RosettaCodeData/Task/Echo-server/Wren/echo-server-1.wren
2023-12-16 21:33:55 -08:00

139 lines
2.8 KiB
Text

/* Echo_server.wren */
var MAX_ENQUEUED = 20
var BUF_LEN = 256
var PORT_STR = "12321"
var AF_UNSPEC = 0
var SOCK_STREAM = 1
var AI_PASSIVE = 1
foreign class AddrInfo {
foreign static getAddrInfo(name, service, req, pai)
construct new() {}
foreign family
foreign family=(f)
foreign sockType
foreign sockType=(st)
foreign flags
foreign flags=(f)
foreign protocol
foreign addr
foreign addrLen
}
foreign class AddrInfoPtr {
construct new() {}
foreign deref
foreign free()
}
class Socket {
foreign static create(domain, type, protocol)
foreign static bind(fd, addr, len)
foreign static listen(fd, n)
foreign static accept(fd, addr, addrLen)
}
foreign class SockAddrPtr {
construct new() {}
foreign size
}
class SigAction {
foreign static cleanUpProcesses()
}
foreign class Buffer {
construct new(size) {}
}
class Posix {
foreign static read(fd, buf, nbytes)
foreign static write(fd, buf, n)
foreign static fork()
foreign static close(fd)
}
// Child process.
var echoLines = Fn.new { |csock|
var buf = Buffer.new(BUF_LEN)
var r
while ((r = Posix.read(csock, buf, BUF_LEN)) > 0) {
Posix.write(csock, buf, r)
}
}
// Parent process.
var takeConnectionsForever = Fn.new { |ssock|
while (true) {
var addr = SockAddrPtr.new()
var addrSize = addr.size
/* Block until we take one connection to the server socket */
var csock = Socket.accept(ssock, addr, addrSize)
/* If it was a successful connection, spawn a worker process to service it. */
if (csock == -1) {
System.print("Error accepting socket.")
} else if (Posix.fork() == 0) {
Posix.close(ssock)
echoLines.call(csock)
return
} else {
Posix.close(csock)
}
}
}
/* Look up the address to bind to. */
var hints = AddrInfo.new()
hints.family = AF_UNSPEC
hints.sockType = SOCK_STREAM
hints.flags = AI_PASSIVE
var addrInfoPtr = AddrInfoPtr.new()
if (AddrInfo.getAddrInfo("", PORT_STR, hints, addrInfoPtr) != 0) {
Fiber.abort("Failed to get pointer to addressinfo.")
}
/* Make a socket. */
var res = addrInfoPtr.deref
var sock = Socket.create(res.family, res.sockType, res.protocol)
if (sock == -1) Fiber.abort("Failed to make a socket.")
/* Arrange to clean up child processes (the workers). */
SigAction.cleanUpProcesses()
/* Associate the socket with its address. */
if (Socket.bind(sock, res.addr, res.addrLen) != 0) {
Fiber.abort("Failed to bind socket.")
}
addrInfoPtr.free()
/* State that we've opened a server socket and are listening for connections. */
if (Socket.listen(sock, MAX_ENQUEUED) != 0) {
Fiber.abort("Failed to listen for connections.")
}
/* Serve the listening socket until killed */
takeConnectionsForever.call(sock)