optimal implementation of caching logic

src/loaders/Cache.js

@@ -1,46 +1,78 @@
 /**
  * @author mrdoob / http://mrdoob.com/
+ * @author vladgaidukov / [email protected]
  */
 
 var Cache = {
 
-	enabled: false,
+    enabled: false,
 
-	files: {},
+    objects: {},
 
-	add: function ( key, file ) {
+    addObject: function ( key, obj ) {
+
+        if ( this.enabled === false ) return;
 
-		if ( this.enabled === false ) return;
+        this.objects[ key ] = {
+            loaded: false,
+            object: obj,
+            callbacks: []
+        };
 
-		// console.log( 'THREE.Cache', 'Adding key:', key );
+    },
 
-		this.files[ key ] = file;
+    addCallback: function ( key, callback ) {
+
+        if ( this.enabled === false ) return;
 
-	},
+        this.objects[ key ].callbacks.push( callback );
 
-	get: function ( key ) {
+    },
 
-		if ( this.enabled === false ) return;
+    isCached: function ( key ) {
 
-		// console.log( 'THREE.Cache', 'Checking key:', key );
+        if ( this.objects [ key ] ) return true;
 
-		return this.files[ key ];
+        return false;
 
-	},
+    },
 
-	remove: function ( key ) {
+    getObject: function ( key ) {
+
+        if ( this.enabled === false ) return;
 
-		delete this.files[ key ];
+        return this.objects[ key ];
 
-	},
+    },
 
-	clear: function () {
+    loaded: function ( key, obj ) {
 
-		this.files = {};
+        if ( !this.objects[ key ] ) return;
 
-	}
+        this.objects[ key ].object = obj;
+        this.objects[ key ].loaded = true;
 
-};
+    },
+
+    isLoaded: function ( key ) {
+
+        if ( !this.objects[ key ] ) return false;
+
+        return this.objects[ key ].loaded;
+
+    },
+
+    remove: function ( key ) {
 
+        delete this.objects[ key ];
+
+    },
+
+    clear: function () {
+
+        this.objects = {};
+
+    }
+};
 
 export { Cache };

src/loaders/FileLoader.js

@@ -1,5 +1,6 @@
 /**
  * @author mrdoob / http://mrdoob.com/
+ * @author vladgaidukov / [email protected]
  */
 
 import { Cache } from './Cache';
@@ -21,19 +22,25 @@ Object.assign( FileLoader.prototype, {
 
 		var scope = this;
 
-		var cached = Cache.get( url );
-
-		if ( cached !== undefined ) {
+		if ( Cache.isLoaded( url ) ) {
+                    
+			var cached = Cache.getObject( url ).object;
 
 			scope.manager.itemStart( url );
 
-			setTimeout( function () {
+			if ( onLoad ) {
+
+				setTimeout ( function () {
+
+					onLoad( cached );
+					scope.manager.itemEnd( url );
 
-				if ( onLoad ) onLoad( cached );
+				}, 0);
+			} else {
 
 				scope.manager.itemEnd( url );
 
-			}, 0 );
+			}
 
 			return cached;
 
@@ -129,72 +136,105 @@ Object.assign( FileLoader.prototype, {
 
 			var request = new XMLHttpRequest();
 			request.open( 'GET', url, true );
+
+                        if ( Cache.isCached( url ) ) {
 
-			request.addEventListener( 'load', function ( event ) {
+                            Cache.addCallback( url, onLoad );
 
-				var response = event.target.response;
+                        } else {
 
-				Cache.add( url, response );
+                            Cache.addObject( url );
+
+                            Cache.addCallback( url, onLoad );
 
-				if ( this.status === 200 ) {
+                            request.addEventListener( 'load', function ( event ) {
 
-					if ( onLoad ) onLoad( response );
+                                var response = event.target.response;
 
-					scope.manager.itemEnd( url );
+                                if ( this.status === 200 ) {
 
-				} else if ( this.status === 0 ) {
+                                    if ( Cache.enabled ) {
+
+                                        Cache.loaded ( url, response );
+                                        var cached = Cache.getObject ( url );
 
-					// Some browsers return HTTP Status 0 when using non-http protocol
-					// e.g. 'file://' or 'data://'. Handle as success.
+                                        for ( var i = 0; i < cached.callbacks.length; i ++ ) {
 
-					console.warn( 'THREE.FileLoader: HTTP Status 0 received.' );
+                                            if ( cached.callbacks[ i ] ) {
 
-					if ( onLoad ) onLoad( response );
+                                                cached.callbacks[ i ]( response );
 
-					scope.manager.itemEnd( url );
+                                            }
 
-				} else {
+                                            scope.manager.itemEnd( url );
 
-					if ( onError ) onError( event );
+                                        }
+                                    } else {
+
+                                        if ( onLoad ) onLoad( response );
+
+                                        scope.manager.itemEnd( url );
+
+                                    }
 
-					scope.manager.itemError( url );
+                                } else if ( this.status === 0 ) {
 
-				}
+                                    // Some browsers return HTTP Status 0 when using non-http protocol
+                                    // e.g. 'file://' or 'data://'. Handle as success.
 
-			}, false );
+                                    console.warn( 'THREE.FileLoader: HTTP Status 0 received.' );
 
-			if ( onProgress !== undefined ) {
+                                    if ( onLoad ) onLoad( response );
 
-				request.addEventListener( 'progress', function ( event ) {
+                                    scope.manager.itemEnd( url );
 
-					onProgress( event );
+                                } else {
 
-				}, false );
+                                    Cache.remove ( url );
 
-			}
+                                    if ( onError ) onError( event );
 
-			request.addEventListener( 'error', function ( event ) {
+                                    scope.manager.itemError( url );
 
-				if ( onError ) onError( event );
+                                }
 
-				scope.manager.itemError( url );
+                            }, false );
 
-			}, false );
+                            if ( onProgress !== undefined ) {
 
-			if ( this.responseType !== undefined ) request.responseType = this.responseType;
-			if ( this.withCredentials !== undefined ) request.withCredentials = this.withCredentials;
+                                request.addEventListener( 'progress', function ( event ) {
 
-			if ( request.overrideMimeType ) request.overrideMimeType( this.mimeType !== undefined ? this.mimeType : 'text/plain' );
+                                    onProgress( event );
 
-			for ( var header in this.requestHeader ) {
+
+                                }, false );
+
+                            }
+
+                            request.addEventListener( 'error', function ( event ) {
+
+                                if ( onError ) onError( event );
+
+                                scope.manager.itemError( url );
+
+                            }, false );
+
+                            if ( this.responseType !== undefined ) request.responseType = this.responseType;
+                            if ( this.withCredentials !== undefined ) request.withCredentials = this.withCredentials;
+
+                            if ( request.overrideMimeType ) request.overrideMimeType( this.mimeType !== undefined ? this.mimeType : 'text/plain' );
+
+                            for ( var header in this.requestHeader ) {
 
 				request.setRequestHeader( header, this.requestHeader[ header ] );
 
-			}
+                            }
 
-			request.send( null );
+                            request.send( null );
+
+                        }
 
-		}
+                }
 
 		scope.manager.itemStart( url );