Add support for indices.stats (opensearch-project#753)

* Add support for indices.stats

Signed-off-by: Thomas Farr <tsfarr@amazon.com>

* Add changelog entry

Signed-off-by: Thomas Farr <tsfarr@amazon.com>

* Fix tests

Signed-off-by: Thomas Farr <tsfarr@amazon.com>

* Fix another test

Signed-off-by: Thomas Farr <tsfarr@amazon.com>

* Fix more tests

Signed-off-by: Thomas Farr <tsfarr@amazon.com>

---------

Signed-off-by: Thomas Farr <tsfarr@amazon.com>
(cherry picked from commit 43ba0de)

CHANGELOG.md

@@ -7,6 +7,7 @@ Inspired from [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
 - Added support for `MinScore` on `ScriptScoreQuery` ([#624](https://github.com/opensearch-project/opensearch-net/pull/624))
 - Added support for serializing the `DateOnly` and `TimeOnly` types ([#734](https://github.com/opensearch-project/opensearch-net/pull/734))
 - Added support for the `Ext` parameter on `SearchRequest` ([#738](https://github.com/opensearch-project/opensearch-net/pull/738))
+- Added support for the `Indices.Stats` API ([#753](https://github.com/opensearch-project/opensearch-net/pull/753))
 
 ### Dependencies
 - Bumps `AWSSDK.Core` from 3.7.204.12 to 3.7.400.4

src/ApiGenerator/Configuration/CodeConfiguration.cs

@@ -44,7 +44,8 @@ public static class CodeConfiguration
             new("cat.{all_pit,pit}_segments"),
             new("cat.segment_replication"),
 			new("cluster.{delete,exists,get,put}_component_template"),
-			new("indices.{delete,exists,get,put}_index_template")
+			new("indices.{delete,exists,get,put}_index_template"),
+            new("indices.stats")
 		};
 
 		public static bool IncludeOperation(string name) => OperationsToInclude.Any(g => g.IsMatch(name));

src/OpenSearch.Client/ApiUrlsLookup.cs

@@ -118,7 +118,6 @@ internal static partial class ApiUrlsLookups
 		internal static ApiUrls IndicesShardStores = new ApiUrls(new[]{"_shard_stores", "{index}/_shard_stores"});
 		internal static ApiUrls IndicesShrink = new ApiUrls(new[]{"{index}/_shrink/{target}"});
 		internal static ApiUrls IndicesSplit = new ApiUrls(new[]{"{index}/_split/{target}"});
-		internal static ApiUrls IndicesStats = new ApiUrls(new[]{"_stats", "_stats/{metric}", "{index}/_stats", "{index}/_stats/{metric}"});
 		internal static ApiUrls IndicesBulkAlias = new ApiUrls(new[]{"_aliases"});
 		internal static ApiUrls IndicesValidateQuery = new ApiUrls(new[]{"_validate/query", "{index}/_validate/query"});
 		internal static ApiUrls NoNamespaceRootNodeInfo = new ApiUrls(new[]{""});

src/OpenSearch.Client/Indices/Stats/IndicesStatsRequest.cs

@@ -0,0 +1,22 @@
+/* SPDX-License-Identifier: Apache-2.0
+*
+* The OpenSearch Contributors require contributions made to
+* this file be licensed under the Apache-2.0 license or a
+* compatible open source license.
+*/
+
+namespace OpenSearch.Client;
+
+[MapsApi("indices.stats")]
+[ReadAs(typeof(IndicesStatsRequest))]
+public partial interface IIndicesStatsRequest
+{
+}
+
+public partial class IndicesStatsRequest
+{
+}
+
+public partial class IndicesStatsDescriptor
+{
+}

src/OpenSearch.Client/Indices/Stats/IndicesStatsResponse.cs

@@ -0,0 +1,244 @@
+/* SPDX-License-Identifier: Apache-2.0
+*
+* The OpenSearch Contributors require contributions made to
+* this file be licensed under the Apache-2.0 license or a
+* compatible open source license.
+*/
+
+using System.Collections.Generic;
+using System.Runtime.Serialization;
+using OpenSearch.Net;
+using OpenSearch.Net.Utf8Json;
+
+namespace OpenSearch.Client;
+
+[DataContract]
+public class IndicesStatsResponse : ResponseBase
+{
+    [DataMember(Name = "_all")]
+    public AllIndicesStats All { get; internal set; }
+
+    [DataMember(Name = "_shards")]
+    public ShardStatistics Shards { get; internal set; }
+
+    [DataMember(Name = "indices")]
+    public IndicesStatsDictionary Indices { get; internal set; }
+}
+
+[JsonFormatter(typeof(Converter))]
+public class IndicesStatsDictionary : ResolvableDictionaryProxy<IndexName, IndicesStats>
+{
+    private IndicesStatsDictionary(IConnectionConfigurationValues s, IReadOnlyDictionary<IndexName, IndicesStats> d)
+        : base(s, d) { }
+
+    private class Converter : ResolvableDictionaryFormatterBase<IndicesStatsDictionary, IndexName, IndicesStats>
+    {
+        protected override IndicesStatsDictionary Create(IConnectionSettingsValues s, Dictionary<IndexName, IndicesStats> d) => new(s, d);
+    }
+}
+
+[DataContract]
+public class AllIndicesStats
+{
+    [DataMember(Name = "primaries")]
+    public IndexStats Primaries { get; internal set; }
+
+    [DataMember(Name = "total")]
+    public IndexStats Total { get; internal set; }
+}
+
+[DataContract]
+public class IndicesStats
+{
+    [DataMember(Name = "uuid")]
+    public string Uuid { get; internal set; }
+
+    [DataMember(Name = "primaries")]
+    public IndexStats Primaries { get; internal set; }
+
+    [DataMember(Name = "total")]
+    public IndexStats Total { get; internal set; }
+
+    [DataMember(Name = "shards")]
+    public IReadOnlyDictionary<string, IReadOnlyCollection<IndexShardStats>> Shards { get; internal set; }
+}
+
+[DataContract]
+public abstract class IndexStatsBase
+{
+    [DataMember(Name = "docs")]
+    public DocStats Documents { get; internal set; }
+
+    [DataMember(Name = "store")]
+    public StoreStats Store { get; internal set; }
+
+    [DataMember(Name = "indexing")]
+    public IndexingStats Indexing { get; internal set; }
+
+    [DataMember(Name = "get")]
+    public GetStats Get { get; internal set; }
+
+    [DataMember(Name = "search")]
+    public SearchStats Search { get; internal set; }
+
+    [DataMember(Name = "merges")]
+    public MergesStats Merges { get; internal set; }
+
+    [DataMember(Name = "refresh")]
+    public RefreshStats Refresh { get; internal set; }
+
+    [DataMember(Name = "flush")]
+    public FlushStats Flush { get; internal set; }
+
+    [DataMember(Name = "warmer")]
+    public WarmerStats Warmer { get; internal set; }
+
+    [DataMember(Name = "query_cache")]
+    public QueryCacheStats QueryCache { get; internal set; }
+
+    [DataMember(Name = "fielddata")]
+    public FielddataStats Fielddata { get; internal set; }
+
+    [DataMember(Name = "completion")]
+    public CompletionStats Completion { get; internal set; }
+
+    [DataMember(Name = "segments")]
+    public SegmentsStats Segments { get; internal set; }
+
+    [DataMember(Name = "translog")]
+    public TranslogStats Translog { get; internal set; }
+
+    [DataMember(Name = "request_cache")]
+    public RequestCacheStats RequestCache { get; internal set; }
+
+    [DataMember(Name = "recovery")]
+    public RecoveryStats Recovery { get; internal set; }
+}
+
+[DataContract]
+public class IndexStats : IndexStatsBase
+{
+
+}
+
+[DataContract]
+public class IndexShardStats : IndexStatsBase
+{
+    [DataMember(Name = "routing")]
+    public ShardRouting Routing { get; internal set; }
+
+    [DataMember(Name = "commit")]
+    public ShardCommitStats Commit { get; internal set; }
+
+    [DataMember(Name = "seq_no")]
+    public ShardSequenceNumberStats SequenceNumber { get; internal set; }
+
+    [DataMember(Name = "retention_leases")]
+    public ShardRetentionLeasesStats RetentionLeases { get; internal set; }
+
+    [DataMember(Name = "shard_path")]
+    public ShardPath ShardPath { get; internal set; }
+}
+
+[DataContract]
+public class ShardRouting
+{
+    [DataMember(Name = "state")]
+    public ShardRoutingState State { get; internal set; }
+
+    [DataMember(Name = "primary")]
+    public bool Primary { get; internal set; }
+
+    [DataMember(Name = "node")]
+    public string Node { get; internal set; }
+
+    [DataMember(Name = "relocating_node")]
+    public string RelocatingNode { get; internal set; }
+}
+
+[StringEnum]
+public enum ShardRoutingState
+{
+    [EnumMember(Value = "INITIALIZING")]
+    Initializing,
+
+    [EnumMember(Value = "RELOCATING")]
+    Relocating,
+
+    [EnumMember(Value = "STARTED")]
+    Started,
+
+    [EnumMember(Value = "UNASSIGNED")]
+    Unassigned
+}
+
+[DataContract]
+public class ShardCommitStats
+{
+    [DataMember(Name = "id")]
+    public string Id { get; internal set; }
+
+    [DataMember(Name = "generation")]
+    public long Generation { get; internal set; }
+
+    [DataMember(Name = "num_docs")]
+    public int NumDocs { get; internal set; }
+
+    [DataMember(Name = "user_data")]
+    public IReadOnlyDictionary<string, string> UserData { get; internal set; }
+}
+
+[DataContract]
+public class ShardSequenceNumberStats
+{
+    [DataMember(Name = "max_seq_no")]
+    public long MaxSequenceNumber { get; internal set; }
+
+    [DataMember(Name = "local_checkpoint")]
+    public long LocalCheckpoint { get; internal set; }
+
+    [DataMember(Name = "global_checkpoint")]
+    public long GlobalCheckpoint { get; internal set; }
+}
+
+[DataContract]
+public class ShardRetentionLeasesStats
+{
+    [DataMember(Name = "primary_term")]
+    public long PrimaryTerm { get; internal set; }
+
+    [DataMember(Name = "version")]
+    public long Version { get; internal set; }
+
+    [DataMember(Name = "leases")]
+    public IReadOnlyCollection<ShardRetentionLease> Leases { get; internal set; }
+}
+
+[DataContract]
+public class ShardRetentionLease
+{
+    [DataMember(Name = "id")]
+    public string Id { get; internal set; }
+
+    [DataMember(Name = "retaining_seq_no")]
+    public long RetainingSequenceNumber { get; internal set; }
+
+    [DataMember(Name = "timestamp")]
+    public long Timestamp { get; internal set; }
+
+    [DataMember(Name = "source")]
+    public string Source { get; internal set; }
+}
+
+[DataContract]
+public class ShardPath
+{
+    [DataMember(Name = "state_path")]
+    public string StatePath { get; internal set; }
+
+    [DataMember(Name = "data_path")]
+    public string DataPath { get; internal set; }
+
+    [DataMember(Name = "is_custom_data_path")]
+    public bool IsCustomDataPath { get; internal set; }
+}

src/OpenSearch.Client/_Generated/ApiUrlsLookup.cs

@@ -88,5 +88,8 @@ internal static partial class ApiUrlsLookups
 
         internal static readonly ApiUrls IndicesPutComposableTemplate =
             new(new[] { "_index_template/{name}" });
+
+        internal static readonly ApiUrls IndicesStats =
+            new(new[] { "_stats", "{index}/_stats", "{index}/_stats/{metric}", "_stats/{metric}" });
     }
 }