ch05 progress: blockingServer

src/main/scala/ch05/blockingServer.scala

@@ -0,0 +1,57 @@
+package ch05.blockingServer
+
+import scalanative.unsafe.{sizeof, Ptr, CQuote}
+import scalanative.unsigned.{UShort, toUShort, toCSize}
+import scalanative.libc.stdlib.malloc
+import scalanative.libc.stdio.EOF
+import scalanative.libc.string.strlen
+import scalanative.posix.unistd
+import scalanative.posix.sys.socket
+import socket.{AF_INET, SOCK_STREAM, sockaddr}
+import scalanative.posix.netinet.in.{sockaddr_in, INADDR_ANY}
+import scalanative.posix.arpa.inet
+
+def serve(port: UShort): Unit =
+  // Allocate and initialize the server address
+  val addrSize = sizeof[sockaddr_in]
+  val serverAddress = malloc(addrSize).asInstanceOf[Ptr[sockaddr_in]] // 0.5: .cast[...]
+  !serverAddress.at1 = AF_INET.toUShort // IP Socket // 0.5: ._1
+  !serverAddress.at2 = inet.htons(port) // port // 0.5: ._2
+  !serverAddress.at3.at1 = INADDR_ANY // bind to 0.0.0.0 // 0.5: ._3._1
+  // needs to be cast back to Ptr[Byte] to be freed,
+
+  // Bind and listen on a socket
+  val sockFd = socket.socket(AF_INET, SOCK_STREAM, 0)
+  val serverSockAddr = serverAddress.asInstanceOf[Ptr[sockaddr]] // .cast[...]
+  val bindResult = socket.bind(sockFd, serverSockAddr, addrSize.toUInt)
+  println(s"bind returned $bindResult")
+
+  val listenResult = socket.listen(sockFd, 128)
+  println(s"listen returned $listenResult")
+  println(s"accepting connections on port $port")
+
+  // Main accept() loop
+  while true do
+    val connectionFd = socket.accept(sockFd, null, null)
+    println(s"accept returned fd $connectionFd")
+    // we will replace handleConnection with fork_and_handle shortly
+    handleConnection(connectionFd)
+
+  unistd.close(sockFd)
+
+def handleConnection(connSocket: Int, maxSize: Int = 1024): Unit =
+  import scala.util.boundary, boundary.break
+
+  val message = c"Connection accepted!  Enter a message and it will be echoed back\n"
+  val promptWrite = unistd.write(connSocket, message, strlen(message))
+  val lineBuffer = malloc(maxSize) // this is never freed, program ends before it can be.
+
+  boundary:
+    while true do
+      val bytesRead = unistd.read(connSocket, lineBuffer, maxSize.toCSize) // 0.5
+      println(s"read $bytesRead bytes")
+
+      if bytesRead == EOF then break() //  connection has been closed by the client
+
+      val bytesWritten = unistd.write(connSocket, lineBuffer, bytesRead.toCSize) // 0.5
+      println(s"wrote $bytesWritten bytes")