From 23690f57282a0b4f323dd6787d12ff8ef91ce825 Mon Sep 17 00:00:00 2001
From: Kevin Ngo <me@ngokevin.com>
Date: Wed, 18 Oct 2017 16:21:31 -0700
Subject: [PATCH 1/2] have fileloader merge multiple concurrent requests for
 the same url (fixes #10644)

---
 src/loaders/FileLoader.js | 27 ++++++++++++++++++++++++++-
 1 file changed, 26 insertions(+), 1 deletion(-)

diff --git a/src/loaders/FileLoader.js b/src/loaders/FileLoader.js
index 9ac2daa355ed6f..533555a720641c 100644
--- a/src/loaders/FileLoader.js
+++ b/src/loaders/FileLoader.js
@@ -23,7 +23,7 @@ Object.assign( FileLoader.prototype, {
 
 		var cached = Cache.get( url );
 
-		if ( cached !== undefined ) {
+		if ( cached !== undefined && ! cached.loaderSubscriptions ) {
 
 			scope.manager.itemStart( url );
 
@@ -39,6 +39,19 @@ Object.assign( FileLoader.prototype, {
 
 		}
 
+		// If file is already in process of loading, wait for it to load.
+		if ( cached !== undefined && cached.loaderSubscriptions ) {
+
+			cached.loaderSubscriptions.push( function () {
+
+				scope.load( url, onLoad, onProgress, onError );
+
+			} );
+
+			return;
+
+		}
+
 		// Check for data: URI
 		var dataUriRegex = /^data:(.*?)(;base64)?,(.*)$/;
 		var dataUriRegexResult = url.match( dataUriRegex );
@@ -128,7 +141,12 @@ Object.assign( FileLoader.prototype, {
 
 		} else {
 
+			var loaderSubscriptions = [];
 			var request = new XMLHttpRequest();
+
+			// Allow other file loaders to wait and subscribe on this request.
+			Cache.add( url, { loaderSubscriptions: loaderSubscriptions } );
+
 			request.open( 'GET', url, true );
 
 			request.addEventListener( 'load', function ( event ) {
@@ -163,6 +181,13 @@ Object.assign( FileLoader.prototype, {
 
 				}
 
+				// Tell other requests for the same file that the file has finished loading.
+				for ( var i = 0; i < loaderSubscriptions.length; i ++ ) {
+
+					loaderSubscriptions[ i ]( response );
+
+				}
+
 			}, false );
 
 			if ( onProgress !== undefined ) {

From eaa5fbcc679313409876bb7356a9a48bfc3633b1 Mon Sep 17 00:00:00 2001
From: Kevin Ngo <me@ngokevin.com>
Date: Wed, 18 Oct 2017 18:49:17 -0700
Subject: [PATCH 2/2] don't use cache object to maintain duplicate requests
 structure

---
 src/loaders/FileLoader.js | 31 ++++++++++++++++++++++---------
 1 file changed, 22 insertions(+), 9 deletions(-)

diff --git a/src/loaders/FileLoader.js b/src/loaders/FileLoader.js
index 533555a720641c..ebc3ecfc9ad613 100644
--- a/src/loaders/FileLoader.js
+++ b/src/loaders/FileLoader.js
@@ -5,6 +5,8 @@
 import { Cache } from './Cache';
 import { DefaultLoadingManager } from './LoadingManager';
 
+var currentlyLoadingFiles = {};
+
 function FileLoader( manager ) {
 
 	this.manager = ( manager !== undefined ) ? manager : DefaultLoadingManager;
@@ -23,7 +25,7 @@ Object.assign( FileLoader.prototype, {
 
 		var cached = Cache.get( url );
 
-		if ( cached !== undefined && ! cached.loaderSubscriptions ) {
+		if ( cached !== undefined ) {
 
 			scope.manager.itemStart( url );
 
@@ -40,9 +42,9 @@ Object.assign( FileLoader.prototype, {
 		}
 
 		// If file is already in process of loading, wait for it to load.
-		if ( cached !== undefined && cached.loaderSubscriptions ) {
+		if ( currentlyLoadingFiles[ url ] !== undefined ) {
 
-			cached.loaderSubscriptions.push( function () {
+			currentlyLoadingFiles[ url ].push( function () {
 
 				scope.load( url, onLoad, onProgress, onError );
 
@@ -141,11 +143,14 @@ Object.assign( FileLoader.prototype, {
 
 		} else {
 
-			var loaderSubscriptions = [];
 			var request = new XMLHttpRequest();
 
-			// Allow other file loaders to wait and subscribe on this request.
-			Cache.add( url, { loaderSubscriptions: loaderSubscriptions } );
+			if ( Cache.enabled ) {
+
+				// Allow other file loaders to wait and subscribe on this request.
+				currentlyLoadingFiles[ url ] = [];
+
+			}
 
 			request.open( 'GET', url, true );
 
@@ -181,10 +186,18 @@ Object.assign( FileLoader.prototype, {
 
 				}
 
-				// Tell other requests for the same file that the file has finished loading.
-				for ( var i = 0; i < loaderSubscriptions.length; i ++ ) {
+				if ( Cache.enabled ) {
+
+					var duplicateRequests = currentlyLoadingFiles[ url ];
+
+					delete currentlyLoadingFiles[ url ];
+
+					// Tell other requests for the same file that the file has finished loading.
+					for ( var i = 0; i < duplicateRequests.length; i ++ ) {
+
+						duplicateRequests[i]( response );
 
-					loaderSubscriptions[ i ]( response );
+					}
 
 				}