timers: refactor internal classes to ES2015 syntax

PR-URL: #37408
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Matteo Collina <matteo.collina@gmail.com>
Reviewed-By: Darshan Sen <raisinten@gmail.com>
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: ttzztztz

lib/internal/timers.js

@@ -136,9 +136,6 @@ let timerListId = NumberMIN_SAFE_INTEGER;
 
 constkRefed=Symbol('refed');
 
-// Create a single linked list instance only once at startup
-constimmediateQueue=newImmediateList();
-
 letnextExpiry=Infinity;
 letrefCount=0;
 
@@ -161,140 +158,148 @@ function initAsyncResource(resource, type) {
 if(initHooksExist())
 emitInit(asyncId,type,triggerAsyncId,resource);
 }
-
-// Timer constructor function.
-// The entire prototype is defined in lib/timers.js
-functionTimeout(callback,after,args,isRepeat,isRefed){
-after*=1;// Coalesce to number or NaN
-if(!(after>=1&&after<=TIMEOUT_MAX)){
-if(after>TIMEOUT_MAX){
-process.emitWarning(`${after} does not fit into`+
-' a 32-bit signed integer.'+
-'\nTimeout duration was set to 1.',
-'TimeoutOverflowWarning');
+classTimeout{
+// Timer constructor function.
+// The entire prototype is defined in lib/timers.js
+constructor(callback,after,args,isRepeat,isRefed){
+after*=1;// Coalesce to number or NaN
+if(!(after>=1&&after<=TIMEOUT_MAX)){
+if(after>TIMEOUT_MAX){
+process.emitWarning(`${after} does not fit into`+
+' a 32-bit signed integer.'+
+'\nTimeout duration was set to 1.',
+'TimeoutOverflowWarning');
+}
+after=1;// Schedule on next tick, follows browser behavior
 }
-after=1;// Schedule on next tick, follows browser behavior
-}
 
-this._idleTimeout=after;
-this._idlePrev=this;
-this._idleNext=this;
-this._idleStart=null;
-// This must be set to null first to avoid function tracking
-// on the hidden class, revisit in V8 versions after 6.2
-this._onTimeout=null;
-this._onTimeout=callback;
-this._timerArgs=args;
-this._repeat=isRepeat ? after : null;
-this._destroyed=false;
-
-if(isRefed)
-incRefCount();
-this[kRefed]=isRefed;
-this[kHasPrimitive]=false;
-
-initAsyncResource(this,'Timeout');
-}
+this._idleTimeout=after;
+this._idlePrev=this;
+this._idleNext=this;
+this._idleStart=null;
+// This must be set to null first to avoid function tracking
+// on the hidden class, revisit in V8 versions after 6.2
+this._onTimeout=null;
+this._onTimeout=callback;
+this._timerArgs=args;
+this._repeat=isRepeat ? after : null;
+this._destroyed=false;
 
-// Make sure the linked list only shows the minimal necessary information.
-Timeout.prototype[inspect.custom]=function(_,options){
-returninspect(this,{
- ...options,
-// Only inspect one level.
-depth: 0,
-// It should not recurse.
-customInspect: false
-});
-};
+if(isRefed)
+incRefCount();
+this[kRefed]=isRefed;
+this[kHasPrimitive]=false;
 
-Timeout.prototype.refresh=function(){
-if(this[kRefed])
-active(this);
-else
-unrefActive(this);
+initAsyncResource(this,'Timeout');
+}
 
-returnthis;
-};
+// Make sure the linked list only shows the minimal necessary information.
+[inspect.custom](_,options){
+returninspect(this,{
+ ...options,
+// Only inspect one level.
+depth: 0,
+// It should not recurse.
+customInspect: false
+});
+}
 
-Timeout.prototype.unref=function(){
-if(this[kRefed]){
-this[kRefed]=false;
-if(!this._destroyed)
-decRefCount();
+refresh(){
+if(this[kRefed])
+active(this);
+else
+unrefActive(this);
+
+returnthis;
 }
-returnthis;
-};
 
-Timeout.prototype.ref=function(){
-if(!this[kRefed]){
-this[kRefed]=true;
-if(!this._destroyed)
-incRefCount();
+unref(){
+if(this[kRefed]){
+this[kRefed]=false;
+if(!this._destroyed)
+decRefCount();
+}
+returnthis;
 }
-returnthis;
-};
 
-Timeout.prototype.hasRef=function(){
-returnthis[kRefed];
-};
+ref(){
+if(!this[kRefed]){
+this[kRefed]=true;
+if(!this._destroyed)
+incRefCount();
+}
+returnthis;
+}
 
-functionTimersList(expiry,msecs){
-this._idleNext=this;// Create the list with the linkedlist properties to
-this._idlePrev=this;// Prevent any unnecessary hidden class changes.
-this.expiry=expiry;
-this.id=timerListId++;
-this.msecs=msecs;
-this.priorityQueuePosition=null;
+hasRef(){
+returnthis[kRefed];
+}
 }
 
-// Make sure the linked list only shows the minimal necessary information.
-TimersList.prototype[inspect.custom]=function(_,options){
-returninspect(this,{
- ...options,
-// Only inspect one level.
-depth: 0,
-// It should not recurse.
-customInspect: false
-});
-};
+classTimersList{
+constructor(expiry,msecs){
+this._idleNext=this;// Create the list with the linkedlist properties to
+this._idlePrev=this;// Prevent any unnecessary hidden class changes.
+this.expiry=expiry;
+this.id=timerListId++;
+this.msecs=msecs;
+this.priorityQueuePosition=null;
+}
 
-// A linked list for storing `setImmediate()` requests
-functionImmediateList(){
-this.head=null;
-this.tail=null;
+// Make sure the linked list only shows the minimal necessary information.
+[inspect.custom](_,options){
+returninspect(this,{
+ ...options,
+// Only inspect one level.
+depth: 0,
+// It should not recurse.
+customInspect: false
+});
+}
 }
 
-// Appends an item to the end of the linked list, adjusting the current tail's
-// next pointer and the item's previous pointer where applicable
-ImmediateList.prototype.append=function(item){
-if(this.tail!==null){
-this.tail._idleNext=item;
-item._idlePrev=this.tail;
-}else{
-this.head=item;
+// A linked list for storing `setImmediate()` requests
+classImmediateList{
+constructor(){
+this.head=null;
+this.tail=null;
 }
-this.tail=item;
-};
 
-// Removes an item from the linked list, adjusting the pointers of adjacent
-// items and the linked list's head or tail pointers as necessary
-ImmediateList.prototype.remove=function(item){
-if(item._idleNext){
-item._idleNext._idlePrev=item._idlePrev;
+// Appends an item to the end of the linked list, adjusting the current tail's
+// next pointer and the item's previous pointer where applicable
+append(item){
+if(this.tail!==null){
+this.tail._idleNext=item;
+item._idlePrev=this.tail;
+}else{
+this.head=item;
+}
+this.tail=item;
 }
 
-if(item._idlePrev){
-item._idlePrev._idleNext=item._idleNext;
-}
+// Removes an item from the linked list, adjusting the pointers of adjacent
+// items and the linked list's head or tail pointers as necessary
+remove(item){
+if(item._idleNext){
+item._idleNext._idlePrev=item._idlePrev;
+}
 
-if(item===this.head)
-this.head=item._idleNext;
-if(item===this.tail)
-this.tail=item._idlePrev;
+if(item._idlePrev){
+item._idlePrev._idleNext=item._idleNext;
+}
 
-item._idleNext=null;
-item._idlePrev=null;
-};
+if(item===this.head)
+this.head=item._idleNext;
+if(item===this.tail)
+this.tail=item._idlePrev;
+
+item._idleNext=null;
+item._idlePrev=null;
+}
+}
+
+// Create a single linked list instance only once at startup
+constimmediateQueue=newImmediateList();
 
 functionincRefCount(){
 if(refCount++===0)