/*
* (C) Copyright 2012-2016 Nuxeo SA (http://nuxeo.com/) and others.
*
* 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.
*
* Contributors:
* Anahide Tchertchian
* Florent Guillaume
*/
package org.nuxeo.ecm.directory;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* Generic {@link BaseDirectoryDescriptor} registry holding registered descriptors and instantiated {@link Directory}
* objects.
* <p>
* The directory descriptors have two special boolean flags that control how merge works:
* <ul>
* <li>{@code remove="true"}: this removes the definition of the directory. The next definition (if any) will be done
* from scratch.
* <li>{@code template="true"}: this defines an abstract descriptor which cannot be directly instantiated as a
* directory. However another descriptor can extend it through {@code extends="templatename"} to inherit all its
* properties.
* </ul>
*
* @since 8.2
*/
public class DirectoryRegistry {
private static final Log log = LogFactory.getLog(DirectoryRegistry.class);
/** All descriptors registered. */
// used under synchronization
protected Map<String, List<BaseDirectoryDescriptor>> allDescriptors = new HashMap<>();
/** Effective descriptors. */
// used under synchronization
protected Map<String, BaseDirectoryDescriptor> descriptors = new HashMap<>();
/** Effective instantiated directories. */
// used under synchronization
protected Map<String, Directory> directories = new HashMap<>();
public synchronized void addContribution(BaseDirectoryDescriptor contrib) {
String id = contrib.name;
log.info("Registered directory" + (contrib.template ? " template" : "") + ": " + id);
allDescriptors.computeIfAbsent(id, k -> new ArrayList<>()).add(contrib);
contributionChanged(contrib);
}
public synchronized void removeContribution(BaseDirectoryDescriptor contrib) {
String id = contrib.name;
log.info("Unregistered directory" + (contrib.template ? " template" : "") + ": " + id);
allDescriptors.getOrDefault(id, Collections.emptyList()).remove(contrib);
contributionChanged(contrib);
}
protected void contributionChanged(BaseDirectoryDescriptor contrib) {
LinkedList<String> todo = new LinkedList<>();
todo.add(contrib.name);
Set<String> done = new HashSet<String>();
while (!todo.isEmpty()) {
String id = todo.removeFirst();
if (!done.add(id)) {
// already done, avoid loops
continue;
}
BaseDirectoryDescriptor desc = recomputeDescriptor(id);
// recompute dependencies
if (desc != null) {
for (List<BaseDirectoryDescriptor> list : allDescriptors.values()) {
for (BaseDirectoryDescriptor d : list) {
if (id.equals(d.extendz)) {
todo.add(d.name);
break;
}
}
}
}
}
}
protected void removeDirectory(String id) {
Directory dir = directories.remove(id);
if (dir != null) {
shutdownDirectory(dir);
}
}
/** Recomputes the effective descriptor for a directory id. */
protected BaseDirectoryDescriptor recomputeDescriptor(String id) {
removeDirectory(id);
// compute effective descriptor
List<BaseDirectoryDescriptor> list = allDescriptors.getOrDefault(id, Collections.emptyList());
BaseDirectoryDescriptor contrib = null;
for (BaseDirectoryDescriptor next : list) {
String extendz = next.extendz;
if (extendz != null) {
// merge from base
BaseDirectoryDescriptor base = descriptors.get(extendz);
if (base != null && base.template) {
// merge generic base descriptor into specific one from the template
contrib = base.clone();
contrib.template = false;
contrib.name = next.name;
contrib.merge(next);
} else {
log.debug("Directory " + id + " extends non-existing directory template: " + extendz);
contrib = null;
}
} else if (next.remove) {
contrib = null;
} else if (contrib == null) {
// first descriptor or first one after a remove
contrib = next.clone();
} else if (contrib.getClass() == next.getClass()) {
contrib.merge(next);
} else {
log.warn("Directory " + id + " redefined with different factory");
contrib = next.clone();
}
}
if (contrib == null) {
descriptors.remove(id);
} else {
descriptors.put(id, contrib);
}
return contrib;
}
/**
* Gets the effective directory descriptor with the given id.
*
* @param id the directory id
* @return the effective directory descriptor, or {@code null} if not found
*/
public synchronized BaseDirectoryDescriptor getDirectoryDescriptor(String id) {
return descriptors.get(id);
}
/**
* Gets the directory with the given id.
*
* @param id the directory id
* @return the directory, or {@code null} if not found
*/
public synchronized Directory getDirectory(String id) {
Directory dir = directories.get(id);
if (dir == null) {
BaseDirectoryDescriptor descriptor = descriptors.get(id);
if (descriptor != null) {
dir = descriptor.newDirectory();
directories.put(id, dir);
}
}
return dir;
}
/**
* Gets all the directory ids.
*
* @return the directory ids
*/
public synchronized List<String> getDirectoryIds() {
List<String> list = new ArrayList<>();
for (BaseDirectoryDescriptor descriptor : descriptors.values()) {
if (descriptor.template) {
continue;
}
list.add(descriptor.name);
}
return list;
}
/**
* Gets all the directories.
*
* @return the directories
*/
public synchronized List<Directory> getDirectories() {
List<Directory> list = new ArrayList<>();
for (BaseDirectoryDescriptor descriptor : descriptors.values()) {
if (descriptor.template) {
continue;
}
list.add(getDirectory(descriptor.name));
}
return list;
}
/**
* Shuts down all directories and clears the registry.
*/
public synchronized void shutdown() {
for (Directory dir : directories.values()) {
shutdownDirectory(dir);
}
allDescriptors.clear();
descriptors.clear();
directories.clear();
}
/**
* Shuts down the given directory and catches any {@link DirectoryException}.
*
* @param dir the directory
*/
protected static void shutdownDirectory(Directory dir) {
try {
dir.shutdown();
} catch (DirectoryException e) {
log.error("Error while shutting down directory:" + dir.getName(), e);
}
}
}