/*
 * 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.queries.function.docvalues;

import java.io.IOException;

import org.apache.lucene.index.DocValues;
import org.apache.lucene.index.LeafReaderContext;
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.ValueSourceScorer;
import org.apache.lucene.search.Weight;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.BytesRefBuilder;
import org.apache.lucene.util.CharsRefBuilder;
import org.apache.lucene.util.mutable.MutableValue;
import org.apache.lucene.util.mutable.MutableValueStr;

Serves as base class for FunctionValues based on DocTermsIndex.
@lucene.internal
/** * Serves as base class for FunctionValues based on DocTermsIndex. * @lucene.internal */
public abstract class DocTermsIndexDocValues extends FunctionValues { protected final SortedDocValues termsIndex; protected final ValueSource vs; protected final MutableValueStr val = new MutableValueStr(); protected final CharsRefBuilder spareChars = new CharsRefBuilder(); private int lastDocID; public DocTermsIndexDocValues(ValueSource vs, LeafReaderContext context, String field) throws IOException { this(vs, open(context, field)); } protected DocTermsIndexDocValues(ValueSource vs, SortedDocValues termsIndex) { this.vs = vs; this.termsIndex = termsIndex; } protected int getOrdForDoc(int doc) throws IOException { if (doc < lastDocID) { throw new IllegalArgumentException("docs were sent out-of-order: lastDocID=" + lastDocID + " vs docID=" + doc); } lastDocID = doc; int curDocID = termsIndex.docID(); if (doc > curDocID) { curDocID = termsIndex.advance(doc); } if (doc == curDocID) { return termsIndex.ordValue(); } else { return -1; } } protected abstract String toTerm(String readableValue); @Override public boolean exists(int doc) throws IOException { return getOrdForDoc(doc) >= 0; } @Override public int ordVal(int doc) throws IOException { return getOrdForDoc(doc); } @Override public int numOrd() { return termsIndex.getValueCount(); } @Override public boolean bytesVal(int doc, BytesRefBuilder target) throws IOException { target.clear(); if (getOrdForDoc(doc) == -1) { return false; } else { target.copyBytes(termsIndex.binaryValue()); return true; } } @Override public String strVal(int doc) throws IOException { if (getOrdForDoc(doc) == -1) { return null; } final BytesRef term = termsIndex.binaryValue(); spareChars.copyUTF8Bytes(term); return spareChars.toString(); } @Override public boolean boolVal(int doc) throws IOException { return exists(doc); } @Override public abstract Object objectVal(int doc) throws IOException; // force subclasses to override @Override public ValueSourceScorer getRangeScorer(Weight weight, LeafReaderContext readerContext, String lowerVal, String upperVal, boolean includeLower, boolean includeUpper) throws IOException { // TODO: are lowerVal and upperVal in indexed form or not? lowerVal = lowerVal == null ? null : toTerm(lowerVal); upperVal = upperVal == null ? null : toTerm(upperVal); int lower = Integer.MIN_VALUE; if (lowerVal != null) { lower = termsIndex.lookupTerm(new BytesRef(lowerVal)); if (lower < 0) { lower = -lower-1; } else if (!includeLower) { lower++; } } int upper = Integer.MAX_VALUE; if (upperVal != null) { upper = termsIndex.lookupTerm(new BytesRef(upperVal)); if (upper < 0) { upper = -upper-2; } else if (!includeUpper) { upper--; } } final int ll = lower; final int uu = upper; return new ValueSourceScorer(weight, readerContext, this) { @Override public boolean matches(int doc) throws IOException { if (!exists(doc)) return false; float docVal = ordVal(doc); return docVal >= ll && docVal <= uu; } }; } @Override public String toString(int doc) throws IOException { return vs.description() + '=' + strVal(doc); } @Override public ValueFiller getValueFiller() { return new ValueFiller() { private final MutableValueStr mval = new MutableValueStr(); @Override public MutableValue getValue() { return mval; } @Override public void fillValue(int doc) throws IOException { int ord = getOrdForDoc(doc); mval.value.clear(); mval.exists = ord >= 0; if (mval.exists) { mval.value.copyBytes(termsIndex.lookupOrd(ord)); } } }; } // TODO: why? static SortedDocValues open(LeafReaderContext context, String field) throws IOException { try { return DocValues.getSorted(context.reader(), field); } catch (RuntimeException e) { throw new DocTermsIndexException(field, e); } }
Custom Exception to be thrown when the DocTermsIndex for a field cannot be generated
/** * Custom Exception to be thrown when the DocTermsIndex for a field cannot be generated */
public static final class DocTermsIndexException extends RuntimeException { public DocTermsIndexException(final String fieldName, final RuntimeException cause) { super("Can't initialize DocTermsIndex to generate (function) FunctionValues for field: " + fieldName, cause); } } }