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use std::fmt::Debug;
use std::net::{ToSocketAddrs, UdpSocket};
use log::{debug, info};
use crate::Packet;
/// A connection to the display.
pub struct Connection {
socket: UdpSocket,
}
impl Connection {
/// Open a new UDP socket and connect to the provided host.
///
/// Note that this is UDP, which means that the open call can succeed even if the display is unreachable.
///
/// # Errors
///
/// Any errors resulting from binding the udp socket.
///
/// # Examples
/// ```rust
/// let connection = servicepoint2::Connection::open("172.23.42.29:2342")
/// .expect("connection failed");
/// ```
pub fn open(addr: impl ToSocketAddrs + Debug) -> std::io::Result<Self> {
info!("connecting to {addr:?}");
let socket = UdpSocket::bind("0.0.0.0:0")?;
socket.connect(addr)?;
Ok(Self { socket })
}
/// Send something packet-like to the display. Usually this is in the form of a Command.
///
/// # Arguments
///
/// * `packet`: the packet-like to send
///
/// returns: Ok if packet was sent, otherwise socket error
///
/// # Errors
///
/// Any errors produced while sending using the underlying socket.
///
/// # Examples
///
/// ```rust
/// use servicepoint2::{Command, CompressionCode, Grid, PixelGrid};
/// let connection = servicepoint2::Connection::open("172.23.42.29:2342")
/// .expect("connection failed");
///
/// // turn off all pixels
/// connection.send(Command::Clear.into())
/// .expect("send failed");
///
/// // turn on all pixels
/// let mut pixels = PixelGrid::max_sized();
/// pixels.fill(true);
///
/// // send pixels to display
/// connection.send(Command::BitmapLinearWin(servicepoint2::Origin(0, 0), pixels, CompressionCode::Uncompressed).into())
/// .expect("send failed");
/// ```
pub fn send(&self, packet: Packet) -> Result<(), std::io::Error> {
debug!("sending {packet:?}");
let data: Vec<u8> = packet.into();
self.socket.send(&data)?;
Ok(())
}
}
#[cfg(feature = "c_api")]
pub mod c_api {
use std::ffi::{c_char, CStr};
use std::ptr::null_mut;
use crate::{Connection, Packet};
/// Creates a new instance of Connection.
/// The returned instance has to be deallocated with `connection_dealloc`.
///
/// returns: NULL if connection fails or connected instance
///
/// Panics: bad string encoding
#[no_mangle]
pub unsafe extern "C" fn sp2_connection_open(
host: *const c_char,
) -> *mut Connection {
let host = CStr::from_ptr(host).to_str().expect("Bad encoding");
let connection = match Connection::open(host) {
Err(_) => return null_mut(),
Ok(value) => value,
};
Box::into_raw(Box::new(connection))
}
/// Sends the command instance. The instance is consumed / destroyed and cannot be used after this call.
#[no_mangle]
pub unsafe extern "C" fn sp2_connection_send(
connection: *const Connection,
command_ptr: *mut Packet,
) -> bool {
let packet = Box::from_raw(command_ptr);
(*connection).send(*packet).is_ok()
}
/// Closes and deallocates a connection instance
#[no_mangle]
pub unsafe extern "C" fn sp2_connection_dealloc(ptr: *mut Connection) {
_ = Box::from_raw(ptr);
}
}