serialize suggestion responses as named writeables

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

@@ -163,8 +163,11 @@
 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;
@@ -1119,11 +1122,11 @@ 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;
     }

plugins/examples/custom-suggester/build.gradle

@@ -0,0 +1,33 @@
+/*
+ * 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.
+ */
+
+apply plugin: 'elasticsearch.esplugin'
+
+esplugin {
+    name 'custom-suggester'
+    description 'An example plugin showing how to write and register a custom suggester'
+    classname 'org.elasticsearch.example.customsuggester.CustomSuggesterPlugin'
+}
+
+integTestCluster {
+    numNodes = 2
+}
+
+// this plugin has no unit tests, only rest tests
+tasks.test.enabled = false

plugins/examples/custom-suggester/src/main/java/org/elasticsearch/example/customsuggester/CustomSuggester.java

@@ -0,0 +1,62 @@
+/*
+ * 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.example.customsuggester;
+
+import org.apache.lucene.search.IndexSearcher;
+import org.apache.lucene.util.CharsRefBuilder;
+import org.elasticsearch.common.text.Text;
+import org.elasticsearch.search.suggest.Suggest;
+import org.elasticsearch.search.suggest.Suggester;
+
+import java.util.Locale;
+
+public class CustomSuggester extends Suggester<CustomSuggestionContext> {
+
+    // This is a pretty dumb implementation which returns the original text + fieldName + custom config option + 12 or 123
+    @Override
+    public Suggest.Suggestion<? extends Suggest.Suggestion.Entry<? extends Suggest.Suggestion.Entry.Option>> innerExecute(
+        String name,
+        CustomSuggestionContext suggestion,
+        IndexSearcher searcher,
+        CharsRefBuilder spare) {
+
+        // Get the suggestion context
+        String text = suggestion.getText().utf8ToString();
+
+        // create two suggestions with 12 and 123 appended
+        CustomSuggestion response = new CustomSuggestion(name, suggestion.getSize(), "suggestion-dummy-value");
+
+        CustomSuggestion.Entry entry = new CustomSuggestion.Entry(new Text(text), 0, text.length(), "entry-dummy-value");
+
+        String firstOption =
+            String.format(Locale.ROOT, "%s-%s-%s-%s", text, suggestion.getField(), suggestion.options.get("suffix"), "12");
+        CustomSuggestion.Entry.Option option12 = new CustomSuggestion.Entry.Option(new Text(firstOption), 0.9f, "option-dummy-value-1");
+        entry.addOption(option12);
+
+        String secondOption =
+            String.format(Locale.ROOT, "%s-%s-%s-%s", text, suggestion.getField(), suggestion.options.get("suffix"), "123");
+        CustomSuggestion.Entry.Option option123 = new CustomSuggestion.Entry.Option(new Text(secondOption), 0.8f, "option-dummy-value-2");
+        entry.addOption(option123);
+
+        response.addTerm(entry);
+
+        return response;
+    }
+}

plugins/examples/custom-suggester/src/main/java/org/elasticsearch/example/customsuggester/CustomSuggesterPlugin.java

@@ -0,0 +1,40 @@
+/*
+ * 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.example.customsuggester;
+
+import org.elasticsearch.plugins.Plugin;
+import org.elasticsearch.plugins.SearchPlugin;
+
+import java.util.Collections;
+import java.util.List;
+
+public class CustomSuggesterPlugin extends Plugin implements SearchPlugin {
+    @Override
+    public List<SearchPlugin.SuggesterSpec<?>> getSuggesters() {
+        return Collections.singletonList(
+            new SearchPlugin.SuggesterSpec<>(
+                CustomSuggestionBuilder.SUGGESTION_NAME,
+                CustomSuggestionBuilder::new,
+                CustomSuggestionBuilder::fromXContent,
+                CustomSuggestion::new
+            )
+        );
+    }
+}

plugins/examples/custom-suggester/src/main/java/org/elasticsearch/example/customsuggester/CustomSuggestion.java

@@ -0,0 +1,227 @@
+/*
+ * 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.example.customsuggester;
+
+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.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.ObjectParser;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.search.suggest.Suggest;
+
+import java.io.IOException;
+
+import static org.elasticsearch.common.xcontent.ConstructingObjectParser.constructorArg;
+
+public class CustomSuggestion extends Suggest.Suggestion<CustomSuggestion.Entry> {
+
+    public static final int TYPE = 999;
+
+    public static final ParseField DUMMY = new ParseField("dummy");
+
+    private String dummy;
+
+    public CustomSuggestion(String name, int size, String dummy) {
+        super(name, size);
+        this.dummy = dummy;
+    }
+
+    public CustomSuggestion(StreamInput in) throws IOException {
+        super(in);
+        dummy = in.readString();
+    }
+
+    @Override
+    public void writeTo(StreamOutput out) throws IOException {
+        super.writeTo(out);
+        out.writeString(dummy);
+    }
+
+    @Override
+    public String getWriteableName() {
+        return CustomSuggestionBuilder.SUGGESTION_NAME;
+    }
+
+    @Override
+    public int getWriteableType() {
+        return TYPE;
+    }
+
+    /**
+     * A meaningless value used to test that plugin suggesters can add fields to their Suggestion types
+     *
+     * This can't be serialized to xcontent because Suggestions appear in xcontent as an array of entries, so there is no place
+     * to add a custom field. But we can still use a custom field internally and use it to define a Suggestion's behavior
+     */
+    public String getDummy() {
+        return dummy;
+    }
+
+    @Override
+    protected Entry newEntry() {
+        return new Entry();
+    }
+
+    @Override
+    protected Entry newEntry(StreamInput in) throws IOException {
+        return new Entry(in);
+    }
+
+    public static CustomSuggestion fromXContent(XContentParser parser, String name) throws IOException {
+        CustomSuggestion suggestion = new CustomSuggestion(name, -1, null);
+        parseEntries(parser, suggestion, Entry::fromXContent);
+        return suggestion;
+    }
+
+    public static class Entry extends Suggest.Suggestion.Entry<CustomSuggestion.Entry.Option> {
+
+        private static final ObjectParser<Entry, Void> PARSER = new ObjectParser<>("CustomSuggestionEntryParser", true, Entry::new);
+
+        static {
+            declareCommonFields(PARSER);
+            PARSER.declareString((entry, dummy) -> entry.dummy = dummy, DUMMY);
+            PARSER.declareObjectArray(Entry::addOptions, (p, c) -> Option.fromXContent(p), new ParseField(OPTIONS));
+        }
+
+        private String dummy;
+
+        public Entry() {}
+
+        public Entry(Text text, int offset, int length, String dummy) {
+            super(text, offset, length);
+            this.dummy = dummy;
+        }
+
+        public Entry(StreamInput in) throws IOException {
+            super(in);
+            dummy = in.readString();
+        }
+
+        @Override
+        public void writeTo(StreamOutput out) throws IOException {
+            super.writeTo(out);
+            out.writeString(dummy);
+        }
+
+        @Override
+        protected Option newOption() {
+            return new Option();
+        }
+
+        @Override
+        protected Option newOption(StreamInput in) throws IOException {
+            return new Option(in);
+        }
+
+        /*
+         * the value of dummy will always be the same, so this just tests that we can merge entries with custom fields
+         */
+        @Override
+        protected void merge(Suggest.Suggestion.Entry<Option> otherEntry) {
+            dummy = ((Entry) otherEntry).getDummy();
+        }
+
+        /**
+         * Meaningless field used to test that plugin suggesters can add fields to their entries
+         */
+        public String getDummy() {
+            return dummy;
+        }
+
+        @Override
+        public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+            builder = super.toXContent(builder, params);
+            builder.field(DUMMY.getPreferredName(), getDummy());
+            return builder;
+        }
+
+        public static Entry fromXContent(XContentParser parser) {
+            return PARSER.apply(parser, null);
+        }
+
+        public static class Option extends Suggest.Suggestion.Entry.Option {
+
+            private static final ConstructingObjectParser<Option, Void> PARSER = new ConstructingObjectParser<>(
+                "CustomSuggestionObjectParser", true,
+                args -> {
+                    Text text = new Text((String) args[0]);
+                    float score = (float) args[1];
+                    String dummy = (String) args[2];
+                    return new Option(text, score, dummy);
+                });
+
+            static {
+                PARSER.declareString(constructorArg(), TEXT);
+                PARSER.declareFloat(constructorArg(), SCORE);
+                PARSER.declareString(constructorArg(), DUMMY);
+            }
+
+            private String dummy;
+
+            public Option() {}
+
+            public Option(Text text, float score, String dummy) {
+                super(text, score);
+                this.dummy = dummy;
+            }
+
+            public Option(StreamInput in) throws IOException {
+                super(in);
+                dummy = in.readString();
+            }
+
+            @Override
+            public void writeTo(StreamOutput out) throws IOException {
+                super.writeTo(out);
+                out.writeString(dummy);
+            }
+
+            /**
+             * A meaningless value used to test that plugin suggesters can add fields to their options
+             */
+            public String getDummy() {
+                return dummy;
+            }
+
+            /*
+             * the value of dummy will always be the same, so this just tests that we can merge options with custom fields
+             */
+            @Override
+            protected void mergeInto(Suggest.Suggestion.Entry.Option otherOption) {
+                super.mergeInto(otherOption);
+                dummy = ((Option) otherOption).getDummy();
+            }
+
+            @Override
+            public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+                builder = super.toXContent(builder, params);
+                builder.field(DUMMY.getPreferredName(), dummy);
+                return builder;
+            }
+
+            public static Option fromXContent(XContentParser parser) {
+                return PARSER.apply(parser, null);
+            }
+        }
+    }
+}