paul-rogers commented on a change in pull request #1914: DRILL-7458: Base framework for storage plugins URL: https://github.com/apache/drill/pull/1914#discussion_r369228513
########## File path: exec/java-exec/src/main/java/org/apache/drill/exec/store/base/BaseStoragePlugin.java ########## @@ -0,0 +1,229 @@ +/* + * 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.base; + +import java.io.IOException; + +import org.apache.calcite.schema.SchemaPlus; +import org.apache.drill.common.JSONOptions; +import org.apache.drill.common.exceptions.ChildErrorContext; +import org.apache.drill.common.exceptions.ExecutionSetupException; +import org.apache.drill.common.exceptions.UserException; +import org.apache.drill.common.logical.StoragePluginConfig; +import org.apache.drill.exec.metastore.MetadataProviderManager; +import org.apache.drill.exec.ops.ExecutorFragmentContext; +import org.apache.drill.exec.physical.base.AbstractGroupScan; +import org.apache.drill.exec.physical.impl.scan.framework.ManagedScanFramework.ScanFrameworkBuilder; +import org.apache.drill.exec.proto.UserBitShared.CoreOperatorType; +import org.apache.drill.exec.record.CloseableRecordBatch; +import org.apache.drill.exec.server.DrillbitContext; +import org.apache.drill.exec.server.options.SessionOptionManager; +import org.apache.drill.exec.store.AbstractStoragePlugin; +import org.apache.drill.exec.store.SchemaConfig; +import org.apache.drill.exec.store.SchemaFactory; +import org.apache.drill.exec.store.StoragePlugin; +import org.apache.drill.exec.store.StoragePluginRegistry; +import org.apache.drill.shaded.guava.com.google.common.base.Preconditions; +import org.slf4j.Logger; +import org.slf4j.LoggerFactory; + +import com.fasterxml.jackson.annotation.JsonTypeName; +import com.fasterxml.jackson.core.type.TypeReference; +import com.fasterxml.jackson.databind.ObjectMapper; + +/** + * Base class for non-DFS storage plugins. Provides a number of convinces to + * abstract away some of the complexity around such plugins. The + * {@link StoragePluginOptions} class captures the many options that would + * otherwise be specified by overriding methods. The + * {@link BaseScanFactory} class provides methods to create various + * objects during planning and execution. + * + * @param <C> the storage plugin configuration class + */ + +public abstract class BaseStoragePlugin<C extends StoragePluginConfig> + extends AbstractStoragePlugin { + + private static final Logger logger = LoggerFactory.getLogger(BaseStoragePlugin.class); + protected static final ObjectMapper DEFAULT_MAPPER = new ObjectMapper(); Review comment: Bingo! You hit on a nasty issue. Yes, Drill adds on all kinds of helpful ser/des. But, as it turns out, there is no good way to get that mapper into this class. I hit this very issue when trying to change the mock plugin: it can't deserialize things like `ColumnMetadata` which require help. Most plugins do exactly what is done here because the scan spec tends to be simple. A larger question is why the heck we serialize the scan spec: it never leaves the planner. There is probably some hacky reason it was done this way. Do you know of a way to get Drill's mapper into this class without changing the constructor? ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
