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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.suggest.phrase;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.common.xcontent.ObjectParser;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.Suggest.Suggestion;
import java.io.IOException;
/**
* Suggestion entry returned from the {@link PhraseSuggester}.
*/
public class PhraseSuggestion extends Suggest.Suggestion {
public static final String NAME = "phrase";
public static final int TYPE = 3;
public PhraseSuggestion() {
}
public PhraseSuggestion(String name, int size) {
super(name, size);
}
@Override
public int getWriteableType() {
return TYPE;
}
@Override
protected String getType() {
return NAME;
}
@Override
protected Entry newEntry() {
return new Entry();
}
public static PhraseSuggestion fromXContent(XContentParser parser, String name) throws IOException {
PhraseSuggestion suggestion = new PhraseSuggestion(name, -1);
parseEntries(parser, suggestion, PhraseSuggestion.Entry::fromXContent);
return suggestion;
}
public static class Entry extends Suggestion.Entry {
protected double cutoffScore = Double.MIN_VALUE;
public Entry(Text text, int offset, int length, double cutoffScore) {
super(text, offset, length);
this.cutoffScore = cutoffScore;
}
Entry() {
}
/**
* @return cutoff score for suggestions. input term score * confidence for phrase suggest, 0 otherwise
*/
public double getCutoffScore() {
return cutoffScore;
}
@Override
protected void merge(Suggestion.Entry other) {
super.merge(other);
// If the cluster contains both pre 0.90.4 and post 0.90.4 nodes then we'll see Suggestion.Entry
// objects being merged with PhraseSuggestion.Entry objects. We merge Suggestion.Entry objects
// by assuming they had a low cutoff score rather than a high one as that is the more common scenario
// and the simplest one for us to implement.
if (!(other instanceof PhraseSuggestion.Entry)) {
return;
}
PhraseSuggestion.Entry otherSuggestionEntry = (PhraseSuggestion.Entry) other;
this.cutoffScore = Math.max(this.cutoffScore, otherSuggestionEntry.cutoffScore);
}
@Override
public void addOption(Suggestion.Entry.Option option) {
if (option.getScore() > this.cutoffScore) {
this.options.add(option);
}
}
private static ObjectParser PARSER = new ObjectParser<>("PhraseSuggestionEntryParser", true, Entry::new);
static {
declareCommonFields(PARSER);
PARSER.declareObjectArray(Entry::addOptions, (p,c) -> Option.fromXContent(p), new ParseField(OPTIONS));
}
public static Entry fromXContent(XContentParser parser) {
return PARSER.apply(parser, null);
}
@Override
public void readFrom(StreamInput in) throws IOException {
super.readFrom(in);
cutoffScore = in.readDouble();
}
@Override
public void writeTo(StreamOutput out) throws IOException {
super.writeTo(out);
out.writeDouble(cutoffScore);
}
}
}