org.elasticsearch.search.suggest.completion.CompletionSuggestion Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of elasticsearch Show documentation
Show all versions of elasticsearch Show documentation
Elasticsearch subproject :server
/*
* 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.completion;
import org.apache.lucene.analysis.CharArraySet;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.suggest.Lookup;
import org.elasticsearch.Version;
import org.elasticsearch.common.ParseField;
import org.elasticsearch.common.io.stream.StreamInput;
import org.elasticsearch.common.io.stream.StreamOutput;
import org.elasticsearch.common.lucene.Lucene;
import org.elasticsearch.common.text.Text;
import org.elasticsearch.common.xcontent.ObjectParser;
import org.elasticsearch.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentParser;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.suggest.Suggest;
import org.elasticsearch.search.suggest.Suggest.Suggestion;
import java.io.IOException;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import static org.elasticsearch.common.xcontent.XContentParserUtils.ensureExpectedToken;
import static org.elasticsearch.search.suggest.Suggest.COMPARATOR;
/**
* Suggestion response for {@link CompletionSuggester} results
*
* Response format for each entry:
* {
* "text" : STRING
* "score" : FLOAT
* "contexts" : CONTEXTS
* }
*
* CONTEXTS : {
* "CONTEXT_NAME" : ARRAY,
* ..
* }
*
*/
public final class CompletionSuggestion extends Suggest.Suggestion {
public static final String NAME = "completion";
public static final int TYPE = 4;
private boolean skipDuplicates;
public CompletionSuggestion() {
}
/**
* Ctr
* @param name The name for the suggestions
* @param size The number of suggestions to return
* @param skipDuplicates Whether duplicate suggestions should be filtered out
*/
public CompletionSuggestion(String name, int size, boolean skipDuplicates) {
super(name, size);
this.skipDuplicates = skipDuplicates;
}
@Override
public void readFrom(StreamInput in) throws IOException {
super.readFrom(in);
if (in.getVersion().onOrAfter(Version.V_6_1_0)) {
skipDuplicates = in.readBoolean();
}
}
@Override
public void writeTo(StreamOutput out) throws IOException {
super.writeTo(out);
if (out.getVersion().onOrAfter(Version.V_6_1_0)) {
out.writeBoolean(skipDuplicates);
}
}
/**
* @return the result options for the suggestion
*/
public List getOptions() {
if (entries.isEmpty() == false) {
assert entries.size() == 1 : "CompletionSuggestion must have only one entry";
return entries.get(0).getOptions();
} else {
return Collections.emptyList();
}
}
/**
* @return whether there is any hits for the suggestion
*/
public boolean hasScoreDocs() {
return getOptions().size() > 0;
}
public static CompletionSuggestion fromXContent(XContentParser parser, String name) throws IOException {
CompletionSuggestion suggestion = new CompletionSuggestion(name, -1, false);
parseEntries(parser, suggestion, CompletionSuggestion.Entry::fromXContent);
return suggestion;
}
private static final class OptionPriorityQueue extends org.apache.lucene.util.PriorityQueue {
private final Comparator comparator;
OptionPriorityQueue(int maxSize, Comparator comparator) {
super(maxSize);
this.comparator = comparator;
}
@Override
protected boolean lessThan(Entry.Option a, Entry.Option b) {
int cmp = comparator.compare(a, b);
if (cmp != 0) {
return cmp > 0;
}
return Lookup.CHARSEQUENCE_COMPARATOR.compare(a.getText().string(), b.getText().string()) > 0;
}
Entry.Option[] get() {
int size = size();
Entry.Option[] results = new Entry.Option[size];
for (int i = size - 1; i >= 0; i--) {
results[i] = pop();
}
return results;
}
}
/**
* Reduces suggestions to a single suggestion containing at most
* top {@link CompletionSuggestion#getSize()} options across toReduce
*/
public static CompletionSuggestion reduceTo(List> toReduce) {
if (toReduce.isEmpty()) {
return null;
} else {
final CompletionSuggestion leader = (CompletionSuggestion) toReduce.get(0);
final Entry leaderEntry = leader.getEntries().get(0);
final String name = leader.getName();
if (toReduce.size() == 1) {
return leader;
} else {
// combine suggestion entries from participating shards on the coordinating node
// the global top size
entries are collected from the shard results
// using a priority queue
OptionPriorityQueue priorityQueue = new OptionPriorityQueue(leader.getSize(), COMPARATOR);
// Dedup duplicate suggestions (based on the surface form) if skip duplicates is activated
final CharArraySet seenSurfaceForms = leader.skipDuplicates ? new CharArraySet(leader.getSize(), false) : null;
for (Suggest.Suggestion suggestion : toReduce) {
assert suggestion.getName().equals(name) : "name should be identical across all suggestions";
for (Entry.Option option : ((CompletionSuggestion) suggestion).getOptions()) {
if (leader.skipDuplicates) {
assert ((CompletionSuggestion) suggestion).skipDuplicates;
String text = option.getText().string();
if (seenSurfaceForms.contains(text)) {
continue;
}
seenSurfaceForms.add(text);
}
if (option == priorityQueue.insertWithOverflow(option)) {
// if the current option has overflown from pq,
// we can assume all of the successive options
// from this shard result will be overflown as well
break;
}
}
}
final CompletionSuggestion suggestion = new CompletionSuggestion(leader.getName(), leader.getSize(), leader.skipDuplicates);
final Entry entry = new Entry(leaderEntry.getText(), leaderEntry.getOffset(), leaderEntry.getLength());
Collections.addAll(entry.getOptions(), priorityQueue.get());
suggestion.addTerm(entry);
return suggestion;
}
}
}
@Override
public Suggest.Suggestion reduce(List> toReduce) {
return reduceTo(toReduce);
}
public void setShardIndex(int shardIndex) {
if (entries.isEmpty() == false) {
for (Entry.Option option : getOptions()) {
option.setShardIndex(shardIndex);
}
}
}
@Override
public int getWriteableType() {
return TYPE;
}
@Override
protected String getType() {
return NAME;
}
@Override
protected Entry newEntry() {
return new Entry();
}
public static final class Entry extends Suggest.Suggestion.Entry {
public Entry(Text text, int offset, int length) {
super(text, offset, length);
}
Entry() {
}
@Override
protected Option newOption() {
return new Option();
}
private static ObjectParser PARSER = new ObjectParser<>("CompletionSuggestionEntryParser", 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);
}
public static class Option extends Suggest.Suggestion.Entry.Option {
private Map> contexts = Collections.emptyMap();
private ScoreDoc doc;
private SearchHit hit;
public static final ParseField CONTEXTS = new ParseField("contexts");
public Option(int docID, Text text, float score, Map> contexts) {
super(text, score);
this.doc = new ScoreDoc(docID, score);
this.contexts = Objects.requireNonNull(contexts, "context map cannot be null");
}
protected Option() {
super();
}
@Override
protected void mergeInto(Suggest.Suggestion.Entry.Option otherOption) {
// Completion suggestions are reduced by
// org.elasticsearch.search.suggest.completion.CompletionSuggestion.reduce()
throw new UnsupportedOperationException();
}
public Map> getContexts() {
return contexts;
}
public ScoreDoc getDoc() {
return doc;
}
public SearchHit getHit() {
return hit;
}
public void setShardIndex(int shardIndex) {
this.doc.shardIndex = shardIndex;
}
public void setHit(SearchHit hit) {
this.hit = hit;
}
@Override
protected XContentBuilder innerToXContent(XContentBuilder builder, Params params) throws IOException {
builder.field(TEXT.getPreferredName(), getText());
if (hit != null) {
hit.toInnerXContent(builder, params);
} else {
builder.field(SCORE.getPreferredName(), getScore());
}
if (contexts.size() > 0) {
builder.startObject(CONTEXTS.getPreferredName());
for (Map.Entry> entry : contexts.entrySet()) {
builder.startArray(entry.getKey());
for (CharSequence context : entry.getValue()) {
builder.value(context.toString());
}
builder.endArray();
}
builder.endObject();
}
return builder;
}
private static ObjectParser