net,http2: refactor _write and _writev

Refactor writable part (the _write and _writev functions) in net.Socket
and http2.Http2Stream classes.
Also involves adding a generic "WriteGeneric" method to the Http2Stream
class based on net.Socket._writeGeneric, but behind a symbol.
PR-URL: #20643
Reviewed-By: Anatoli Papirovski <apapirovski@mac.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

Author: ryzokuken

lib/internal/http2/core.js

@@ -146,6 +146,7 @@ const kSession = Symbol('session');
 constkState=Symbol('state');
 constkType=Symbol('type');
 constkUpdateTimer=Symbol('update-timer');
+constkWriteGeneric=Symbol('write-generic');
 
 constkDefaultSocketTimeout=2*60*1000;
 
@@ -1657,13 +1658,16 @@ class Http2Stream extends Duplex {
 'bug in Node.js');
 }
 
-_write(data,encoding,cb){
+[kWriteGeneric](writev,data,encoding,cb){
 // When the Http2Stream is first created, it is corked until the
 // handle and the stream ID is assigned. However, if the user calls
 // uncork() before that happens, the Duplex will attempt to pass
 // writes through. Those need to be queued up here.
 if(this.pending){
-this.once('ready',this._write.bind(this,data,encoding,cb));
+this.once(
+'ready',
+this[kWriteGeneric].bind(this,writev,data,encoding,cb)
+);
 return;
 }
 
@@ -1683,41 +1687,20 @@ class Http2Stream extends Duplex {
 constreq=createWriteWrap(this[kHandle],afterDoStreamWrite);
 req.stream=this[kID];
 
-writeGeneric(this,req,data,encoding,cb);
+if(writev)
+writevGeneric(this,req,data,cb);
+else
+writeGeneric(this,req,data,encoding,cb);
 
 trackWriteState(this,req.bytes);
 }
 
-_writev(data,cb){
-// When the Http2Stream is first created, it is corked until the
-// handle and the stream ID is assigned. However, if the user calls
-// uncork() before that happens, the Duplex will attempt to pass
-// writes through. Those need to be queued up here.
-if(this.pending){
-this.once('ready',this._writev.bind(this,data,cb));
-return;
-}
-
-// If the stream has been destroyed, there's nothing else we can do
-// because the handle has been destroyed. This should only be an
-// issue if a write occurs before the 'ready' event in the case where
-// the duplex is uncorked before the stream is ready to go. In that
-// case, drop the data on the floor. An error should have already been
-// emitted.
-if(this.destroyed)
-return;
-
-this[kUpdateTimer]();
-
-if(!this.headersSent)
-this[kProceed]();
-
-varreq=createWriteWrap(this[kHandle],afterDoStreamWrite);
-req.stream=this[kID];
-
-writevGeneric(this,req,data,cb);
+_write(data,encoding,cb){
+this[kWriteGeneric](false,data,encoding,cb);
+}
 
-trackWriteState(this,req.bytes);
+_writev(data,cb){
+this[kWriteGeneric](true,data,'',cb);
 }
 
 _final(cb){

lib/net.js

@@ -744,13 +744,13 @@ Socket.prototype._writeGeneric = function(writev, data, encoding, cb) {
 this._pendingData=null;
 this._pendingEncoding='';
 
-this._unrefTimer();
-
 if(!this._handle){
 this.destroy(newERR_SOCKET_CLOSED(),cb);
 returnfalse;
 }
 
+this._unrefTimer();
+
 varreq=createWriteWrap(this._handle,afterWrite);
 if(writev)
 writevGeneric(this,req,data,cb);