x.net: new net module (#6130)

vlib/x/net/common.v

@@ -0,0 +1,122 @@
+module net
+
+import time
+
+// Shutdown shutsdown a socket and closes it
+fn shutdown(handle int) ? {
+	$if windows {
+		C.shutdown(handle, C.SD_BOTH)
+		socket_error(C.closesocket(handle))?
+	} $else {
+		C.shutdown(handle, C.SHUT_RDWR)
+		socket_error(C.close(handle))?
+	}
+
+	return none
+}
+
+// Select waits for an io operation (specified by parameter `test`) to be available
+fn @select(handle int, test Select, timeout time.Duration) ?bool {
+	set := C.fd_set{}
+
+	C.FD_ZERO(&set)
+	C.FD_SET(handle, &set)
+
+	seconds := timeout.milliseconds() / 1000
+	microseconds := timeout - (seconds * time.second)
+
+	mut tt := C.timeval{
+		tv_sec: u64(seconds)
+		tv_usec: u64(microseconds)
+	}
+
+	mut timeval_timeout := &tt
+
+	// infinite timeout is signaled by passing null as the timeout to
+	// select
+	if timeout == infinite_timeout {
+		timeval_timeout = &C.timeval(0)
+	}
+
+	match test {
+		.read {
+			socket_error(C.@select(handle+1, &set, C.NULL, C.NULL, timeval_timeout))?
+		}
+		.write {
+			socket_error(C.@select(handle+1, C.NULL, &set, C.NULL, timeval_timeout))?
+		}
+		.except {
+			socket_error(C.@select(handle+1, C.NULL, C.NULL, &set, timeval_timeout))?
+		}
+	}
+
+	return C.FD_ISSET(handle, &set)
+}
+
+// wait_for_common wraps the common wait code
+fn wait_for_common(
+	handle int,
+	deadline time.Time,
+	timeout time.Duration,
+	test Select) ? {
+	if deadline.unix == 0 {
+		// only accept infinite_timeout as a valid
+		// negative timeout - it is handled in @select however
+		if timeout < 0 && timeout != infinite_timeout {
+			return err_timed_out
+		}
+		ready := @select(handle, test, timeout)?
+		if ready {
+			return none
+		}
+		return err_timed_out
+	}
+	// Convert the deadline into a timeout
+	// and use that
+	d_timeout := deadline.unix - time.now().unix
+	if d_timeout < 0 {
+		// deadline is in the past so this has already
+		// timed out
+		return err_timed_out
+	}
+
+	ready := @select(handle, test, d_timeout)?
+	if ready {
+		return none
+	}
+	return err_timed_out
+}
+
+// wait_for_write waits for a write io operation to be available
+fn wait_for_write(
+	handle int,
+	deadline time.Time,
+	timeout time.Duration) ? {
+	return wait_for_common(handle, deadline, timeout, .write)
+}
+
+// wait_for_read waits for a read io operation to be available
+fn wait_for_read(
+	handle int,
+	deadline time.Time,
+	timeout time.Duration) ? {
+	return wait_for_common(handle, deadline, timeout, .read)
+}
+
+// no_deadline should be given to functions when no deadline is wanted (i.e. all functions
+// return instantly)
+const (
+	no_deadline = time.Time{unix: 0}
+)
+
+// no_timeout should be given to functions when no timeout is wanted (i.e. all functions
+// return instantly)
+const (
+	no_timeout = time.Duration(0)
+)
+
+// infinite_timeout should be given to functions when an infinite_timeout is wanted (i.e. functions
+// only ever return with data)
+const (
+	infinite_timeout = time.Duration(-1)
+)