| /* |
| * 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.cassandra.db.rows; |
| |
| import java.util.Iterator; |
| |
| import org.apache.cassandra.config.CFMetaData; |
| import org.apache.cassandra.db.*; |
| |
| /** |
| * An iterator over the rows of a given partition that also includes deletion informations. |
| * <p> |
| * An {@code UnfilteredRowIterator} contains a few partition top-level informations and is an |
| * iterator of {@code Unfiltered}, that is of either {@code Row} or {@code RangeTombstoneMarker}. |
| * An implementation of {@code UnfilteredRowIterator} <b>must</b> provide the following |
| * guarantees: |
| * 1. the returned {@code Unfiltered} must be in clustering order, or in reverse clustering |
| * order iff {@link #isReverseOrder} returns true. |
| * 2. the iterator should not shadow its own data. That is, no deletion |
| * (partition level deletion, row deletion, range tombstone, complex |
| * deletion) should delete anything else returned by the iterator (cell, row, ...). |
| * 3. every "start" range tombstone marker should have a corresponding "end" marker, and no other |
| * marker should be in-between this start-end pair of marker. Note that due to the |
| * previous rule this means that between a "start" and a corresponding "end" marker there |
| * can only be rows that are not deleted by the markers. Also note that when iterating |
| * in reverse order, "end" markers are returned before their "start" counterpart (i.e. |
| * "start" and "end" are always in the sense of the clustering order). |
| * |
| * Note further that the objects returned by next() are only valid until the |
| * next call to hasNext() or next(). If a consumer wants to keep a reference on |
| * the returned objects for longer than the iteration, it must make a copy of |
| * it explicitly. |
| */ |
| public interface UnfilteredRowIterator extends BaseRowIterator<Unfiltered> |
| { |
| /** |
| * The partition level deletion for the partition this iterate over. |
| */ |
| public DeletionTime partitionLevelDeletion(); |
| |
| /** |
| * Return "statistics" about what is returned by this iterator. Those are used for |
| * performance reasons (for delta-encoding for instance) and code should not |
| * expect those to be exact. |
| */ |
| public EncodingStats stats(); |
| |
| /** |
| * Returns whether this iterator has no data (including no deletion data). |
| */ |
| public default boolean isEmpty() |
| { |
| return partitionLevelDeletion().isLive() |
| && staticRow().isEmpty() |
| && !hasNext(); |
| } |
| } |