zabetak commented on a change in pull request #2071: URL: https://github.com/apache/hive/pull/2071#discussion_r616536470
########## File path: ql/src/java/org/apache/hadoop/hive/ql/exec/HiveMapComparator.java ########## @@ -0,0 +1,72 @@ +/* + * 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.hadoop.hive.ql.exec; + +import org.apache.hadoop.hive.ql.util.NullOrdering; +import org.apache.hadoop.io.WritableComparable; +import org.apache.hadoop.io.WritableComparator; + +import java.util.Iterator; +import java.util.Map; + +final class HiveMapComparator extends HiveWritableComparator { + private WritableComparator comparatorValue = null; + private WritableComparator comparatorKey = null; + + HiveMapComparator(boolean nullSafe, NullOrdering nullOrdering) { + super(nullSafe, nullOrdering); + } + + @Override + public int compare(Object key1, Object key2) { + int result = checkNull(key1, key2); + if (result != not_null) { + return result; + } + + Map map1 = (Map) key1; + Map map2 = (Map) key2; + if (comparatorKey == null) { + comparatorKey = + WritableComparatorFactory.get(map1.keySet().iterator().next(), nullSafe, nullOrdering); + comparatorValue = + WritableComparatorFactory.get(map1.values().iterator().next(), nullSafe, nullOrdering); + } + + Iterator map1KeyIterator = map1.keySet().iterator(); + Iterator map2KeyIterator = map2.keySet().iterator(); + Iterator map1ValueIterator = map1.values().iterator(); + Iterator map2ValueIterator = map2.values().iterator(); + + // For map of size greater than 1, the ordering is based on the key value. If key values are same till the + // size of smaller map, then the size is checked for ordering. + int size = map1.size() > map2.size() ? map2.size() : map1.size(); + for (int i = 0; i < size; i++) { + result = comparatorKey.compare(map1KeyIterator.next(), map2KeyIterator.next()); + if (result != 0) { + return result; + } + result = comparatorValue.compare(map1ValueIterator.next(), map2ValueIterator.next()); + if (result != 0) { + return result; + } + } + return map1.size() == map2.size() ? 0 : map1.size() > map2.size() ? 1 : -1; + } Review comment: If I understand well this code will not consider equal two maps that have the same key/value pairs but in different order. In other words `map1.equals(map2)` may return `true` while this code could return `-1 or 1` for instance. I am not sure how we treat MAP equalities in other places of the code (other joins, etc.) so just want to make sure that we are consistent. ########## File path: ql/src/java/org/apache/hadoop/hive/ql/exec/HiveMapComparator.java ########## @@ -0,0 +1,72 @@ +/* + * 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.hadoop.hive.ql.exec; + +import org.apache.hadoop.hive.ql.util.NullOrdering; +import org.apache.hadoop.io.WritableComparable; +import org.apache.hadoop.io.WritableComparator; + +import java.util.Iterator; +import java.util.Map; + +final class HiveMapComparator extends HiveWritableComparator { + private WritableComparator comparatorValue = null; + private WritableComparator comparatorKey = null; + + HiveMapComparator(boolean nullSafe, NullOrdering nullOrdering) { + super(nullSafe, nullOrdering); + } + + @Override + public int compare(Object key1, Object key2) { + int result = checkNull(key1, key2); + if (result != not_null) { + return result; + } + + Map map1 = (Map) key1; + Map map2 = (Map) key2; + if (comparatorKey == null) { Review comment: To make the code more uniform with `HiveStructComparator` (and more readable) consider moving the size related checks above: ``` if (map1.size() != map2.size()) { return map1.size() > map2.size() ? 1 : -1; } if (map1.size() == 0) { return 0; } ``` -- 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] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
