serialize suggestion responses as named writeables

client/rest-high-level/src/main/java/org/elasticsearch/client/RestHighLevelClient.java

@@ -149,8 +149,11 @@
 import org.elasticsearch.search.aggregations.pipeline.derivative.ParsedDerivative;
 import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
+import org.elasticsearch.search.suggest.completion.CompletionSuggestionBuilder;
 import org.elasticsearch.search.suggest.phrase.PhraseSuggestion;
+import org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder;
 import org.elasticsearch.search.suggest.term.TermSuggestion;
+import org.elasticsearch.search.suggest.term.TermSuggestionBuilder;
 
 import java.io.Closeable;
 import java.io.IOException;
@@ -707,11 +710,11 @@ static List<NamedXContentRegistry.Entry> getDefaultNamedXContents() {
         List<NamedXContentRegistry.Entry> entries = map.entrySet().stream()
                 .map(entry -> new NamedXContentRegistry.Entry(Aggregation.class, new ParseField(entry.getKey()), entry.getValue()))
                 .collect(Collectors.toList());
-        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(TermSuggestion.NAME),
+        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(TermSuggestionBuilder.SUGGESTION_NAME),
                 (parser, context) -> TermSuggestion.fromXContent(parser, (String)context)));
-        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(PhraseSuggestion.NAME),
+        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(PhraseSuggestionBuilder.SUGGESTION_NAME),
                 (parser, context) -> PhraseSuggestion.fromXContent(parser, (String)context)));
-        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(CompletionSuggestion.NAME),
+        entries.add(new NamedXContentRegistry.Entry(Suggest.Suggestion.class, new ParseField(CompletionSuggestionBuilder.SUGGESTION_NAME),
                 (parser, context) -> CompletionSuggestion.fromXContent(parser, (String)context)));
         return entries;
     }

server/src/main/java/org/elasticsearch/plugins/SearchPlugin.java

@@ -50,6 +50,7 @@
 import org.elasticsearch.search.fetch.subphase.highlight.Highlighter;
 import org.elasticsearch.search.rescore.RescorerBuilder;
 import org.elasticsearch.search.rescore.Rescorer;
+import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.Suggester;
 import org.elasticsearch.search.suggest.SuggestionBuilder;
 
@@ -151,31 +152,59 @@ public ScoreFunctionSpec(String name, Writeable.Reader<T> reader, ScoreFunctionP
      * Specification for a {@link Suggester}.
      */
     class SuggesterSpec<T extends SuggestionBuilder<T>> extends SearchExtensionSpec<T, CheckedFunction<XContentParser, T, IOException>> {
+
+        private Map<String, Writeable.Reader<? extends Suggest.Suggestion>> suggestionReaders = new TreeMap<>();
+
         /**
          * Specification of custom {@link Suggester}.
          *
          * @param name holds the names by which this suggester might be parsed. The {@link ParseField#getPreferredName()} is special as it
-         *        is the name by under which the reader is registered. So it is the name that the query should use as its
-         *        {@link NamedWriteable#getWriteableName()} too.
-         * @param reader the reader registered for this suggester's builder. Typically a reference to a constructor that takes a
+         *        is the name by under which the request builder and Suggestion response readers are registered. So it is the name that the
+         *        query and Suggestion response should use as their {@link NamedWriteable#getWriteableName()} return values too.
+         * @param builderReader the reader registered for this suggester's builder. Typically a reference to a constructor that takes a
          *        {@link StreamInput}
-         * @param parser the parser the reads the query suggester from xcontent
+         * @param builderParser a parser that reads the suggester's builder from xcontent
+         * @param suggestionReader the reader registered for this suggester's Suggestion response. Typically a reference to a constructor
+         *        that takes a {@link StreamInput}
          */
-        public SuggesterSpec(ParseField name, Writeable.Reader<T> reader, CheckedFunction<XContentParser, T, IOException> parser) {
-            super(name, reader, parser);
+        public SuggesterSpec(
+                ParseField name,
+                Writeable.Reader<T> builderReader,
+                CheckedFunction<XContentParser, T, IOException> builderParser,
+                Writeable.Reader<? extends Suggest.Suggestion> suggestionReader) {
+
+            super(name, builderReader, builderParser);
+            addSuggestionReader(name.getPreferredName(), suggestionReader);
         }
 
         /**
          * Specification of custom {@link Suggester}.
          *
-         * @param name the name by which this suggester might be parsed or deserialized. Make sure that the query builder returns this name
-         *        for {@link NamedWriteable#getWriteableName()}.
-         * @param reader the reader registered for this suggester's builder. Typically a reference to a constructor that takes a
+         * @param name the name by which this suggester might be parsed or deserialized. Make sure that the query builder and Suggestion
+         *        response reader return this name for {@link NamedWriteable#getWriteableName()}.
+         * @param builderReader the reader registered for this suggester's builder. Typically a reference to a constructor that takes a
          *        {@link StreamInput}
-         * @param parser the parser the reads the suggester builder from xcontent
+         * @param builderParser a parser that reads the suggester's builder from xcontent
+         * @param suggestionReader the reader registered for this suggester's Suggestion response. Typically a reference to a constructor
+         *        that takes a {@link StreamInput}
          */
-        public SuggesterSpec(String name, Writeable.Reader<T> reader, CheckedFunction<XContentParser, T, IOException> parser) {
-            super(name, reader, parser);
+        public SuggesterSpec(
+                String name,
+                Writeable.Reader<T> builderReader,
+                CheckedFunction<XContentParser, T, IOException> builderParser,
+                Writeable.Reader<? extends Suggest.Suggestion> suggestionReader) {
+
+            super(name, builderReader, builderParser);
+            addSuggestionReader(name, suggestionReader);
+        }
+
+        public SuggesterSpec addSuggestionReader(String writeableName, Writeable.Reader<? extends Suggest.Suggestion> reader) {
+            suggestionReaders.put(writeableName, reader);
+            return this;
+        }
+
+        public Map<String, Writeable.Reader<? extends Suggest.Suggestion>> getSuggestionReaders() {
+            return suggestionReaders;
         }
     }
 

server/src/main/java/org/elasticsearch/search/SearchModule.java

@@ -242,13 +242,17 @@
 import org.elasticsearch.search.sort.ScoreSortBuilder;
 import org.elasticsearch.search.sort.ScriptSortBuilder;
 import org.elasticsearch.search.sort.SortBuilder;
+import org.elasticsearch.search.suggest.Suggest;
 import org.elasticsearch.search.suggest.SuggestionBuilder;
+import org.elasticsearch.search.suggest.completion.CompletionSuggestion;
 import org.elasticsearch.search.suggest.completion.CompletionSuggestionBuilder;
 import org.elasticsearch.search.suggest.phrase.Laplace;
 import org.elasticsearch.search.suggest.phrase.LinearInterpolation;
+import org.elasticsearch.search.suggest.phrase.PhraseSuggestion;
 import org.elasticsearch.search.suggest.phrase.PhraseSuggestionBuilder;
 import org.elasticsearch.search.suggest.phrase.SmoothingModel;
 import org.elasticsearch.search.suggest.phrase.StupidBackoff;
+import org.elasticsearch.search.suggest.term.TermSuggestion;
 import org.elasticsearch.search.suggest.term.TermSuggestionBuilder;
 
 import java.util.ArrayList;
@@ -577,9 +581,14 @@ public static void registerSmoothingModels(List<Entry> namedWriteables) {
     private void registerSuggesters(List<SearchPlugin> plugins) {
         registerSmoothingModels(namedWriteables);
 
-        registerSuggester(new SuggesterSpec<>("term", TermSuggestionBuilder::new, TermSuggestionBuilder::fromXContent));
-        registerSuggester(new SuggesterSpec<>("phrase", PhraseSuggestionBuilder::new, PhraseSuggestionBuilder::fromXContent));
-        registerSuggester(new SuggesterSpec<>("completion", CompletionSuggestionBuilder::new, CompletionSuggestionBuilder::fromXContent));
+        registerSuggester(new SuggesterSpec<>(TermSuggestionBuilder.SUGGESTION_NAME,
+            TermSuggestionBuilder::new, TermSuggestionBuilder::fromXContent, TermSuggestion::new));
+
+        registerSuggester(new SuggesterSpec<>(PhraseSuggestionBuilder.SUGGESTION_NAME,
+            PhraseSuggestionBuilder::new, PhraseSuggestionBuilder::fromXContent, PhraseSuggestion::new));
+
+        registerSuggester(new SuggesterSpec<>(CompletionSuggestionBuilder.SUGGESTION_NAME,
+            CompletionSuggestionBuilder::new, CompletionSuggestionBuilder::fromXContent, CompletionSuggestion::new));
 
         registerFromPlugin(plugins, SearchPlugin::getSuggesters, this::registerSuggester);
     }
@@ -589,6 +598,12 @@ private void registerSuggester(SuggesterSpec<?> suggester) {
                 SuggestionBuilder.class, suggester.getName().getPreferredName(), suggester.getReader()));
         namedXContents.add(new NamedXContentRegistry.Entry(SuggestionBuilder.class, suggester.getName(),
                 suggester.getParser()));
+
+        for (Map.Entry<String, Writeable.Reader<? extends Suggest.Suggestion>> entry : suggester.getSuggestionReaders().entrySet()) {
+            String writeableName = entry.getKey();
+            Writeable.Reader<? extends Suggest.Suggestion> reader = entry.getValue();
+            namedWriteables.add(new NamedWriteableRegistry.Entry(Suggest.Suggestion.class, writeableName, reader));
+        }
     }
 
     private Map<String, Highlighter> setupHighlighters(Settings settings, List<SearchPlugin> plugins) {

server/src/main/java/org/elasticsearch/search/internal/InternalSearchResponse.java

@@ -50,7 +50,7 @@ public InternalSearchResponse(StreamInput in) throws IOException {
         super(
                 SearchHits.readSearchHits(in),
                 in.readBoolean() ? InternalAggregations.readAggregations(in) : null,
-                in.readBoolean() ? Suggest.readSuggest(in) : null,
+                in.readBoolean() ? new Suggest(in) : null,
                 in.readBoolean(),
                 in.readOptionalBoolean(),
                 in.readOptionalWriteable(SearchProfileShardResults::new),
@@ -62,7 +62,7 @@ public InternalSearchResponse(StreamInput in) throws IOException {
     public void writeTo(StreamOutput out) throws IOException {
         hits.writeTo(out);
         out.writeOptionalStreamable((InternalAggregations)aggregations);
-        out.writeOptionalStreamable(suggest);
+        out.writeOptionalWriteable(suggest);
         out.writeBoolean(timedOut);
         out.writeOptionalBoolean(terminatedEarly);
         out.writeOptionalWriteable(profileResults);

server/src/main/java/org/elasticsearch/search/query/QuerySearchResult.java

@@ -293,7 +293,7 @@ public void readFromWithId(long id, StreamInput in) throws IOException {
         pipelineAggregators = in.readNamedWriteableList(PipelineAggregator.class).stream().map(a -> (SiblingPipelineAggregator) a)
                 .collect(Collectors.toList());
         if (in.readBoolean()) {
-            suggest = Suggest.readSuggest(in);
+            suggest = new Suggest(in);
         }
         searchTimedOut = in.readBoolean();
         terminatedEarly = in.readOptionalBoolean();