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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.completion;
import org.apache.lucene.search.ScoreDoc;
import org.apache.lucene.search.suggest.Lookup;
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.XContentBuilder;
import org.elasticsearch.search.internal.InternalSearchHit;
import org.elasticsearch.search.internal.InternalSearchHits;
import org.elasticsearch.search.suggest.Suggest;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashSet;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Set;
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 int TYPE = 4;
public CompletionSuggestion() {
}
public CompletionSuggestion(String name, int size) {
super(name, size);
}
/**
* @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;
}
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);
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 (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());
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 getType() {
return TYPE;
}
@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);
}
protected Entry() {
super();
}
@Override
protected Option newOption() {
return new Option();
}
public static class Option extends Suggest.Suggestion.Entry.Option {
private Map> contexts;
private ScoreDoc doc;
private InternalSearchHit hit;
public Option(int docID, Text text, float score, Map> contexts) {
super(text, score);
this.doc = new ScoreDoc(docID, score);
this.contexts = contexts;
}
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 InternalSearchHit getHit() {
return hit;
}
public void setShardIndex(int shardIndex) {
this.doc.shardIndex = shardIndex;
}
public void setHit(InternalSearchHit hit) {
this.hit = hit;
}
@Override
protected XContentBuilder innerToXContent(XContentBuilder builder, Params params) throws IOException {
builder.field("text", getText());
if (hit != null) {
hit.toInnerXContent(builder, params);
} else {
builder.field("score", getScore());
}
if (contexts.size() > 0) {
builder.startObject("contexts");
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;
}
@Override
public void readFrom(StreamInput in) throws IOException {
super.readFrom(in);
this.doc = Lucene.readScoreDoc(in);
if (in.readBoolean()) {
this.hit = InternalSearchHit.readSearchHit(in);
}
int contextSize = in.readInt();
this.contexts = new LinkedHashMap<>(contextSize);
for (int i = 0; i < contextSize; i++) {
String contextName = in.readString();
int nContexts = in.readVInt();
Set contexts = new HashSet<>(nContexts);
for (int j = 0; j < nContexts; j++) {
contexts.add(in.readString());
}
this.contexts.put(contextName, contexts);
}
}
@Override
public void writeTo(StreamOutput out) throws IOException {
super.writeTo(out);
Lucene.writeScoreDoc(out, doc);
if (hit != null) {
out.writeBoolean(true);
hit.writeTo(out);
} else {
out.writeBoolean(false);
}
out.writeInt(contexts.size());
for (Map.Entry> entry : contexts.entrySet()) {
out.writeString(entry.getKey());
out.writeVInt(entry.getValue().size());
for (CharSequence ctx : entry.getValue()) {
out.writeString(ctx.toString());
}
}
}
@Override
public String toString() {
StringBuilder stringBuilder = new StringBuilder();
stringBuilder.append("text:");
stringBuilder.append(getText());
stringBuilder.append(" score:");
stringBuilder.append(getScore());
stringBuilder.append(" context:[");
for (Map.Entry> entry: contexts.entrySet()) {
stringBuilder.append(" ");
stringBuilder.append(entry.getKey());
stringBuilder.append(":");
stringBuilder.append(entry.getValue());
}
stringBuilder.append("]");
return stringBuilder.toString();
}
}
}
}