| 1 | package org.jtoolkit.essence.concurrency.impl; |
| 2 | |
| 3 | import org.apache.commons.logging.Log; |
| 4 | import org.apache.commons.logging.LogFactory; |
| 5 | import org.jetbrains.annotations.NotNull; |
| 6 | import org.jtoolkit.essence.concurrency.Callback; |
| 7 | import org.jtoolkit.essence.concurrency.CallbackEx; |
| 8 | import org.jtoolkit.essence.concurrency.CallbackSet; |
| 9 | import org.jtoolkit.essence.concurrency.CallbackUtils; |
| 10 | |
| 11 | import java.util.LinkedHashSet; |
| 12 | import java.util.Set; |
| 13 | |
| 14 | /* |
| 15 | Copyright 2006 Peter Lawrey |
| 16 | |
| 17 | Licensed under the Apache License, Version 2.0 (the "License"); |
| 18 | you may not use this file except in compliance with the License. |
| 19 | You may obtain a copy of the License at |
| 20 | |
| 21 | http://www.apache.org/licenses/LICENSE-2.0 |
| 22 | |
| 23 | Unless required by applicable law or agreed to in writing, software |
| 24 | distributed under the License is distributed on an "AS IS" BASIS, |
| 25 | WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 26 | See the License for the specific language governing permissions and |
| 27 | limitations under the License. |
| 28 | */ |
| 29 | |
| 30 | /** |
| 31 | * @author Peter Lawrey |
| 32 | */ |
| 33 | @Callback.Immediate |
| 34 | public class CallbackSetImpl<T> implements CallbackSet<T> { |
| 35 | private static final Log LOG = LogFactory.getLog(CallbackSetImpl.class); |
| 36 | private static final Callback[] NO_CALLBACK = new Callback[0]; |
| 37 | protected final Set<Callback<T>> callbacks = new LinkedHashSet<Callback<T>>(); |
| 38 | @SuppressWarnings({"FieldAccessedSynchronizedAndUnsynchronized", "unchecked"}) |
| 39 | private Callback<T>[] callbackArray = NO_CALLBACK; |
| 40 | protected final CallbackMode callbackMode; |
| 41 | |
| 42 | public CallbackSetImpl(@NotNull CallbackMode callbackMode) { |
| 43 | this.callbackMode = callbackMode; |
| 44 | } |
| 45 | |
| 46 | protected Callback<T>[] getCallbackArray() { |
| 47 | return callbackArray; |
| 48 | } |
| 49 | |
| 50 | public void onCallback(@NotNull T value) { |
| 51 | Callback<T>[] callbackArray; |
| 52 | synchronized (callbacks) { |
| 53 | callbackArray = this.callbackArray; |
| 54 | } |
| 55 | for (Callback<T> callback : callbackArray) |
| 56 | try { |
| 57 | callback.onCallback(value); |
| 58 | } catch (Exception e) { |
| 59 | dropCallback(callback, e); |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | protected void dropCallback(Callback<T> callback, Exception e) { |
| 64 | if (LOG.isDebugEnabled()) LOG.debug(getThreadName() + ": Dropping callback " + callback, e); |
| 65 | callbacks.remove(callback); |
| 66 | } |
| 67 | |
| 68 | private static String getThreadName() { |
| 69 | return Thread.currentThread().getName(); |
| 70 | } |
| 71 | |
| 72 | public void onException(@NotNull Throwable t) throws IllegalStateException { |
| 73 | Callback<T>[] callbackArray; |
| 74 | synchronized (callbacks) { |
| 75 | callbackArray = this.callbackArray; |
| 76 | } |
| 77 | for (Callback<T> callback : callbackArray) |
| 78 | if (callback instanceof CallbackEx) |
| 79 | try { |
| 80 | ((CallbackEx) callback).onException(t); |
| 81 | } catch (Exception e) { |
| 82 | dropCallback(callback, e); |
| 83 | } |
| 84 | } |
| 85 | |
| 86 | public void addCallback(@NotNull Callback<T> callback) { |
| 87 | synchronized (callbacks) { |
| 88 | switch (callbackMode) { |
| 89 | case SIMPLE: |
| 90 | if (callbacks.add(callback)) |
| 91 | resetCallbackArray(); |
| 92 | break; |
| 93 | case THREADED: |
| 94 | CallbackEx<T> callback2 = CallbackUtils.makeThreaded(callback); |
| 95 | if (callbacks.add(callback2)) |
| 96 | resetCallbackArray(); |
| 97 | break; |
| 98 | } |
| 99 | } |
| 100 | } |
| 101 | |
| 102 | public void removeCallback(@NotNull Callback<T> callback) { |
| 103 | synchronized (callbacks) { |
| 104 | if (callbacks.remove(callback)) |
| 105 | resetCallbackArray(); |
| 106 | } |
| 107 | } |
| 108 | |
| 109 | private void resetCallbackArray() { |
| 110 | callbackArray = callbacks.toArray(new Callback[callbacks.size()]); |
| 111 | } |
| 112 | |
| 113 | public boolean isEmpty() { |
| 114 | return callbackArray.length == 0; |
| 115 | } |
| 116 | } |