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Posted to commits@mina.apache.org by tr...@apache.org on 2008/05/22 05:39:24 UTC
svn commit: r658990 -
/mina/branches/buffer/core/src/main/java/org/apache/mina/queue/AbstractIoQueue.java
Author: trustin
Date: Wed May 21 20:39:23 2008
New Revision: 658990
URL: http://svn.apache.org/viewvc?rev=658990&view=rev
Log:
Added AbstractIoQueue
Added:
mina/branches/buffer/core/src/main/java/org/apache/mina/queue/AbstractIoQueue.java (with props)
Added: mina/branches/buffer/core/src/main/java/org/apache/mina/queue/AbstractIoQueue.java
URL: http://svn.apache.org/viewvc/mina/branches/buffer/core/src/main/java/org/apache/mina/queue/AbstractIoQueue.java?rev=658990&view=auto
==============================================================================
--- mina/branches/buffer/core/src/main/java/org/apache/mina/queue/AbstractIoQueue.java (added)
+++ mina/branches/buffer/core/src/main/java/org/apache/mina/queue/AbstractIoQueue.java Wed May 21 20:39:23 2008
@@ -0,0 +1,203 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements. See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership. The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License. You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied. See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ *
+ */
+package org.apache.mina.queue;
+
+import java.util.AbstractQueue;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+/**
+ * A skeletal implementation of {@link IoQueue} which lessens the burden of
+ * writing a new {@link IoQueue} implementation.
+ *
+ * @author The Apache MINA project (dev@mina.apache.org)
+ *
+ * @param <E> the type of the queue's elements
+ */
+public abstract class AbstractIoQueue<E> extends AbstractQueue<E> implements IoQueue<E> {
+
+ private static final Logger LOG = LoggerFactory.getLogger(AbstractIoQueue.class);
+
+ private volatile IoQueueListener<? super E>[] listeners = newListenerArray(0);
+
+ /**
+ * {@inheritDoc}
+ */
+ public final void addListener(IoQueueListener<? super E> listener) {
+ if (listener == null) {
+ throw new NullPointerException("listener");
+ }
+
+ synchronized (this) {
+ IoQueueListener<? super E>[] oldListeners = this.listeners;
+ IoQueueListener<? super E>[] newListeners =
+ newListenerArray(oldListeners.length + 1);
+ System.arraycopy(
+ oldListeners, 0, newListeners, 0, oldListeners.length);
+ newListeners[oldListeners.length] = listener;
+ this.listeners = newListeners;
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public final void removeListener(IoQueueListener<? super E> listener) {
+ synchronized (this) {
+ int index = -1;
+ IoQueueListener<? super E>[] oldListeners = this.listeners;
+ for (int i = 0; i < oldListeners.length; i ++) {
+ if (oldListeners[i] == listener) {
+ index = i;
+ break;
+ }
+ }
+ if (index < 0) {
+ return;
+ }
+
+ IoQueueListener<? super E>[] newListeners =
+ newListenerArray(oldListeners.length - 1);
+
+ if (index == 0) {
+ System.arraycopy(
+ oldListeners, 1, newListeners, 0, newListeners.length);
+
+ } else if (index == newListeners.length) {
+ System.arraycopy(
+ oldListeners, 0, newListeners, 0, newListeners.length);
+
+ } else {
+ System.arraycopy(
+ oldListeners, 0, newListeners, 0, index);
+ System.arraycopy(
+ oldListeners, index + 1,
+ newListeners, index, newListeners.length - index);
+ }
+
+ this.listeners = newListeners;
+ }
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public final boolean offer(E e) {
+ try {
+ if (!accept(e)) {
+ return false;
+ }
+ } catch (RuntimeException ex) {
+ throw ex;
+ } catch (Error ex) {
+ throw ex;
+ } catch (Throwable t) {
+ throw new RuntimeException("Failed to accept: " + e, t);
+ }
+
+ doOffer(e);
+ offered(e);
+ return true;
+ }
+
+ /**
+ * {@inheritDoc}
+ */
+ public final E poll() {
+ E e = doPoll();
+ if (e == null) {
+ return null;
+ }
+
+ polled(e);
+ return e;
+ }
+
+ /**
+ * Performs the actual insertion operation.
+ *
+ * @param e an element to add to the tail of this queue.
+ */
+ protected abstract void doOffer(E e);
+
+ /**
+ * Performs the actual removal operation.
+ *
+ * @return the removed head object if this queue is not empty.
+ * <tt>null</tt> if this queue is empty.
+ */
+ protected abstract E doPoll();
+
+ /**
+ * Calls {@link IoQueueListener#accept(IoQueue, Object)} for all
+ * registered listeners and returns if the element should be accepted to
+ * this queue or not. This operation fails fast, which means that
+ * this method will return <tt>false</tt> as soon as any listener
+ * returns <tt>false</tt>, not iterating the whole listeners.
+ */
+ private boolean accept(E element) throws Exception {
+ IoQueueListener<? super E>[] listeners = this.listeners;
+ for (IoQueueListener<? super E> l: listeners) {
+ if (!l.accept(this, element)) {
+ return false;
+ }
+ }
+ return true;
+ }
+
+ /**
+ * Calls {@link IoQueueListener#offered(IoQueue, Object)} for all
+ * registered listeners.
+ */
+ private void offered(E element) {
+ IoQueueListener<? super E>[] listeners = this.listeners;
+ for (IoQueueListener<? super E> l: listeners) {
+ try {
+ l.offered(this, element);
+ } catch (Throwable t) {
+ LOG.warn("Exception raised from an IoQueueListener.", t);
+ }
+ }
+ }
+
+ /**
+ * Calls {@link IoQueueListener#polled(IoQueue, Object)} for all
+ * registered listeners.
+ */
+ private void polled(E element) {
+ IoQueueListener<? super E>[] listeners = this.listeners;
+ for (IoQueueListener<? super E> l: listeners) {
+ try {
+ l.offered(this, element);
+ } catch (Throwable t) {
+ LOG.warn("Exception raised from an IoQueueListener.", t);
+ }
+ }
+ }
+
+ /**
+ * Creates a new listener array of the specified length.
+ */
+ @SuppressWarnings("unchecked")
+ private IoQueueListener<? super E>[] newListenerArray(int length) {
+ return new IoQueueListener[length];
+ }
+}
Propchange: mina/branches/buffer/core/src/main/java/org/apache/mina/queue/AbstractIoQueue.java
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Propchange: mina/branches/buffer/core/src/main/java/org/apache/mina/queue/AbstractIoQueue.java
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