| /* |
| * 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.lucene.search.join; |
| |
| import org.apache.lucene.index.NumericDocValues; |
| import org.apache.lucene.index.SortedDocValues; |
| import org.apache.lucene.index.SortedNumericDocValues; |
| import org.apache.lucene.index.SortedSetDocValues; |
| import org.apache.lucene.search.DocIdSetIterator; |
| import org.apache.lucene.search.SortField; |
| import org.apache.lucene.search.SortedNumericSelector; |
| import org.apache.lucene.search.SortedSetSelector; |
| import org.apache.lucene.util.BitSet; |
| import org.apache.lucene.util.BitSetIterator; |
| import org.apache.lucene.util.Bits; |
| |
| /** Select a value from a block of documents. |
| * @lucene.internal */ |
| public class BlockJoinSelector { |
| |
| private BlockJoinSelector() {} |
| |
| /** Type of selection to perform. If none of the documents in the block have |
| * a value then no value will be selected. */ |
| public enum Type { |
| /** Only consider the minimum value from the block when sorting. */ |
| MIN, |
| /** Only consider the maximum value from the block when sorting. */ |
| MAX; |
| } |
| |
| /** Return a {@link Bits} instance that returns true if, and only if, any of |
| * the children of the given parent document has a value. */ |
| public static Bits wrap(final Bits docsWithValue, BitSet parents, BitSet children) { |
| return new Bits() { |
| |
| @Override |
| public boolean get(int docID) { |
| assert parents.get(docID) : "this selector may only be used on parent documents"; |
| |
| if (docID == 0) { |
| // no children |
| return false; |
| } |
| |
| final int firstChild = parents.prevSetBit(docID - 1) + 1; |
| for (int child = children.nextSetBit(firstChild); child < docID; child = children.nextSetBit(child + 1)) { |
| if (docsWithValue.get(child)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| @Override |
| public int length() { |
| return docsWithValue.length(); |
| } |
| |
| }; |
| } |
| |
| /** Wraps the provided {@link SortedSetDocValues} in order to only select |
| * one value per parent among its {@code children} using the configured |
| * {@code selection} type. */ |
| @Deprecated |
| public static SortedDocValues wrap(SortedSetDocValues sortedSet, Type selection, BitSet parents, BitSet children) { |
| return wrap(sortedSet, selection, parents, toIter(children)); |
| } |
| |
| /** Wraps the provided {@link SortedSetDocValues} in order to only select |
| * one value per parent among its {@code children} using the configured |
| * {@code selection} type. */ |
| public static SortedDocValues wrap(SortedSetDocValues sortedSet, Type selection, BitSet parents, DocIdSetIterator children) { |
| SortedDocValues values; |
| switch (selection) { |
| case MIN: |
| values = SortedSetSelector.wrap(sortedSet, SortedSetSelector.Type.MIN); |
| break; |
| case MAX: |
| values = SortedSetSelector.wrap(sortedSet, SortedSetSelector.Type.MAX); |
| break; |
| default: |
| throw new AssertionError(); |
| } |
| return wrap(values, selection, parents, children); |
| } |
| |
| /** Wraps the provided {@link SortedDocValues} in order to only select |
| * one value per parent among its {@code children} using the configured |
| * {@code selection} type. */ |
| @Deprecated |
| public static SortedDocValues wrap(final SortedDocValues values, Type selection, BitSet parents, BitSet children) { |
| return wrap(values, selection, parents, toIter(children)); |
| } |
| |
| /** Wraps the provided {@link SortedDocValues} in order to only select |
| * one value per parent among its {@code children} using the configured |
| * {@code selection} type. */ |
| public static SortedDocValues wrap(final SortedDocValues values, Type selection, BitSet parents, DocIdSetIterator children) { |
| if (values.docID() != -1) { |
| throw new IllegalArgumentException("values iterator was already consumed: values.docID=" + values.docID()); |
| } |
| return ToParentDocValues.wrap(values, selection, parents, children); |
| } |
| |
| /** Wraps the provided {@link SortedNumericDocValues} in order to only select |
| * one value per parent among its {@code children} using the configured |
| * {@code selection} type. */ |
| @Deprecated |
| public static NumericDocValues wrap(SortedNumericDocValues sortedNumerics, Type selection, BitSet parents, BitSet children) { |
| return wrap(sortedNumerics, selection, parents, toIter(children)); |
| } |
| |
| /** creates an iterator for the given bitset */ |
| protected static BitSetIterator toIter(BitSet children) { |
| return new BitSetIterator(children, 0); |
| } |
| |
| /** Wraps the provided {@link SortedNumericDocValues} in order to only select |
| * one value per parent among its {@code children} using the configured |
| * {@code selection} type. */ |
| public static NumericDocValues wrap(SortedNumericDocValues sortedNumerics, Type selection, BitSet parents, DocIdSetIterator children) { |
| NumericDocValues values; |
| switch (selection) { |
| case MIN: |
| values = SortedNumericSelector.wrap(sortedNumerics, SortedNumericSelector.Type.MIN, SortField.Type.LONG); |
| break; |
| case MAX: |
| values = SortedNumericSelector.wrap(sortedNumerics, SortedNumericSelector.Type.MAX, SortField.Type.LONG); |
| break; |
| default: |
| throw new AssertionError(); |
| } |
| return wrap(values, selection, parents, children); |
| } |
| |
| /** Wraps the provided {@link NumericDocValues}, iterating over only |
| * child documents, in order to only select one value per parent among |
| * its {@code children} using the configured {@code selection} type. */ |
| @Deprecated |
| public static NumericDocValues wrap(final NumericDocValues values, Type selection, BitSet parents, BitSet children) { |
| return wrap(values,selection, parents, toIter(children)); |
| } |
| |
| /** Wraps the provided {@link NumericDocValues}, iterating over only |
| * child documents, in order to only select one value per parent among |
| * its {@code children} using the configured {@code selection} type. */ |
| public static NumericDocValues wrap(final NumericDocValues values, Type selection, BitSet parents, DocIdSetIterator children) { |
| if (values.docID() != -1) { |
| throw new IllegalArgumentException("values iterator was already consumed: values.docID=" + values.docID()); |
| } |
| return ToParentDocValues.wrap(values,selection, parents, children); |
| } |
| } |