/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.elasticsearch.index.query;
import org.apache.lucene.search.Query;
import org.apache.lucene.search.spans.SpanNearQuery;
import org.apache.lucene.search.spans.SpanQuery;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.ParsingException;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
/**
* Matches spans which are near one another. One can specify slop, the maximum number
* of intervening unmatched positions, as well as whether matches are required to be in-order.
* The span near query maps to Lucene {@link SpanNearQuery}.
*/
public class SpanNearQueryBuilder extends AbstractQueryBuilder<SpanNearQueryBuilder> implements SpanQueryBuilder {
public static final String NAME = "span_near";
/** Default for flag controlling whether matches are required to be in-order */
public static boolean DEFAULT_IN_ORDER = true;
private static final ParseField SLOP_FIELD = new ParseField("slop");
private static final ParseField CLAUSES_FIELD = new ParseField("clauses");
private static final ParseField IN_ORDER_FIELD = new ParseField("in_order");
private final List<SpanQueryBuilder> clauses = new ArrayList<>();
private final int slop;
private boolean inOrder = DEFAULT_IN_ORDER;
/**
* @param initialClause an initial span query clause
* @param slop controls the maximum number of intervening unmatched positions permitted
*/
public SpanNearQueryBuilder(SpanQueryBuilder initialClause, int slop) {
if (initialClause == null) {
throw new IllegalArgumentException("[" + NAME + "] must include at least one clause");
}
this.clauses.add(initialClause);
this.slop = slop;
}
/**
* Read from a stream.
*/
public SpanNearQueryBuilder(StreamInput in) throws IOException {
super(in);
for (QueryBuilder clause : readQueries(in)) {
this.clauses.add((SpanQueryBuilder) clause);
}
slop = in.readVInt();
inOrder = in.readBoolean();
}
@Override
protected void doWriteTo(StreamOutput out) throws IOException {
writeQueries(out, clauses);
out.writeVInt(slop);
out.writeBoolean(inOrder);
}
/**
* @return the maximum number of intervening unmatched positions permitted
*/
public int slop() {
return this.slop;
}
/**
* Add a span clause to the current list of clauses
*/
public SpanNearQueryBuilder addClause(SpanQueryBuilder clause) {
if (clause == null) {
throw new IllegalArgumentException("[" + NAME + "] clauses cannot be null");
}
clauses.add(clause);
return this;
}
/**
* @return the {@link SpanQueryBuilder} clauses that were set for this query
*/
public List<SpanQueryBuilder> clauses() {
return Collections.unmodifiableList(this.clauses);
}
/**
* When <code>inOrder</code> is true, the spans from each clause
* must be in the same order as in <code>clauses</code> and must be non-overlapping.
* Defaults to <code>true</code>
*/
public SpanNearQueryBuilder inOrder(boolean inOrder) {
this.inOrder = inOrder;
return this;
}
/**
* @see SpanNearQueryBuilder#inOrder(boolean)
*/
public boolean inOrder() {
return this.inOrder;
}
@Override
protected void doXContent(XContentBuilder builder, Params params) throws IOException {
builder.startObject(NAME);
builder.startArray(CLAUSES_FIELD.getPreferredName());
for (SpanQueryBuilder clause : clauses) {
clause.toXContent(builder, params);
}
builder.endArray();
builder.field(SLOP_FIELD.getPreferredName(), slop);
builder.field(IN_ORDER_FIELD.getPreferredName(), inOrder);
printBoostAndQueryName(builder);
builder.endObject();
}
public static SpanNearQueryBuilder fromXContent(QueryParseContext parseContext) throws IOException {
XContentParser parser = parseContext.parser();
float boost = AbstractQueryBuilder.DEFAULT_BOOST;
Integer slop = null;
boolean inOrder = SpanNearQueryBuilder.DEFAULT_IN_ORDER;
String queryName = null;
List<SpanQueryBuilder> clauses = new ArrayList<>();
String currentFieldName = null;
XContentParser.Token token;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (token == XContentParser.Token.START_ARRAY) {
if (CLAUSES_FIELD.match(currentFieldName)) {
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
QueryBuilder query = parseContext.parseInnerQueryBuilder();
if (query instanceof SpanQueryBuilder == false) {
throw new ParsingException(parser.getTokenLocation(), "spanNear [clauses] must be of type span query");
}
clauses.add((SpanQueryBuilder) query);
}
} else {
throw new ParsingException(parser.getTokenLocation(), "[span_near] query does not support [" + currentFieldName + "]");
}
} else if (token.isValue()) {
if (IN_ORDER_FIELD.match(currentFieldName)) {
inOrder = parser.booleanValue();
} else if (SLOP_FIELD.match(currentFieldName)) {
slop = parser.intValue();
} else if (AbstractQueryBuilder.BOOST_FIELD.match(currentFieldName)) {
boost = parser.floatValue();
} else if (AbstractQueryBuilder.NAME_FIELD.match(currentFieldName)) {
queryName = parser.text();
} else {
throw new ParsingException(parser.getTokenLocation(), "[span_near] query does not support [" + currentFieldName + "]");
}
} else {
throw new ParsingException(parser.getTokenLocation(), "[span_near] query does not support [" + currentFieldName + "]");
}
}
if (clauses.isEmpty()) {
throw new ParsingException(parser.getTokenLocation(), "span_near must include [clauses]");
}
if (slop == null) {
throw new ParsingException(parser.getTokenLocation(), "span_near must include [slop]");
}
SpanNearQueryBuilder queryBuilder = new SpanNearQueryBuilder(clauses.get(0), slop);
for (int i = 1; i < clauses.size(); i++) {
queryBuilder.addClause(clauses.get(i));
}
queryBuilder.inOrder(inOrder);
queryBuilder.boost(boost);
queryBuilder.queryName(queryName);
return queryBuilder;
}
@Override
protected Query doToQuery(QueryShardContext context) throws IOException {
SpanQuery[] spanQueries = new SpanQuery[clauses.size()];
for (int i = 0; i < clauses.size(); i++) {
Query query = clauses.get(i).toQuery(context);
assert query instanceof SpanQuery;
spanQueries[i] = (SpanQuery) query;
}
return new SpanNearQuery(spanQueries, slop, inOrder);
}
@Override
protected int doHashCode() {
return Objects.hash(clauses, slop, inOrder);
}
@Override
protected boolean doEquals(SpanNearQueryBuilder other) {
return Objects.equals(clauses, other.clauses) &&
Objects.equals(slop, other.slop) &&
Objects.equals(inOrder, other.inOrder);
}
@Override
public String getWriteableName() {
return NAME;
}
}