linux-kcapi 0.1.1

//! Error definition for this crate

use std::error;
use std::fmt;

pub use nix::errno::Errno;

#[derive(Debug, PartialEq)]
/// KCAPI errors
pub enum Error {
    /// Error from C.
    /// See `man 3 errno`
    Sys(Errno),
    /// Operation did not complete
    Incomplete,
    /// Unknown error
    Unmanaged,
}

impl fmt::Display for Error {
    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
        match self {
            Error::Sys(e) => write!(f, "Error from C ({})", e),
            Error::Incomplete => write!(f, "Operation did not complete"),
            Error::Unmanaged => write!(f, "Unmanaged error"),
        }
    }
}

impl error::Error for Error {
    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
        None
    }
}

impl From<nix::Error> for Error {
    fn from(e: nix::Error) -> Self {
        Self::Sys(e)
    }
}

impl From<i32> for Error {
    fn from(error: i32) -> Self {
        Self::Sys(Errno::from_i32(error))
    }
}

use core::num::NonZeroU32;

#[cfg(feature = "rand_trait")]
impl Into<rand_core::Error> for Error {
    fn into(self) -> rand_core::Error {
        let r = unsafe { NonZeroU32::new_unchecked(0xFFFF_FFFF) };

        match self {
            Error::Sys(e) => NonZeroU32::new(e as u32)
                .map_or_else(|| rand_core::Error::from(r), rand_core::Error::from),
            _ => rand_core::Error::from(r),
        }
    }
}