Java tutorial
package org.apache.solr.request; /* * 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. */ import java.io.IOException; import java.util.List; import org.apache.lucene.index.AtomicReaderContext; import org.apache.lucene.index.MultiDocValues.MultiSortedDocValues; import org.apache.lucene.index.MultiDocValues.MultiSortedSetDocValues; import org.apache.lucene.index.MultiDocValues.OrdinalMap; import org.apache.lucene.index.SingletonSortedSetDocValues; import org.apache.lucene.index.SortedDocValues; import org.apache.lucene.index.SortedSetDocValues; import org.apache.lucene.search.DocIdSet; import org.apache.lucene.search.DocIdSetIterator; import org.apache.lucene.search.Filter; import org.apache.lucene.util.BytesRef; import org.apache.lucene.util.CharsRef; import org.apache.lucene.util.UnicodeUtil; import org.apache.solr.common.params.FacetParams; import org.apache.solr.common.util.NamedList; import org.apache.solr.schema.FieldType; import org.apache.solr.schema.SchemaField; import org.apache.solr.search.DocSet; import org.apache.solr.search.SolrIndexSearcher; import org.apache.solr.util.LongPriorityQueue; /** * Computes term facets for docvalues field (single or multivalued). * <p> * This is basically a specialized case of the code in SimpleFacets. * Instead of working on a top-level reader view (binary-search per docid), * it collects per-segment, but maps ordinals to global ordinal space using * MultiDocValues' OrdinalMap. * <p> * This means the ordinal map is created per-reopen: O(nterms), but this may * perform better than PerSegmentSingleValuedFaceting which has to merge O(nterms) * per query. Additionally it works for multi-valued fields. */ public class DocValuesFacets { private DocValuesFacets() { } public static NamedList<Integer> getCounts(SolrIndexSearcher searcher, DocSet docs, String fieldName, int offset, int limit, int mincount, boolean missing, String sort, String prefix) throws IOException { SchemaField schemaField = searcher.getSchema().getField(fieldName); FieldType ft = schemaField.getType(); NamedList<Integer> res = new NamedList<Integer>(); final SortedSetDocValues si; // for term lookups only OrdinalMap ordinalMap = null; // for mapping per-segment ords to global ones if (schemaField.multiValued()) { si = searcher.getAtomicReader().getSortedSetDocValues(fieldName); if (si instanceof MultiSortedSetDocValues) { ordinalMap = ((MultiSortedSetDocValues) si).mapping; } } else { SortedDocValues single = searcher.getAtomicReader().getSortedDocValues(fieldName); si = single == null ? null : new SingletonSortedSetDocValues(single); if (single instanceof MultiSortedDocValues) { ordinalMap = ((MultiSortedDocValues) single).mapping; } } if (si == null) { return finalize(res, searcher, schemaField, docs, -1, missing); } if (si.getValueCount() >= Integer.MAX_VALUE) { throw new UnsupportedOperationException( "Currently this faceting method is limited to " + Integer.MAX_VALUE + " unique terms"); } final BytesRef br = new BytesRef(); final BytesRef prefixRef; if (prefix == null) { prefixRef = null; } else if (prefix.length() == 0) { prefix = null; prefixRef = null; } else { prefixRef = new BytesRef(prefix); } int startTermIndex, endTermIndex; if (prefix != null) { startTermIndex = (int) si.lookupTerm(prefixRef); if (startTermIndex < 0) startTermIndex = -startTermIndex - 1; prefixRef.append(UnicodeUtil.BIG_TERM); endTermIndex = (int) si.lookupTerm(prefixRef); assert endTermIndex < 0; endTermIndex = -endTermIndex - 1; } else { startTermIndex = -1; endTermIndex = (int) si.getValueCount(); } final int nTerms = endTermIndex - startTermIndex; int missingCount = -1; final CharsRef charsRef = new CharsRef(10); if (nTerms > 0 && docs.size() >= mincount) { // count collection array only needs to be as big as the number of terms we are // going to collect counts for. final int[] counts = new int[nTerms]; Filter filter = docs.getTopFilter(); List<AtomicReaderContext> leaves = searcher.getTopReaderContext().leaves(); for (int subIndex = 0; subIndex < leaves.size(); subIndex++) { AtomicReaderContext leaf = leaves.get(subIndex); DocIdSet dis = filter.getDocIdSet(leaf, null); // solr docsets already exclude any deleted docs DocIdSetIterator disi = null; if (dis != null) { disi = dis.iterator(); } if (disi != null) { if (schemaField.multiValued()) { SortedSetDocValues sub = leaf.reader().getSortedSetDocValues(fieldName); if (sub == null) { sub = SortedSetDocValues.EMPTY; } if (sub instanceof SingletonSortedSetDocValues) { // some codecs may optimize SORTED_SET storage for single-valued fields final SortedDocValues values = ((SingletonSortedSetDocValues) sub).getSortedDocValues(); accumSingle(counts, startTermIndex, values, disi, subIndex, ordinalMap); } else { accumMulti(counts, startTermIndex, sub, disi, subIndex, ordinalMap); } } else { SortedDocValues sub = leaf.reader().getSortedDocValues(fieldName); if (sub == null) { sub = SortedDocValues.EMPTY; } accumSingle(counts, startTermIndex, sub, disi, subIndex, ordinalMap); } } } if (startTermIndex == -1) { missingCount = counts[0]; } // IDEA: we could also maintain a count of "other"... everything that fell outside // of the top 'N' int off = offset; int lim = limit >= 0 ? limit : Integer.MAX_VALUE; if (sort.equals(FacetParams.FACET_SORT_COUNT) || sort.equals(FacetParams.FACET_SORT_COUNT_LEGACY)) { int maxsize = limit > 0 ? offset + limit : Integer.MAX_VALUE - 1; maxsize = Math.min(maxsize, nTerms); LongPriorityQueue queue = new LongPriorityQueue(Math.min(maxsize, 1000), maxsize, Long.MIN_VALUE); int min = mincount - 1; // the smallest value in the top 'N' values for (int i = (startTermIndex == -1) ? 1 : 0; i < nTerms; i++) { int c = counts[i]; if (c > min) { // NOTE: we use c>min rather than c>=min as an optimization because we are going in // index order, so we already know that the keys are ordered. This can be very // important if a lot of the counts are repeated (like zero counts would be). // smaller term numbers sort higher, so subtract the term number instead long pair = (((long) c) << 32) + (Integer.MAX_VALUE - i); boolean displaced = queue.insert(pair); if (displaced) min = (int) (queue.top() >>> 32); } } // if we are deep paging, we don't have to order the highest "offset" counts. int collectCount = Math.max(0, queue.size() - off); assert collectCount <= lim; // the start and end indexes of our list "sorted" (starting with the highest value) int sortedIdxStart = queue.size() - (collectCount - 1); int sortedIdxEnd = queue.size() + 1; final long[] sorted = queue.sort(collectCount); for (int i = sortedIdxStart; i < sortedIdxEnd; i++) { long pair = sorted[i]; int c = (int) (pair >>> 32); int tnum = Integer.MAX_VALUE - (int) pair; si.lookupOrd(startTermIndex + tnum, br); ft.indexedToReadable(br, charsRef); res.add(charsRef.toString(), c); } } else { // add results in index order int i = (startTermIndex == -1) ? 1 : 0; if (mincount <= 0) { // if mincount<=0, then we won't discard any terms and we know exactly // where to start. i += off; off = 0; } for (; i < nTerms; i++) { int c = counts[i]; if (c < mincount || --off >= 0) continue; if (--lim < 0) break; si.lookupOrd(startTermIndex + i, br); ft.indexedToReadable(br, charsRef); res.add(charsRef.toString(), c); } } } return finalize(res, searcher, schemaField, docs, missingCount, missing); } /** finalizes result: computes missing count if applicable */ static NamedList<Integer> finalize(NamedList<Integer> res, SolrIndexSearcher searcher, SchemaField schemaField, DocSet docs, int missingCount, boolean missing) throws IOException { if (missing) { if (missingCount < 0) { missingCount = SimpleFacets.getFieldMissingCount(searcher, docs, schemaField.getName()); } res.add(null, missingCount); } return res; } /** accumulates per-segment single-valued facet counts, mapping to global ordinal space */ // specialized since the single-valued case is different static void accumSingle(int counts[], int startTermIndex, SortedDocValues si, DocIdSetIterator disi, int subIndex, OrdinalMap map) throws IOException { int doc; while ((doc = disi.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) { int term = si.getOrd(doc); if (map != null && term >= 0) { term = (int) map.getGlobalOrd(subIndex, term); } int arrIdx = term - startTermIndex; if (arrIdx >= 0 && arrIdx < counts.length) counts[arrIdx]++; } } /** accumulates per-segment multi-valued facet counts, mapping to global ordinal space */ static void accumMulti(int counts[], int startTermIndex, SortedSetDocValues si, DocIdSetIterator disi, int subIndex, OrdinalMap map) throws IOException { int doc; while ((doc = disi.nextDoc()) != DocIdSetIterator.NO_MORE_DOCS) { si.setDocument(doc); // strange do-while to collect the missing count (first ord is NO_MORE_ORDS) int term = (int) si.nextOrd(); if (term < 0) { if (startTermIndex == -1) { counts[0]++; // missing count } continue; } do { if (map != null) { term = (int) map.getGlobalOrd(subIndex, term); } int arrIdx = term - startTermIndex; if (arrIdx >= 0 && arrIdx < counts.length) counts[arrIdx]++; } while ((term = (int) si.nextOrd()) >= 0); } } }