/* * 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); } }