io.cdap.cdap.internal.events.EventWriterExtensionProvider Maven / Gradle / Ivy
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/*
* Copyright © 2022 Cask Data, Inc.
*
* 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.
*/
package io.cdap.cdap.internal.events;
import com.google.inject.Inject;
import io.cdap.cdap.common.conf.CConfiguration;
import io.cdap.cdap.common.conf.Constants;
import io.cdap.cdap.common.lang.ClassPathResources;
import io.cdap.cdap.common.lang.FilterClassLoader;
import io.cdap.cdap.extension.AbstractExtensionLoader;
import io.cdap.cdap.spi.events.EventWriter;
import java.io.IOException;
import java.util.Collection;
import java.util.Collections;
import java.util.Map;
import java.util.Set;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
* Implementation of {@link EventWriterProvider} which provides Event writer extension classes
* extending from {@link AbstractExtensionLoader}
*/
public class EventWriterExtensionProvider extends AbstractExtensionLoader
implements EventWriterProvider {
private static final Logger LOG = LoggerFactory.getLogger(EventWriterExtensionProvider.class);
private static final Set ALLOWED_RESOURCES = createAllowedResources();
private static final Set ALLOWED_PACKAGES = createPackageSets(ALLOWED_RESOURCES);
private Collection enabledEventWriters;
@Inject
public EventWriterExtensionProvider(CConfiguration cConf) {
super(cConf.get(Constants.Event.EVENTS_WRITER_EXTENSIONS_DIR) != null
? cConf.get(Constants.Event.EVENTS_WRITER_EXTENSIONS_DIR) : "");
this.enabledEventWriters = cConf.getStringCollection(
Constants.Event.EVENTS_WRITER_EXTENSIONS_ENABLED_LIST);
if (this.enabledEventWriters == null || this.enabledEventWriters.isEmpty()) {
LOG.debug("No event writers enabled.");
return;
}
LOG.debug("Enabled event writers are {} .", enabledEventWriters);
}
private static Set createAllowedResources() {
try {
return ClassPathResources.getResourcesWithDependencies(EventWriter.class.getClassLoader(),
EventWriter.class);
} catch (IOException e) {
throw new RuntimeException("Failed to trace dependencies for writer extension. "
+ "Usage of events writer might fail.", e);
}
}
@Override
public Map loadEventWriters() {
return getAll();
}
@Override
protected Set getSupportedTypesForProvider(EventWriter eventWriter) {
if (enabledEventWriters == null || !enabledEventWriters.contains(eventWriter.getID())) {
LOG.debug("{} is not present in the enabled list of event writers.", eventWriter.getID());
return Collections.emptySet();
}
return Collections.singleton(eventWriter.getID());
}
@Override
protected FilterClassLoader.Filter getExtensionParentClassLoaderFilter() {
// Only allow spi classes.
return new FilterClassLoader.Filter() {
@Override
public boolean acceptResource(String resource) {
return ALLOWED_RESOURCES.contains(resource);
}
@Override
public boolean acceptPackage(String packageName) {
return ALLOWED_PACKAGES.contains(packageName);
}
};
}
}