[HLRC][ML] Add ML get model snapshots API

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

@@ -43,6 +43,7 @@
 import org.elasticsearch.client.ml.GetInfluencersRequest;
 import org.elasticsearch.client.ml.GetJobRequest;
 import org.elasticsearch.client.ml.GetJobStatsRequest;
+import org.elasticsearch.client.ml.GetModelSnapshotsRequest;
 import org.elasticsearch.client.ml.GetOverallBucketsRequest;
 import org.elasticsearch.client.ml.GetRecordsRequest;
 import org.elasticsearch.client.ml.OpenJobRequest;
@@ -361,6 +362,19 @@ static Request getCategories(GetCategoriesRequest getCategoriesRequest) throws I
         return request;
     }
 
+    static Request getModelSnapshots(GetModelSnapshotsRequest getModelSnapshotsRequest) throws IOException {
+        String endpoint = new EndpointBuilder()
+            .addPathPartAsIs("_xpack")
+            .addPathPartAsIs("ml")
+            .addPathPartAsIs("anomaly_detectors")
+            .addPathPart(getModelSnapshotsRequest.getJobId())
+            .addPathPartAsIs("model_snapshots")
+            .build();
+        Request request = new Request(HttpGet.METHOD_NAME, endpoint);
+        request.setEntity(createEntity(getModelSnapshotsRequest, REQUEST_BODY_CONTENT_TYPE));
+        return request;
+    }
+
     static Request getOverallBuckets(GetOverallBucketsRequest getOverallBucketsRequest) throws IOException {
         String endpoint = new EndpointBuilder()
                 .addPathPartAsIs("_xpack")

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

@@ -49,6 +49,8 @@
 import org.elasticsearch.client.ml.GetJobResponse;
 import org.elasticsearch.client.ml.GetJobStatsRequest;
 import org.elasticsearch.client.ml.GetJobStatsResponse;
+import org.elasticsearch.client.ml.GetModelSnapshotsRequest;
+import org.elasticsearch.client.ml.GetModelSnapshotsResponse;
 import org.elasticsearch.client.ml.GetOverallBucketsRequest;
 import org.elasticsearch.client.ml.GetOverallBucketsResponse;
 import org.elasticsearch.client.ml.GetRecordsRequest;
@@ -897,6 +899,46 @@ public void getCategoriesAsync(GetCategoriesRequest request, RequestOptions opti
                 Collections.emptySet());
     }
 
+    /**
+     * Gets the snapshots for a Machine Learning Job.
+     * <p>
+     * For additional info
+     * see <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/ml-get-snapshot.html">
+     * ML GET model snapshots documentation</a>
+     *
+     * @param request The request
+     * @param options Additional request options (e.g. headers), use {@link RequestOptions#DEFAULT} if nothing needs to be customized
+     * @throws IOException when there is a serialization issue sending the request or receiving the response
+     */
+    public GetModelSnapshotsResponse getModelSnapshots(GetModelSnapshotsRequest request, RequestOptions options) throws IOException {
+        return restHighLevelClient.performRequestAndParseEntity(request,
+            MLRequestConverters::getModelSnapshots,
+            options,
+            GetModelSnapshotsResponse::fromXContent,
+            Collections.emptySet());
+    }
+
+    /**
+     * Gets the snapshots for a Machine Learning Job, notifies listener once the requested snapshots are retrieved.
+     * <p>
+     * For additional info
+     * see <a href="https://www.elastic.co/guide/en/elasticsearch/reference/current/ml-get-snapshot.html">
+     * ML GET model snapshots 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 getModelSnapshotsAsync(GetModelSnapshotsRequest request, RequestOptions options,
+                                       ActionListener<GetModelSnapshotsResponse> listener) {
+        restHighLevelClient.performRequestAsyncAndParseEntity(request,
+            MLRequestConverters::getModelSnapshots,
+            options,
+            GetModelSnapshotsResponse::fromXContent,
+            listener,
+            Collections.emptySet());
+    }
+
     /**
      * Gets overall buckets for a set of Machine Learning Jobs.
      * <p>

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

@@ -0,0 +1,208 @@
+/*
+ * 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.client.ml;
+
+import org.elasticsearch.action.ActionRequest;
+import org.elasticsearch.action.ActionRequestValidationException;
+import org.elasticsearch.client.ml.job.config.Job;
+import org.elasticsearch.client.ml.job.util.PageParams;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.ToXContentObject;
+import org.elasticsearch.common.xcontent.XContentBuilder;
+
+import java.io.IOException;
+import java.util.Objects;
+
+/**
+ * A request to retrieve information about model snapshots for a given job
+ */
+public class GetModelSnapshotsRequest extends ActionRequest implements ToXContentObject {
+
+
+    public static final ParseField SNAPSHOT_ID = new ParseField("snapshot_id");
+    public static final ParseField SORT = new ParseField("sort");
+    public static final ParseField START = new ParseField("start");
+    public static final ParseField END = new ParseField("end");
+    public static final ParseField DESC = new ParseField("desc");
+
+    public static final ConstructingObjectParser<GetModelSnapshotsRequest, Void> PARSER = new ConstructingObjectParser<>(
+        "get_model_snapshots_request", a -> new GetModelSnapshotsRequest((String) a[0]));
+
+
+    static {
+        PARSER.declareString(ConstructingObjectParser.constructorArg(), Job.ID);
+        PARSER.declareString(GetModelSnapshotsRequest::setSnapshotId, SNAPSHOT_ID);
+        PARSER.declareString(GetModelSnapshotsRequest::setSort, SORT);
+        PARSER.declareStringOrNull(GetModelSnapshotsRequest::setStart, START);
+        PARSER.declareStringOrNull(GetModelSnapshotsRequest::setEnd, END);
+        PARSER.declareBoolean(GetModelSnapshotsRequest::setDesc, DESC);
+        PARSER.declareObject(GetModelSnapshotsRequest::setPageParams, PageParams.PARSER, PageParams.PAGE);
+    }
+
+    private final String jobId;
+    private String snapshotId;
+    private String sort;
+    private String start;
+    private String end;
+    private Boolean desc;
+    private PageParams pageParams;
+
+    /**
+     * Constructs a request to retrieve snapshot information from a given job
+     * @param jobId id of the job from which to retrieve results
+     */
+    public GetModelSnapshotsRequest(String jobId) {
+        this.jobId = Objects.requireNonNull(jobId);
+    }
+
+    public String getJobId() {
+        return jobId;
+    }
+
+    public String getSnapshotId() {
+        return snapshotId;
+    }
+
+    /**
+     * Sets the id of the snapshot to retrieve.
+     * @param snapshotId the snapshot id
+     */
+    public void setSnapshotId(String snapshotId) {
+        this.snapshotId = snapshotId;
+    }
+
+    public String getSort() {
+        return sort;
+    }
+
+    /**
+     * Sets the value of "sort".
+     * Specifies the snapshot field to sort on.
+     * @param sort value of "sort".
+     */
+    public void setSort(String sort) {
+        this.sort = sort;
+    }
+
+    public PageParams getPageParams() {
+        return pageParams;
+    }
+
+    /**
+     * Sets the paging parameters
+     * @param pageParams the paging parameters
+     */
+    public void setPageParams(PageParams pageParams) {
+        this.pageParams = pageParams;
+    }
+
+    public String getStart() {
+        return start;
+    }
+
+    /**
+     * Sets the value of "start" which is a timestamp.
+     * Only snapshots whose timestamp is on or after the "start" value will be returned.
+     * @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;
+    }
+
+
+    public String getEnd() {
+        return end;
+    }
+
+    /**
+     * Sets the value of "end" which is a timestamp.
+     * Only snapshots whose timestamp is before the "end" value will be returned.
+     * @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;
+    }
+
+    public Boolean getDesc() {
+        return desc;
+    }
+
+    /**
+     * Sets the value of "desc".
+     * Specifies the sorting order.
+     * @param desc value of "desc"
+     */
+    public void setDesc(boolean desc) {
+        this.desc = desc;
+    }
+
+    @Override
+    public ActionRequestValidationException validate() {
+        return null;
+    }
+
+    @Override
+    public XContentBuilder toXContent(XContentBuilder builder, Params params) throws IOException {
+        builder.startObject();
+        builder.field(Job.ID.getPreferredName(), jobId);
+        if (snapshotId != null) {
+            builder.field(SNAPSHOT_ID.getPreferredName(), snapshotId);
+        }
+        if (sort != null) {
+            builder.field(SORT.getPreferredName(), sort);
+        }
+        if (start != null) {
+            builder.field(START.getPreferredName(), start);
+        }
+        if (end != null) {
+            builder.field(END.getPreferredName(), end);
+        }
+        if (desc != null) {
+            builder.field(DESC.getPreferredName(), desc);
+        }
+        if (pageParams != null) {
+            builder.field(PageParams.PAGE.getPreferredName(), pageParams);
+        }        builder.endObject();
+        return builder;
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        GetModelSnapshotsRequest request = (GetModelSnapshotsRequest) obj;
+        return Objects.equals(jobId, request.jobId)
+            && Objects.equals(snapshotId, request.snapshotId)
+            && Objects.equals(sort, request.sort)
+            && Objects.equals(start, request.start)
+            && Objects.equals(end, request.end)
+            && Objects.equals(desc, request.desc)
+            && Objects.equals(pageParams, request.pageParams);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(jobId, snapshotId, pageParams, start, end, sort, desc);
+    }
+}

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

@@ -0,0 +1,80 @@
+/*
+ * 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.client.ml;
+
+import org.elasticsearch.client.ml.job.process.ModelSnapshot;
+import org.elasticsearch.common.ParseField;
+import org.elasticsearch.common.xcontent.ConstructingObjectParser;
+import org.elasticsearch.common.xcontent.XContentParser;
+
+import java.io.IOException;
+import java.util.List;
+import java.util.Objects;
+import java.util.stream.Collectors;
+
+/**
+ * A response containing the requested snapshots
+ */
+public class GetModelSnapshotsResponse extends AbstractResultResponse<ModelSnapshot> {
+
+    public static final ParseField SNAPSHOTS = new ParseField("model_snapshots");
+
+    @SuppressWarnings("unchecked")
+    public static final ConstructingObjectParser<GetModelSnapshotsResponse, Void> PARSER =
+            new ConstructingObjectParser<>("get_model_snapshots_response", true,
+                    a -> new GetModelSnapshotsResponse((List<ModelSnapshot.Builder>) a[0], (long) a[1]));
+
+    static {
+        PARSER.declareObjectArray(ConstructingObjectParser.constructorArg(), ModelSnapshot.PARSER, SNAPSHOTS);
+        PARSER.declareLong(ConstructingObjectParser.constructorArg(), COUNT);
+    }
+
+    public static GetModelSnapshotsResponse fromXContent(XContentParser parser) throws IOException {
+        return PARSER.parse(parser, null);
+    }
+
+    GetModelSnapshotsResponse(List<ModelSnapshot.Builder> snapshotBuilders, long count) {
+        super(SNAPSHOTS, snapshotBuilders.stream().map(ModelSnapshot.Builder::build).collect(Collectors.toList()), count);
+    }
+
+    /**
+     * The retrieved snapshots
+     * @return the retrieved snapshots
+     */
+    public List<ModelSnapshot> snapshots() {
+        return results;
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(count, results);
+    }
+
+    @Override
+    public boolean equals(Object obj) {
+        if (obj == null) {
+            return false;
+        }
+        if (getClass() != obj.getClass()) {
+            return false;
+        }
+        GetModelSnapshotsResponse other = (GetModelSnapshotsResponse) obj;
+        return count == other.count && Objects.equals(results, other.results);
+    }
+}