/*
* 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.logging.log4j.spi;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Map;
import java.util.Objects;
import java.util.WeakHashMap;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.ConcurrentMap;
import org.apache.logging.log4j.message.MessageFactory;
/**
* Convenience class to be used by {@code LoggerContext} implementations.
*/
public class LoggerRegistry<T extends ExtendedLogger> {
private static final String DEFAULT_FACTORY_KEY = AbstractLogger.DEFAULT_MESSAGE_FACTORY_CLASS.getName();
private final MapFactory<T> factory;
private final Map<String, Map<String, T>> map;
/**
* Interface to control the data structure used by the registry to store the Loggers.
* @param <T> subtype of {@code ExtendedLogger}
*/
public interface MapFactory<T extends ExtendedLogger> {
Map<String, T> createInnerMap();
Map<String, Map<String, T>> createOuterMap();
void putIfAbsent(Map<String, T> innerMap, String name, T logger);
}
/**
* Generates ConcurrentHashMaps for use by the registry to store the Loggers.
* @param <T> subtype of {@code ExtendedLogger}
*/
public static class ConcurrentMapFactory<T extends ExtendedLogger> implements MapFactory<T> {
@Override
public Map<String, T> createInnerMap() {
return new ConcurrentHashMap<>();
}
@Override
public Map<String, Map<String, T>> createOuterMap() {
return new ConcurrentHashMap<>();
}
@Override
public void putIfAbsent(final Map<String, T> innerMap, final String name, final T logger) {
((ConcurrentMap<String, T>) innerMap).putIfAbsent(name, logger);
}
}
/**
* Generates WeakHashMaps for use by the registry to store the Loggers.
* @param <T> subtype of {@code ExtendedLogger}
*/
public static class WeakMapFactory<T extends ExtendedLogger> implements MapFactory<T> {
@Override
public Map<String, T> createInnerMap() {
return new WeakHashMap<>();
}
@Override
public Map<String, Map<String, T>> createOuterMap() {
return new WeakHashMap<>();
}
@Override
public void putIfAbsent(final Map<String, T> innerMap, final String name, final T logger) {
innerMap.put(name, logger);
}
}
public LoggerRegistry() {
this(new ConcurrentMapFactory<T>());
}
public LoggerRegistry(final MapFactory<T> factory) {
this.factory = Objects.requireNonNull(factory, "factory");
this.map = factory.createOuterMap();
}
private static String factoryClassKey(final Class<? extends MessageFactory> messageFactoryClass) {
return messageFactoryClass == null ? DEFAULT_FACTORY_KEY : messageFactoryClass.getName();
}
private static String factoryKey(final MessageFactory messageFactory) {
return messageFactory == null ? DEFAULT_FACTORY_KEY : messageFactory.getClass().getName();
}
/**
* Returns an ExtendedLogger.
* @param name The name of the Logger to return.
* @return The logger with the specified name.
*/
public T getLogger(final String name) {
return getOrCreateInnerMap(DEFAULT_FACTORY_KEY).get(name);
}
/**
* Returns an ExtendedLogger.
* @param name The name of the Logger to return.
* @param messageFactory The message factory is used only when creating a logger, subsequent use does not change
* the logger but will log a warning if mismatched.
* @return The logger with the specified name.
*/
public T getLogger(final String name, final MessageFactory messageFactory) {
return getOrCreateInnerMap(factoryKey(messageFactory)).get(name);
}
public Collection<T> getLoggers() {
return getLoggers(new ArrayList<T>());
}
public Collection<T> getLoggers(final Collection<T> destination) {
for (final Map<String, T> inner : map.values()) {
destination.addAll(inner.values());
}
return destination;
}
private Map<String, T> getOrCreateInnerMap(final String factoryName) {
Map<String, T> inner = map.get(factoryName);
if (inner == null) {
inner = factory.createInnerMap();
map.put(factoryName, inner);
}
return inner;
}
/**
* Detects if a Logger with the specified name exists.
* @param name The Logger name to search for.
* @return true if the Logger exists, false otherwise.
*/
public boolean hasLogger(final String name) {
return getOrCreateInnerMap(DEFAULT_FACTORY_KEY).containsKey(name);
}
/**
* Detects if a Logger with the specified name and MessageFactory exists.
* @param name The Logger name to search for.
* @param messageFactory The message factory to search for.
* @return true if the Logger exists, false otherwise.
* @since 2.5
*/
public boolean hasLogger(final String name, final MessageFactory messageFactory) {
return getOrCreateInnerMap(factoryKey(messageFactory)).containsKey(name);
}
/**
* Detects if a Logger with the specified name and MessageFactory type exists.
* @param name The Logger name to search for.
* @param messageFactoryClass The message factory class to search for.
* @return true if the Logger exists, false otherwise.
* @since 2.5
*/
public boolean hasLogger(final String name, final Class<? extends MessageFactory> messageFactoryClass) {
return getOrCreateInnerMap(factoryClassKey(messageFactoryClass)).containsKey(name);
}
public void putIfAbsent(final String name, final MessageFactory messageFactory, final T logger) {
factory.putIfAbsent(getOrCreateInnerMap(factoryKey(messageFactory)), name, logger);
}
}