/*
* 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.fetch;
import org.elasticsearch.common.ParsingException;
import org.elasticsearch.common.Strings;
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.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.index.query.QueryParseContext;
import org.elasticsearch.rest.RestRequest;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;
import java.util.Objects;
/**
* Context used to fetch the {@code stored_fields}.
*/
public class StoredFieldsContext implements Writeable {
public static final String _NONE_ = "_none_";
private final List<String> fieldNames;
private boolean fetchFields;
private StoredFieldsContext(boolean fetchFields) {
this.fetchFields = fetchFields;
this.fieldNames = null;
}
private StoredFieldsContext(List<String> fieldNames) {
Objects.requireNonNull(fieldNames, "fieldNames must not be null");
this.fetchFields = true;
this.fieldNames = new ArrayList<>(fieldNames);
}
public StoredFieldsContext(StoredFieldsContext other) {
this.fetchFields = other.fetchFields();
if (other.fieldNames() != null) {
this.fieldNames = new ArrayList<>(other.fieldNames());
} else {
this.fieldNames = null;
}
}
public StoredFieldsContext(StreamInput in) throws IOException {
this.fetchFields = in.readBoolean();
if (fetchFields) {
this.fieldNames = (List<String>) in.readGenericValue();
} else {
this.fieldNames = null;
}
}
@Override
public void writeTo(StreamOutput out) throws IOException {
out.writeBoolean(fetchFields);
if (fetchFields) {
out.writeGenericValue(fieldNames);
}
}
/**
* Gets the field names to load and return as part of the search request.
*/
public List<String> fieldNames() {
return fieldNames;
}
/**
* Adds the field names {@code fieldNames} to the list of fields to load.
*/
public StoredFieldsContext addFieldNames(List<String> fieldNames) {
if (fetchFields == false || fieldNames.contains(_NONE_)) {
throw new IllegalArgumentException("cannot combine _none_ with other fields");
}
this.fieldNames.addAll(fieldNames);
return this;
}
/**
* Adds a field name {@code field} to the list of fields to load.
*/
public StoredFieldsContext addFieldName(String field) {
if (fetchFields == false || _NONE_.equals(field)) {
throw new IllegalArgumentException("cannot combine _none_ with other fields");
}
this.fieldNames.add(field);
return this;
}
/**
* Returns true if the stored fields should be fetched, false otherwise.
*/
public boolean fetchFields() {
return fetchFields;
}
@Override
public boolean equals(Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
StoredFieldsContext that = (StoredFieldsContext) o;
if (fetchFields != that.fetchFields) return false;
return fieldNames != null ? fieldNames.equals(that.fieldNames) : that.fieldNames == null;
}
@Override
public int hashCode() {
int result = fieldNames != null ? fieldNames.hashCode() : 0;
result = 31 * result + (fetchFields ? 1 : 0);
return result;
}
public void toXContent(String preferredName, XContentBuilder builder) throws IOException {
if (fetchFields == false) {
builder.field(preferredName, _NONE_);
}
if (fieldNames != null) {
if (fieldNames.size() == 1) {
builder.field(preferredName, fieldNames.get(0));
} else {
builder.startArray(preferredName);
for (String fieldName : fieldNames) {
builder.value(fieldName);
}
builder.endArray();
}
}
}
public static StoredFieldsContext fromList(List<String> fieldNames) {
if (fieldNames.size() == 1 && _NONE_.equals(fieldNames.get(0))) {
return new StoredFieldsContext(false);
}
if (fieldNames.contains(_NONE_)) {
throw new IllegalArgumentException("cannot combine _none_ with other fields");
}
return new StoredFieldsContext(fieldNames);
}
public static StoredFieldsContext fromXContent(String fieldName, QueryParseContext context) throws IOException {
XContentParser parser = context.parser();
XContentParser.Token token = parser.currentToken();
if (token == XContentParser.Token.VALUE_STRING) {
return fromList(Collections.singletonList(parser.text()));
} else if (token == XContentParser.Token.START_ARRAY) {
ArrayList<String> list = new ArrayList<>();
while ((token = parser.nextToken()) != XContentParser.Token.END_ARRAY) {
list.add(parser.text());
}
return fromList(list);
} else {
throw new ParsingException(parser.getTokenLocation(),
"Expected [" + XContentParser.Token.VALUE_STRING + "] or ["
+ XContentParser.Token.START_ARRAY + "] in [" + fieldName + "] but found [" + token + "]",
parser.getTokenLocation());
}
}
public static StoredFieldsContext fromRestRequest(String name, RestRequest request) {
String sField = request.param(name);
if (sField != null) {
String[] sFields = Strings.splitStringByCommaToArray(sField);
return fromList(Arrays.asList(sFields));
}
return null;
}
}