stream: simplify isBuf

PR-URL: #31067
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: Denys Otrishko <shishugi@gmail.com>

Author: ronag

lib/_stream_writable.js

@@ -313,7 +313,7 @@ Writable.prototype.write = function(chunk, encoding, cb) {
 writeAfterEnd(this,cb);
 elseif(isBuf||validChunk(this,state,chunk,cb)){
 state.pendingcb++;
-ret=writeOrBuffer(this,state,isBuf,chunk,encoding,cb);
+ret=writeOrBuffer(this,state,chunk,encoding,cb);
 }
 
 returnret;
@@ -357,15 +357,6 @@ ObjectDefineProperty(Writable.prototype, 'writableBuffer', {
 }
 });
 
-functiondecodeChunk(state,chunk,encoding){
-if(!state.objectMode&&
-state.decodeStrings!==false&&
-typeofchunk==='string'){
-chunk=Buffer.from(chunk,encoding);
-}
-returnchunk;
-}
-
 ObjectDefineProperty(Writable.prototype,'writableEnded',{
 // Making it explicit this property is not enumerable
 // because otherwise some prototype manipulation in
@@ -399,14 +390,13 @@ ObjectDefineProperty(Writable.prototype, 'writableCorked', {
 // If we're already writing something, then just put this
 // in the queue, and wait our turn. Otherwise, call _write
 // If we return false, then we need a drain event, so set that flag.
-functionwriteOrBuffer(stream,state,isBuf,chunk,encoding,cb){
-if(!isBuf){
-varnewChunk=decodeChunk(state,chunk,encoding);
-if(chunk!==newChunk){
-isBuf=true;
-encoding='buffer';
-chunk=newChunk;
-}
+functionwriteOrBuffer(stream,state,chunk,encoding,cb){
+if(!state.objectMode&&
+state.decodeStrings!==false&&
+encoding!=='buffer'&&
+typeofchunk==='string'){
+chunk=Buffer.from(chunk,encoding);
+encoding='buffer';
 }
 constlen=state.objectMode ? 1 : chunk.length;
 
@@ -422,7 +412,6 @@ function writeOrBuffer(stream, state, isBuf, chunk, encoding, cb) {
 state.lastBufferedRequest={
  chunk,
  encoding,
- isBuf,
 callback: cb,
 next: null
 };
@@ -558,7 +547,7 @@ function clearBuffer(stream, state) {
 varallBuffers=true;
 while(entry){
 buffer[count]=entry;
-if(!entry.isBuf)
+if(entry.encoding!=='buffer')
 allBuffers=false;
 entry=entry.next;
 count+=1;