| /* |
| * 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.calcite.adapter.enumerable; |
| |
| import org.apache.calcite.linq4j.tree.Expression; |
| |
| /** |
| * Provides information on the current window. |
| * |
| * <p>All the indexes are ready to be used in |
| * {@link WinAggResultContext#arguments(org.apache.calcite.linq4j.tree.Expression)}, |
| * {@link WinAggFrameResultContext#rowTranslator(org.apache.calcite.linq4j.tree.Expression)} |
| * and similar methods. |
| */ |
| public interface WinAggFrameContext { |
| /** |
| * Returns the index of the current row in the partition. |
| * In other words, it is close to ~ROWS BETWEEN CURRENT ROW. |
| * Note to use {@link #startIndex()} when you need zero-based row position. |
| * @return the index of the very first row in partition |
| */ |
| Expression index(); |
| |
| /** |
| * Returns the index of the very first row in partition. |
| * @return index of the very first row in partition |
| */ |
| Expression startIndex(); |
| |
| /** |
| * Returns the index of the very last row in partition. |
| * @return index of the very last row in partition |
| */ |
| Expression endIndex(); |
| |
| /** |
| * Returns the boolean expression that tells if the partition has rows. |
| * The partition might lack rows in cases like ROWS BETWEEN 1000 PRECEDING |
| * AND 900 PRECEDING. |
| * @return boolean expression that tells if the partition has rows |
| */ |
| Expression hasRows(); |
| |
| /** |
| * Returns the number of rows in the current frame (subject to framing |
| * clause). |
| * @return number of rows in the current partition or 0 if the partition |
| * is empty |
| */ |
| Expression getFrameRowCount(); |
| |
| /** |
| * Returns the number of rows in the current partition (as determined by |
| * PARTITION BY clause). |
| * @return number of rows in the current partition or 0 if the partition |
| * is empty |
| */ |
| Expression getPartitionRowCount(); |
| } |