Support OBJECT ENCODING

docs/ReleaseNotes.md

@@ -16,6 +16,7 @@
 - Adds: Support for `LPOS` with `.ListPosition()`/`.ListPositionAsync()` and `.ListPositions()`/`.ListPositionsAsync()` ([#2080 by slorello89](https://github.com/StackExchange/StackExchange.Redis/pull/2080))
 - Fix: For streams, properly hash `XACK`, `XCLAIM`, and `XPENDING` in cluster scenarios to eliminate `MOVED` retries ([#2085 by nielsderdaele](https://github.com/StackExchange/StackExchange.Redis/pull/2085))
 - Adds: Support for `OBJECT REFCOUNT` with `.KeyRefCount()`/`.KeyRefCountAsync()` ([#2087 by Avital-Fine](https://github.com/StackExchange/StackExchange.Redis/pull/2087))
+- Adds: Support for `OBJECT ENCODIND` with `.KeyEncoding()`/`.KeyEncodingAsync()` ([#2088 by Avital-Fine](https://github.com/StackExchange/StackExchange.Redis/pull/2088))
 
 ## 2.5.61
 

src/StackExchange.Redis/Interfaces/IDatabase.cs

@@ -516,6 +516,15 @@ public interface IDatabase : IRedis, IDatabaseAsync
         /// <remarks>https://redis.io/commands/dump</remarks>
         byte[]? KeyDump(RedisKey key, CommandFlags flags = CommandFlags.None);
 
+        /// <summary>
+        /// Returns the internal encoding for the Redis object stored at <paramref name="key"/>.
+        /// </summary>
+        /// <param name="key">The key to dump.</param>
+        /// <param name="flags">The flags to use for this operation.</param>
+        /// <returns>The Redis encoding for the value or <see langword="null"/> is the key does not exist.</returns>
+        /// <remarks>https://redis.io/commands/object-encoding</remarks>
+        string? KeyEncoding(RedisKey key, CommandFlags flags = CommandFlags.None);
+
         /// <summary>
         /// Returns if key exists.
         /// </summary>

src/StackExchange.Redis/Interfaces/IDatabaseAsync.cs

@@ -492,6 +492,15 @@ public interface IDatabaseAsync : IRedisAsync
         /// <remarks>https://redis.io/commands/dump</remarks>
         Task<byte[]?> KeyDumpAsync(RedisKey key, CommandFlags flags = CommandFlags.None);
 
+        /// <summary>
+        /// Returns the internal encoding for the Redis object stored at <paramref name="key"/>.
+        /// </summary>
+        /// <param name="key">The key to dump.</param>
+        /// <param name="flags">The flags to use for this operation.</param>
+        /// <returns>The Redis encoding for the value or <see langword="null"/> is the key does not exist.</returns>
+        /// <remarks>https://redis.io/commands/object-encoding</remarks>
+        Task<string?> KeyEncodingAsync(RedisKey key, CommandFlags flags = CommandFlags.None);
+
         /// <summary>
         /// Returns if key exists.
         /// </summary>

src/StackExchange.Redis/KeyspaceIsolation/DatabaseWrapper.cs

@@ -138,6 +138,9 @@ public bool KeyDelete(RedisKey key, CommandFlags flags = CommandFlags.None) =>
         public byte[]? KeyDump(RedisKey key, CommandFlags flags = CommandFlags.None) =>
             Inner.KeyDump(ToInner(key), flags);
 
+        public string? KeyEncoding(RedisKey key, CommandFlags flags = CommandFlags.None) =>
+            Inner.KeyEncoding(ToInner(key), flags);
+
         public bool KeyExists(RedisKey key, CommandFlags flags = CommandFlags.None) =>
             Inner.KeyExists(ToInner(key), flags);
         public long KeyExists(RedisKey[] keys, CommandFlags flags = CommandFlags.None) =>

src/StackExchange.Redis/KeyspaceIsolation/WrapperBase.cs

@@ -147,6 +147,9 @@ public Task<bool> KeyDeleteAsync(RedisKey key, CommandFlags flags = CommandFlags
         public Task<byte[]?> KeyDumpAsync(RedisKey key, CommandFlags flags = CommandFlags.None) =>
             Inner.KeyDumpAsync(ToInner(key), flags);
 
+        public Task<string?> KeyEncodingAsync(RedisKey key, CommandFlags flags = CommandFlags.None) =>
+            Inner.KeyEncodingAsync(ToInner(key), flags);
+
         public Task<bool> KeyExistsAsync(RedisKey key, CommandFlags flags = CommandFlags.None) =>
             Inner.KeyExistsAsync(ToInner(key), flags);
 

src/StackExchange.Redis/PublicAPI.Shipped.txt

@@ -522,6 +522,7 @@ StackExchange.Redis.IDatabase.KeyCopy(StackExchange.Redis.RedisKey sourceKey, St
 StackExchange.Redis.IDatabase.KeyDelete(StackExchange.Redis.RedisKey key, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> bool
 StackExchange.Redis.IDatabase.KeyDelete(StackExchange.Redis.RedisKey[]! keys, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> long
 StackExchange.Redis.IDatabase.KeyDump(StackExchange.Redis.RedisKey key, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> byte[]?
+StackExchange.Redis.IDatabase.KeyEncoding(StackExchange.Redis.RedisKey key, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> string?
 StackExchange.Redis.IDatabase.KeyExists(StackExchange.Redis.RedisKey key, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> bool
 StackExchange.Redis.IDatabase.KeyExists(StackExchange.Redis.RedisKey[]! keys, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> long
 StackExchange.Redis.IDatabase.KeyExpire(StackExchange.Redis.RedisKey key, System.DateTime? expiry, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> bool
@@ -723,6 +724,7 @@ StackExchange.Redis.IDatabaseAsync.KeyCopyAsync(StackExchange.Redis.RedisKey sou
 StackExchange.Redis.IDatabaseAsync.KeyDeleteAsync(StackExchange.Redis.RedisKey key, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> System.Threading.Tasks.Task<bool>!
 StackExchange.Redis.IDatabaseAsync.KeyDeleteAsync(StackExchange.Redis.RedisKey[]! keys, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> System.Threading.Tasks.Task<long>!
 StackExchange.Redis.IDatabaseAsync.KeyDumpAsync(StackExchange.Redis.RedisKey key, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> System.Threading.Tasks.Task<byte[]?>!
+StackExchange.Redis.IDatabaseAsync.KeyEncodingAsync(StackExchange.Redis.RedisKey key, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> System.Threading.Tasks.Task<string?>!
 StackExchange.Redis.IDatabaseAsync.KeyExistsAsync(StackExchange.Redis.RedisKey key, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> System.Threading.Tasks.Task<bool>!
 StackExchange.Redis.IDatabaseAsync.KeyExistsAsync(StackExchange.Redis.RedisKey[]! keys, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> System.Threading.Tasks.Task<long>!
 StackExchange.Redis.IDatabaseAsync.KeyExpireAsync(StackExchange.Redis.RedisKey key, System.DateTime? expiry, StackExchange.Redis.CommandFlags flags = StackExchange.Redis.CommandFlags.None) -> System.Threading.Tasks.Task<bool>!

src/StackExchange.Redis/RedisDatabase.cs

@@ -673,6 +673,18 @@ private RedisCommand GetDeleteCommand(RedisKey key, CommandFlags flags, out Serv
             return ExecuteAsync(msg, ResultProcessor.ByteArray);
         }
 
+        public string? KeyEncoding(RedisKey key, CommandFlags flags = CommandFlags.None)
+        {
+            var msg = Message.Create(Database, flags, RedisCommand.OBJECT, RedisLiterals.ENCODING, key);
+            return ExecuteSync(msg, ResultProcessor.String);
+        }
+
+        public Task<string?> KeyEncodingAsync(RedisKey key, CommandFlags flags = CommandFlags.None)
+        {
+            var msg = Message.Create(Database, flags, RedisCommand.OBJECT, RedisLiterals.ENCODING, key);
+            return ExecuteAsync(msg, ResultProcessor.String);
+        }
+
         public bool KeyExists(RedisKey key, CommandFlags flags = CommandFlags.None)
         {
             var msg = Message.Create(Database, flags, RedisCommand.EXISTS, key);
@@ -3620,7 +3632,7 @@ private Message GetStreamPendingMessagesMessage(RedisKey key, RedisValue groupNa
 
             if (consumerName != RedisValue.Null)
             {
-                values[4] = consumerName; 
+                values[4] = consumerName;
             }
 
             return Message.Create(Database,

src/StackExchange.Redis/RedisLiterals.cs

@@ -56,6 +56,7 @@ public static readonly RedisValue
             DB = "DB",
             DESC = "DESC",
             DOCTOR = "DOCTOR",
+            ENCODING = "ENCODING",
             EX = "EX",
             EXAT = "EXAT",
             EXISTS = "EXISTS",

tests/StackExchange.Redis.Tests/DatabaseWrapperTests.cs

@@ -266,6 +266,13 @@ public void KeyDump()
             mock.Verify(_ => _.KeyDump("prefix:key", CommandFlags.None));
         }
 
+        [Fact]
+        public void KeyEncoding()
+        {
+            wrapper.KeyEncoding("key", CommandFlags.None);
+            mock.Verify(_ => _.KeyEncoding("prefix:key", CommandFlags.None));
+        }
+
         [Fact]
         public void KeyExists()
         {

tests/StackExchange.Redis.Tests/Keys.cs

@@ -265,6 +265,32 @@ public async Task TouchIdleTimeAsync()
             }
         }
 
+        [Fact]
+        public async Task KeyEncoding()
+        {
+            using var muxer = Create();
+            var key = Me();
+            var db = muxer.GetDatabase();
+
+            db.KeyDelete(key, CommandFlags.FireAndForget);
+            db.StringSet(key, "new value", flags: CommandFlags.FireAndForget);
+
+            Assert.Equal("embstr", db.KeyEncoding(key));
+            Assert.Equal("embstr", await db.KeyEncodingAsync(key));
+
+            db.KeyDelete(key, CommandFlags.FireAndForget);
+            db.ListLeftPush(key, "new value", flags: CommandFlags.FireAndForget);
+
+            // Depending on server version, this is going to vary - we're sanity checking here.
+            var listTypes = new [] { "ziplist", "quicklist" };
+            Assert.Contains(db.KeyEncoding(key), listTypes);
+            Assert.Contains(await db.KeyEncodingAsync(key), listTypes);
+
+            var keyNotExists = key + "no-exist";
+            Assert.Null(db.KeyEncoding(keyNotExists));
+            Assert.Null(await db.KeyEncodingAsync(keyNotExists));
+        }
+
         [Fact]
         public async Task KeyRefCount()
         {

tests/StackExchange.Redis.Tests/WrapperBaseTests.cs

@@ -226,6 +226,14 @@ public void KeyDumpAsync()
             mock.Verify(_ => _.KeyDumpAsync("prefix:key", CommandFlags.None));
         }
 
+        [Fact]
+        public void KeyEncodingAsync()
+        {
+            wrapper.KeyEncodingAsync("key", CommandFlags.None);
+            mock.Verify(_ => _.KeyEncodingAsync("prefix:key", CommandFlags.None));
+        }
+
+
         [Fact]
         public void KeyExistsAsync()
         {