zachjsh commented on code in PR #13627: URL: https://github.com/apache/druid/pull/13627#discussion_r1066584622
########## server/src/main/java/org/apache/druid/catalog/model/table/BaseInputSourceDefn.java: ########## @@ -0,0 +1,278 @@ +/* + * 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.druid.catalog.model.table; + +import com.fasterxml.jackson.databind.ObjectMapper; +import org.apache.druid.catalog.model.ColumnSpec; +import org.apache.druid.catalog.model.Columns; +import org.apache.druid.catalog.model.TableDefnRegistry; +import org.apache.druid.data.input.InputFormat; +import org.apache.druid.data.input.InputSource; +import org.apache.druid.java.util.common.IAE; +import org.apache.druid.utils.CollectionUtils; + +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +/** + * Base class for input source definitions. + * + * @see {@link FormattedInputSourceDefn} for the base class for (most) input formats + * which take an input format. + */ +public abstract class BaseInputSourceDefn implements InputSourceDefn +{ + /** + * The "from-scratch" table function for this input source. The parameters + * are those defined by the subclass, and the apply simply turns around and + * asks the input source definition to do the conversion. + */ + public class AdHocTableFunction extends BaseTableFunction + { + public AdHocTableFunction(List<ParameterDefn> parameters) + { + super(parameters); + } + + @Override + public ExternalTableSpec apply( + final String fnName, + final Map<String, Object> args, + final List<ColumnSpec> columns, + final ObjectMapper jsonMapper + ) + { + requireSchema(fnName, columns); + return convertArgsToTable(args, columns, jsonMapper); + } + } + + /** + * The "partial" table function that starts with a catalog external table spec, then + * uses SQL function arguments to "complete" (i.e. fill in) the missing properties to + * produce a complete table which is then converted to an external table which Calcite + * can use. + * <p> + * The set of parameters depends on the input source and on whether or not the catalog + * spec provides a format. + */ + public class PartialTableFunction extends BaseTableFunction + { + private final ResolvedExternalTable table; + + public PartialTableFunction(final ResolvedExternalTable table, List<ParameterDefn> params) + { + super(params); + this.table = table; + } + + @Override + public ExternalTableSpec apply( + final String fnName, + final Map<String, Object> args, + final List<ColumnSpec> columns, + final ObjectMapper jsonMapper + ) + { + if (CollectionUtils.isNullOrEmpty(table.resolvedTable().spec().columns())) { + requireSchema(fnName, columns); + } + return convertCompletedTable(table, args, columns); + } + } + + /** + * The one and only from-scratch table function for this input source. The + * function is defined a bind time, not construction time, since it typically + * needs visibility to the set of available input formats. + */ + private AdHocTableFunction adHocTableFn; + + /** + * Overridden by each subclass to return the input source class to be + * used for JSON conversions. + */ + protected abstract Class<? extends InputSource> inputSourceClass(); + + @Override + public void bind(TableDefnRegistry registry) + { + this.adHocTableFn = defineAdHocTableFunction(); + } + + @Override + public void validate(ResolvedExternalTable table) + { + convertTableToSource(table); + } + + /** + * Overridden by each subclass to define the parameters needed by each + * input source. + */ + protected abstract AdHocTableFunction defineAdHocTableFunction(); + + @Override + public TableFunction adHocTableFn() + { + return adHocTableFn; + } + + /** + * Define a table "from scratch" using SQL function arguments. + */ + protected ExternalTableSpec convertArgsToTable( Review Comment: This this be moved into the `AdHocTableFunction` class, since it seems it should only be used in that case? -- This is an automated message from the Apache Git Service. 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