/*
* Copyright © 2014 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 co.cask.cdap.data2.datafabric.dataset.type;
import co.cask.cdap.api.dataset.DatasetDefinition;
import co.cask.cdap.api.dataset.module.DatasetDefinitionRegistry;
import co.cask.cdap.api.dataset.module.DatasetModule;
import co.cask.cdap.common.lang.ApiResourceListHolder;
import co.cask.cdap.common.lang.ClassLoaders;
import co.cask.cdap.common.lang.jar.BundleJarUtil;
import co.cask.cdap.common.utils.DirUtils;
import co.cask.cdap.data2.dataset2.InMemoryDatasetDefinitionRegistry;
import co.cask.cdap.data2.dataset2.module.lib.DatasetModules;
import co.cask.cdap.proto.DatasetModuleMeta;
import co.cask.cdap.proto.DatasetTypeMeta;
import com.google.common.io.Files;
import org.apache.twill.filesystem.LocationFactory;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.IOException;
import java.util.List;
/**
* Loads {@link DatasetDefinition} using its metadata info
*/
class DatasetDefinitionLoader {
private static final Logger LOG = LoggerFactory.getLogger(DatasetDefinitionLoader.class);
private final LocationFactory locationFactory;
/**
* Creates instance of {@link DatasetDefinitionLoader}
* @param locationFactory instance of {@link LocationFactory} used to access dataset modules jars
*/
public DatasetDefinitionLoader(LocationFactory locationFactory) {
this.locationFactory = locationFactory;
}
/**
* Same as {@link #load(DatasetTypeMeta, DatasetDefinitionRegistry)} but uses empty registry to star with`.
*/
public <T extends DatasetDefinition> T load(DatasetTypeMeta meta) throws IOException {
return load(meta, new InMemoryDatasetDefinitionRegistry());
}
/**
* Loads {@link DatasetDefinition} using {@link DatasetTypeMeta} info. It will use given
* {@link DatasetDefinitionRegistry} to load all required modules and types. If registry is missing some of them,
* it will load respective jars and add them to the registry (thus, modifying the given registry).
* @param meta info of type to load
* @param registry registry to use for loading
* @param <T> type of the definition
* @return instance of {@link DatasetDefinition}
* @throws IOException
*/
public <T extends DatasetDefinition> T load(DatasetTypeMeta meta, DatasetDefinitionRegistry registry)
throws IOException {
ClassLoader classLoader = DatasetDefinitionLoader.class.getClassLoader();
List<DatasetModuleMeta> modulesToLoad = meta.getModules();
File unpackedLocation = Files.createTempDir();
int index = 0;
try {
for (DatasetModuleMeta moduleMeta : modulesToLoad) {
File temp = new File(unpackedLocation, String.valueOf(index++));
temp.mkdir();
// for default "system" modules it can be null, see getJarLocation() javadoc
if (moduleMeta.getJarLocation() != null) {
BundleJarUtil.unpackProgramJar(locationFactory.create(moduleMeta.getJarLocation()), temp);
classLoader = ClassLoaders.newProgramClassLoader(temp, ApiResourceListHolder.getResourceList(),
this.getClass().getClassLoader());
}
Class<?> moduleClass = ClassLoaders.loadClass(moduleMeta.getClassName(), classLoader, this);
DatasetModule module = DatasetModules.getDatasetModule(moduleClass);
module.register(registry);
}
} catch (Exception e) {
LOG.warn("Exception while loading DatasetDefinition for DatasetTypeMeta : {}", meta.getName());
} finally {
try {
DirUtils.deleteDirectoryContents(unpackedLocation);
} catch (IOException e) {
LOG.warn("Failed to delete directory {}", unpackedLocation, e);
}
}
return registry.get(meta.getName());
}
}