/*
* 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;
import java.io.IOException;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.util.BytesRefBuilder;
import org.apache.lucene.util.mutable.MutableValue;
import org.apache.lucene.util.mutable.MutableValueFloat;
/**
* Represents field values as different types.
* Normally created via a {@link ValueSource} for a particular field and reader.
*
*
*/
// FunctionValues is distinct from ValueSource because
// there needs to be an object created at query evaluation time that
// is not referenced by the query itself because:
// - Query objects should be MT safe
// - For caching, Query objects are often used as keys... you don't
// want the Query carrying around big objects
public abstract class FunctionValues {
public byte byteVal(int doc) throws IOException { throw new UnsupportedOperationException(); }
public short shortVal(int doc) throws IOException { throw new UnsupportedOperationException(); }
public float floatVal(int doc) throws IOException { throw new UnsupportedOperationException(); }
public int intVal(int doc) throws IOException { throw new UnsupportedOperationException(); }
public long longVal(int doc) throws IOException { throw new UnsupportedOperationException(); }
public double doubleVal(int doc) throws IOException { throw new UnsupportedOperationException(); }
// TODO: should we make a termVal, returns BytesRef?
public String strVal(int doc) throws IOException { throw new UnsupportedOperationException(); }
public boolean boolVal(int doc) throws IOException {
return intVal(doc) != 0;
}
/** returns the bytes representation of the string val - TODO: should this return the indexed raw bytes not? */
public boolean bytesVal(int doc, BytesRefBuilder target) throws IOException {
String s = strVal(doc);
if (s==null) {
target.clear();
return false;
}
target.copyChars(s);
return true;
}
/** Native Java Object representation of the value */
public Object objectVal(int doc) throws IOException {
// most FunctionValues are functions, so by default return a Float()
return floatVal(doc);
}
/** Returns true if there is a value for this document */
public boolean exists(int doc) throws IOException {
return true;
}
/**
* @param doc The doc to retrieve to sort ordinal for
* @return the sort ordinal for the specified doc
* TODO: Maybe we can just use intVal for this...
*/
public int ordVal(int doc) throws IOException {
throw new UnsupportedOperationException();
}
/**
* @return the number of unique sort ordinals this instance has
*/
public int numOrd() { throw new UnsupportedOperationException(); }
public abstract String toString(int doc) throws IOException;
/**
* Abstraction of the logic required to fill the value of a specified doc into
* a reusable {@link MutableValue}. Implementations of {@link FunctionValues}
* are encouraged to define their own implementations of ValueFiller if their
* value is not a float.
*
* @lucene.experimental
*/
public static abstract class ValueFiller {
/** MutableValue will be reused across calls */
public abstract MutableValue getValue();
/** MutableValue will be reused across calls. Returns true if the value exists. */
public abstract void fillValue(int doc) throws IOException;
}
/** @lucene.experimental */
public ValueFiller getValueFiller() {
return new ValueFiller() {
private final MutableValueFloat mval = new MutableValueFloat();
@Override
public MutableValue getValue() {
return mval;
}
@Override
public void fillValue(int doc) throws IOException {
mval.value = floatVal(doc);
}
};
}
//For Functions that can work with multiple values from the same document. This does not apply to all functions
public void byteVal(int doc, byte [] vals) throws IOException { throw new UnsupportedOperationException(); }
public void shortVal(int doc, short [] vals) throws IOException { throw new UnsupportedOperationException(); }
public void floatVal(int doc, float [] vals) throws IOException { throw new UnsupportedOperationException(); }
public void intVal(int doc, int [] vals) throws IOException { throw new UnsupportedOperationException(); }
public void longVal(int doc, long [] vals) throws IOException { throw new UnsupportedOperationException(); }
public void doubleVal(int doc, double [] vals) throws IOException { throw new UnsupportedOperationException(); }
// TODO: should we make a termVal, fills BytesRef[]?
public void strVal(int doc, String [] vals) throws IOException { throw new UnsupportedOperationException(); }
public Explanation explain(int doc) throws IOException {
return Explanation.match(floatVal(doc), toString(doc));
}
/**
* Yields a {@link Scorer} that matches all documents,
* and that which produces scores equal to {@link #floatVal(int)}.
*/
public ValueSourceScorer getScorer(LeafReaderContext readerContext) {
return new ValueSourceScorer(readerContext, this) {
@Override
public boolean matches(int doc) {
return true;
}
};
}
/**
* Yields a {@link Scorer} that matches documents with values between the specified range,
* and that which produces scores equal to {@link #floatVal(int)}.
*/
// A RangeValueSource can't easily be a ValueSource that takes another ValueSource
// because it needs different behavior depending on the type of fields. There is also
// a setup cost - parsing and normalizing params, and doing a binary search on the StringIndex.
// TODO: change "reader" to LeafReaderContext
public ValueSourceScorer getRangeScorer(LeafReaderContext readerContext, String lowerVal, String upperVal, boolean includeLower, boolean includeUpper) throws IOException {
float lower;
float upper;
if (lowerVal == null) {
lower = Float.NEGATIVE_INFINITY;
} else {
lower = Float.parseFloat(lowerVal);
}
if (upperVal == null) {
upper = Float.POSITIVE_INFINITY;
} else {
upper = Float.parseFloat(upperVal);
}
final float l = lower;
final float u = upper;
if (includeLower && includeUpper) {
return new ValueSourceScorer(readerContext, this) {
@Override
public boolean matches(int doc) throws IOException {
if (!exists(doc)) return false;
float docVal = floatVal(doc);
return docVal >= l && docVal <= u;
}
};
}
else if (includeLower && !includeUpper) {
return new ValueSourceScorer(readerContext, this) {
@Override
public boolean matches(int doc) throws IOException {
if (!exists(doc)) return false;
float docVal = floatVal(doc);
return docVal >= l && docVal < u;
}
};
}
else if (!includeLower && includeUpper) {
return new ValueSourceScorer(readerContext, this) {
@Override
public boolean matches(int doc) throws IOException {
if (!exists(doc)) return false;
float docVal = floatVal(doc);
return docVal > l && docVal <= u;
}
};
}
else {
return new ValueSourceScorer(readerContext, this) {
@Override
public boolean matches(int doc) throws IOException {
if (!exists(doc)) return false;
float docVal = floatVal(doc);
return docVal > l && docVal < u;
}
};
}
}
}