A TCP echo server written in Terra using libuv

echo_server.t

uv = terralib.includecstring([[
  #include <uv.h>

  // Keep uv_write_s alive by tricking clang with a dummy function.
  void __ignore(uv_write_t*);
]])
terralib.linklibrary("libuv.dylib")

stdlib = terralib.includec("stdlib.h")
stdio = terralib.includec("stdio.h")

terra alloc_buffer(handle : &uv.uv_handle_t, suggested_size : uv.size_t) : uv.uv_buf_t
  return uv.uv_buf_init([&int8](stdlib.malloc(suggested_size)), suggested_size)
end

terra echo_write(req : &uv.uv_write_t, status : int)
  stdlib.free(req.data)
  stdlib.free(req)
end

terra echo_read(client : &uv.uv_stream_t, nread : uv.ssize_t, buf : uv.uv_buf_t)
  if nread == -1 then
    uv.uv_close([&uv.uv_handle_t](client), nil)
  end

  var req = [&uv.uv_write_t](stdlib.malloc(sizeof(uv.uv_write_t)))
  req.data = buf.base
  buf.len = nread
  uv.uv_write(req, client, &buf, 1, echo_write)
end

terra on_connect(server : &uv.uv_stream_t, status : int)
  if status == -1 then
    return
  end

  var client = [&uv.uv_tcp_t](stdlib.malloc(sizeof(uv.uv_tcp_t)))
  uv.uv_tcp_init(uv.uv_default_loop(), client)
  if uv.uv_accept(server, [&uv.uv_stream_t](client)) == 0 then
    uv.uv_read_start([&uv.uv_stream_t](client), alloc_buffer, echo_read)
  else
    uv.uv_close([&uv.uv_handle_t](client), nil)
  end
end

terra main()
  var loop = uv.uv_default_loop()

  var server : uv.uv_tcp_t;
  uv.uv_tcp_init(loop, &server)

  var bind_addr : uv.sockaddr_in = uv.uv_ip4_addr("0.0.0.0", 2000)
  uv.uv_tcp_bind(&server, bind_addr)

  uv.uv_listen([&uv.uv_stream_t](&server), 128, on_connect)

  uv.uv_run(loop, 0)
end

main()