alvinalexander.com | career | drupal | java | mac | mysql | perl | scala | uml | unix  

What this is

This file is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" TM.

Other links

The source code

/*
 *  Copyright 1999-2004 The Apache Software Foundation
 *
 *  Licensed 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.tomcat.util.buf;

import java.io.Serializable;

// XXX Shouldn't be here - has nothing to do with buffers.

/**
 * Main tool for object expiry. 
 * Marks creation and access time of an "expirable" object,
 * and extra properties like "id", "valid", etc.
 *
 * Used for objects that expire - originally Sessions, but 
 * also Contexts, Servlets, cache - or any other object that
 * expires.
 * 
 * @author Costin Manolache
 */
public final class TimeStamp implements  Serializable {
    private long creationTime = 0L;
    private long lastAccessedTime = creationTime;
    private long thisAccessedTime = creationTime;
    private boolean isNew = true;
    private long maxInactiveInterval = -1;
    private boolean isValid = false;
    MessageBytes name;
    int id=-1;
    
    Object parent;
    
    public TimeStamp() {
    }

    // -------------------- Active methods --------------------

    /**
     *  Access notification. This method takes a time parameter in order
     *  to allow callers to efficiently manage expensive calls to
     *  System.currentTimeMillis() 
     */
    public void touch(long time) {
	this.lastAccessedTime = this.thisAccessedTime;
	this.thisAccessedTime = time;
	this.isNew=false;
    }

    // -------------------- Property access --------------------

    /** Return the "name" of the timestamp. This can be used
     *  to associate unique identifier with each timestamped object.
     *  The name is a MessageBytes - i.e. a modifiable byte[] or char[]. 
     */
    public MessageBytes getName() {
	if( name==null ) name=MessageBytes.newInstance();//lazy
	return name;
    }

    /** Each object can have an unique id, similar with name but
     *  providing faster access ( array vs. hashtable lookup )
     */
    public int getId() {
	return id;
    }

    public void setId( int id ) {
	this.id=id;
    }
    
    /** Returns the owner of this stamp ( the object that is
     *  time-stamped ).
     *  For a 
     */
    public void setParent( Object o ) {
	parent=o;
    }

    public Object getParent() {
	return parent;
    }

    public void setCreationTime(long time) {
	this.creationTime = time;
	this.lastAccessedTime = time;
	this.thisAccessedTime = time;
    }


    public long getLastAccessedTime() {
	return lastAccessedTime;
    }

    public long getThisAccessedTime() {
        return thisAccessedTime;
    }

    /** Inactive interval in millis - the time is computed
     *  in millis, convert to secs in the upper layer
     */
    public long getMaxInactiveInterval() {
	return maxInactiveInterval;
    }

    public void setMaxInactiveInterval(long interval) {
	maxInactiveInterval = interval;
    }

    public boolean isValid() {
	return isValid;
    }

    public void setValid(boolean isValid) {
	this.isValid = isValid;
    }

    public boolean isNew() {
	return isNew;
    }

    public void setNew(boolean isNew) {
	this.isNew = isNew;
    }

    public long getCreationTime() {
	return creationTime;
    }

    // -------------------- Maintainance --------------------

    public void recycle() {
	creationTime = 0L;
	lastAccessedTime = 0L;
	maxInactiveInterval = -1;
	isNew = true;
	isValid = false;
	id=-1;
	if( name!=null) name.recycle();
    }

}

... this post is sponsored by my books ...

#1 New Release!

FP Best Seller

 

new blog posts

 

Copyright 1998-2024 Alvin Alexander, alvinalexander.com
All Rights Reserved.

A percentage of advertising revenue from
pages under the /java/jwarehouse URI on this website is
paid back to open source projects.