/*
* 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.AtomicReaderContext;
import org.apache.lucene.index.IndexReader;
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.FieldCache;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.CharsRef;
import org.apache.lucene.util.UnicodeUtil;
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
*/
public abstract class DocTermsIndexDocValues extends FunctionValues {
protected final SortedDocValues termsIndex;
protected final ValueSource vs;
protected final MutableValueStr val = new MutableValueStr();
protected final CharsRef spareChars = new CharsRef();
public DocTermsIndexDocValues(ValueSource vs, AtomicReaderContext context, String field) throws IOException {
try {
termsIndex = FieldCache.DEFAULT.getTermsIndex(context.reader(), field);
} catch (RuntimeException e) {
throw new DocTermsIndexException(field, e);
}
this.vs = vs;
}
protected abstract String toTerm(String readableValue);
@Override
public boolean exists(int doc) {
return ordVal(doc) >= 0;
}
@Override
public int ordVal(int doc) {
return termsIndex.getOrd(doc);
}
@Override
public int numOrd() {
return termsIndex.getValueCount();
}
@Override
public boolean bytesVal(int doc, BytesRef target) {
target.length = 0;
target.copyBytes(termsIndex.get(doc));
return target.length > 0;
}
@Override
public String strVal(int doc) {
final BytesRef term = termsIndex.get(doc);
if (term.length == 0) {
return null;
}
UnicodeUtil.UTF8toUTF16(term, spareChars);
return spareChars.toString();
}
@Override
public boolean boolVal(int doc) {
return exists(doc);
}
@Override
public abstract Object objectVal(int doc); // force subclasses to override
@Override
public ValueSourceScorer getRangeScorer(IndexReader reader, String lowerVal, String upperVal, boolean includeLower, boolean includeUpper) {
// 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(reader, this) {
@Override
public boolean matchesValue(int doc) {
int ord = termsIndex.getOrd(doc);
return ord >= ll && ord <= uu;
}
};
}
@Override
public String toString(int doc) {
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) {
int ord = termsIndex.getOrd(doc);
mval.value.length = 0;
mval.exists = ord >= 0;
if (mval.exists) {
mval.value.copyBytes(termsIndex.lookupOrd(ord));
}
}
};
}
/**
* 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);
}
}
}