org.apache.activemq.artemis.core.paging.cursor.impl.LivePageCacheImpl Maven / Gradle / Ivy
/*
* 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.activemq.artemis.core.paging.cursor.impl;
import org.apache.activemq.artemis.core.paging.PagedMessage;
import org.apache.activemq.artemis.core.paging.cursor.LivePageCache;
import org.apache.activemq.artemis.core.paging.cursor.PagePosition;
import org.apache.activemq.artemis.utils.collections.ConcurrentAppendOnlyChunkedList;
import org.jboss.logging.Logger;
/**
* This is the same as PageCache, however this is for the page that's being currently written.
*/
public final class LivePageCacheImpl implements LivePageCache {
private static final Logger logger = Logger.getLogger(LivePageCacheImpl.class);
private static final int CHUNK_SIZE = 32;
private final PagedMessage[] initialMessages;
private final ConcurrentAppendOnlyChunkedList liveMessages;
private final long pageId;
private volatile boolean isLive = true;
public LivePageCacheImpl(final long pageId) {
this.pageId = pageId;
this.liveMessages = new ConcurrentAppendOnlyChunkedList<>(CHUNK_SIZE);
this.initialMessages = null;
}
public LivePageCacheImpl(final long pageId, PagedMessage[] initialMessages) {
this.pageId = pageId;
this.liveMessages = new ConcurrentAppendOnlyChunkedList<>(CHUNK_SIZE);
this.initialMessages = initialMessages;
}
private int initialMessagesSize() {
final PagedMessage[] initialMessages = this.initialMessages;
return initialMessages == null ? 0 : initialMessages.length;
}
@Override
public long getPageId() {
return pageId;
}
@Override
public int getNumberOfMessages() {
return initialMessagesSize() + liveMessages.size();
}
@Override
public PagedMessage getMessage(PagePosition pagePosition) {
final int messageNr = pagePosition.getMessageNr();
if (messageNr < 0) {
return null;
}
final int initialOffset = initialMessagesSize();
if (messageNr < initialOffset) {
return initialMessages[messageNr];
}
final int index = messageNr - initialOffset;
return liveMessages.get(index);
}
@Override
public boolean isLive() {
return isLive;
}
@Override
public void addLiveMessage(PagedMessage message) {
message.getMessage().usageUp();
liveMessages.add(message);
}
@Override
public void close() {
logger.tracef("Closing %s", this);
this.isLive = false;
}
@Override
public PagedMessage[] getMessages() {
final PagedMessage[] pagedMessages = liveMessages.toArray(size -> new PagedMessage[initialMessagesSize() + size], initialMessagesSize());
final PagedMessage[] initialMessages = this.initialMessages;
if (initialMessages != null) {
System.arraycopy(initialMessages, 0, pagedMessages, 0, initialMessages.length);
}
return pagedMessages;
}
@Override
public String toString() {
return "LivePacheCacheImpl::page=" + pageId + " number of messages=" + getNumberOfMessages() + " isLive = " + isLive;
}
}