| /* |
| * 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.jackrabbit.oak.plugins.index.aggregate; |
| |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.NoSuchElementException; |
| import java.util.Set; |
| |
| import org.apache.jackrabbit.oak.api.PropertyValue; |
| import org.apache.jackrabbit.oak.api.Result.SizePrecision; |
| import org.apache.jackrabbit.oak.spi.query.Cursor; |
| import org.apache.jackrabbit.oak.spi.query.IndexRow; |
| import org.apache.jackrabbit.oak.plugins.index.Cursors.AbstractCursor; |
| import org.apache.jackrabbit.oak.spi.query.QueryIndex; |
| import org.apache.jackrabbit.oak.spi.state.NodeState; |
| |
| import com.google.common.base.Predicates; |
| import com.google.common.collect.Iterators; |
| |
| /** |
| * An aggregation aware cursor. |
| */ |
| class AggregationCursor extends AbstractCursor { |
| |
| private final Cursor cursor; |
| private final QueryIndex.NodeAggregator aggregator; |
| private final NodeState rootState; |
| |
| private boolean init; |
| private boolean closed; |
| |
| /** |
| * the current row |
| */ |
| private IndexRow currentRow; |
| |
| /** |
| * the path of the current item of the cursor |
| */ |
| private String currentPath; |
| |
| /** |
| * all of the item's known aggregates |
| */ |
| private Iterator<String> aggregates; |
| |
| /** |
| * should enforce uniqueness of the aggregated paths |
| */ |
| private Set<String> seenPaths = new HashSet<String>(); |
| |
| public AggregationCursor(Cursor cursor, QueryIndex.NodeAggregator aggregator, |
| NodeState rootState) { |
| this.cursor = cursor; |
| this.aggregator = aggregator; |
| this.rootState = rootState; |
| } |
| |
| @Override |
| public boolean hasNext() { |
| if (!closed && !init) { |
| fetchNext(); |
| init = true; |
| } |
| return !closed; |
| } |
| |
| private void fetchNext() { |
| if (aggregates != null && aggregates.hasNext()) { |
| currentPath = aggregates.next(); |
| init = true; |
| return; |
| } |
| aggregates = null; |
| if (cursor.hasNext()) { |
| currentRow = cursor.next(); |
| if (!currentRow.isVirtualRow()) { |
| String path = currentRow.getPath(); |
| aggregates = Iterators.filter(Iterators.concat( |
| Iterators.singletonIterator(path), |
| aggregator.getParents(rootState, path)), Predicates |
| .not(Predicates.in(seenPaths))); |
| } |
| fetchNext(); |
| return; |
| } |
| closed = true; |
| } |
| |
| @Override |
| public IndexRow next() { |
| if (!hasNext()) { |
| throw new NoSuchElementException(); |
| } |
| seenPaths.add(currentPath); |
| init = false; |
| if (currentRow.getPath().equals(currentPath)) { |
| return currentRow; |
| } |
| // create a new overlayed index row, |
| // where the path is different but all other |
| // properties are kept |
| return new IndexRow() { |
| |
| @Override |
| public boolean isVirtualRow() { |
| return false; |
| } |
| |
| @Override |
| public String getPath() { |
| return currentPath; |
| } |
| |
| @Override |
| public PropertyValue getValue(String columnName) { |
| return currentRow.getValue(columnName); |
| } |
| |
| }; |
| } |
| |
| @Override |
| public long getSize(SizePrecision precision, long max) { |
| return cursor.getSize(precision, max); |
| } |
| |
| } |