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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.sort;
import org.apache.lucene.search.SortField;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.xcontent.ObjectParser;
import org.elasticsearch.common.xcontent.ObjectParser.ValueType;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.index.fielddata.IndexFieldData;
import org.elasticsearch.index.fielddata.IndexFieldData.XFieldComparatorSource.Nested;
import org.elasticsearch.index.fielddata.IndexNumericFieldData;
import org.elasticsearch.index.mapper.MappedFieldType;
import org.elasticsearch.index.query.QueryBuilder;
import org.elasticsearch.index.query.QueryParseContext;
import org.elasticsearch.index.query.QueryShardContext;
import org.elasticsearch.index.query.QueryShardException;
import org.elasticsearch.search.DocValueFormat;
import org.elasticsearch.search.MultiValueMode;
import java.io.IOException;
import java.util.Objects;
/**
* A sort builder to sort based on a document field.
*/
public class FieldSortBuilder extends SortBuilder<FieldSortBuilder> {
public static final String NAME = "field_sort";
public static final ParseField MISSING = new ParseField("missing");
public static final ParseField SORT_MODE = new ParseField("mode");
public static final ParseField UNMAPPED_TYPE = new ParseField("unmapped_type");
/**
* special field name to sort by index order
*/
public static final String DOC_FIELD_NAME = "_doc";
private static final SortFieldAndFormat SORT_DOC = new SortFieldAndFormat(
new SortField(null, SortField.Type.DOC), DocValueFormat.RAW);
private static final SortFieldAndFormat SORT_DOC_REVERSE = new SortFieldAndFormat(
new SortField(null, SortField.Type.DOC, true), DocValueFormat.RAW);
private final String fieldName;
private Object missing;
private String unmappedType;
private SortMode sortMode;
private QueryBuilder nestedFilter;
private String nestedPath;
/** Copy constructor. */
public FieldSortBuilder(FieldSortBuilder template) {
this(template.fieldName);
this.order(template.order());
this.missing(template.missing());
this.unmappedType(template.unmappedType());
if (template.sortMode != null) {
this.sortMode(template.sortMode());
}
this.setNestedFilter(template.getNestedFilter());
this.setNestedPath(template.getNestedPath());
}
/**
* Constructs a new sort based on a document field.
*
* @param fieldName
* The field name.
*/
public FieldSortBuilder(String fieldName) {
if (fieldName == null) {
throw new IllegalArgumentException("fieldName must not be null");
}
this.fieldName = fieldName;
}
/**
* Read from a stream.
*/
public FieldSortBuilder(StreamInput in) throws IOException {
fieldName = in.readString();
nestedFilter = in.readOptionalNamedWriteable(QueryBuilder.class);
nestedPath = in.readOptionalString();
missing = in.readGenericValue();
order = in.readOptionalWriteable(SortOrder::readFromStream);
sortMode = in.readOptionalWriteable(SortMode::readFromStream);
unmappedType = in.readOptionalString();
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeString(fieldName);
out.writeOptionalNamedWriteable(nestedFilter);
out.writeOptionalString(nestedPath);
out.writeGenericValue(missing);
out.writeOptionalWriteable(order);
out.writeOptionalWriteable(sortMode);
out.writeOptionalString(unmappedType);
}
/** Returns the document field this sort should be based on. */
public String getFieldName() {
return this.fieldName;
}
/**
* Sets the value when a field is missing in a doc. Can also be set to <tt>_last</tt> or
* <tt>_first</tt> to sort missing last or first respectively.
*/
public FieldSortBuilder missing(Object missing) {
this.missing = missing;
return this;
}
/** Returns the value used when a field is missing in a doc. */
public Object missing() {
return missing;
}
/**
* Set the type to use in case the current field is not mapped in an index.
* Specifying a type tells Elasticsearch what type the sort values should
* have, which is important for cross-index search, if there are sort fields
* that exist on some indices only. If the unmapped type is <tt>null</tt>
* then query execution will fail if one or more indices don't have a
* mapping for the current field.
*/
public FieldSortBuilder unmappedType(String type) {
this.unmappedType = type;
return this;
}
/**
* Returns the type to use in case the current field is not mapped in an
* index.
*/
public String unmappedType() {
return this.unmappedType;
}
/**
* Defines what values to pick in the case a document contains multiple
* values for the targeted sort field. Possible values: min, max, sum and
* avg
*
* <p>
* The last two values are only applicable for number based fields.
*/
public FieldSortBuilder sortMode(SortMode sortMode) {
Objects.requireNonNull(sortMode, "sort mode cannot be null");
this.sortMode = sortMode;
return this;
}
/**
* Returns what values to pick in the case a document contains multiple
* values for the targeted sort field.
*/
public SortMode sortMode() {
return this.sortMode;
}
/**
* Sets the nested filter that the nested objects should match with in order
* to be taken into account for sorting.
*
* TODO should the above getters and setters be deprecated/ changed in
* favour of real getters and setters?
*/
public FieldSortBuilder setNestedFilter(QueryBuilder nestedFilter) {
this.nestedFilter = nestedFilter;
return this;
}
/**
* Returns the nested filter that the nested objects should match with in
* order to be taken into account for sorting.
*/
public QueryBuilder getNestedFilter() {
return this.nestedFilter;
}
/**
* Sets the nested path if sorting occurs on a field that is inside a nested
* object. By default when sorting on a field inside a nested object, the
* nearest upper nested object is selected as nested path.
*/
public FieldSortBuilder setNestedPath(String nestedPath) {
this.nestedPath = nestedPath;
return this;
}
/**
* Returns the nested path if sorting occurs in a field that is inside a
* nested object.
*/
public String getNestedPath() {
return this.nestedPath;
}
@Override
public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
builder.startObject();
builder.startObject(fieldName);
builder.field(ORDER_FIELD.getPreferredName(), order);
if (missing != null) {
builder.field(MISSING.getPreferredName(), missing);
}
if (unmappedType != null) {
builder.field(UNMAPPED_TYPE.getPreferredName(), unmappedType);
}
if (sortMode != null) {
builder.field(SORT_MODE.getPreferredName(), sortMode);
}
if (nestedFilter != null) {
builder.field(NESTED_FILTER_FIELD.getPreferredName(), nestedFilter, params);
}
if (nestedPath != null) {
builder.field(NESTED_PATH_FIELD.getPreferredName(), nestedPath);
}
builder.endObject();
builder.endObject();
return builder;
}
@Override
public SortFieldAndFormat build(QueryShardContext context) throws IOException {
if (DOC_FIELD_NAME.equals(fieldName)) {
if (order == SortOrder.DESC) {
return SORT_DOC_REVERSE;
} else {
return SORT_DOC;
}
} else {
MappedFieldType fieldType = context.fieldMapper(fieldName);
if (fieldType == null) {
if (unmappedType != null) {
fieldType = context.getMapperService().unmappedFieldType(unmappedType);
} else {
throw new QueryShardException(context, "No mapping found for [" + fieldName + "] in order to sort on");
}
}
MultiValueMode localSortMode = null;
if (sortMode != null) {
localSortMode = MultiValueMode.fromString(sortMode.toString());
}
boolean reverse = (order == SortOrder.DESC);
if (localSortMode == null) {
localSortMode = reverse ? MultiValueMode.MAX : MultiValueMode.MIN;
}
final Nested nested = resolveNested(context, nestedPath, nestedFilter);
IndexFieldData<?> fieldData = context.getForField(fieldType);
if (fieldData instanceof IndexNumericFieldData == false
&& (sortMode == SortMode.SUM || sortMode == SortMode.AVG || sortMode == SortMode.MEDIAN)) {
throw new QueryShardException(context, "we only support AVG, MEDIAN and SUM on number based fields");
}
SortField field = fieldData.sortField(missing, localSortMode, nested, reverse);
return new SortFieldAndFormat(field, fieldType.docValueFormat(null, null));
}
}
@Override
public boolean equals(Object other) {
if (this == other) {
return true;
}
if (other == null || getClass() != other.getClass()) {
return false;
}
FieldSortBuilder builder = (FieldSortBuilder) other;
return (Objects.equals(this.fieldName, builder.fieldName) && Objects.equals(this.nestedFilter, builder.nestedFilter)
&& Objects.equals(this.nestedPath, builder.nestedPath) && Objects.equals(this.missing, builder.missing)
&& Objects.equals(this.order, builder.order) && Objects.equals(this.sortMode, builder.sortMode)
&& Objects.equals(this.unmappedType, builder.unmappedType));
}
@Override
public int hashCode() {
return Objects.hash(this.fieldName, this.nestedFilter, this.nestedPath, this.missing, this.order, this.sortMode, this.unmappedType);
}
@Override
public String getWriteableName() {
return NAME;
}
/**
* Creates a new {@link FieldSortBuilder} from the query held by the {@link QueryParseContext} in
* {@link org.elasticsearch.common.xcontent.XContent} format.
*
* @param context the input parse context. The state on the parser contained in this context will be changed as a side effect of this
* method call
* @param fieldName in some sort syntax variations the field name precedes the xContent object that specifies further parameters, e.g.
* in '{ "foo": { "order" : "asc"} }'. When parsing the inner object, the field name can be passed in via this argument
*/
public static FieldSortBuilder fromXContent(QueryParseContext context, String fieldName) throws IOException {
return PARSER.parse(context.parser(), new FieldSortBuilder(fieldName), context);
}
private static ObjectParser<FieldSortBuilder, QueryParseContext> PARSER = new ObjectParser<>(NAME);
static {
PARSER.declareField(FieldSortBuilder::missing, p -> p.objectText(), MISSING, ValueType.VALUE);
PARSER.declareString(FieldSortBuilder::setNestedPath , NESTED_PATH_FIELD);
PARSER.declareString(FieldSortBuilder::unmappedType , UNMAPPED_TYPE);
PARSER.declareString((b, v) -> b.order(SortOrder.fromString(v)) , ORDER_FIELD);
PARSER.declareString((b, v) -> b.sortMode(SortMode.fromString(v)), SORT_MODE);
PARSER.declareObject(FieldSortBuilder::setNestedFilter, SortBuilder::parseNestedFilter, NESTED_FILTER_FIELD);
}
}