solution: access logging for SubscribeTxStatus method

src/main/kotlin/io/emeraldpay/dshackle/monitoring/accesslog/AccessHandler.kt

@@ -39,6 +39,7 @@ class AccessHandler(
         return when (val method = call.methodDescriptor.bareMethodName) {
             "SubscribeHead" -> processSubscribeHead(call, headers, next)
             "SubscribeBalance" -> processSubscribeBalance(call, headers, next, true)
+            "SubscribeTxStatus" -> processSubscribeTxStatus(call, headers, next)
             "GetBalance" -> processSubscribeBalance(call, headers, next, false)
             "NativeCall" -> processNativeCall(call, headers, next)
             else -> {
@@ -81,6 +82,22 @@ class AccessHandler(
         ) as ServerCall.Listener<ReqT>
     }
 
+    @Suppress("UNCHECKED_CAST")
+    private fun <ReqT : Any, RespT : Any> processSubscribeTxStatus(
+            call: ServerCall<ReqT, RespT>,
+            headers: Metadata,
+            next: ServerCallHandler<ReqT, RespT>
+    ): ServerCall.Listener<ReqT> {
+        val builder = EventsBuilder.TxStatus()
+                .start(headers, call.attributes)
+        val callWrapper: ServerCall<ReqT, RespT> = OnTxStatusResponse(
+                call as ServerCall<BlockchainOuterClass.TxStatusRequest, BlockchainOuterClass.TxStatus>, builder, accessLogWriter) as ServerCall<ReqT, RespT>
+        return OnSubscribeTxStatus(
+                next.startCall(callWrapper, headers) as ServerCall.Listener<BlockchainOuterClass.TxStatusRequest>,
+                builder
+        ) as ServerCall.Listener<ReqT>
+    }
+
     @Suppress("UNCHECKED_CAST")
     private fun <ReqT : Any, RespT : Any> processNativeCall(
             call: ServerCall<ReqT, RespT>,
@@ -131,6 +148,21 @@ class AccessHandler(
         }
     }
 
+    class OnSubscribeTxStatus(
+            val next: ServerCall.Listener<BlockchainOuterClass.TxStatusRequest>,
+            val builder: EventsBuilder.TxStatus
+    ) : ForwardingServerCallListener<BlockchainOuterClass.TxStatusRequest>() {
+
+        override fun onMessage(message: BlockchainOuterClass.TxStatusRequest) {
+            builder.withRequest(message)
+            super.onMessage(message)
+        }
+
+        override fun delegate(): ServerCall.Listener<BlockchainOuterClass.TxStatusRequest> {
+            return next
+        }
+    }
+
     class OnNativeCall(
             val next: ServerCall.Listener<BlockchainOuterClass.NativeCallRequest>,
             val builder: EventsBuilder.NativeCall,
@@ -213,4 +245,17 @@ class AccessHandler(
             super.sendMessage(message)
         }
     }
+
+    class OnTxStatusResponse(
+            next: ServerCall<BlockchainOuterClass.TxStatusRequest, BlockchainOuterClass.TxStatus>,
+            val builder: EventsBuilder.TxStatus,
+            val accessLogWriter: AccessLogWriter
+    ) : BaseCallResponse<BlockchainOuterClass.TxStatusRequest, BlockchainOuterClass.TxStatus>(next) {
+
+        override fun sendMessage(message: BlockchainOuterClass.TxStatus) {
+            val event = builder.onReply(message)
+            accessLogWriter.submit(event)
+            super.sendMessage(message)
+        }
+    }
 }

src/main/kotlin/io/emeraldpay/dshackle/monitoring/accesslog/Events.kt

@@ -57,6 +57,24 @@ class Events {
             val index: Int
     ) : ChainBase(blockchain, if (subscribe) "SubscribeBalance" else "GetBalance", id)
 
+    @JsonInclude(JsonInclude.Include.NON_NULL)
+    class TxStatus(
+            blockchain: Chain, id: UUID,
+            val request: StreamRequestDetails,
+            val txStatusRequest: TxStatusRequest,
+            val txStatus: TxStatusResponse,
+            // index of the current response
+            val index: Int
+    ) : ChainBase(blockchain, "SubscribeTxStatus", id)
+
+    data class TxStatusRequest(
+            val txId: String
+    )
+
+    data class TxStatusResponse(
+            val confirmations: Int
+    )
+
     @JsonInclude(JsonInclude.Include.NON_NULL)
     class NativeCall(
             blockchain: Chain, id: UUID,

src/main/kotlin/io/emeraldpay/dshackle/monitoring/accesslog/EventsBuilder.kt

@@ -160,6 +160,29 @@ class EventsBuilder {
         }
     }
 
+    class TxStatus() : Base<TxStatus>() {
+        private var index = 0
+        private var txStatusRequest: Events.TxStatusRequest? = null
+
+        fun withRequest(req: BlockchainOuterClass.TxStatusRequest): TxStatus {
+            this.txStatusRequest = Events.TxStatusRequest(req.txId)
+            return withChain(req.chainValue)
+        }
+
+        fun onReply(resp: BlockchainOuterClass.TxStatus): Events.TxStatus {
+            return Events.TxStatus(
+                    chain, UUID.randomUUID(), requestDetails, txStatusRequest!!,
+                    Events.TxStatusResponse(resp.confirmations),
+                    index++
+            )
+        }
+
+        override fun getT(): TxStatus {
+            return this
+        }
+
+    }
+
     class NativeCall : Base<NativeCall>() {
         val items = ArrayList<Events.NativeCallItemDetails>()
         val replies = HashMap<Int, Events.NativeCallReplyDetails>()