/*
* #%L
* JavaHg parent POM
* %%
* Copyright (C) 2011 aragost Trifork ag
* %%
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
* #L%
*/
package com.aragost.javahg.internals;
import java.util.Collection;
import java.util.List;
import java.util.concurrent.ExecutionException;
import com.aragost.javahg.MercurialExtension;
import com.aragost.javahg.log.Logger;
import com.aragost.javahg.log.LoggerFactory;
import com.google.common.cache.CacheBuilder;
import com.google.common.cache.CacheLoader;
import com.google.common.cache.LoadingCache;
import com.google.common.collect.Lists;
/**
* This is a singleton to manage Mercurial extensions.
* <p>
* To use a Mercurial extension with JavaHg there has to be an
* implementation of {@link MercurialExtension}. Call the process()
* method with this class to enable an extension.
*/
public class ExtensionManager {
private static final Logger LOG = LoggerFactory.getLogger(ExtensionManager.class);
private static final ExtensionManager INSTANCE = new ExtensionManager();
private CacheLoader<Class<? extends MercurialExtension>, MercurialExtension> createExtInstance = new CacheLoader<Class<? extends MercurialExtension>, MercurialExtension>() {
public MercurialExtension load(Class<? extends MercurialExtension> klass) {
MercurialExtension instance = null;
try {
instance = klass.newInstance();
} catch (InstantiationException e) {
throw Utils.asRuntime(e);
} catch (IllegalAccessException e) {
throw Utils.asRuntime(e);
}
try {
instance.initialize();
} catch (Exception e) {
LOG.error("Initialization of {} failed", klass);
LOG.error("The extension will be used anyway");
LOG.error("Exception: {}", e);
}
return instance;
}
};
private LoadingCache<Class<? extends MercurialExtension>, MercurialExtension> extInstances = CacheBuilder.newBuilder().build(
createExtInstance);
public static ExtensionManager getInstance() {
return INSTANCE;
}
/**
* Enable the Mercurial extension for the classes.
*
* @param classes
* @return list of command line flags needed to enable the
* extensions
*/
public List<String> process(Collection<Class<? extends MercurialExtension>> classes) {
List<String> result = Lists.newArrayList();
for (Class<? extends MercurialExtension> k : classes) {
MercurialExtension ext;
try {
ext = this.extInstances.get(k);
} catch (ExecutionException e) {
throw Utils.asRuntime(e);
}
String path = ext.getPath();
if (path == null) {
path = "";
}
result.add("--config");
result.add("extensions." + ext.getName() + "=" + path);
}
return result;
}
}