| /* |
| * 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.solr.search.function; |
| |
| import java.io.IOException; |
| import java.util.List; |
| import java.util.Map; |
| |
| import org.apache.lucene.index.DocValues; |
| import org.apache.lucene.index.IndexReader; |
| import org.apache.lucene.index.LeafReader; |
| import org.apache.lucene.index.LeafReaderContext; |
| import org.apache.lucene.index.MultiReader; |
| import org.apache.lucene.index.ReaderUtil; |
| import org.apache.lucene.index.SortedDocValues; |
| import org.apache.lucene.queries.function.FunctionValues; |
| import org.apache.lucene.queries.function.ValueSource; |
| import org.apache.lucene.queries.function.docvalues.IntDocValues; |
| import org.apache.lucene.search.SortedSetSelector; |
| import org.apache.solr.common.SolrException; |
| import org.apache.solr.index.SlowCompositeReaderWrapper; |
| import org.apache.solr.schema.SchemaField; |
| import org.apache.solr.search.Insanity; |
| import org.apache.solr.search.SolrIndexSearcher; |
| |
| /** |
| * Obtains the ordinal of the field value from {@link org.apache.lucene.index.LeafReader#getSortedDocValues} |
| * and reverses the order. |
| * <br> |
| * The native lucene index order is used to assign an ordinal value for each field value. |
| * <br>Field values (terms) are lexicographically ordered by unicode value, and numbered starting at 1. |
| * <br> |
| * Example of reverse ordinal (rord):<br> |
| * If there were only three field values: "apple","banana","pear" |
| * <br>then rord("apple")=3, rord("banana")=2, ord("pear")=1 |
| * <p> |
| * WARNING: ord() depends on the position in an index and can thus change when other documents are inserted or deleted, |
| * or if a MultiSearcher is used. |
| * <br> |
| * WARNING: as of Solr 1.4, ord() and rord() can cause excess memory use since they must use a FieldCache entry |
| * at the top level reader, while sorting and function queries now use entries at the segment level. Hence sorting |
| * or using a different function query, in addition to ord()/rord() will double memory use. |
| * |
| * |
| */ |
| |
| public class ReverseOrdFieldSource extends ValueSource { |
| public final String field; |
| |
| public ReverseOrdFieldSource(String field) { |
| this.field = field; |
| } |
| |
| @Override |
| public String description() { |
| return "rord("+field+')'; |
| } |
| |
| @Override |
| @SuppressWarnings({"rawtypes"}) |
| public FunctionValues getValues(Map context, LeafReaderContext readerContext) throws IOException { |
| final int off = readerContext.docBase; |
| final LeafReader r; |
| Object o = context.get("searcher"); |
| if (o instanceof SolrIndexSearcher) { |
| @SuppressWarnings("resource") final SolrIndexSearcher is = (SolrIndexSearcher) o; |
| SchemaField sf = is.getSchema().getFieldOrNull(field); |
| if (sf != null && sf.getType().isPointField()) { |
| throw new SolrException(SolrException.ErrorCode.BAD_REQUEST, |
| "rord() is not supported over Points based field " + field); |
| } |
| if (sf != null && sf.hasDocValues() == false && sf.multiValued() == false && sf.getType().getNumberType() != null) { |
| // it's a single-valued numeric field: we must currently create insanity :( |
| List<LeafReaderContext> leaves = is.getIndexReader().leaves(); |
| LeafReader insaneLeaves[] = new LeafReader[leaves.size()]; |
| int upto = 0; |
| for (LeafReaderContext raw : leaves) { |
| insaneLeaves[upto++] = Insanity.wrapInsanity(raw.reader(), field); |
| } |
| r = SlowCompositeReaderWrapper.wrap(new MultiReader(insaneLeaves)); |
| } else { |
| // reuse ordinalmap |
| r = ((SolrIndexSearcher)o).getSlowAtomicReader(); |
| } |
| } else { |
| IndexReader topReader = ReaderUtil.getTopLevelContext(readerContext).reader(); |
| r = SlowCompositeReaderWrapper.wrap(topReader); |
| } |
| // if it's e.g. tokenized/multivalued, emulate old behavior of single-valued fc |
| final SortedDocValues sindex = SortedSetSelector.wrap(DocValues.getSortedSet(r, field), SortedSetSelector.Type.MIN); |
| final int end = sindex.getValueCount(); |
| |
| return new IntDocValues(this) { |
| @Override |
| public int intVal(int doc) throws IOException { |
| if (doc+off > sindex.docID()) { |
| sindex.advance(doc+off); |
| } |
| if (doc+off == sindex.docID()) { |
| return (end - sindex.ordValue() - 1); |
| } else { |
| return end; |
| } |
| } |
| }; |
| } |
| |
| @Override |
| public boolean equals(Object o) { |
| if (o == null || (o.getClass() != ReverseOrdFieldSource.class)) return false; |
| ReverseOrdFieldSource other = (ReverseOrdFieldSource)o; |
| return this.field.equals(other.field); |
| } |
| |
| private static final int hcode = ReverseOrdFieldSource.class.hashCode(); |
| @Override |
| public int hashCode() { |
| return hcode + field.hashCode(); |
| } |
| |
| } |