HLRC: Add ML get influencers API (#33389)

Relates #29827

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

@@ -28,6 +28,7 @@
 import org.elasticsearch.client.ml.DeleteJobRequest;
 import org.elasticsearch.client.ml.FlushJobRequest;
 import org.elasticsearch.client.ml.GetBucketsRequest;
+import org.elasticsearch.client.ml.GetInfluencersRequest;
 import org.elasticsearch.client.ml.GetJobRequest;
 import org.elasticsearch.client.ml.GetJobStatsRequest;
 import org.elasticsearch.client.ml.GetOverallBucketsRequest;
@@ -186,4 +187,18 @@ static Request getRecords(GetRecordsRequest getRecordsRequest) throws IOExceptio
         request.setEntity(createEntity(getRecordsRequest, REQUEST_BODY_CONTENT_TYPE));
         return request;
     }
+
+    static Request getInfluencers(GetInfluencersRequest getInfluencersRequest) throws IOException {
+        String endpoint = new EndpointBuilder()
+                .addPathPartAsIs("_xpack")
+                .addPathPartAsIs("ml")
+                .addPathPartAsIs("anomaly_detectors")
+                .addPathPart(getInfluencersRequest.getJobId())
+                .addPathPartAsIs("results")
+                .addPathPartAsIs("influencers")
+                .build();
+        Request request = new Request(HttpGet.METHOD_NAME, endpoint);
+        request.setEntity(createEntity(getInfluencersRequest, REQUEST_BODY_CONTENT_TYPE));
+        return request;
+    }
 }

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

@@ -19,19 +19,20 @@
 package org.elasticsearch.client;
 
 import org.elasticsearch.action.ActionListener;
-import org.elasticsearch.client.ml.FlushJobRequest;
-import org.elasticsearch.client.ml.FlushJobResponse;
-import org.elasticsearch.client.ml.GetJobStatsRequest;
-import org.elasticsearch.client.ml.GetJobStatsResponse;
-import org.elasticsearch.client.ml.job.stats.JobStats;
 import org.elasticsearch.client.ml.CloseJobRequest;
 import org.elasticsearch.client.ml.CloseJobResponse;
 import org.elasticsearch.client.ml.DeleteJobRequest;
 import org.elasticsearch.client.ml.DeleteJobResponse;
+import org.elasticsearch.client.ml.FlushJobRequest;
+import org.elasticsearch.client.ml.FlushJobResponse;
 import org.elasticsearch.client.ml.GetBucketsRequest;
 import org.elasticsearch.client.ml.GetBucketsResponse;
+import org.elasticsearch.client.ml.GetInfluencersRequest;
+import org.elasticsearch.client.ml.GetInfluencersResponse;
 import org.elasticsearch.client.ml.GetJobRequest;
 import org.elasticsearch.client.ml.GetJobResponse;
+import org.elasticsearch.client.ml.GetJobStatsRequest;
+import org.elasticsearch.client.ml.GetJobStatsResponse;
 import org.elasticsearch.client.ml.GetOverallBucketsRequest;
 import org.elasticsearch.client.ml.GetOverallBucketsResponse;
 import org.elasticsearch.client.ml.GetRecordsRequest;
@@ -40,6 +41,7 @@
 import org.elasticsearch.client.ml.OpenJobResponse;
 import org.elasticsearch.client.ml.PutJobRequest;
 import org.elasticsearch.client.ml.PutJobResponse;
+import org.elasticsearch.client.ml.job.stats.JobStats;
 
 import java.io.IOException;
 import java.util.Collections;
@@ -464,4 +466,43 @@ public void getRecordsAsync(GetRecordsRequest request, RequestOptions options, A
                 listener,
                 Collections.emptySet());
     }
+
+    /**
+     * Gets the influencers for a Machine Learning Job.
+     * <p>
+     * For additional info
+     * see <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/ml-get-influencer.html">
+     *     ML GET influencers documentation</a>
+     *
+     * @param request  the request
+     * @param options  Additional request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     */
+    public GetInfluencersResponse getInfluencers(GetInfluencersRequest request, RequestOptions options) throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(request,
+                MLRequestConverters::getInfluencers,
+                options,
+                GetInfluencersResponse::fromXContent,
+                Collections.emptySet());
+    }
+
+    /**
+     * Gets the influencers for a Machine Learning Job, notifies listener once the requested influencers are retrieved.
+     * <p>
+     * For additional info
+     * * see <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/ml-get-influencer.html">
+     *     ML GET influencers documentation</a>
+     *
+     * @param request  the request
+     * @param options  Additional request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     * @param listener Listener to be notified upon request completion
+     */
+    public void getInfluencersAsync(GetInfluencersRequest request, RequestOptions options,
+                                    ActionListener<GetInfluencersResponse> listener) {
+        restHighLevelClient.performRequestAsyncAndParseEntity(request,
+                MLRequestConverters::getInfluencers,
+                options,
+                GetInfluencersResponse::fromXContent,
+                listener,
+                Collections.emptySet());
+    }
 }

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

@@ -41,7 +41,6 @@ public class GetBucketsRequest extends ActionRequest implements ToXContentObject
     public static final ParseField START = new ParseField("start");
     public static final ParseField END = new ParseField("end");
     public static final ParseField ANOMALY_SCORE = new ParseField("anomaly_score");
-    public static final ParseField TIMESTAMP = new ParseField("timestamp");
     public static final ParseField SORT = new ParseField("sort");
     public static final ParseField DESCENDING = new ParseField("desc");
 
@@ -87,7 +86,7 @@ public String getJobId() {
 
     /**
      * Sets the timestamp of a specific bucket to be retrieved.
-     * @param timestamp the timestamp of a specific bucket to be retrieved
+     * @param timestamp String representation of a timestamp; may be an epoch seconds, epoch millis or an ISO string
      */
     public void setTimestamp(String timestamp) {
         this.timestamp = timestamp;
@@ -106,11 +105,11 @@ public boolean isExpand() {
      * When {@code true}, buckets will be expanded to include their records.
      * @param expand value of "expand" to be set
      */
-    public void setExpand(boolean expand) {
+    public void setExpand(Boolean expand) {
         this.expand = expand;
     }
 
-    public boolean isExcludeInterim() {
+    public Boolean isExcludeInterim() {
         return excludeInterim;
     }
 
@@ -119,7 +118,7 @@ public boolean isExcludeInterim() {
      * When {@code true}, interim buckets will be filtered out.
      * @param excludeInterim value of "exclude_interim" to be set
      */
-    public void setExcludeInterim(boolean excludeInterim) {
+    public void setExcludeInterim(Boolean excludeInterim) {
         this.excludeInterim = excludeInterim;
     }
 
@@ -130,7 +129,7 @@ public String getStart() {
     /**
      * Sets the value of "start" which is a timestamp.
      * Only buckets whose timestamp is on or after the "start" value will be returned.
-     * @param start value of "start" to be set
+     * @param start String representation of a timestamp; may be an epoch seconds, epoch millis or an ISO string
      */
     public void setStart(String start) {
         this.start = start;
@@ -143,7 +142,7 @@ public String getEnd() {
     /**
      * Sets the value of "end" which is a timestamp.
      * Only buckets whose timestamp is before the "end" value will be returned.
-     * @param end value of "end" to be set
+     * @param end String representation of a timestamp; may be an epoch seconds, epoch millis or an ISO string
      */
     public void setEnd(String end) {
         this.end = end;
@@ -170,7 +169,7 @@ public Double getAnomalyScore() {
      * Only buckets with "anomaly_score" equal or greater will be returned.
      * @param anomalyScore value of "anomaly_score".
      */
-    public void setAnomalyScore(double anomalyScore) {
+    public void setAnomalyScore(Double anomalyScore) {
         this.anomalyScore = anomalyScore;
     }
 
@@ -187,7 +186,7 @@ public void setSort(String sort) {
         this.sort = sort;
     }
 
-    public boolean isDescending() {
+    public Boolean isDescending() {
         return descending;
     }