[.NET] Rework how users pass in topic tokens to invokers/executors/senders/receivers (#553)

Previously:
- Code gen'd classes publicly exposed several topic token fields that
were defined such that users could add to them, but our implementation
ignored any changes the user made.
- This led to a lot of confusion around how to set topic tokens properly
- Custom topic tokens on RPC requests and telemetry could only be set at
invoke/publish telemetry time. Not constructor time.
- Custom topic tokens could not be set on a telemetry receiver/command
executor, so they always subscribed to the DTDL topic with a wildcard
for each custom topic token

With some suggested requirements from @abhipsaMisra to allow our SDK to
be used in the upcoming ADR mRPC service, this proposed design allows
for:
- Code gen'd client/service classes allow a user to pass in a topic
token map at ctor time and it will be used for all
requests/subscriptions made by that client/service
- Code gen'd command invocation/telemetry send methods additionally take
an optional topic token map param that will resolve in addition to the
above ctor level token map
- Code gen'd telemetry command executor/receivers additionally take an
optional topic token map param that will resolve in addition to the
above ctor level token map

Note that the code gen'd output classes and our command/telemetry base
classes still give the user all the "default" topic token evaluation
that they would expect (i.e. invokerClientId token is handled for the
user automatically). Like before, users are only responsible for adding
custom topic tokens in their application layer.

Generally, this follows the patterns used by Rust and Go for handling
topic tokens

---------

Co-authored-by: timtay-microsoft <[email protected]>

Author: timtay-microsoft

.github/workflows/run-codegen.yml

@@ -13,6 +13,12 @@ jobs:
     steps:
       - uses: actions/checkout@v4
 
+      - name: Install Protoc
+        uses: arduino/setup-protoc@v3
+
+      - name: Install AvroGen
+        run: (pushd /; dotnet tool install --global Apache.Avro.Tools; popd) # need to install from root to avoid using the nuget.config we for build and push
+    
       - name: Setup .NET 8
         uses: actions/setup-dotnet@v4
         with:

codegen/src/Azure.Iot.Operations.ProtocolCompiler/T4/communication/dotnet/Command/t4/DotNetCommandExecutor.tt

@@ -36,38 +36,18 @@ namespace <#=this.projectName#>.<#=this.genNamespace.GetTypeName(TargetLanguage.
 <# } #>
         public class <#=this.commandName.GetTypeName(TargetLanguage.CSharp, "command", "executor")#> : CommandExecutor<#=this.TypeParams()#>
         {
-            private CombinedPrefixedReadOnlyDictionary<string> effectiveTopicTokenMap;
-
-            /// <summary>
-            /// Optionally initializes a custom token map to a dictionary that maps token values to replacement strings; defaults to new empty dictionary.
-            /// </summary>
-            public Dictionary<string, string> CustomTopicTokenMap { private get; init; } = new();
-
-            /// <summary>
-            /// Gets a dictionary for adding custom token keys and their replacement strings, which will be substituted in request and response topic patterns.
-            /// Note that keys will automatically be prefixed by "ex:" when used for substitution searches in topic pattern strings.
-            /// </summary>
-            public override Dictionary<string, string> TopicTokenMap { get => CustomTopicTokenMap; }
-
-            /// <summary>
-            /// Gets a dictionary used by the base class's code for substituting tokens in request and response topic patterns.
-            /// </summary>
-            protected override IReadOnlyDictionary<string, string> EffectiveTopicTokenMap { get => effectiveTopicTokenMap; }
-
             /// <summary>
             /// Initializes a new instance of the <see cref="<#=this.commandName.GetTypeName(TargetLanguage.CSharp, "command", "executor")#>"/> class.
             /// </summary>
             public <#=this.commandName.GetTypeName(TargetLanguage.CSharp, "command", "executor")#>(ApplicationContext applicationContext, IMqttPubSubClient mqttClient)
                 : base(applicationContext, mqttClient, "<#=this.commandName.AsGiven#>", new <#=string.Format(this.serializerClassName, this.TypeParams())#>())
             {
-                this.effectiveTopicTokenMap = new(string.Empty, (IReadOnlyDictionary<string, string>)base.TopicTokenMap, "ex:", this.CustomTopicTokenMap);
-
-                base.TopicTokenMap["modelId"] = "<#=this.modelId#>";
+                TopicTokenMap["modelId"] = "<#=this.modelId#>";
                 if (mqttClient.ClientId != null)
                 {
-                    base.TopicTokenMap["executorId"] = mqttClient.ClientId;
+                    TopicTokenMap["executorId"] = mqttClient.ClientId;
                 }
-                base.TopicTokenMap["commandName"] = "<#=this.commandName.AsGiven#>";
+                TopicTokenMap["commandName"] = "<#=this.commandName.AsGiven#>";
             }
         }
     }

codegen/src/Azure.Iot.Operations.ProtocolCompiler/T4/communication/dotnet/Command/t4/DotNetCommandInvoker.tt

@@ -25,24 +25,6 @@ namespace <#=this.projectName#>.<#=this.genNamespace.GetTypeName(TargetLanguage.
         /// </summary>
         public class <#=this.commandName.GetTypeName(TargetLanguage.CSharp, "command", "invoker")#> : CommandInvoker<#=this.TypeParams()#>
         {
-            private CombinedPrefixedReadOnlyDictionary<string> effectiveTopicTokenMap;
-
-            /// <summary>
-            /// Optionally initializes a custom token map to a dictionary that maps token values to replacement strings; defaults to new empty dictionary.
-            /// </summary>
-            public Dictionary<string, string> CustomTopicTokenMap { private get; init; } = new();
-
-            /// <summary>
-            /// Gets a dictionary for adding custom token keys and their replacement strings, which will be substituted in request and response topic patterns.
-            /// Note that keys will automatically be prefixed by "ex:" when used for substitution searches in topic pattern strings.
-            /// </summary>
-            public override Dictionary<string, string> TopicTokenMap { get => CustomTopicTokenMap; }
-
-            /// <summary>
-            /// Gets a dictionary used by the base class's code for substituting tokens in request and response topic patterns.
-            /// </summary>
-            protected override IReadOnlyDictionary<string, string> EffectiveTopicTokenMap { get => effectiveTopicTokenMap; }
-
             /// <summary>
             /// Initializes a new instance of the <see cref="<#=this.commandName.GetTypeName(TargetLanguage.CSharp, "command", "invoker")#>"/> class.
             /// </summary>
@@ -51,14 +33,12 @@ namespace <#=this.projectName#>.<#=this.genNamespace.GetTypeName(TargetLanguage.
             {
                 this.ResponseTopicPrefix = "clients/{invokerClientId}"; // default value, can be overwritten by user code
 
-                this.effectiveTopicTokenMap = new(string.Empty, (IReadOnlyDictionary<string, string>)base.TopicTokenMap, "ex:", this.CustomTopicTokenMap);
-
-                base.TopicTokenMap["modelId"] = "<#=this.modelId#>";
+                TopicTokenMap["modelId"] = "<#=this.modelId#>";
                 if (mqttClient.ClientId != null)
                 {
-                    base.TopicTokenMap["invokerClientId"] = mqttClient.ClientId;
+                    TopicTokenMap["invokerClientId"] = mqttClient.ClientId;
                 }
-                base.TopicTokenMap["commandName"] = "<#=this.commandName.AsGiven#>";
+                TopicTokenMap["commandName"] = "<#=this.commandName.AsGiven#>";
             }
         }
     }