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* 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.search;
import org.apache.lucene.search.SortField;
import org.apache.lucene.search.TotalHits;
import org.apache.lucene.search.TotalHits.Relation;
import org.elasticsearch.Version;
import org.elasticsearch.common.Nullable;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.io.stream.Writeable;
import org.elasticsearch.common.lucene.Lucene;
import org.elasticsearch.common.xcontent.ToXContentFragment;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.rest.action.search.RestSearchAction;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import java.util.Objects;
import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
public final class SearchHits implements Writeable, ToXContentFragment, Iterable {
public static SearchHits empty() {
return empty(true);
}
public static SearchHits empty(boolean withTotalHits) {
// We shouldn't use static final instance, since that could directly be returned by native transport clients
return new SearchHits(EMPTY, withTotalHits ? new TotalHits(0, Relation.EQUAL_TO) : null, 0);
}
public static final SearchHit[] EMPTY = new SearchHit[0];
private final SearchHit[] hits;
private final TotalHits totalHits;
private final float maxScore;
@Nullable
private final SortField[] sortFields;
@Nullable
private final String collapseField;
@Nullable
private final Object[] collapseValues;
public SearchHits(SearchHit[] hits, @Nullable TotalHits totalHits, float maxScore) {
this(hits, totalHits, maxScore, null, null, null);
}
public SearchHits(SearchHit[] hits, @Nullable TotalHits totalHits, float maxScore, @Nullable SortField[] sortFields,
@Nullable String collapseField, @Nullable Object[] collapseValues) {
this.hits = hits;
this.totalHits = totalHits;
this.maxScore = maxScore;
this.sortFields = sortFields;
this.collapseField = collapseField;
this.collapseValues = collapseValues;
}
public SearchHits(StreamInput in) throws IOException {
if (in.readBoolean()) {
totalHits = Lucene.readTotalHits(in);
} else {
// track_total_hits is false
totalHits = null;
}
maxScore = in.readFloat();
int size = in.readVInt();
if (size == 0) {
hits = EMPTY;
} else {
hits = new SearchHit[size];
for (int i = 0; i < hits.length; i++) {
hits[i] = new SearchHit(in);
}
}
if (in.getVersion().onOrAfter(Version.V_6_6_0)) {
sortFields = in.readOptionalArray(Lucene::readSortField, SortField[]::new);
collapseField = in.readOptionalString();
collapseValues = in.readOptionalArray(Lucene::readSortValue, Object[]::new);
} else {
sortFields = null;
collapseField = null;
collapseValues = null;
}
}
@Override
public void writeTo(StreamOutput out) throws IOException {
final boolean hasTotalHits = totalHits != null;
out.writeBoolean(hasTotalHits);
if (hasTotalHits) {
Lucene.writeTotalHits(out, totalHits);
}
out.writeFloat(maxScore);
out.writeVInt(hits.length);
if (hits.length > 0) {
for (SearchHit hit : hits) {
hit.writeTo(out);
}
}
if (out.getVersion().onOrAfter(Version.V_6_6_0)) {
out.writeOptionalArray(Lucene::writeSortField, sortFields);
out.writeOptionalString(collapseField);
out.writeOptionalArray(Lucene::writeSortValue, collapseValues);
}
}
/**
* The total number of hits for the query or null if the tracking of total hits
* is disabled in the request.
*/
@Nullable
public TotalHits getTotalHits() {
return totalHits;
}
/**
* The maximum score of this query.
*/
public float getMaxScore() {
return maxScore;
}
/**
* The hits of the search request (based on the search type, and from / size provided).
*/
public SearchHit[] getHits() {
return this.hits;
}
/**
* Return the hit as the provided position.
*/
public SearchHit getAt(int position) {
return hits[position];
}
/**
* In case documents were sorted by field(s), returns information about such field(s), null otherwise
* @see SortField
*/
@Nullable
public SortField[] getSortFields() {
return sortFields;
}
/**
* In case field collapsing was performed, returns the field used for field collapsing, null otherwise
*/
@Nullable
public String getCollapseField() {
return collapseField;
}
/**
* In case field collapsing was performed, returns the values of the field that field collapsing was performed on, null otherwise
*/
@Nullable
public Object[] getCollapseValues() {
return collapseValues;
}
@Override
public Iterator iterator() {
return Arrays.stream(getHits()).iterator();
}
public static final class Fields {
public static final String HITS = "hits";
public static final String TOTAL = "total";
public static final String MAX_SCORE = "max_score";
}
@Override
public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
builder.startObject(Fields.HITS);
boolean totalHitAsInt = params.paramAsBoolean(RestSearchAction.TOTAL_HITS_AS_INT_PARAM, false);
if (totalHitAsInt) {
long total = totalHits == null ? -1 : totalHits.value;
builder.field(Fields.TOTAL, total);
} else if (totalHits != null) {
builder.startObject(Fields.TOTAL);
builder.field("value", totalHits.value);
builder.field("relation", totalHits.relation == Relation.EQUAL_TO ? "eq" : "gte");
builder.endObject();
}
if (Float.isNaN(maxScore)) {
builder.nullField(Fields.MAX_SCORE);
} else {
builder.field(Fields.MAX_SCORE, maxScore);
}
builder.field(Fields.HITS);
builder.startArray();
for (SearchHit hit : hits) {
hit.toXContent(builder, params);
}
builder.endArray();
builder.endObject();
return builder;
}
public static SearchHits fromXContent(XContentParser parser) throws IOException {
if (parser.currentToken() != XContentParser.Token.START_OBJECT) {
parser.nextToken();
ensureExpectedToken(XContentParser.Token.START_OBJECT, parser.currentToken(), parser::getTokenLocation);
}
XContentParser.Token token = parser.currentToken();
String currentFieldName = null;
List hits = new ArrayList<>();
TotalHits totalHits = null;
float maxScore = 0f;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (token.isValue()) {
if (Fields.TOTAL.equals(currentFieldName)) {
// For BWC with nodes pre 7.0
long value = parser.longValue();
totalHits = value == -1 ? null : new TotalHits(value, Relation.EQUAL_TO);
} else if (Fields.MAX_SCORE.equals(currentFieldName)) {
maxScore = parser.floatValue();
}
} else if (token == XContentParser.Token.VALUE_NULL) {
if (Fields.MAX_SCORE.equals(currentFieldName)) {
maxScore = Float.NaN; // NaN gets rendered as null-field
}
} else if (token == XContentParser.Token.START_ARRAY) {
if (Fields.HITS.equals(currentFieldName)) {
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
hits.add(SearchHit.fromXContent(parser));
}
} else {
parser.skipChildren();
}
} else if (token == XContentParser.Token.START_OBJECT) {
if (Fields.TOTAL.equals(currentFieldName)) {
totalHits = parseTotalHitsFragment(parser);
} else {
parser.skipChildren();
}
}
}
return new SearchHits(hits.toArray(new SearchHit[0]), totalHits, maxScore);
}
@Override
public boolean equals(Object obj) {
if (obj == null || getClass() != obj.getClass()) {
return false;
}
SearchHits other = (SearchHits) obj;
return Objects.equals(totalHits, other.totalHits)
&& Objects.equals(maxScore, other.maxScore)
&& Arrays.equals(hits, other.hits)
&& Arrays.equals(sortFields, other.sortFields)
&& Objects.equals(collapseField, other.collapseField)
&& Arrays.equals(collapseValues, other.collapseValues);
}
@Override
public int hashCode() {
return Objects.hash(totalHits, maxScore, Arrays.hashCode(hits),
Arrays.hashCode(sortFields), collapseField, Arrays.hashCode(collapseValues));
}
public static TotalHits parseTotalHitsFragment(XContentParser parser) throws IOException {
long value = -1;
Relation relation = null;
XContentParser.Token token;
String currentFieldName = null;
while ((token = parser.nextToken()) != XContentParser.Token.END_OBJECT) {
if (token == XContentParser.Token.FIELD_NAME) {
currentFieldName = parser.currentName();
} else if (token.isValue()) {
if ("value".equals(currentFieldName)) {
value = parser.longValue();
} else if ("relation".equals(currentFieldName)) {
relation = parseRelation(parser.text());
}
} else {
parser.skipChildren();
}
}
return new TotalHits(value, relation);
}
private static Relation parseRelation(String relation) {
if ("gte".equals(relation)) {
return Relation.GREATER_THAN_OR_EQUAL_TO;
} else if ("eq".equals(relation)) {
return Relation.EQUAL_TO;
} else {
throw new IllegalArgumentException("invalid total hits relation: " + relation);
}
}
}