solution: refactoring

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

@@ -58,7 +58,7 @@ class AccessHandler(
             headers: Metadata,
             next: ServerCallHandler<ReqT, RespT>
     ): ServerCall.Listener<ReqT> {
-        val builder = Events.SubscribeHeadBuilder()
+        val builder = EventsBuilder.SubscribeHead()
                 .start(headers, call.attributes)
         val callWrapper: ServerCall<ReqT, RespT> = OnSubscribeHeadResponse(
                 call as ServerCall<Common.Chain, BlockchainOuterClass.ChainHead>, builder, accessLogWriter) as ServerCall<ReqT, RespT>
@@ -74,7 +74,7 @@ class AccessHandler(
             headers: Metadata,
             next: ServerCallHandler<ReqT, RespT>
     ): ServerCall.Listener<ReqT> {
-        val builder = Events.NativeCallBuilder()
+        val builder = EventsBuilder.NativeCall()
                 .start(headers, call.attributes)
 
         val callWrapper: ServerCall<ReqT, RespT> = OnNativeCallResponse(
@@ -89,7 +89,7 @@ class AccessHandler(
 
     class OnSubscribeHead(
             val next: ServerCall.Listener<Common.Chain>,
-            val builder: Events.SubscribeHeadBuilder
+            val builder: EventsBuilder.SubscribeHead
     ) : ForwardingServerCallListener<Common.Chain>() {
 
         override fun onMessage(message: Common.Chain) {
@@ -105,7 +105,7 @@ class AccessHandler(
 
     class OnNativeCall(
             val next: ServerCall.Listener<BlockchainOuterClass.NativeCallRequest>,
-            val builder: Events.NativeCallBuilder,
+            val builder: EventsBuilder.NativeCall,
             val done: (List<Events.NativeCall>) -> Unit
     ) : ForwardingServerCallListener<BlockchainOuterClass.NativeCallRequest>() {
 
@@ -151,7 +151,7 @@ class AccessHandler(
 
     class OnNativeCallResponse(
             next: ServerCall<BlockchainOuterClass.NativeCallRequest, BlockchainOuterClass.NativeCallReplyItem>,
-            val builder: Events.NativeCallBuilder
+            val builder: EventsBuilder.NativeCall
     ) : BaseCallResponse<BlockchainOuterClass.NativeCallRequest, BlockchainOuterClass.NativeCallReplyItem>(next) {
 
         override fun sendMessage(message: BlockchainOuterClass.NativeCallReplyItem) {
@@ -162,7 +162,7 @@ class AccessHandler(
 
     class OnSubscribeHeadResponse(
             next: ServerCall<Common.Chain, BlockchainOuterClass.ChainHead>,
-            val builder: Events.SubscribeHeadBuilder,
+            val builder: EventsBuilder.SubscribeHead,
             val accessLogWriter: AccessLogWriter
     ) : BaseCallResponse<Common.Chain, BlockchainOuterClass.ChainHead>(next) {
 

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

@@ -98,148 +98,4 @@ class Events {
             val ts: Instant = Instant.now()
     )
 
-    abstract class BaseBuilder<T>() {
-        companion object {
-            private val remoteIpKeys = listOf(
-                    Metadata.Key.of("x-real-ip", Metadata.ASCII_STRING_MARSHALLER),
-                    Metadata.Key.of("x-forwarded-for", Metadata.ASCII_STRING_MARSHALLER)
-            )
-            private val invalidCharacters = Regex("[\n\t]+")
-        }
-
-        var requestDetails = StreamRequestDetails(
-                UUID.randomUUID(),
-                Instant.now(),
-                Remote(emptyList(), "", "")
-        )
-
-        var chainId: Int = Chain.UNSPECIFIED.id
-        var chain = Chain.UNSPECIFIED
-
-        private fun toInetAddress(ip: String): InetAddress? {
-            val isIp = Character.digit(ip[0], 16) != -1
-            if (!isIp) {
-                return null
-            }
-            return try {
-                InetAddress.getByName(ip)
-            } catch (t: Throwable) {
-                null
-            }
-        }
-
-        private fun findBestIp(ips: List<InetAddress>): InetAddress? {
-            // check if a real remote address is provided, otherwise use any local address
-            return ips.sortedWith(kotlin.Comparator { a, b ->
-                val aLocal = a.isLoopbackAddress || a.isSiteLocalAddress
-                val bLocal = b.isLoopbackAddress || b.isSiteLocalAddress
-                when {
-                    aLocal && bLocal -> 0
-                    aLocal -> 1
-                    else -> -1
-                }
-            }).firstOrNull()
-        }
-
-        private fun clean(s: String): String {
-            return StringUtils.truncate(s, 128)
-                    .replace(invalidCharacters, " ")
-                    .trim()
-        }
-
-        abstract protected fun getT(): T
-
-        fun start(metadata: Metadata, attributes: Attributes): T {
-            val userAgent = metadata.get(Metadata.Key.of("user-agent", Metadata.ASCII_STRING_MARSHALLER))
-                    ?.let(this@BaseBuilder::clean)
-                    ?: ""
-            val ips = ArrayList<InetAddress>()
-            remoteIpKeys.forEach { key ->
-                metadata.get(key)?.let {
-                    it.trim().ifEmpty { null }
-                            ?.let(this@BaseBuilder::toInetAddress)
-                            ?.let(ips::add)
-                }
-            }
-            attributes.get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR)?.let { addr ->
-                if (addr is InetSocketAddress) {
-                    ips.add(addr.address)
-                }
-            }
-            val ip = findBestIp(ips)?.hostAddress ?: ""
-            this.requestDetails = this.requestDetails
-                    .copy(remote = Remote(
-                            ips = ips.map { it.hostAddress },
-                            ip = ip,
-                            userAgent = userAgent
-                    ))
-            return getT()
-        }
-
-        fun withChain(chain: Int): T {
-            this.chainId = chain
-            this.chain = Chain.byId(chainId)
-            return getT()
-        }
-    }
-
-    class SubscribeHeadBuilder() : BaseBuilder<SubscribeHeadBuilder>() {
-        private var index = 0
-
-        override fun getT(): SubscribeHeadBuilder {
-            return this
-        }
-
-        fun onReply(resp: BlockchainOuterClass.ChainHead): SubscribeHead {
-            return SubscribeHead(
-                    chain, UUID.randomUUID(), requestDetails, index++
-            )
-        }
-    }
-
-    class NativeCallBuilder : BaseBuilder<NativeCallBuilder>() {
-
-        val items = ArrayList<NativeCallItemDetails>()
-        val replies = HashMap<Int, NativeCallReplyDetails>()
-
-        override fun getT(): NativeCallBuilder {
-            return this
-        }
-
-        fun onItem(item: BlockchainOuterClass.NativeCallItem): NativeCallBuilder {
-            this.items.add(
-                    NativeCallItemDetails(
-                            item.method,
-                            item.id,
-                            item.payload.size().toLong()
-                    )
-            )
-            return this
-        }
-
-        fun onItemReply(reply: BlockchainOuterClass.NativeCallReplyItem): NativeCallBuilder {
-            this.replies[reply.id] = NativeCallReplyDetails(
-                    reply.id,
-                    reply.succeed,
-                    reply.payload?.size()?.toLong() ?: 0L
-            )
-            return this
-        }
-
-        fun build(): List<NativeCall> {
-            return items.mapIndexed { index, item ->
-                val reply = replies[item.id]
-                NativeCall(
-                        request = requestDetails,
-                        total = items.size,
-                        index = index,
-                        succeed = reply?.succeed ?: false,
-                        blockchain = chain,
-                        nativeCall = item,
-                        payloadSizeBytes = item.payloadSizeBytes,
-                        id = UUID.randomUUID()
-                )
-            }
-        }
-    }
 }

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

@@ -0,0 +1,180 @@
+/**
+ * Copyright (c) 2021 EmeraldPay, Inc
+ *
+ * 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
+ *
+ *        http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package io.emeraldpay.dshackle.monitoring.accesslog
+
+import io.emeraldpay.api.proto.BlockchainOuterClass
+import io.emeraldpay.grpc.Chain
+import io.grpc.Attributes
+import io.grpc.Grpc
+import io.grpc.Metadata
+import org.apache.commons.lang3.StringUtils
+import org.slf4j.LoggerFactory
+import java.net.InetAddress
+import java.net.InetSocketAddress
+import java.time.Instant
+import java.util.*
+
+class EventsBuilder {
+
+    companion object {
+        private val log = LoggerFactory.getLogger(EventsBuilder::class.java)
+    }
+
+    abstract class Base<T>() {
+        companion object {
+            private val remoteIpKeys = listOf(
+                    Metadata.Key.of("x-real-ip", Metadata.ASCII_STRING_MARSHALLER),
+                    Metadata.Key.of("x-forwarded-for", Metadata.ASCII_STRING_MARSHALLER)
+            )
+            private val invalidCharacters = Regex("[\n\t]+")
+        }
+
+        var requestDetails = Events.StreamRequestDetails(
+                UUID.randomUUID(),
+                Instant.now(),
+                Events.Remote(emptyList(), "", "")
+        )
+
+        var chainId: Int = Chain.UNSPECIFIED.id
+        var chain = Chain.UNSPECIFIED
+
+        private fun toInetAddress(ip: String): InetAddress? {
+            val isIp = Character.digit(ip[0], 16) != -1
+            if (!isIp) {
+                return null
+            }
+            return try {
+                InetAddress.getByName(ip)
+            } catch (t: Throwable) {
+                null
+            }
+        }
+
+        private fun findBestIp(ips: List<InetAddress>): InetAddress? {
+            // check if a real remote address is provided, otherwise use any local address
+            return ips.sortedWith(kotlin.Comparator { a, b ->
+                val aLocal = a.isLoopbackAddress || a.isSiteLocalAddress
+                val bLocal = b.isLoopbackAddress || b.isSiteLocalAddress
+                when {
+                    aLocal && bLocal -> 0
+                    aLocal -> 1
+                    else -> -1
+                }
+            }).firstOrNull()
+        }
+
+        private fun clean(s: String): String {
+            return StringUtils.truncate(s, 128)
+                    .replace(invalidCharacters, " ")
+                    .trim()
+        }
+
+        abstract protected fun getT(): T
+
+        fun start(metadata: Metadata, attributes: Attributes): T {
+            val userAgent = metadata.get(Metadata.Key.of("user-agent", Metadata.ASCII_STRING_MARSHALLER))
+                    ?.let(this@Base::clean)
+                    ?: ""
+            val ips = ArrayList<InetAddress>()
+            remoteIpKeys.forEach { key ->
+                metadata.get(key)?.let {
+                    it.trim().ifEmpty { null }
+                            ?.let(this@Base::toInetAddress)
+                            ?.let(ips::add)
+                }
+            }
+            attributes.get(Grpc.TRANSPORT_ATTR_REMOTE_ADDR)?.let { addr ->
+                if (addr is InetSocketAddress) {
+                    ips.add(addr.address)
+                }
+            }
+            val ip = findBestIp(ips)?.hostAddress ?: ""
+            this.requestDetails = this.requestDetails
+                    .copy(remote = Events.Remote(
+                            ips = ips.map { it.hostAddress },
+                            ip = ip,
+                            userAgent = userAgent
+                    ))
+            return getT()
+        }
+
+        fun withChain(chain: Int): T {
+            this.chainId = chain
+            this.chain = Chain.byId(chainId)
+            return getT()
+        }
+    }
+
+    class SubscribeHead() : Base<SubscribeHead>() {
+        private var index = 0
+
+        override fun getT(): SubscribeHead {
+            return this
+        }
+
+        fun onReply(resp: BlockchainOuterClass.ChainHead): Events.SubscribeHead {
+            return Events.SubscribeHead(
+                    chain, UUID.randomUUID(), requestDetails, index++
+            )
+        }
+    }
+
+    class NativeCall : Base<NativeCall>() {
+
+        val items = ArrayList<Events.NativeCallItemDetails>()
+        val replies = HashMap<Int, Events.NativeCallReplyDetails>()
+
+        override fun getT(): NativeCall {
+            return this
+        }
+
+        fun onItem(item: BlockchainOuterClass.NativeCallItem): NativeCall {
+            this.items.add(
+                    Events.NativeCallItemDetails(
+                            item.method,
+                            item.id,
+                            item.payload.size().toLong()
+                    )
+            )
+            return this
+        }
+
+        fun onItemReply(reply: BlockchainOuterClass.NativeCallReplyItem): NativeCall {
+            this.replies[reply.id] = Events.NativeCallReplyDetails(
+                    reply.id,
+                    reply.succeed,
+                    reply.payload?.size()?.toLong() ?: 0L
+            )
+            return this
+        }
+
+        fun build(): List<Events.NativeCall> {
+            return items.mapIndexed { index, item ->
+                val reply = replies[item.id]
+                Events.NativeCall(
+                        request = requestDetails,
+                        total = items.size,
+                        index = index,
+                        succeed = reply?.succeed ?: false,
+                        blockchain = chain,
+                        nativeCall = item,
+                        payloadSizeBytes = item.payloadSizeBytes,
+                        id = UUID.randomUUID()
+                )
+            }
+        }
+    }
+}

src/test/groovy/io/emeraldpay/dshackle/monitoring/accesslog/EventsBaseBuilderSpec.groovy

@@ -32,7 +32,7 @@ class EventsBaseBuilderSpec extends Specification {
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InetSocketAddress(Inet4Address.getByName("127.0.0.1"), 2448))
                 .build()
         when:
-        def act = new Events.NativeCallBuilder()
+        def act = new EventsBuilder.NativeCall()
                 .start(metadata, attributes)
                 .withChain(Chain.ETHEREUM.id)
                 .onItem(BlockchainOuterClass.NativeCallItem.getDefaultInstance())
@@ -59,7 +59,7 @@ class EventsBaseBuilderSpec extends Specification {
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InetSocketAddress(Inet4Address.getByName("127.0.0.1"), 2448))
                 .build()
         when:
-        def act = new Events.NativeCallBuilder()
+        def act = new EventsBuilder.NativeCall()
                 .start(metadata, attributes)
                 .withChain(Chain.ETHEREUM.id)
                 .onItem(BlockchainOuterClass.NativeCallItem.getDefaultInstance())
@@ -81,7 +81,7 @@ class EventsBaseBuilderSpec extends Specification {
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InetSocketAddress(Inet4Address.getByName("30.56.100.15"), 2448))
                 .build()
         when:
-        def act = new Events.NativeCallBuilder()
+        def act = new EventsBuilder.NativeCall()
                 .start(metadata, attributes)
                 .withChain(Chain.ETHEREUM.id)
                 .onItem(BlockchainOuterClass.NativeCallItem.getDefaultInstance())
@@ -104,7 +104,7 @@ class EventsBaseBuilderSpec extends Specification {
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InetSocketAddress(Inet4Address.getByName("30.56.100.15"), 2448))
                 .build()
         when:
-        def act = new Events.NativeCallBuilder()
+        def act = new EventsBuilder.NativeCall()
                 .start(metadata, attributes)
                 .withChain(Chain.ETHEREUM.id)
                 .onItem(BlockchainOuterClass.NativeCallItem.getDefaultInstance())
@@ -127,7 +127,7 @@ class EventsBaseBuilderSpec extends Specification {
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InetSocketAddress(Inet4Address.getByName("30.56.100.15"), 2448))
                 .build()
         when:
-        def act = new Events.NativeCallBuilder()
+        def act = new EventsBuilder.NativeCall()
                 .start(metadata, attributes)
                 .withChain(Chain.ETHEREUM.id)
                 .onItem(BlockchainOuterClass.NativeCallItem.getDefaultInstance())
@@ -150,7 +150,7 @@ class EventsBaseBuilderSpec extends Specification {
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InetSocketAddress(Inet6Address.getByName("::1"), 2448))
                 .build()
         when:
-        def act = new Events.NativeCallBuilder()
+        def act = new EventsBuilder.NativeCall()
                 .start(metadata, attributes)
                 .withChain(Chain.ETHEREUM.id)
                 .onItem(BlockchainOuterClass.NativeCallItem.getDefaultInstance())
@@ -171,7 +171,7 @@ class EventsBaseBuilderSpec extends Specification {
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InetSocketAddress(Inet4Address.getByName("30.56.100.15"), 2448))
                 .build()
         when:
-        def act = new Events.NativeCallBuilder()
+        def act = new EventsBuilder.NativeCall()
                 .start(metadata, attributes)
                 .withChain(Chain.ETHEREUM.id)
                 .onItem(BlockchainOuterClass.NativeCallItem.getDefaultInstance())
@@ -192,7 +192,7 @@ class EventsBaseBuilderSpec extends Specification {
                 .set(Grpc.TRANSPORT_ATTR_REMOTE_ADDR, new InetSocketAddress(Inet4Address.getByName("30.56.100.15"), 2448))
                 .build()
         when:
-        def act = new Events.NativeCallBuilder()
+        def act = new EventsBuilder.NativeCall()
                 .start(metadata, attributes)
                 .withChain(Chain.ETHEREUM.id)
                 .onItem(BlockchainOuterClass.NativeCallItem.getDefaultInstance())