/*
 * 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;

import org.apache.activemq.artemis.core.paging.PagedMessage;
import org.apache.activemq.artemis.utils.SoftValueHashMap;

public interface PageCache extends SoftValueHashMap.ValueCache {

   long getPageId();

   int getNumberOfMessages();

   void setMessages(PagedMessage[] messages);

   PagedMessage[] getMessages();

   /**
    * @return whether this cache is still being updated
    */
   boolean isLive();

   /**
    * @param messageNumber The order of the message on the page
    * @return
    */
   PagedMessage getMessage(int messageNumber);

   /**
    * When the cache is being created,
    * We need to first read the files before other threads can get messages from this.
    */
   void lock();

   /**
    * You have to call this method within the same thread you called lock
    */
   void unlock();

   void close();

}
