[ML-DataFrame] add field reason to DataFrameTransformState and add hlrc protocol tests

client/rest-high-level/src/main/java/org/elasticsearch/client/dataframe/transforms/DataFrameTransformState.java

@@ -43,14 +43,16 @@ public class DataFrameTransformState {
     private static final ParseField TASK_STATE = new ParseField("task_state");
     private static final ParseField CURRENT_POSITION = new ParseField("current_position");
     private static final ParseField GENERATION = new ParseField("generation");
+    private static final ParseField REASON = new ParseField("reason");
 
     @SuppressWarnings("unchecked")
     public static final ConstructingObjectParser<DataFrameTransformState, Void> PARSER =
-            new ConstructingObjectParser<>("data_frame_transform_state",
+            new ConstructingObjectParser<>("data_frame_transform_state", true,
                     args -> new DataFrameTransformState((DataFrameTransformTaskState) args[0],
                         (IndexerState) args[1],
                         (HashMap<String, Object>) args[2],
-                        (long) args[3]));
+                        (long) args[3],
+                        (String) args[4]));
 
     static {
         PARSER.declareField(constructorArg(),
@@ -68,6 +70,7 @@ public class DataFrameTransformState {
             throw new IllegalArgumentException("Unsupported token [" + p.currentToken() + "]");
         }, CURRENT_POSITION, ObjectParser.ValueType.VALUE_OBJECT_ARRAY);
         PARSER.declareLong(ConstructingObjectParser.optionalConstructorArg(), GENERATION);
+        PARSER.declareString(ConstructingObjectParser.optionalConstructorArg(), REASON);
     }
 
     public static DataFrameTransformState fromXContent(XContentParser parser) throws IOException {
@@ -78,15 +81,18 @@ public static DataFrameTransformState fromXContent(XContentParser parser) throws
     private final IndexerState indexerState;
     private final long generation;
     private final SortedMap<String, Object> currentPosition;
+    private final String reason;
 
     public DataFrameTransformState(DataFrameTransformTaskState taskState,
                                    IndexerState indexerState,
                                    @Nullable Map<String, Object> position,
-                                   long generation) {
+                                   long generation,
+                                   @Nullable String reason) {
         this.taskState = taskState;
         this.indexerState = indexerState;
         this.currentPosition = position == null ? null : Collections.unmodifiableSortedMap(new TreeMap<>(position));
         this.generation = generation;
+        this.reason = reason;
     }
 
     public IndexerState getIndexerState() {
@@ -106,6 +112,11 @@ public long getGeneration() {
         return generation;
     }
 
+    @Nullable
+    public String getReason() {
+        return reason;
+    }
+
     @Override
     public boolean equals(Object other) {
         if (this == other) {
@@ -121,11 +132,13 @@ public boolean equals(Object other) {
         return Objects.equals(this.taskState, that.taskState) &&
             Objects.equals(this.indexerState, that.indexerState) &&
             Objects.equals(this.currentPosition, that.currentPosition) &&
-            this.generation == that.generation;
+            this.generation == that.generation &&
+            Objects.equals(this.reason, that.reason);
     }
 
     @Override
     public int hashCode() {
-        return Objects.hash(taskState, indexerState, currentPosition, generation);
+        return Objects.hash(taskState, indexerState, currentPosition, generation, reason);
     }
+
 }

client/rest-high-level/src/test/java/org/elasticsearch/client/DataFrameTransformIT.java

@@ -358,6 +358,7 @@ public void testGetStats() throws Exception {
             DataFrameTransformStateAndStats stateAndStats = response.getTransformsStateAndStats().get(0);
             assertEquals(IndexerState.STARTED, stateAndStats.getTransformState().getIndexerState());
             assertEquals(DataFrameTransformTaskState.STARTED, stateAndStats.getTransformState().getTaskState());
+            assertEquals(null, stateAndStats.getTransformState().getReason());
             assertNotEquals(zeroIndexerStats, stateAndStats.getTransformStats());
         });
     }

client/rest-high-level/src/test/java/org/elasticsearch/client/dataframe/transforms/DataFrameTransformStateTests.java

@@ -36,15 +36,17 @@ public void testFromXContent() throws IOException {
                 DataFrameTransformStateTests::randomDataFrameTransformState,
                 DataFrameTransformStateTests::toXContent,
                 DataFrameTransformState::fromXContent)
-                .supportsUnknownFields(false)
+                .supportsUnknownFields(true)
+                .randomFieldsExcludeFilter(field -> field.equals("current_position"))
                 .test();
     }
 
     public static DataFrameTransformState randomDataFrameTransformState() {
         return new DataFrameTransformState(randomFrom(DataFrameTransformTaskState.values()),
             randomFrom(IndexerState.values()),
             randomPositionMap(),
-            randomLongBetween(0,10));
+            randomLongBetween(0,10),
+            randomBoolean() ? null : randomAlphaOfLength(10));
     }
 
     public static void toXContent(DataFrameTransformState state, XContentBuilder builder) throws IOException {
@@ -55,6 +57,9 @@ public static void toXContent(DataFrameTransformState state, XContentBuilder bui
             builder.field("current_position", state.getPosition());
         }
         builder.field("generation", state.getGeneration());
+        if (state.getReason() != null) {
+            builder.field("reason", state.getReason());
+        }
         builder.endObject();
     }
 

x-pack/plugin/core/src/test/java/org/elasticsearch/xpack/core/dataframe/transforms/DataFrameTransformStateHlrcTests.java

@@ -0,0 +1,51 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+package org.elasticsearch.xpack.core.dataframe.transforms;
+
+import org.elasticsearch.common.xcontent.XContentParser;
+import org.elasticsearch.protocol.AbstractHlrcXContentTestCase;
+import org.elasticsearch.xpack.core.indexing.IndexerState;
+
+import java.io.IOException;
+import java.util.function.Predicate;
+
+public class DataFrameTransformStateHlrcTests extends AbstractHlrcXContentTestCase<DataFrameTransformState,
+        org.elasticsearch.client.dataframe.transforms.DataFrameTransformState> {
+
+    @Override
+    public org.elasticsearch.client.dataframe.transforms.DataFrameTransformState doHlrcParseInstance(XContentParser parser)
+            throws IOException {
+        return org.elasticsearch.client.dataframe.transforms.DataFrameTransformState.fromXContent(parser);
+    }
+
+    @Override
+    public DataFrameTransformState convertHlrcToInternal(org.elasticsearch.client.dataframe.transforms.DataFrameTransformState instance) {
+        return new DataFrameTransformState(DataFrameTransformTaskState.fromString(instance.getTaskState().value()),
+                IndexerState.fromString(instance.getIndexerState().value()),
+                instance.getPosition(), instance.getGeneration(), instance.getReason());
+    }
+
+    @Override
+    protected DataFrameTransformState createTestInstance() {
+        return DataFrameTransformStateTests.randomDataFrameTransformState();
+    }
+
+    @Override
+    protected DataFrameTransformState doParseInstance(XContentParser parser) throws IOException {
+        return DataFrameTransformState.fromXContent(parser);
+    }
+
+    @Override
+    protected boolean supportsUnknownFields() {
+        return true;
+    }
+
+    @Override
+    protected Predicate<String> getRandomFieldsExcludeFilter() {
+        return field -> field.equals("current_position");
+    }
+}