/*
* #%L
* OW2 Chameleon - Fuchsia Framework
* %%
* Copyright (C) 2009 - 2014 OW2 Chameleon
* %%
* 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.
* #L%
*/
/*
Calimero - A library for KNX network access
Copyright (C) 2006-2008 B. Malinowsky
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or at your option any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
Linking this library statically or dynamically with other modules is
making a combined work based on this library. Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.
As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under terms
of your choice, provided that you also meet, for each linked independent
module, the terms and conditions of the license of that module. An
independent module is a module which is not derived from or based on
this library. If you modify this library, you may extend this exception
to your version of the library, but you are not obligated to do so. If
you do not wish to do so, delete this exception statement from your
version.
*/
package tuwien.auto.calimero.log;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Vector;
/**
* A LogService is used to categorize logging information with regard to logging level and
* topic, and offer it to its {@link LogWriter}s.
* <p>
* The default log level by the LogService is {@link LogLevel#ALL}. This means all log
* information levels (except {@link LogLevel#OFF}) will be offered.
* <p>
* LogWriter can register at a log service to receive information the log service is
* offering to its writers.
* <p>
* Use {@link LogManager} to create new or get existing log services.<br>
* Usage:<br> - A LogService may be created for different parts in calimero, so it
* distinguishes log information by source.<br> - A LogService may be created for a
* particular subject, i.e. to divide information into topics.<br>
* A log service may restrict offered information through its own log level.<br> - ...
*
* @author B. Malinowsky
* @see LogLevel
* @see LogWriter
*/
public class LogService
{
// NOTE: log dispatcher is a daemon thread and never closed explicitly
private static final class Dispatcher extends Thread
{
private static final class LogData
{
final List wr;
final String svc;
final LogLevel lvl;
final String msg;
final Throwable trow;
LogData(List writers, String service, LogLevel level, String message,
Throwable t)
{
wr = writers;
svc = service;
lvl = level;
msg = message;
trow = t;
}
}
private final List data = new LinkedList();
private volatile boolean quit;
Dispatcher()
{
super("Log dispatcher");
setDaemon(true);
start();
}
public void run()
{
while (!quit) {
try {
LogData d;
synchronized (data) {
while (data.isEmpty())
data.wait();
d = (LogData) data.remove(0);
}
dispatch(d);
}
catch (final InterruptedException ignore) {}
}
// empty log data list
synchronized (data) {
while (!data.isEmpty())
dispatch((LogData) data.remove(0));
}
}
void add(List writers, String service, LogLevel level, String msg, Throwable t)
{
if (!quit) {
synchronized (data) {
data.add(new LogData(writers, service, level, msg, t));
data.notify();
}
}
}
void quit()
{
quit = true;
interrupt();
if (currentThread() != this) {
try {
join();
}
catch (final InterruptedException e) {}
}
}
private void dispatch(LogData d)
{
synchronized (d.wr) {
for (final Iterator i = d.wr.iterator(); i.hasNext();)
((LogWriter) i.next()).write(d.svc, d.lvl, d.msg, d.trow);
}
}
}
private static final Dispatcher logger = new Dispatcher();
/** Name of this log service. */
protected final String name;
private LogLevel logLevel = LogLevel.ALL;
private List writers = new Vector();
/**
* Creates a new log service with the specified <code>name</code>.
* <p>
*
* @param name name of log service
*/
protected LogService(String name)
{
this.name = name;
}
/**
* Creates a new log service with the specified <code>name</code> and log
* <code>level</code>.
* <p>
*
* @param name name of log service
* @param level log level for this log service
*/
protected LogService(String name, LogLevel level)
{
this.name = name;
setLogLevel(level);
}
/**
* Returns the name of this log service.
* <p>
*
* @return the log service name
*/
public String getName()
{
return name;
}
/**
* Sets a new log level for this log service.
* <p>
* All log information will be checked against and restricted to at most this level.<br>
* Log information not allowed will be ignored.
* <p>
* For example: set log level to {@link LogLevel#WARN} to allow log info with
* {@link LogLevel#FATAL}, {@link LogLevel#ERROR} and {@link LogLevel#WARN}.
*
* @param level new log level
*/
public void setLogLevel(LogLevel level)
{
logLevel = level;
}
/**
* Returns the currently set log level of this log service.
* <p>
*
* @return the log {@link LogLevel}
*/
public LogLevel getLogLevel()
{
return logLevel;
}
/**
* Adds the <code>writer</code> to this log service.
* <p>
* No check is made to detect (or prevent) duplicate writers.
*
* @param writer LogWriter to add
*/
public void addWriter(LogWriter writer)
{
writers.add(writer);
}
/**
* Removes <code>writer</code> from this log service.
* <p>
* No check is made to detect and remove duplicate writers.
*
* @param writer LogWriter to remove
*/
public void removeWriter(LogWriter writer)
{
writers.remove(writer);
}
/**
* Removes all registered log writer from this log service.
* <p>
*
* @param close should the writers be closed before removal
*/
public void removeAllWriter(boolean close)
{
if (close)
synchronized (writers) {
for (final Iterator i = writers.iterator(); i.hasNext();)
((LogWriter) i.next()).close();
}
writers = new Vector();
}
/**
* Offers <code>msg</code> with log level {@link LogLevel#TRACE}.
* <p>
*
* @param msg log information
*/
public void trace(String msg)
{
log(LogLevel.TRACE, msg);
}
/**
* Offers <code>msg</code> with log level {@link LogLevel#INFO}.
* <p>
*
* @param msg log information
*/
public void info(String msg)
{
log(LogLevel.INFO, msg);
}
/**
* Offers <code>msg</code> with log level {@link LogLevel#WARN}.
* <p>
*
* @param msg log information
*/
public void warn(String msg)
{
log(LogLevel.WARN, msg);
}
/**
* Offers <code>msg</code> and the <code>throwable</code> object with log level
* {@link LogLevel#WARN}.
* <p>
*
* @param msg log information
* @param t throwable object
*/
public void warn(String msg, Throwable t)
{
log(LogLevel.WARN, msg, t);
}
/**
* Offers <code>msg</code> with log level {@link LogLevel#ERROR}.
* <p>
*
* @param msg log information
*/
public void error(String msg)
{
log(LogLevel.ERROR, msg);
}
/**
* Offers <code>msg</code> and the <code>throwable</code> object with log level
* {@link LogLevel#ERROR}.
* <p>
*
* @param msg log information
* @param t throwable object
*/
public void error(String msg, Throwable t)
{
log(LogLevel.ERROR, msg, t);
}
/**
* Offers <code>msg</code> with log level {@link LogLevel#FATAL}.
* <p>
*
* @param msg log information
*/
public void fatal(String msg)
{
log(LogLevel.FATAL, msg);
}
/**
* Offers <code>msg</code> and the <code>throwable</code> object with log level
* {@link LogLevel#FATAL}.
* <p>
*
* @param msg log information
* @param t throwable object
*/
public void fatal(String msg, Throwable t)
{
log(LogLevel.FATAL, msg, t);
}
/**
* Offers <code>msg</code> with log <code>level</code>.
* <p>
*
* @param level log level for this message
* @param msg log information
*/
public void log(LogLevel level, String msg)
{
if (level != LogLevel.OFF && level.level <= logLevel.level)
logger.add(writers, name, level, msg, null);
}
/**
* Offers <code>msg</code> and the <code>throwable</code> object with log
* <code>level</code>.
* <p>
*
* @param level log level for this message and throwable
* @param msg log information
* @param t throwable object
*/
public void log(LogLevel level, String msg, Throwable t)
{
if (level != LogLevel.OFF && level.level <= logLevel.level)
logger.add(writers, name, level, msg, t);
}
/* (non-Javadoc)
* @see java.lang.Object#toString()
*/
public String toString()
{
return name + ", log level " + logLevel + ", " + writers.size() + " log writers";
}
}