nng 0.3.0

//! Implementation details about implementing options.
use std::ptr;
use std::time::Duration;
use std::os::raw::{c_char, c_int, c_void};
use std::ffi::{CString, CStr};
use crate::error::{Result, ErrorKind};
use crate::addr::SocketAddr;

/// Exposes the ability to get and set the option.
///
/// This trait does not enforce the availability of any specific options on
/// any specific type. Calling these methods incorrectly will result in `nng`
/// returning an error code.
pub trait OptOps: super::Opt
{
	/// Get the value of the option using the specified type.
	fn get<T: HasOpts>(s: &T) -> Result<Self::OptType>;

	/// Set the value of the option using the specified type.
	fn set<T: HasOpts>(s: &T, val: Self::OptType) -> Result<()>;
}

/// Marks a type that can get and set `nng` options.
pub trait HasOpts: Sized
{
	/// Underlying `nng` type.
	type Handle;

	/// Raw `nng` function for getting a boolean option.
	const GETOPT_BOOL: unsafe extern "C" fn(Self::Handle, *const c_char, *mut bool) -> c_int;
	/// Rawn `nng` funcion for getting an integer otion.
	const GETOPT_INT: unsafe extern "C" fn(Self::Handle, *const c_char, *mut c_int) -> c_int;
	/// Raw `nng` function to get an `nng_duration`.
	const GETOPT_MS: unsafe extern "C" fn(Self::Handle, *const c_char, *mut nng_sys::nng_duration) -> c_int;
	/// Raw `nng` function for getting a `size_t` option.
	const GETOPT_SIZE: unsafe extern "C" fn(Self::Handle, *const c_char, *mut usize) -> c_int;
	/// Raw `nng` function for getting an `nng_sockaddr` option.
	const GETOPT_SOCKADDR: unsafe extern "C" fn(Self::Handle, *const c_char, *mut nng_sys::nng_sockaddr) -> c_int;
	/// Raw `nng` function for getting a string value.
	const GETOPT_STRING: unsafe extern "C" fn(Self::Handle, *const c_char, *mut *mut c_char) -> c_int;

	/// Raw `nng` function for setting opaque data.
	const SETOPT: unsafe extern "C" fn (Self::Handle, *const c_char, *const c_void, usize) -> c_int;
	/// Raw `nng` function for setting a boolean.
	const SETOPT_BOOL: unsafe extern "C" fn(Self::Handle, *const c_char, bool) -> c_int;
	/// Raw `nng` function to set an integer.
	const SETOPT_INT: unsafe extern "C" fn(Self::Handle, *const c_char, c_int) -> c_int;
	/// Raw `nng` function to set an `nng_duration`.
	const SETOPT_MS: unsafe extern "C" fn(Self::Handle, *const c_char, nng_sys::nng_duration) -> c_int;
	/// Raw `nng` function to set a `size_t` option.
	const SETOPT_SIZE: unsafe extern "C" fn(Self::Handle, *const c_char, usize) -> c_int;
	/// Raw `nng` function to set a string value.
	const SETOPT_STRING: unsafe extern "C" fn(Self::Handle, *const c_char, *const c_char) -> c_int;

	/// Returns the underlying `nng` type.
	fn handle(&self) -> Self::Handle;

	/// Get the boolean option.
	fn getopt_bool(&self, opt: *const c_char) -> Result<bool>
	{
		let mut raw = false;
		let rv = unsafe {
			(Self::GETOPT_BOOL)(self.handle(), opt, &mut raw as _)
		};

		rv2res!(rv, raw)
	}

	/// Get an integer option.
	fn getopt_int(&self, opt: *const c_char) -> Result<i32>
	{
		let mut res = 0;
		let rv = unsafe {
			(Self::GETOPT_INT)(self.handle(), opt, &mut res as _)
		};

		rv2res!(rv, res)
	}

	/// Get the duration from the option.
	fn getopt_ms(&self, opt: *const c_char) -> Result<Option<Duration>>
	{
		let mut dur: nng_sys::nng_duration = 0;
		let rv = unsafe {
			(Self::GETOPT_MS)(self.handle(), opt, &mut dur as _)
		};

		rv2res!(rv, crate::nng_to_duration(dur))
	}

	/// Get the `size_t` option.
	fn getopt_size(&self, opt: *const c_char) -> Result<usize>
	{
		let mut sz = 0;
		let rv = unsafe {
			(Self::GETOPT_SIZE)(self.handle(), opt, &mut sz as _)
		};

		rv2res!(rv, sz)
	}

	/// Get the specified socket address option.
	fn getopt_sockaddr(&self, opt: *const c_char) -> Result<SocketAddr>
	{
		unsafe {
			let mut addr: nng_sys::nng_sockaddr = std::mem::uninitialized();
			let rv = (Self::GETOPT_SOCKADDR)(self.handle(), opt, &mut addr as _);

			rv2res!(rv, addr.into())
		}
	}

	/// Get the string value of the specified option.
	fn getopt_string(&self, opt: *const c_char) -> Result<String>
	{
		unsafe {
			let mut ptr: *mut c_char = ptr::null_mut();
			let rv = (Self::GETOPT_STRING)(self.handle(), opt, &mut ptr as *mut _);
			validate_ptr!(rv, ptr);

			let name = CStr::from_ptr(ptr).to_string_lossy().into_owned();
			nng_sys::nng_strfree(ptr);

			Ok(name)
		}
	}

	/// Sets the value of opaque data.
	fn setopt(&self, opt: *const c_char, val: &[u8]) -> Result<()>
	{
		let rv = unsafe {
			(Self::SETOPT)(self.handle(), opt, val.as_ptr() as _, val.len())
		};

		rv2res!(rv)
	}

	/// Sets the value of a boolean option.
	fn setopt_bool(&self, opt: *const c_char, val: bool) -> Result<()>
	{
		let rv = unsafe {
			(Self::SETOPT_BOOL)(self.handle(), opt, val)
		};

		rv2res!(rv)
	}

	/// Set the value of an integer option.
	fn setopt_int(&self, opt: *const c_char, val: i32) -> Result<()>
	{
		let rv = unsafe {
			(Self::SETOPT_INT)(self.handle(), opt, val)
		};

		rv2res!(rv)
	}

	/// Set the duration to the option.
	fn setopt_ms(&self, opt: *const c_char, dur: Option<Duration>) -> Result<()>
	{
		let ms = crate::duration_to_nng(dur);

		let rv = unsafe {
			(Self::SETOPT_MS)(self.handle(), opt, ms)
		};
		rv2res!(rv)
	}

	/// Set the value of a `size` option.
	fn setopt_size(&self, opt: *const c_char, val: usize) -> Result<()>
	{
		let rv = unsafe {
			(Self::SETOPT_SIZE)(self.handle(), opt, val)
		};

		rv2res!(rv)
	}

	/// Set the value of the option to the value of the string.
	fn setopt_string(&self, opt: *const c_char, val: &str) -> Result<()>
	{
		let cval = CString::new(val).map_err(|_| ErrorKind::InvalidInput)?;
		let rv = unsafe {
			(Self::SETOPT_STRING)(self.handle(), opt, cval.as_ptr())
		};

		rv2res!(rv)
	}
}