Logback: the reliable, generic, fast and flexible logging framework.
Copyright (C) 1999-2015, QOS.ch. All rights reserved.
This program and the accompanying materials are dual-licensed under
either the terms of the Eclipse Public License v1.0 as published by
the Eclipse Foundation
  or (per the licensee's choosing)
under the terms of the GNU Lesser General Public License version 2.1
as published by the Free Software Foundation.
/**
 * Logback: the reliable, generic, fast and flexible logging framework.
 * Copyright (C) 1999-2015, QOS.ch. All rights reserved.
 *
 * This program and the accompanying materials are dual-licensed under
 * either the terms of the Eclipse Public License v1.0 as published by
 * the Eclipse Foundation
 *
 *   or (per the licensee's choosing)
 *
 * under the terms of the GNU Lesser General Public License version 2.1
 * as published by the Free Software Foundation.
 */
package ch.qos.logback.classic;

import static ch.qos.logback.core.CoreConstants.EVALUATOR_MAP;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ScheduledFuture;

import org.slf4j.ILoggerFactory;
import org.slf4j.Marker;

import ch.qos.logback.classic.spi.LoggerComparator;
import ch.qos.logback.classic.spi.LoggerContextListener;
import ch.qos.logback.classic.spi.LoggerContextVO;
import ch.qos.logback.classic.spi.TurboFilterList;
import ch.qos.logback.classic.turbo.TurboFilter;
import ch.qos.logback.classic.util.LoggerNameUtil;
import ch.qos.logback.core.ContextBase;
import ch.qos.logback.core.boolex.EventEvaluator;
import ch.qos.logback.core.spi.FilterReply;
import ch.qos.logback.core.spi.LifeCycle;
import ch.qos.logback.core.status.StatusListener;
import ch.qos.logback.core.status.StatusManager;
import ch.qos.logback.core.status.WarnStatus;

LoggerContext glues many of the logback-classic components together. In principle, every logback-classic component instance is attached either directly or indirectly to a LoggerContext instance. Just as importantly LoggerContext implements the ILoggerFactory acting as the manufacturing source of Logger instances. 
Author:
Ceki Gulcu/**
 * LoggerContext glues many of the logback-classic components together. In
 * principle, every logback-classic component instance is attached either
 * directly or indirectly to a LoggerContext instance. Just as importantly
 * LoggerContext implements the {@link ILoggerFactory} acting as the
 * manufacturing source of {@link Logger} instances.
 *
 * @author Ceki Gulcu
 */
public class LoggerContext extends ContextBase implements ILoggerFactory, LifeCycle {

    
Default setting of packaging data in stack traces /** Default setting of packaging data in stack traces */
    public static final boolean DEFAULT_PACKAGING_DATA = false;

    final Logger root;
    private int size;
    private int noAppenderWarning = 0;
    final private List<LoggerContextListener> loggerContextListenerList = new ArrayList<LoggerContextListener>();

    private Map<String, Logger> loggerCache;

    private LoggerContextVO loggerContextRemoteView;
    private final TurboFilterList turboFilterList = new TurboFilterList();
    private boolean packagingDataEnabled = DEFAULT_PACKAGING_DATA;

    private int maxCallerDataDepth = ClassicConstants.DEFAULT_MAX_CALLEDER_DATA_DEPTH;

    int resetCount = 0;
    private List<String> frameworkPackages;

    public LoggerContext() {
        super();
        this.loggerCache = new ConcurrentHashMap<String, Logger>();

        this.loggerContextRemoteView = new LoggerContextVO(this);
        this.root = new Logger(Logger.ROOT_LOGGER_NAME, null, this);
        this.root.setLevel(Level.DEBUG);
        loggerCache.put(Logger.ROOT_LOGGER_NAME, root);
        initEvaluatorMap();
        size = 1;
        this.frameworkPackages = new ArrayList<String>();
    }

    void initEvaluatorMap() {
        putObject(EVALUATOR_MAP, new HashMap<String, EventEvaluator<?>>());
    }

    
A new instance of LoggerContextRemoteView needs to be created each time the
name or propertyMap (including keys or values) changes.
/**
     * A new instance of LoggerContextRemoteView needs to be created each time the
     * name or propertyMap (including keys or values) changes.
     */
    private void updateLoggerContextVO() {
        loggerContextRemoteView = new LoggerContextVO(this);
    }

    @Override
    public void putProperty(String key, String val) {
        super.putProperty(key, val);
        updateLoggerContextVO();
    }

    @Override
    public void setName(String name) {
        super.setName(name);
        updateLoggerContextVO();
    }

    public final Logger getLogger(final Class<?> clazz) {
        return getLogger(clazz.getName());
    }

    @Override
    public final Logger getLogger(final String name) {

        if (name == null) {
            throw new IllegalArgumentException("name argument cannot be null");
        }

        // if we are asking for the root logger, then let us return it without
        // wasting time
        if (Logger.ROOT_LOGGER_NAME.equalsIgnoreCase(name)) {
            return root;
        }

        int i = 0;
        Logger logger = root;

        // check if the desired logger exists, if it does, return it
        // without further ado.
        Logger childLogger = (Logger) loggerCache.get(name);
        // if we have the child, then let us return it without wasting time
        if (childLogger != null) {
            return childLogger;
        }

        // if the desired logger does not exist, them create all the loggers
        // in between as well (if they don't already exist)
        String childName;
        while (true) {
            int h = LoggerNameUtil.getSeparatorIndexOf(name, i);
            if (h == -1) {
                childName = name;
            } else {
                childName = name.substring(0, h);
            }
            // move i left of the last point
            i = h + 1;
            synchronized (logger) {
                childLogger = logger.getChildByName(childName);
                if (childLogger == null) {
                    childLogger = logger.createChildByName(childName);
                    loggerCache.put(childName, childLogger);
                    incSize();
                }
            }
            logger = childLogger;
            if (h == -1) {
                return childLogger;
            }
        }
    }

    private void incSize() {
        size++;
    }

    int size() {
        return size;
    }

    
Check if the named logger exists in the hierarchy. If so return its
reference, otherwise returns null.
Params:
name – the name of the logger to search for./**
     * Check if the named logger exists in the hierarchy. If so return its
     * reference, otherwise returns <code>null</code>.
     *
     * @param name the name of the logger to search for.
     */
    public Logger exists(String name) {
        return (Logger) loggerCache.get(name);
    }

    final void noAppenderDefinedWarning(final Logger logger) {
        if (noAppenderWarning++ == 0) {
            getStatusManager().add(new WarnStatus("No appenders present in context [" + getName() + "] for logger [" + logger.getName() + "].", logger));
        }
    }

    public List<Logger> getLoggerList() {
        Collection<Logger> collection = loggerCache.values();
        List<Logger> loggerList = new ArrayList<Logger>(collection);
        Collections.sort(loggerList, new LoggerComparator());
        return loggerList;
    }

    public LoggerContextVO getLoggerContextRemoteView() {
        return loggerContextRemoteView;
    }

    public void setPackagingDataEnabled(boolean packagingDataEnabled) {
        this.packagingDataEnabled = packagingDataEnabled;
    }

    public boolean isPackagingDataEnabled() {
        return packagingDataEnabled;
    }

    
This method clears all internal properties, except internal status messages,
closes all appenders, removes any turboFilters, fires an OnReset event,
removes all status listeners, removes all context listeners
(except those which are reset resistant).

As mentioned above, internal status messages survive resets.
/**
     * This method clears all internal properties, except internal status messages,
     * closes all appenders, removes any turboFilters, fires an OnReset event,
     * removes all status listeners, removes all context listeners
     * (except those which are reset resistant).
     * <p/>
     * As mentioned above, internal status messages survive resets.
     */
    @Override
    public void reset() {
        resetCount++;
        super.reset();
        initEvaluatorMap();
        initCollisionMaps();
        root.recursiveReset();
        resetTurboFilterList();
        cancelScheduledTasks();
        fireOnReset();
        resetListenersExceptResetResistant();
        resetStatusListeners();
    }

    private void cancelScheduledTasks() {
        for(ScheduledFuture<?> sf: scheduledFutures) {
            sf.cancel(false);
        }
        scheduledFutures.clear();
    }

    private void resetStatusListeners() {
        StatusManager sm = getStatusManager();
        for (StatusListener sl : sm.getCopyOfStatusListenerList()) {
            sm.remove(sl);
        }
    }

    public TurboFilterList getTurboFilterList() {
        return turboFilterList;
    }

    public void addTurboFilter(TurboFilter newFilter) {
        turboFilterList.add(newFilter);
    }

    
First processPriorToRemoval all registered turbo filters and then clear the registration
list.
/**
     * First processPriorToRemoval all registered turbo filters and then clear the registration
     * list.
     */
    public void resetTurboFilterList() {
        for (TurboFilter tf : turboFilterList) {
            tf.stop();
        }
        turboFilterList.clear();
    }

    final FilterReply getTurboFilterChainDecision_0_3OrMore(final Marker marker, final Logger logger, final Level level, final String format,
                    final Object[] params, final Throwable t) {
        if (turboFilterList.size() == 0) {
            return FilterReply.NEUTRAL;
        }
        return turboFilterList.getTurboFilterChainDecision(marker, logger, level, format, params, t);
    }

    final FilterReply getTurboFilterChainDecision_1(final Marker marker, final Logger logger, final Level level, final String format, final Object param,
                    final Throwable t) {
        if (turboFilterList.size() == 0) {
            return FilterReply.NEUTRAL;
        }
        return turboFilterList.getTurboFilterChainDecision(marker, logger, level, format, new Object[] { param }, t);
    }

    final FilterReply getTurboFilterChainDecision_2(final Marker marker, final Logger logger, final Level level, final String format, final Object param1,
                    final Object param2, final Throwable t) {
        if (turboFilterList.size() == 0) {
            return FilterReply.NEUTRAL;
        }
        return turboFilterList.getTurboFilterChainDecision(marker, logger, level, format, new Object[] { param1, param2 }, t);
    }

    // === start listeners ==============================================
    public void addListener(LoggerContextListener listener) {
        loggerContextListenerList.add(listener);
    }

    public void removeListener(LoggerContextListener listener) {
        loggerContextListenerList.remove(listener);
    }

    private void resetListenersExceptResetResistant() {
        List<LoggerContextListener> toRetain = new ArrayList<LoggerContextListener>();

        for (LoggerContextListener lcl : loggerContextListenerList) {
            if (lcl.isResetResistant()) {
                toRetain.add(lcl);
            }
        }
        loggerContextListenerList.retainAll(toRetain);
    }

    private void resetAllListeners() {
        loggerContextListenerList.clear();
    }

    public List<LoggerContextListener> getCopyOfListenerList() {
        return new ArrayList<LoggerContextListener>(loggerContextListenerList);
    }

    void fireOnLevelChange(Logger logger, Level level) {
        for (LoggerContextListener listener : loggerContextListenerList) {
            listener.onLevelChange(logger, level);
        }
    }

    private void fireOnReset() {
        for (LoggerContextListener listener : loggerContextListenerList) {
            listener.onReset(this);
        }
    }

    private void fireOnStart() {
        for (LoggerContextListener listener : loggerContextListenerList) {
            listener.onStart(this);
        }
    }

    private void fireOnStop() {
        for (LoggerContextListener listener : loggerContextListenerList) {
            listener.onStop(this);
        }
    }

    // === end listeners ==============================================

    public void start() {
        super.start();
        fireOnStart();
    }

    public void stop() {
        reset();
        fireOnStop();
        resetAllListeners();
        super.stop();
    }

    @Override
    public String toString() {
        return this.getClass().getName() + "[" + getName() + "]";
    }

    public int getMaxCallerDataDepth() {
        return maxCallerDataDepth;
    }

    public void setMaxCallerDataDepth(int maxCallerDataDepth) {
        this.maxCallerDataDepth = maxCallerDataDepth;
    }

    
List of packages considered part of the logging framework such that they are never considered
as callers of the logging framework. This list used to compute the caller for logging events.

To designate package "com.foo" as well as all its subpackages as being part of the logging framework, simply add
"com.foo" to this list.
Returns:
list of framework packages/**
     * List of packages considered part of the logging framework such that they are never considered
     * as callers of the logging framework. This list used to compute the caller for logging events.
     * <p/>
     * To designate package "com.foo" as well as all its subpackages as being part of the logging framework, simply add
     * "com.foo" to this list.
     *
     * @return list of framework packages
     */
    public List<String> getFrameworkPackages() {
        return frameworkPackages;
    }
}