org.apache.solr.search.function.TermFreqValueSource.java Source code

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Here is the source code for org.apache.solr.search.function.TermFreqValueSource.java

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/**
 * 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 org.apache.lucene.index.*;
import org.apache.lucene.index.IndexReader.AtomicReaderContext;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.util.BytesRef;
import org.apache.solr.common.SolrException;

import java.io.IOException;
import java.util.Map;

public class TermFreqValueSource extends DocFreqValueSource {
    public TermFreqValueSource(String field, String val, String indexedField, BytesRef indexedBytes) {
        super(field, val, indexedField, indexedBytes);
    }

    @Override
    public String name() {
        return "termfreq";
    }

    @Override
    public DocValues getValues(Map context, AtomicReaderContext readerContext) throws IOException {
        Fields fields = readerContext.reader.fields();
        final Terms terms = fields.terms(field);

        return new IntDocValues(this) {
            DocsEnum docs;
            int atDoc;
            int lastDocRequested = -1;

            {
                reset();
            }

            public void reset() throws IOException {
                // no one should call us for deleted docs?
                docs = terms.docs(null, indexedBytes, null);
                if (docs == null) {
                    docs = new DocsEnum() {
                        @Override
                        public int freq() {
                            return 0;
                        }

                        @Override
                        public int docID() {
                            return DocIdSetIterator.NO_MORE_DOCS;
                        }

                        @Override
                        public int nextDoc() throws IOException {
                            return DocIdSetIterator.NO_MORE_DOCS;
                        }

                        @Override
                        public int advance(int target) throws IOException {
                            return DocIdSetIterator.NO_MORE_DOCS;
                        }
                    };
                }
                atDoc = -1;
            }

            @Override
            public int intVal(int doc) {
                try {
                    if (doc < lastDocRequested) {
                        // out-of-order access.... reset
                        reset();
                    }
                    lastDocRequested = doc;

                    if (atDoc < doc) {
                        atDoc = docs.advance(doc);
                    }

                    if (atDoc > doc) {
                        // term doesn't match this document... either because we hit the
                        // end, or because the next doc is after this doc.
                        return 0;
                    }

                    // a match!
                    return docs.freq();
                } catch (IOException e) {
                    throw new SolrException(SolrException.ErrorCode.SERVER_ERROR,
                            "caught exception in function " + description() + " : doc=" + doc, e);
                }
            }
        };
    }
}