paul-rogers commented on a change in pull request #1870: DRILL-7359: Add support for DICT type in RowSet Framework URL: https://github.com/apache/drill/pull/1870#discussion_r347115621
########## File path: exec/vector/src/main/java/org/apache/drill/exec/vector/accessor/writer/DictEntryWriter.java ########## @@ -0,0 +1,97 @@ +/* + * 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.vector.accessor.writer; + +import java.util.List; +import java.util.Map; + +import org.apache.drill.exec.record.metadata.ColumnMetadata; +import org.apache.drill.exec.vector.accessor.ColumnWriterIndex; +import org.apache.drill.exec.vector.accessor.impl.HierarchicalFormatter; + +/** + * Writer for a Dict entry. The entry is a special kind of tuple. + */ +public class DictEntryWriter extends AbstractTupleWriter { + + public static class DictEntryObjectWriter extends TupleObjectWriter { + + public DictEntryObjectWriter(DictEntryWriter entryWriter) { + super(entryWriter); + } + + public void setObject(int col, Object value) { + tupleWriter.set(col, value); + } + + @Override + public void dump(HierarchicalFormatter format) { + format.startObject(this) + .attribute("dictEntryWriter"); + tupleWriter.dump(format); + format.endObject(); + } + } + + public static DictEntryObjectWriter buildDictEntryWriter(ColumnMetadata schema, + List<AbstractObjectWriter> keyValueWriters) { + assert keyValueWriters.size() == 2; + DictEntryWriter dictEntryWriter = new DictEntryWriter(schema, keyValueWriters); + return new DictEntryObjectWriter(dictEntryWriter); + } + + private final ColumnMetadata dictColumnSchema; + + public DictEntryWriter(ColumnMetadata schema, List<AbstractObjectWriter> writers) { + super(schema.tupleSchema(), writers); + dictColumnSchema = schema; + } + + @Override + public void bindIndex(ColumnWriterIndex index) { + + // Similarly to a repeated map, the provided index is an array element + // index. Convert this to an index that will not increment the element + // index on each write so that a dict with key and value members won't + // increment the index for each member. Rather, the index must be + // incremented at the array level. + + bindIndex(index, new MemberWriterIndex(index)); + } + + @Override + public boolean isProjected() { + return true; + } Review comment: Can't remember how this is supposed to work; it could be it ended up not be being used. But, this does suggest a missing test case: in the result set loader tests, test the case in which a reader can provide a DICT, but the client does not project that. That is, if a reader has a DICT `d`, along with other columns `a`, `b` and `c`, we want to make sure this works: ``` SELECT a, c FROM myTable ``` Then, we write to the Dict. In other cases, we create dummy writers which accept the unwanted values, but then just throw them away. That way, the (data) reader code need not special case whether the column is projected or not. ---------------------------------------------------------------- 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: us...@infra.apache.org With regards, Apache Git Services
