/*
* 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.spatial.serialized;
import java.io.ByteArrayInputStream;
import java.io.ByteArrayOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.FilterOutputStream;
import java.io.IOException;
import java.util.Map;
import org.apache.lucene.document.BinaryDocValuesField;
import org.apache.lucene.document.Field;
import org.apache.lucene.index.BinaryDocValues;
import org.apache.lucene.index.LeafReaderContext;
import org.apache.lucene.queries.function.FunctionValues;
import org.apache.lucene.queries.function.ValueSource;
import org.apache.lucene.search.ConstantScoreScorer;
import org.apache.lucene.search.ConstantScoreWeight;
import org.apache.lucene.search.DocIdSetIterator;
import org.apache.lucene.search.Explanation;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.Scorer;
import org.apache.lucene.search.TwoPhaseIterator;
import org.apache.lucene.search.Weight;
import org.apache.lucene.spatial.SpatialStrategy;
import org.apache.lucene.spatial.query.SpatialArgs;
import org.apache.lucene.spatial.util.DistanceToShapeValueSource;
import org.apache.lucene.spatial.util.ShapePredicateValueSource;
import org.apache.lucene.util.BytesRef;
import org.apache.lucene.util.BytesRefBuilder;
import org.locationtech.spatial4j.context.SpatialContext;
import org.locationtech.spatial4j.io.BinaryCodec;
import org.locationtech.spatial4j.shape.Point;
import org.locationtech.spatial4j.shape.Shape;
/**
* A SpatialStrategy based on serializing a Shape stored into BinaryDocValues.
* This is not at all fast; it's designed to be used in conjunction with another index based
* SpatialStrategy that is approximated (like {@link org.apache.lucene.spatial.prefix.RecursivePrefixTreeStrategy})
* to add precision or eventually make more specific / advanced calculations on the per-document
* geometry.
* The serialization uses Spatial4j's {@link org.locationtech.spatial4j.io.BinaryCodec}.
*
* @lucene.experimental
*/
public class SerializedDVStrategy extends SpatialStrategy {
/**
* A cache heuristic for the buf size based on the last shape size.
*/
//TODO do we make this non-volatile since it's merely a heuristic?
private volatile int indexLastBufSize = 8 * 1024;//8KB default on first run
/**
* Constructs the spatial strategy with its mandatory arguments.
*/
public SerializedDVStrategy(SpatialContext ctx, String fieldName) {
super(ctx, fieldName);
}
@Override
public Field[] createIndexableFields(Shape shape) {
int bufSize = Math.max(128, (int) (this.indexLastBufSize * 1.5));//50% headroom over last
ByteArrayOutputStream byteStream = new ByteArrayOutputStream(bufSize);
final BytesRef bytesRef = new BytesRef();//receiver of byteStream's bytes
try {
ctx.getBinaryCodec().writeShape(new DataOutputStream(byteStream), shape);
//this is a hack to avoid redundant byte array copying by byteStream.toByteArray()
byteStream.writeTo(new FilterOutputStream(null/*not used*/) {
@Override
public void write(byte[] b, int off, int len) throws IOException {
bytesRef.bytes = b;
bytesRef.offset = off;
bytesRef.length = len;
}
});
} catch (IOException e) {
throw new RuntimeException(e);
}
this.indexLastBufSize = bytesRef.length;//cache heuristic
return new Field[]{new BinaryDocValuesField(getFieldName(), bytesRef)};
}
@Override
public ValueSource makeDistanceValueSource(Point queryPoint, double multiplier) {
//TODO if makeShapeValueSource gets lifted to the top; this could become a generic impl.
return new DistanceToShapeValueSource(makeShapeValueSource(), queryPoint, multiplier, ctx);
}
/**
* Returns a Query that should be used in a random-access fashion.
* Use in another manner will be SLOW.
*/
@Override
public Query makeQuery(SpatialArgs args) {
ValueSource shapeValueSource = makeShapeValueSource();
ShapePredicateValueSource predicateValueSource = new ShapePredicateValueSource(
shapeValueSource, args.getOperation(), args.getShape());
return new PredicateValueSourceQuery(predicateValueSource);
}
/**
* Provides access to each shape per document as a ValueSource in which
* {@link org.apache.lucene.queries.function.FunctionValues#objectVal(int)} returns a {@link
* Shape}.
*/ //TODO raise to SpatialStrategy
public ValueSource makeShapeValueSource() {
return new ShapeDocValueSource(getFieldName(), ctx.getBinaryCodec());
}
/** Warning: don't iterate over the results of this query; it's designed for use in a random-access fashion
* by {@link TwoPhaseIterator}.
*/
static class PredicateValueSourceQuery extends Query {
private final ValueSource predicateValueSource;//we call boolVal(doc)
public PredicateValueSourceQuery(ValueSource predicateValueSource) {
this.predicateValueSource = predicateValueSource;
}
@Override
public Weight createWeight(IndexSearcher searcher, boolean needsScores, float boost) throws IOException {
return new ConstantScoreWeight(this, boost) {
@Override
public Scorer scorer(LeafReaderContext context) throws IOException {
DocIdSetIterator approximation = DocIdSetIterator.all(context.reader().maxDoc());
final FunctionValues predFuncValues = predicateValueSource.getValues(null, context);
return new ConstantScoreScorer(this, score(), new TwoPhaseIterator(approximation) {
@Override
public boolean matches() throws IOException {
final int docID = approximation.docID();
return predFuncValues.boolVal(docID);
}
@Override
public float matchCost() {
// TODO: what is the cost of the predicateValueSource
return 100f;
}
});
}
};
}
@Override
public boolean equals(Object other) {
return sameClassAs(other) &&
predicateValueSource.equals(((PredicateValueSourceQuery) other).predicateValueSource);
}
@Override
public int hashCode() {
return classHash() + 31 * predicateValueSource.hashCode();
}
@Override
public String toString(String field) {
return "PredicateValueSourceQuery(" +
predicateValueSource.toString() +
")";
}
}//PredicateValueSourceQuery
/**
* Implements a ValueSource by deserializing a Shape in from BinaryDocValues using BinaryCodec.
* @see #makeShapeValueSource()
*/
static class ShapeDocValueSource extends ValueSource {
private final String fieldName;
private final BinaryCodec binaryCodec;//spatial4j
private ShapeDocValueSource(String fieldName, BinaryCodec binaryCodec) {
this.fieldName = fieldName;
this.binaryCodec = binaryCodec;
}
@Override
public FunctionValues getValues(Map context, LeafReaderContext readerContext) throws IOException {
final BinaryDocValues docValues = readerContext.reader().getBinaryDocValues(fieldName);
return new FunctionValues() {
int bytesRefDoc = -1;
BytesRefBuilder bytesRef = new BytesRefBuilder();
boolean fillBytes(int doc) throws IOException {
if (bytesRefDoc != doc) {
if (docValues.docID() < doc) {
docValues.advance(doc);
}
if (docValues.docID() == doc) {
bytesRef.copyBytes(docValues.binaryValue());
} else {
bytesRef.clear();
}
bytesRefDoc = doc;
}
return bytesRef.length() != 0;
}
@Override
public boolean exists(int doc) throws IOException {
return fillBytes(doc);
}
@Override
public boolean bytesVal(int doc, BytesRefBuilder target) throws IOException {
target.clear();
if (fillBytes(doc)) {
target.copyBytes(bytesRef);
return true;
} else {
return false;
}
}
@Override
public Object objectVal(int docId) throws IOException {
if (!fillBytes(docId))
return null;
DataInputStream dataInput = new DataInputStream(
new ByteArrayInputStream(bytesRef.bytes(), 0, bytesRef.length()));
try {
return binaryCodec.readShape(dataInput);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
@Override
public Explanation explain(int doc) throws IOException {
return Explanation.match(Float.NaN, toString(doc));
}
@Override
public String toString(int doc) throws IOException {
return description() + "=" + objectVal(doc);//TODO truncate?
}
};
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
ShapeDocValueSource that = (ShapeDocValueSource) o;
if (!fieldName.equals(that.fieldName)) return false;
return true;
}
@Override
public int hashCode() {
int result = fieldName.hashCode();
return result;
}
@Override
public String description() {
return "shapeDocVal(" + fieldName + ")";
}
}//ShapeDocValueSource
}