil <gpunathi@in.ibm.com>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: telenord

lib/_http_server.js

@@ -253,13 +253,13 @@ function writeHead(statusCode, reason, obj) {
 }
 this.statusCode=statusCode;
 
-varheaders;
+letheaders;
 if(this[kOutHeaders]){
 // Slow-case: when progressive API and header fields are passed.
-vark;
+letk;
 if(obj){
-varkeys=Object.keys(obj);
-for(vari=0;i<keys.length;i++){
+constkeys=Object.keys(obj);
+for(leti=0;i<keys.length;i++){
 k=keys[i];
 if(k)this.setHeader(k,obj[k]);
 }
@@ -487,7 +487,7 @@ function socketOnClose(socket, state) {
 
 functionabortIncoming(incoming){
 while(incoming.length){
-varreq=incoming.shift();
+constreq=incoming.shift();
 req.aborted=true;
 req.emit('aborted');
 req.emit('close');
@@ -577,8 +577,7 @@ function onParserExecuteCommon(server, socket, parser, state, ret, d) {
 socketOnError.call(socket,ret);
 }elseif(parser.incoming&&parser.incoming.upgrade){
 // Upgrade or CONNECT
-varbytesParsed=ret;
-varreq=parser.incoming;
+constreq=parser.incoming;
 debug('SERVER upgrade or connect',req.method);
 
 if(!d)
@@ -594,10 +593,10 @@ function onParserExecuteCommon(server, socket, parser, state, ret, d) {
 freeParser(parser,req,socket);
 parser=null;
 
-vareventName=req.method==='CONNECT' ? 'connect' : 'upgrade';
+consteventName=req.method==='CONNECT' ? 'connect' : 'upgrade';
 if(eventName==='upgrade'||server.listenerCount(eventName)>0){
 debug('SERVER have listener for %s',eventName);
-varbodyHead=d.slice(bytesParsed,d.length);
+constbodyHead=d.slice(ret,d.length);
 
 socket.readableFlowing=null;
 server.emit(eventName,req,socket,bodyHead);
@@ -659,7 +658,7 @@ function resOnFinish(req, res, socket, state, server) {
 }
 }else{
 // Start sending the next message
-varm=state.outgoing.shift();
+constm=state.outgoing.shift();
 if(m){
 m.assignSocket(socket);
 }
@@ -696,7 +695,7 @@ function parserOnIncoming(server, socket, state, req, keepAlive) {
 // so that we don't become overwhelmed by a flood of
 // pipelined requests that may never be resolved.
 if(!socket._paused){
-varws=socket._writableState;
+constws=socket._writableState;
 if(ws.needDrain||state.outgoingData>=socket.writableHighWaterMark){
 socket._paused=true;
 // We also need to pause the parser, but don't do that until after