Avoid allocations in TLSEngine when logging is disabled (#2462)

* Avoid allocations in TLSEngine when logging is disabled

* Scalafmt

* Scalafmt

* Fix 2.12 build

* Mima exclusions

* Scalafmt

build.sbt

@@ -95,7 +95,16 @@ ThisBuild / mimaBinaryIssueFilters ++= Seq(
   ProblemFilters.exclude[MissingClassProblem]("fs2.Pull$CloseScope$"),
   ProblemFilters.exclude[ReversedAbstractMethodProblem]("fs2.Pull#CloseScope.*"),
   ProblemFilters.exclude[Problem]("fs2.io.Watcher#Registration.*"),
-  ProblemFilters.exclude[Problem]("fs2.io.Watcher#DefaultWatcher.*")
+  ProblemFilters.exclude[Problem]("fs2.io.Watcher#DefaultWatcher.*"),
+  ProblemFilters.exclude[ReversedMissingMethodProblem]("fs2.io.net.tls.TLSContext.clientBuilder"),
+  ProblemFilters.exclude[ReversedMissingMethodProblem]("fs2.io.net.tls.TLSContext.serverBuilder"),
+  ProblemFilters.exclude[ReversedMissingMethodProblem](
+    "fs2.io.net.tls.TLSContext.dtlsClientBuilder"
+  ),
+  ProblemFilters.exclude[ReversedMissingMethodProblem](
+    "fs2.io.net.tls.TLSContext.dtlsServerBuilder"
+  ),
+  ProblemFilters.exclude[Problem]("fs2.io.net.tls.TLSEngine*")
 )
 
 lazy val root = project

core/shared/src/test/scala/fs2/StreamCombinatorsSuite.scala

@@ -25,7 +25,6 @@ import scala.concurrent.duration._
 import scala.concurrent.TimeoutException
 import cats.effect.{IO, SyncIO}
 import cats.effect.kernel.Ref
-import cats.effect.std.Queue
 import cats.effect.std.Semaphore
 import cats.syntax.all._
 import org.scalacheck.Gen
@@ -1316,7 +1315,7 @@ class StreamCombinatorsSuite extends Fs2Suite {
       val action =
         Vector.fill(streamSize)(Deferred[IO, Unit]).sequence.map { seenArr =>
           def peek(ind: Int)(f: Option[Unit] => Boolean) =
-            seenArr.get(ind).fold(true.pure[IO])(_.tryGet.map(f))
+            seenArr.get(ind.toLong).fold(true.pure[IO])(_.tryGet.map(f))
 
           Stream
             .emits(0 until streamSize)

io/src/main/scala/fs2/io/net/tls/TLSContext.scala

@@ -33,8 +33,7 @@ import javax.net.ssl.{
   SSLContext,
   SSLEngine,
   TrustManagerFactory,
-  X509ExtendedTrustManager,
-  X509TrustManager
+  X509ExtendedTrustManager
 }
 import cats.Applicative
 import cats.effect.kernel.{Async, Resource}
@@ -47,43 +46,85 @@ import java.util.function.BiFunction
   */
 sealed trait TLSContext[F[_]] {
 
-  /** Creates a `TLSSocket` in client mode, using the supplied parameters.
-    * Internal debug logging of the session can be enabled by passing a logger.
-    */
+  /** Creates a `TLSSocket` builder in client mode. */
+  def client(socket: Socket[F]): Resource[F, TLSSocket[F]] =
+    clientBuilder(socket).build
+
+  /** Creates a `TLSSocket` builder in client mode, allowing optional parameters to be configured. */
+  def clientBuilder(socket: Socket[F]): TLSContext.SocketBuilder[F, TLSSocket]
+
+  @deprecated("Use client(socket) or clientBuilder(socket).with(...).build", "3.0.6")
   def client(
       socket: Socket[F],
       params: TLSParameters = TLSParameters.Default,
       logger: Option[String => F[Unit]] = None
-  ): Resource[F, TLSSocket[F]]
+  ): Resource[F, TLSSocket[F]] =
+    clientBuilder(socket).withParameters(params).withOldLogging(logger).build
+
+  /** Creates a `TLSSocket` builder in server mode. */
+  def server(socket: Socket[F]): Resource[F, TLSSocket[F]] =
+    serverBuilder(socket).build
 
-  /** Creates a `TLSSocket` in server mode, using the supplied parameters.
-    * Internal debug logging of the session can be enabled by passing a logger.
-    */
+  /** Creates a `TLSSocket` builder in server mode, allowing optional parameters to be configured. */
+  def serverBuilder(socket: Socket[F]): TLSContext.SocketBuilder[F, TLSSocket]
+
+  @deprecated("Use server(socket) or serverBuilder(socket).with(...).build", "3.0.6")
   def server(
       socket: Socket[F],
       params: TLSParameters = TLSParameters.Default,
       logger: Option[String => F[Unit]] = None
-  ): Resource[F, TLSSocket[F]]
+  ): Resource[F, TLSSocket[F]] =
+    serverBuilder(socket).withParameters(params).withOldLogging(logger).build
+
+  /** Creates a `DTLSSocket` builder in client mode. */
+  def dtlsClient(
+      socket: DatagramSocket[F],
+      remoteAddress: SocketAddress[IpAddress]
+  ): Resource[F, DTLSSocket[F]] =
+    dtlsClientBuilder(socket, remoteAddress).build
+
+  /** Creates a `DTLSSocket` builder in client mode, allowing optional parameters to be configured. */
+  def dtlsClientBuilder(
+      socket: DatagramSocket[F],
+      remoteAddress: SocketAddress[IpAddress]
+  ): TLSContext.SocketBuilder[F, DTLSSocket]
 
-  /** Creates a `DTLSSocket` in client mode, using the supplied parameters.
-    * Internal debug logging of the session can be enabled by passing a logger.
-    */
+  @deprecated(
+    "Use dtlsClient(socket, remoteAddress) or dtlsClientBuilder(socket, remoteAddress).with(...).build",
+    "3.0.6"
+  )
   def dtlsClient(
       socket: DatagramSocket[F],
       remoteAddress: SocketAddress[IpAddress],
       params: TLSParameters = TLSParameters.Default,
       logger: Option[String => F[Unit]] = None
-  ): Resource[F, DTLSSocket[F]]
+  ): Resource[F, DTLSSocket[F]] =
+    dtlsClientBuilder(socket, remoteAddress).withParameters(params).withOldLogging(logger).build
 
-  /** Creates a `DTLSSocket` in server mode, using the supplied parameters.
-    * Internal debug logging of the session can be enabled by passing a logger.
-    */
+  /** Creates a `DTLSSocket` builder in server mode. */
+  def dtlsServer(
+      socket: DatagramSocket[F],
+      remoteAddress: SocketAddress[IpAddress]
+  ): Resource[F, DTLSSocket[F]] =
+    dtlsServerBuilder(socket, remoteAddress).build
+
+  /** Creates a `DTLSSocket` builder in client mode, allowing optional parameters to be configured. */
+  def dtlsServerBuilder(
+      socket: DatagramSocket[F],
+      remoteAddress: SocketAddress[IpAddress]
+  ): TLSContext.SocketBuilder[F, DTLSSocket]
+
+  @deprecated(
+    "Use dtlsServer(socket, remoteAddress) or dtlsClientBuilder(socket, remoteAddress).with(...).build",
+    "3.0.6"
+  )
   def dtlsServer(
       socket: DatagramSocket[F],
       remoteAddress: SocketAddress[IpAddress],
       params: TLSParameters = TLSParameters.Default,
       logger: Option[String => F[Unit]] = None
-  ): Resource[F, DTLSSocket[F]]
+  ): Resource[F, DTLSSocket[F]] =
+    dtlsServerBuilder(socket, remoteAddress).withParameters(params).withOldLogging(logger).build
 }
 
 object TLSContext {
@@ -128,35 +169,17 @@ object TLSContext {
           ctx: SSLContext
       ): TLSContext[F] =
         new TLSContext[F] {
-          def client(
-              socket: Socket[F],
-              params: TLSParameters,
-              logger: Option[String => F[Unit]]
-          ): Resource[F, TLSSocket[F]] =
-            mkSocket(
-              socket,
-              true,
-              params,
-              logger
-            )
-
-          def server(
-              socket: Socket[F],
-              params: TLSParameters,
-              logger: Option[String => F[Unit]]
-          ): Resource[F, TLSSocket[F]] =
-            mkSocket(
-              socket,
-              false,
-              params,
-              logger
-            )
+          def clientBuilder(socket: Socket[F]) =
+            SocketBuilder((p, l) => mkSocket(socket, true, p, l))
+
+          def serverBuilder(socket: Socket[F]) =
+            SocketBuilder((p, l) => mkSocket(socket, false, p, l))
 
           private def mkSocket(
               socket: Socket[F],
               clientMode: Boolean,
               params: TLSParameters,
-              logger: Option[String => F[Unit]]
+              logger: TLSLogger[F]
           ): Resource[F, TLSSocket[F]] =
             Resource
               .eval(
@@ -174,40 +197,24 @@ object TLSContext {
               )
               .flatMap(engine => TLSSocket(socket, engine))
 
-          def dtlsClient(
+          def dtlsClientBuilder(
               socket: DatagramSocket[F],
-              remoteAddress: SocketAddress[IpAddress],
-              params: TLSParameters,
-              logger: Option[String => F[Unit]]
-          ): Resource[F, DTLSSocket[F]] =
-            mkDtlsSocket(
-              socket,
-              remoteAddress,
-              true,
-              params,
-              logger
-            )
-
-          def dtlsServer(
+              remoteAddress: SocketAddress[IpAddress]
+          ) =
+            SocketBuilder((p, l) => mkDtlsSocket(socket, remoteAddress, true, p, l))
+
+          def dtlsServerBuilder(
               socket: DatagramSocket[F],
-              remoteAddress: SocketAddress[IpAddress],
-              params: TLSParameters,
-              logger: Option[String => F[Unit]]
-          ): Resource[F, DTLSSocket[F]] =
-            mkDtlsSocket(
-              socket,
-              remoteAddress,
-              false,
-              params,
-              logger
-            )
+              remoteAddress: SocketAddress[IpAddress]
+          ) =
+            SocketBuilder((p, l) => mkDtlsSocket(socket, remoteAddress, false, p, l))
 
           private def mkDtlsSocket(
               socket: DatagramSocket[F],
               remoteAddress: SocketAddress[IpAddress],
               clientMode: Boolean,
               params: TLSParameters,
-              logger: Option[String => F[Unit]]
+              logger: TLSLogger[F]
           ): Resource[F, DTLSSocket[F]] =
             Resource
               .eval(
@@ -230,7 +237,7 @@ object TLSContext {
               binding: TLSEngine.Binding[F],
               clientMode: Boolean,
               params: TLSParameters,
-              logger: Option[String => F[Unit]]
+              logger: TLSLogger[F]
           ): F[TLSEngine[F]] = {
             val sslEngine = Async[F].blocking {
               val engine = ctx.createSSLEngine()
@@ -345,4 +352,46 @@ object TLSContext {
           .map(fromSSLContext(_))
     }
   }
+
+  sealed trait SocketBuilder[F[_], S[_[_]]] {
+    def withParameters(params: TLSParameters): SocketBuilder[F, S]
+    def withLogging(log: (=> String) => F[Unit]): SocketBuilder[F, S]
+    def withoutLogging: SocketBuilder[F, S]
+    def withLogger(logger: TLSLogger[F]): SocketBuilder[F, S]
+    private[TLSContext] def withOldLogging(log: Option[String => F[Unit]]): SocketBuilder[F, S]
+    def build: Resource[F, S[F]]
+  }
+
+  object SocketBuilder {
+    private[TLSContext] type Build[F[_], S[_[_]]] =
+      (TLSParameters, TLSLogger[F]) => Resource[F, S[F]]
+
+    private[TLSContext] def apply[F[_], S[_[_]]](
+        mkSocket: Build[F, S]
+    ): SocketBuilder[F, S] =
+      instance(mkSocket, TLSParameters.Default, TLSLogger.Disabled)
+
+    private def instance[F[_], S[_[_]]](
+        mkSocket: Build[F, S],
+        params: TLSParameters,
+        logger: TLSLogger[F]
+    ): SocketBuilder[F, S] =
+      new SocketBuilder[F, S] {
+        def withParameters(params: TLSParameters): SocketBuilder[F, S] =
+          instance(mkSocket, params, logger)
+        def withLogging(log: (=> String) => F[Unit]): SocketBuilder[F, S] =
+          withLogger(TLSLogger.Enabled(log))
+        def withoutLogging: SocketBuilder[F, S] =
+          withLogger(TLSLogger.Disabled)
+        def withLogger(logger: TLSLogger[F]): SocketBuilder[F, S] =
+          instance(mkSocket, params, logger)
+        private[TLSContext] def withOldLogging(
+            log: Option[String => F[Unit]]
+        ): SocketBuilder[F, S] =
+          log.map(f => withLogging(m => f(m))).getOrElse(withoutLogging)
+        def build: Resource[F, S[F]] =
+          mkSocket(params, logger)
+      }
+  }
+
 }

io/src/main/scala/fs2/io/net/tls/TLSEngine.scala

@@ -54,7 +54,7 @@ private[tls] object TLSEngine {
   def apply[F[_]: Async](
       engine: SSLEngine,
       binding: Binding[F],
-      logger: Option[String => F[Unit]] = None
+      logger: TLSLogger[F]
   ): F[TLSEngine[F]] =
     for {
       wrapBuffer <- InputOutputBuffer[F](
@@ -70,8 +70,13 @@ private[tls] object TLSEngine {
       handshakeSemaphore <- Semaphore[F](1)
       sslEngineTaskRunner = SSLEngineTaskRunner[F](engine)
     } yield new TLSEngine[F] {
-      private def log(msg: String): F[Unit] =
-        logger.map(_(msg)).getOrElse(Applicative[F].unit)
+      private val doLog: (() => String) => F[Unit] =
+        logger match {
+          case e: TLSLogger.Enabled[_] => msg => e.log(msg())
+          case TLSLogger.Disabled      => _ => Applicative[F].unit
+        }
+
+      private def log(msg: => String): F[Unit] = doLog(() => msg)
 
       def beginHandshake = Sync[F].delay(engine.beginHandshake())
       def session = Sync[F].delay(engine.getSession())

io/src/main/scala/fs2/io/net/tls/TLSLogger.scala

@@ -0,0 +1,29 @@
+/*
+ * Copyright (c) 2013 Functional Streams for Scala
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy of
+ * this software and associated documentation files (the "Software"), to deal in
+ * the Software without restriction, including without limitation the rights to
+ * use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
+ * the Software, and to permit persons to whom the Software is furnished to do so,
+ * subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in all
+ * copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
+ * FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
+ * COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
+ * IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+package fs2.io.net.tls
+
+sealed trait TLSLogger[+F[_]]
+
+object TLSLogger {
+  case object Disabled extends TLSLogger[Nothing]
+  case class Enabled[F[_]](log: (=> String) => F[Unit]) extends TLSLogger[F]
+}

io/src/test/scala/fs2/io/net/tls/DTLSSocketSuite.scala

@@ -45,8 +45,14 @@ class DTLSSocketSuite extends TLSSuite {
         serverAddress <- address(serverSocket)
         clientSocket <- Network[IO].openDatagramSocket()
         clientAddress <- address(clientSocket)
-        tlsServerSocket <- tlsContext.dtlsServer(serverSocket, clientAddress, logger = logger)
-        tlsClientSocket <- tlsContext.dtlsClient(clientSocket, serverAddress, logger = logger)
+        tlsServerSocket <- tlsContext
+          .dtlsServerBuilder(serverSocket, clientAddress)
+          .withLogger(logger)
+          .build
+        tlsClientSocket <- tlsContext
+          .dtlsClientBuilder(clientSocket, serverAddress)
+          .withLogger(logger)
+          .build
       } yield (tlsServerSocket, tlsClientSocket, serverAddress)
 
       Stream

io/src/test/scala/fs2/io/net/tls/TLSDebugExample.scala

@@ -39,10 +39,11 @@ object TLSDebug {
     host.resolve.flatMap { socketAddress =>
       Network[F].client(socketAddress).use { rawSocket =>
         tlsContext
-          .client(
-            rawSocket,
+          .clientBuilder(rawSocket)
+          .withParameters(
             TLSParameters(serverNames = Some(List(new SNIHostName(host.host.toString))))
           )
+          .build
           .use { tlsSocket =>
             tlsSocket.write(Chunk.empty) >>
               tlsSocket.session.map { session =>