Add dimensions and similarity to ServiceSettings, create ModelSetting…

…s class

server/src/main/java/org/elasticsearch/inference/ModelSettings.java

@@ -0,0 +1,77 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+package org.elasticsearch.inference;
+
+import org.elasticsearch.core.Nullable;
+import org.elasticsearch.xcontent.ConstructingObjectParser;
+import org.elasticsearch.xcontent.ParseField;
+import org.elasticsearch.xcontent.XContentParser;
+
+import java.io.IOException;
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Objects;
+
+public record ModelSettings(TaskType taskType, String inferenceId, @Nullable Integer dimensions, @Nullable SimilarityMeasure similarity) {
+
+    public static final String NAME = "model_settings";
+    private static final ParseField TASK_TYPE_FIELD = new ParseField("task_type");
+    private static final ParseField INFERENCE_ID_FIELD = new ParseField("inference_id");
+    private static final ParseField DIMENSIONS_FIELD = new ParseField("dimensions");
+    private static final ParseField SIMILARITY_FIELD = new ParseField("similarity");
+
+    public ModelSettings(TaskType taskType, String inferenceId, Integer dimensions, SimilarityMeasure similarity) {
+        Objects.requireNonNull(taskType, "task type must not be null");
+        Objects.requireNonNull(inferenceId, "inferenceId must not be null");
+        this.taskType = taskType;
+        this.inferenceId = inferenceId;
+        this.dimensions = dimensions;
+        this.similarity = similarity;
+    }
+
+    public ModelSettings(Model model) {
+        this(
+            model.getTaskType(),
+            model.getInferenceEntityId(),
+            model.getServiceSettings().dimensions(),
+            model.getServiceSettings().similarity()
+        );
+    }
+
+    public static ModelSettings parse(XContentParser parser) throws IOException {
+        return PARSER.apply(parser, null);
+    }
+
+    private static final ConstructingObjectParser<ModelSettings, Void> PARSER = new ConstructingObjectParser<>(NAME, args -> {
+        TaskType taskType = TaskType.fromString((String) args[0]);
+        String inferenceId = (String) args[1];
+        Integer dimensions = (Integer) args[2];
+        SimilarityMeasure similarity = args[3] == null ? null : SimilarityMeasure.fromString((String) args[2]);
+        return new ModelSettings(taskType, inferenceId, dimensions, similarity);
+    });
+    static {
+        PARSER.declareString(ConstructingObjectParser.constructorArg(), TASK_TYPE_FIELD);
+        PARSER.declareString(ConstructingObjectParser.constructorArg(), INFERENCE_ID_FIELD);
+        PARSER.declareInt(ConstructingObjectParser.optionalConstructorArg(), DIMENSIONS_FIELD);
+        PARSER.declareString(ConstructingObjectParser.optionalConstructorArg(), SIMILARITY_FIELD);
+    }
+
+    public Map<String, Object> asMap() {
+        Map<String, Object> attrsMap = new HashMap<>();
+        attrsMap.put(TASK_TYPE_FIELD.getPreferredName(), taskType.toString());
+        attrsMap.put(INFERENCE_ID_FIELD.getPreferredName(), inferenceId);
+        if (dimensions != null) {
+            attrsMap.put(DIMENSIONS_FIELD.getPreferredName(), dimensions);
+        }
+        if (similarity != null) {
+            attrsMap.put(SIMILARITY_FIELD.getPreferredName(), similarity);
+        }
+        return Map.of(NAME, attrsMap);
+    }
+}

server/src/main/java/org/elasticsearch/inference/ServiceSettings.java

@@ -17,4 +17,13 @@ public interface ServiceSettings extends ToXContentObject, VersionedNamedWriteab
      * Returns a {@link ToXContentObject} that only writes the exposed fields. Any hidden fields are not written.
      */
     ToXContentObject getFilteredXContentObject();
+
+    default SimilarityMeasure similarity() {
+        return null;
+    }
+
+    default Integer dimensions() {
+        return null;
+    }
+
 }