1 /*
2 * Entreri, an entity-component framework in Java
3 *
4 * Copyright (c) 2013, Michael Ludwig
5 * All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without modification,
8 * are permitted provided that the following conditions are met:
9 *
10 * Redistributions of source code must retain the above copyright notice,
11 * this list of conditions and the following disclaimer.
12 * Redistributions in binary form must reproduce the above copyright notice,
13 * this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
18 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
19 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
20 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
21 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
22 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
23 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
25 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27 package com.lhkbob.entreri.impl;
28
29 import com.lhkbob.entreri.Component;
30
31 import java.util.HashMap;
32 import java.util.Map;
33
34 /**
35 * CachingDelegatingFactoryProvider implements the ComponentFactoryProvider interface to
36 * delegate to a list of factory providers and caches their created factories in a thread
37 * safe manner so that actual implementations can be implemented simpler.
38 *
39 * @author Michael Ludwig
40 */
41 public class CachingDelegatingFactoryProvider extends ComponentFactoryProvider {
42 private final Map<Class<? extends Component>, Factory<?>> cachedFactories;
43
44 private final CompiledFactoryProvider compiledFactoryProvider;
45
46 private final Object lock;
47
48 public CachingDelegatingFactoryProvider() {
49 cachedFactories = new HashMap<Class<? extends Component>, Factory<? extends Component>>();
50 compiledFactoryProvider = new CompiledFactoryProvider();
51
52 lock = new Object();
53 }
54
55 @Override
56 @SuppressWarnings("unchecked")
57 public <T extends Component> Factory<T> getFactory(Class<T> componentType) {
58 // blocking synchronization is easiest to do and it shouldn't be a high contention
59 // point because factories are only gotten when the component repository is created
60 // the first time for a system and type
61 synchronized (lock) {
62 Factory<?> cached = cachedFactories.get(componentType);
63 if (cached != null) {
64 return (Factory<T>) cached;
65 }
66
67 Factory<T> precompiled = compiledFactoryProvider.getFactory(componentType);
68 if (precompiled != null) {
69 cachedFactories.put(componentType, precompiled);
70 return precompiled;
71 }
72 }
73
74 throw new UnsupportedOperationException(
75 "Unable to find or generate a component implementation for " +
76 componentType);
77 }
78 }