| /* |
| * 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.drill.exec.store; |
| |
| import java.io.IOException; |
| import java.lang.reflect.Constructor; |
| import java.util.Collection; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| import org.apache.drill.common.logical.StoragePluginConfig; |
| import org.apache.drill.common.map.CaseInsensitiveMap; |
| import org.apache.drill.common.scanner.persistence.AnnotatedClassDescriptor; |
| import org.apache.drill.exec.planner.logical.StoragePlugins; |
| import org.apache.drill.exec.server.DrillbitContext; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Locates system storage plugins. These are special in that they take |
| * no configuration: the configuration and connector names are the same so |
| * that the configuration name can be resolved directly to the connector. |
| * <p> |
| * System plugins are defined in the Drill core, reside on the default class |
| * path, and are annotated with {@code @SystemPlugin}. |
| */ |
| public class SystemPluginLocator implements ConnectorLocator { |
| private static final Logger logger = LoggerFactory.getLogger(SystemPluginLocator.class); |
| |
| private final PluginRegistryContext context; |
| private final Map<String, StoragePlugin> plugins = CaseInsensitiveMap.newHashMap(); |
| |
| public SystemPluginLocator(PluginRegistryContext context) { |
| this.context = context; |
| } |
| |
| /** |
| * Dynamically loads system plugins annotated with {@link SystemPlugin}. |
| * Will skip plugin initialization if no matching constructor, incorrect |
| * class implementation, name absence are detected. |
| * |
| * @return map with system plugins stored by name |
| */ |
| @Override |
| public void init() { |
| List<AnnotatedClassDescriptor> annotatedClasses = |
| context.classpathScan().getAnnotatedClasses(SystemPlugin.class.getName()); |
| logger.trace("Found {} annotated classes with SystemPlugin annotation: {}.", |
| annotatedClasses.size(), annotatedClasses); |
| |
| for (AnnotatedClassDescriptor annotatedClass : annotatedClasses) { |
| try { |
| loadPlugin(annotatedClass); |
| } catch (ReflectiveOperationException e) { |
| logger.warn("Error during system plugin {} initialization. Plugin initialization will be skipped.", |
| annotatedClass.getClassName(), e); |
| } |
| } |
| logger.trace("The following system plugins have been initialized: {}.", plugins.keySet()); |
| } |
| |
| private void loadPlugin(AnnotatedClassDescriptor annotatedClass) throws ReflectiveOperationException { |
| Class<?> aClass = Class.forName(annotatedClass.getClassName()); |
| |
| for (Constructor<?> constructor : aClass.getConstructors()) { |
| Class<?>[] parameterTypes = constructor.getParameterTypes(); |
| |
| if (parameterTypes.length != 1 || parameterTypes[0] != DrillbitContext.class) { |
| logger.trace("Not matching constructor for {}. Expecting constructor with one parameter for DrillbitContext class.", |
| annotatedClass.getClassName()); |
| continue; |
| } |
| |
| Object instance = constructor.newInstance(context.drillbitContext()); |
| if (!(instance instanceof StoragePlugin)) { |
| logger.debug("Created instance of {} does not implement StoragePlugin interface.", annotatedClass.getClassName()); |
| continue; |
| } |
| |
| StoragePlugin storagePlugin = (StoragePlugin) instance; |
| String name = storagePlugin.getName(); |
| if (name == null) { |
| logger.debug("Storage plugin name {} is not defined. Skipping plugin initialization.", annotatedClass.getClassName()); |
| continue; |
| } |
| storagePlugin.getConfig().setEnabled(true); |
| plugins.put(name, storagePlugin); |
| return; |
| } |
| logger.debug("Skipping plugin registration for {}, did not find matching constructor or initialized object of wrong type.", |
| aClass.getName()); |
| } |
| |
| @Override |
| public StoragePlugins bootstrapPlugins() throws IOException { |
| // System plugins are not stored, so no bootstrap |
| return null; |
| } |
| |
| @Override |
| public StoragePlugins updatedPlugins() { |
| // ... and no upgrades |
| return null; |
| } |
| |
| @Override |
| public void onUpgrade() { } |
| |
| @Override |
| public StoragePlugin get(String name) { |
| return plugins.get(name); |
| } |
| |
| @Override |
| public Collection<StoragePlugin> intrinsicPlugins() { |
| return plugins.values(); |
| } |
| |
| @Override |
| public StoragePlugin create(String name, StoragePluginConfig pluginConfig) { |
| throw new IllegalStateException("Should not create instances of system plugins"); |
| } |
| |
| @Override |
| public Set<Class<? extends StoragePluginConfig>> configClasses() { |
| return null; |
| } |
| |
| @Override |
| public boolean storable() { |
| // TODO Auto-generated method stub |
| return false; |
| } |
| |
| @Override |
| public Class<? extends StoragePlugin> connectorClassFor( |
| Class<? extends StoragePluginConfig> configClass) { |
| |
| // Not very efficient, but this method is generally for testing |
| // and their are only a few system plugins. Not worth adding a map. |
| for (StoragePlugin plugin : plugins.values()) { |
| if (configClass.isInstance(plugin.getConfig())) { |
| return plugin.getClass(); |
| } |
| } |
| return null; |
| } |
| |
| @Override |
| public void close() { } |
| } |