Catch exceptions when parsing request header

Also make all class variables lazy just in case we don't use them
lichess-org · Feb 23, 2024 · c2446fa · c2446fa
1 parent 981950b
commit c2446fa
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Showing 2 changed files with 33 additions and 26 deletions.
diff --git a/src/main/scala/netty/RequestHandler.scala b/src/main/scala/netty/RequestHandler.scala
@@ -18,28 +18,30 @@ final private class RequestHandler(router: Router)(using Executor)
     ):
 
   override def channelRead0(ctx: ChannelHandlerContext, req: FullHttpRequest): Unit =
-    val request = util.RequestHeader(RequestUri(req.uri), req.headers)
-    router(request) foreach:
-      case Left(status) =>
-        sendErrorResponse(
-          ctx,
-          DefaultFullHttpResponse(req.protocolVersion(), status, Unpooled.EMPTY_BUFFER)
-        )
-        req.release()
-      case Right(_) if req.method != HttpMethod.GET =>
-        val response = DefaultFullHttpResponse(
-          req.protocolVersion(),
-          HttpResponseStatus.METHOD_NOT_ALLOWED,
-          Unpooled.EMPTY_BUFFER
-        )
-        response.headers.set(HttpHeaderNames.ALLOW, "GET")
-        sendErrorResponse(ctx, response)
-        req.release()
-      case Right(endpoint) =>
-        Monitor.mobile.connect(request)
-        // Forward to ProtocolHandler with endpoint attribute
-        ctx.channel.attr(ProtocolHandler.key.endpoint).set(endpoint)
-        ctx.fireChannelRead(req)
+    util
+      .RequestHeader(RequestUri(req.uri), req.headers)
+      .foreach: request =>
+        router(request).foreach:
+          case Left(status) =>
+            sendErrorResponse(
+              ctx,
+              DefaultFullHttpResponse(req.protocolVersion(), status, Unpooled.EMPTY_BUFFER)
+            )
+            req.release()
+          case Right(_) if req.method != HttpMethod.GET =>
+            val response = DefaultFullHttpResponse(
+              req.protocolVersion(),
+              HttpResponseStatus.METHOD_NOT_ALLOWED,
+              Unpooled.EMPTY_BUFFER
+            )
+            response.headers.set(HttpHeaderNames.ALLOW, "GET")
+            sendErrorResponse(ctx, response)
+            req.release()
+          case Right(endpoint) =>
+            Monitor.mobile.connect(request)
+            // Forward to ProtocolHandler with endpoint attribute
+            ctx.channel.attr(ProtocolHandler.key.endpoint).set(endpoint)
+            ctx.fireChannelRead(req)
 
   private def sendErrorResponse(ctx: ChannelHandlerContext, response: DefaultFullHttpResponse) =
     val f = ctx.writeAndFlush(response)

diff --git a/src/main/scala/util/RequestHeader.scala b/src/main/scala/util/RequestHeader.scala
@@ -12,11 +12,11 @@ object RequestUri extends OpaqueString[RequestUri]
 opaque type Domain = String
 object Domain extends OpaqueString[Domain]
 
-final class RequestHeader(val uri: RequestUri, headers: HttpHeaders):
+final class RequestHeader private (val uri: RequestUri, headers: HttpHeaders):
 
-  val (path, parameters) =
-    val qsd = QueryStringDecoder(uri.value)
-    (qsd.path, qsd.parameters)
+  lazy val qsd        = QueryStringDecoder(uri.value)
+  lazy val path       = qsd.path
+  lazy val parameters = qsd.parameters
 
   def header(name: CharSequence): Option[String] =
     Option(headers get name).filter(_.nonEmpty)
@@ -56,3 +56,8 @@ final class RequestHeader(val uri: RequestUri, headers: HttpHeaders):
   def domain = Domain(header(HttpHeaderNames.HOST) getOrElse "?")
 
   override def toString = s"$name origin: $origin"
+
+object RequestHeader:
+  import cats.syntax.all.*
+  def apply(uri: RequestUri, headers: HttpHeaders): Either[Throwable, RequestHeader] =
+    Either.catchNonFatal(new RequestHeader(uri, headers))