Add support for Consumer Create Action

src/NATS.Client/JetStream/ApiConstants.cs

@@ -18,6 +18,7 @@ public static class ApiConstants
         public const string AckFloor = "ack_floor";
         public const string AckPolicy = "ack_policy";
         public const string AckWait = "ack_wait";
+        public const string Action = "action";
         public const string Active = "active";
         public const string AllowRollupHdrs = "allow_rollup_hdrs";
         public const string AllowDirect = "allow_direct";

src/NATS.Client/JetStream/ApiEnums.cs

@@ -27,6 +27,8 @@ public enum StorageType { File, Memory }
 
     public enum CompressionOption { None, S2 }
 
+    public enum ConsumerCreateRequestAction { Create, Update, CreateOrUpdate }
+
     public static class ApiEnums
     {
         public static string GetString(this AckPolicy ackPolicy)
@@ -105,6 +107,17 @@ public static string GetString(this CompressionOption compressionOption)
             return null;
         }
 
+        public static string GetString(this ConsumerCreateRequestAction action)
+        {
+            switch (action)
+            {
+                case ConsumerCreateRequestAction.Create:         return "create";
+                case ConsumerCreateRequestAction.Update:         return "update";
+                case ConsumerCreateRequestAction.CreateOrUpdate: return null;
+            }
+            return null;
+        }
+
         public static AckPolicy? GetAckPolicy(string value)
         {
             if (value != null)

src/NATS.Client/JetStream/ConsumerCreateRequest.cs

@@ -1,4 +1,4 @@
-// Copyright 2021 The NATS Authors
+// Copyright 2021-2024 The NATS Authors
 // Licensed 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:
@@ -11,28 +11,32 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+using NATS.Client.Internals;
 using NATS.Client.Internals.SimpleJSON;
 
 namespace NATS.Client.JetStream
 {
+
     public sealed class ConsumerCreateRequest : JsonSerializable
     {
         public string StreamName { get; }
         public ConsumerConfiguration Config { get; }
+        public ConsumerCreateRequestAction Action { get; }
 
-        internal ConsumerCreateRequest(string streamName, ConsumerConfiguration config)
+        internal ConsumerCreateRequest(string streamName, ConsumerConfiguration config, ConsumerCreateRequestAction action)
         {
             StreamName = streamName;
             Config = config;
+            Action = action;
         }
 
         public override JSONNode ToJsonNode()
         {
-            return new JSONObject
-            {
-                [ApiConstants.StreamName] = StreamName,
-                [ApiConstants.Config] = Config.ToJsonNode()
-            };
+            JSONObject o = new JSONObject();
+            JsonUtils.AddField(o, ApiConstants.StreamName, StreamName);
+            JsonUtils.AddField(o, ApiConstants.Config, Config);
+            JsonUtils.AddField(o, ApiConstants.Action, Action.GetString());
+            return o;
         }
     }
 }

src/NATS.Client/JetStream/IJetStreamManagement.cs

@@ -90,6 +90,22 @@ public interface IJetStreamManagement
         /// <returns></returns>
         ConsumerInfo AddOrUpdateConsumer(string streamName, ConsumerConfiguration config);
 
+        /// <summary>
+        /// Creates a consumer. Must not already exist.
+        /// </summary>
+        /// <param name="streamName">The name of the stream the consumer is attached to.</param>
+        /// <param name="config">The consumer configuration to use.</param>
+        /// <returns></returns>
+        ConsumerInfo CreateConsumer(string streamName, ConsumerConfiguration config);
+
+        /// <summary>
+        /// Updates an existing consumer. Must already exist.
+        /// </summary>
+        /// <param name="streamName">The name of the stream the consumer is attached to.</param>
+        /// <param name="config">The consumer configuration to use.</param>
+        /// <returns></returns>
+        ConsumerInfo UpdateConsumer(string streamName, ConsumerConfiguration config);
+
         /// <summary>
         /// Deletes a consumer.
         /// </summary>

src/NATS.Client/JetStream/JetStream.cs

@@ -495,7 +495,7 @@ internal Subscription CreateSubscription(string userSubscribeSubject,
             {
                 try
                 {
-                    ConsumerInfo ci = CreateConsumerInternal(settledStream, settledCC);
+                    ConsumerInfo ci = CreateConsumerInternal(settledStream, settledCC, ConsumerCreateRequestAction.CreateOrUpdate);
                     if (sub is JetStreamAbstractSyncSubscription syncSub)
                     {
                         syncSub.SetConsumerName(ci.Name);

src/NATS.Client/JetStream/JetStreamBase.cs

@@ -100,7 +100,7 @@ internal ConsumerInfo GetConsumerInfoInternal(string streamName, string consumer
             return new ConsumerInfo(m, true);
         }
 
-        internal ConsumerInfo CreateConsumerInternal(string streamName, ConsumerConfiguration config)
+        internal ConsumerInfo CreateConsumerInternal(string streamName, ConsumerConfiguration config, ConsumerCreateRequestAction ccrAction)
         {
             // ConsumerConfiguration validates that name and durable are the same if both are supplied.
             string consumerName = Validator.EmptyAsNull(config.Name);
@@ -145,7 +145,7 @@ internal ConsumerInfo CreateConsumerInternal(string streamName, ConsumerConfigur
                 subj = string.Format(JetStreamConstants.JsapiDurableCreate, streamName, durable);
             }
 
-            var ccr = new ConsumerCreateRequest(streamName, config);
+            var ccr = new ConsumerCreateRequest(streamName, config, ccrAction);
             var m = RequestResponseRequired(subj, ccr.Serialize(), Timeout);
             return new ConsumerInfo(m, true);
         }

src/NATS.Client/JetStream/JetStreamManagement.cs

@@ -89,7 +89,21 @@ public ConsumerInfo AddOrUpdateConsumer(string streamName, ConsumerConfiguration
         {
             Validator.ValidateStreamName(streamName, true);
             Validator.ValidateNotNull(config, nameof(config));
-            return CreateConsumerInternal(streamName, config);
+            return CreateConsumerInternal(streamName, config, ConsumerCreateRequestAction.CreateOrUpdate);
+        }
+
+        public ConsumerInfo CreateConsumer(string streamName, ConsumerConfiguration config)
+        {
+            Validator.ValidateStreamName(streamName, true);
+            Validator.ValidateNotNull(config, nameof(config));
+            return CreateConsumerInternal(streamName, config, ConsumerCreateRequestAction.Create);
+        }
+
+        public ConsumerInfo UpdateConsumer(string streamName, ConsumerConfiguration config)
+        {
+            Validator.ValidateStreamName(streamName, true);
+            Validator.ValidateNotNull(config, nameof(config));
+            return CreateConsumerInternal(streamName, config, ConsumerCreateRequestAction.Update);
         }
 
         public bool DeleteConsumer(string streamName, string consumer)

src/NATS.Client/JetStream/OrderedMessageManager.cs

@@ -92,7 +92,7 @@ private void HandleErrorCondition()
                 // 3. make a new consumer using the same deliver subject but
                 //    with a new starting point
                 ConsumerConfiguration userCc = Js.ConsumerConfigurationForOrdered(OriginalCc, LastStreamSeq, newDeliverSubject, actualConsumerName, null);
-                ConsumerInfo ci = Js.CreateConsumerInternal(Stream, userCc);
+                ConsumerInfo ci = Js.CreateConsumerInternal(Stream, userCc, ConsumerCreateRequestAction.Create);
                 if (Sub is JetStreamAbstractSyncSubscription syncSub)
                 {
                     syncSub.SetConsumerName(ci.Name);

src/Tests/IntegrationTests/TestJetStreamManagement.cs

@@ -1195,5 +1195,132 @@ public void TestPauseConsumer()
                 Assert.Throws<NATSJetStreamException>(() => jsm.ResumeConsumer(stream, Name()));
             });
         }
+
+        [Fact]
+        public void TestCreateConsumerUpdateConsumer()
+        {
+            Context.RunInJsServer(AtLeast2_9_0, c =>
+            {
+                string streamPrefix = Variant();
+                IJetStreamManagement jsmNew = c.CreateJetStreamManagementContext();
+                IJetStreamManagement jsmPre290 = c.CreateJetStreamManagementContext(
+                    JetStreamOptions.Builder().WithOptOut290ConsumerCreate(true).Build());
+
+                // --------------------------------------------------------
+                // New without filter
+                // --------------------------------------------------------
+                string stream1 = streamPrefix + "-new";
+                string name = Name();
+                string subject = Name();
+                CreateMemoryStream(jsmNew, stream1, subject + ".*");
+
+                ConsumerConfiguration cc11 = ConsumerConfiguration.Builder().WithName(name).Build();
+
+                // update no good when not exist
+                NATSJetStreamException e = Assert.Throws<NATSJetStreamException>(() => jsmNew.UpdateConsumer(stream1, cc11));
+                Assert.Equal(10149, e.ApiErrorCode);
+
+                // initial create ok
+                ConsumerInfo ci = jsmNew.CreateConsumer(stream1, cc11);
+                Assert.Equal(name, ci.Name);
+                Assert.Null(ci.ConsumerConfiguration.FilterSubject);
+
+                // any other create no good
+                e = Assert.Throws<NATSJetStreamException>(() => jsmNew.CreateConsumer(stream1, cc11));
+                Assert.Equal(10148, e.ApiErrorCode);
+
+                // update ok when exists
+                ConsumerConfiguration cc12 = ConsumerConfiguration.Builder().WithName(name).WithDescription(Variant()).Build();
+                ci = jsmNew.UpdateConsumer(stream1, cc12);
+                Assert.Equal(name, ci.Name);
+                Assert.Null(ci.ConsumerConfiguration.FilterSubject);
+
+                // --------------------------------------------------------
+                // New with filter subject
+                // --------------------------------------------------------
+                String stream2 = streamPrefix + "-new-fs";
+                name = Name();
+                subject = Name();
+                String fs1 = subject + ".A";
+                String fs2 = subject + ".B";
+                CreateMemoryStream(jsmNew, stream2, subject + ".*");
+
+                ConsumerConfiguration cc21 = ConsumerConfiguration.Builder().WithName(name).WithFilterSubject(fs1).Build();
+
+                // update no good when not exist
+                e = Assert.Throws<NATSJetStreamException>(() => jsmNew.UpdateConsumer(stream2, cc21));
+                Assert.Equal(10149, e.ApiErrorCode);
+
+                // initial create ok
+                ci = jsmNew.CreateConsumer(stream2, cc21);
+                Assert.Equal(name, ci.Name);
+                Assert.Equal(fs1, ci.ConsumerConfiguration.FilterSubject);
+
+                // any other create no good
+                e = Assert.Throws<NATSJetStreamException>(() => jsmNew.CreateConsumer(stream2, cc21));
+                Assert.Equal(10148, e.ApiErrorCode);
+
+                // update ok when exists
+                ConsumerConfiguration cc22 = ConsumerConfiguration.Builder().WithName(name).WithFilterSubjects(fs2).Build();
+                ci = jsmNew.UpdateConsumer(stream2, cc22);
+                Assert.Equal(name, ci.Name);
+                Assert.Equal(fs2, ci.ConsumerConfiguration.FilterSubject);
+
+                // --------------------------------------------------------
+                // Pre 290 durable pathway
+                // --------------------------------------------------------
+                String stream3 = streamPrefix + "-old-durable";
+                name = Name();
+                subject = Name();
+                fs1 = subject + ".A";
+                fs2 = subject + ".B";
+                String fs3 = subject + ".C";
+                CreateMemoryStream(jsmPre290, stream3, subject + ".*");
+
+                ConsumerConfiguration cc31 = ConsumerConfiguration.Builder().WithDurable(name).WithFilterSubject(fs1).Build();
+
+                // update no good when not exist
+                e = Assert.Throws<NATSJetStreamException>(() => jsmPre290.UpdateConsumer(stream3, cc31));
+                Assert.Equal(10149, e.ApiErrorCode);
+
+                // initial create ok
+                ci = jsmPre290.CreateConsumer(stream3, cc31);
+                Assert.Equal(name, ci.Name);
+                Assert.Equal(fs1, ci.ConsumerConfiguration.FilterSubject);
+
+                // opt out of 209, create on existing ok
+                // This is not exactly the same behavior as with the new consumer create api, but it's what the server does
+                jsmPre290.CreateConsumer(stream3, cc31);
+
+                ConsumerConfiguration cc32 = ConsumerConfiguration.Builder().WithDurable(name).WithFilterSubject(fs2).Build();
+                e = Assert.Throws<NATSJetStreamException>(() => jsmPre290.CreateConsumer(stream3, cc32));
+                Assert.Equal(10148, e.ApiErrorCode);
+
+                // update ok when exists
+                ConsumerConfiguration cc33 = ConsumerConfiguration.Builder().WithDurable(name).WithFilterSubjects(fs3).Build();
+                ci = jsmPre290.UpdateConsumer(stream3, cc33);
+                Assert.Equal(name, ci.Name);
+                Assert.Equal(fs3, ci.ConsumerConfiguration.FilterSubject);
+
+                // --------------------------------------------------------
+                // Pre 290 ephemeral pathway
+                // --------------------------------------------------------
+                subject = Name();
+
+                String stream4 = streamPrefix + "-old-ephemeral";
+                fs1 = subject + ".A";
+                CreateMemoryStream(jsmPre290, stream4, subject + ".*");
+
+                ConsumerConfiguration cc4 = ConsumerConfiguration.Builder().WithFilterSubject(fs1).Build();
+
+                // update no good when not exist
+                e = Assert.Throws<NATSJetStreamException>(() => jsmPre290.UpdateConsumer(stream4, cc4));
+                Assert.Equal(10149, e.ApiErrorCode);
+
+                // initial create ok
+                ci = jsmPre290.CreateConsumer(stream4, cc4);
+                Assert.Equal(fs1, ci.ConsumerConfiguration.FilterSubject);
+            });
+        }
     }
 }

src/Tests/UnitTests/JetStream/TestConsumerConfiguration.cs

@@ -60,7 +60,7 @@ public void BuilderWorks()
 
             AssertAsBuilt(c, dt);
 
-            ConsumerCreateRequest ccr = new ConsumerCreateRequest("stream", c);
+            ConsumerCreateRequest ccr = new ConsumerCreateRequest("stream", c, ConsumerCreateRequestAction.CreateOrUpdate);
             Assert.Equal("stream", ccr.StreamName);
             Assert.NotNull(ccr.Config);