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use core::fmt;
use core::num::NonZeroU32;
#[derive(Copy, Clone, Eq, PartialEq)]
pub struct Error(NonZeroU32);
impl Error {
#[deprecated(since = "0.1.7")]
pub const UNKNOWN: Error = UNSUPPORTED;
#[deprecated(since = "0.1.7")]
pub const UNAVAILABLE: Error = UNSUPPORTED;
pub const INTERNAL_START: u32 = 1 << 31;
pub const CUSTOM_START: u32 = (1 << 31) + (1 << 30);
#[inline]
pub fn raw_os_error(&self) -> Option<i32> {
if self.0.get() < Self::INTERNAL_START {
Some(self.0.get() as i32)
} else {
None
}
}
#[inline]
pub fn code(&self) -> NonZeroU32 {
self.0
}
}
#[cfg(any(unix, target_os = "redox"))]
fn os_err_desc(errno: i32, buf: &mut [u8]) -> Option<&str> {
let buf_ptr = buf.as_mut_ptr() as *mut libc::c_char;
if unsafe { libc::strerror_r(errno, buf_ptr, buf.len()) } != 0 {
return None;
}
let idx = buf.iter().position(|&b| b == 0).unwrap_or(buf.len());
core::str::from_utf8(&buf[..idx]).ok()
}
#[cfg(not(any(unix, target_os = "redox")))]
fn os_err_desc(_errno: i32, _buf: &mut [u8]) -> Option<&str> {
None
}
impl fmt::Debug for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
let mut dbg = f.debug_struct("Error");
if let Some(errno) = self.raw_os_error() {
dbg.field("os_error", &errno);
let mut buf = [0u8; 128];
if let Some(desc) = os_err_desc(errno, &mut buf) {
dbg.field("description", &desc);
}
} else if let Some(desc) = internal_desc(*self) {
dbg.field("internal_code", &self.0.get());
dbg.field("description", &desc);
} else {
dbg.field("unknown_code", &self.0.get());
}
dbg.finish()
}
}
impl fmt::Display for Error {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
if let Some(errno) = self.raw_os_error() {
let mut buf = [0u8; 128];
match os_err_desc(errno, &mut buf) {
Some(desc) => f.write_str(desc),
None => write!(f, "OS Error: {}", errno),
}
} else if let Some(desc) = internal_desc(*self) {
f.write_str(desc)
} else {
write!(f, "Unknown Error: {}", self.0.get())
}
}
}
impl From<NonZeroU32> for Error {
fn from(code: NonZeroU32) -> Self {
Self(code)
}
}
macro_rules! internal_error {
($n:expr) => {
Error(unsafe { NonZeroU32::new_unchecked(Error::INTERNAL_START + $n as u16 as u32) })
};
}
pub(crate) const UNSUPPORTED: Error = internal_error!(0);
pub(crate) const ERRNO_NOT_POSITIVE: Error = internal_error!(1);
pub(crate) const UNKNOWN_IO_ERROR: Error = internal_error!(2);
pub(crate) const SEC_RANDOM_FAILED: Error = internal_error!(3);
pub(crate) const RTL_GEN_RANDOM_FAILED: Error = internal_error!(4);
pub(crate) const FAILED_RDRAND: Error = internal_error!(5);
pub(crate) const NO_RDRAND: Error = internal_error!(6);
pub(crate) const BINDGEN_CRYPTO_UNDEF: Error = internal_error!(7);
pub(crate) const BINDGEN_GRV_UNDEF: Error = internal_error!(8);
pub(crate) const STDWEB_NO_RNG: Error = internal_error!(9);
pub(crate) const STDWEB_RNG_FAILED: Error = internal_error!(10);
fn internal_desc(error: Error) -> Option<&'static str> {
match error {
UNSUPPORTED => Some("getrandom: this target is not supported"),
ERRNO_NOT_POSITIVE => Some("errno: did not return a positive value"),
UNKNOWN_IO_ERROR => Some("Unknown std::io::Error"),
SEC_RANDOM_FAILED => Some("SecRandomCopyBytes: call failed"),
RTL_GEN_RANDOM_FAILED => Some("RtlGenRandom: call failed"),
FAILED_RDRAND => Some("RDRAND: failed multiple times: CPU issue likely"),
NO_RDRAND => Some("RDRAND: instruction not supported"),
BINDGEN_CRYPTO_UNDEF => Some("wasm-bindgen: self.crypto is undefined"),
BINDGEN_GRV_UNDEF => Some("wasm-bindgen: crypto.getRandomValues is undefined"),
STDWEB_NO_RNG => Some("stdweb: no randomness source available"),
STDWEB_RNG_FAILED => Some("stdweb: failed to get randomness"),
_ => None,
}
}
#[cfg(test)]
mod tests {
use super::Error;
use core::mem::size_of;
#[test]
fn test_size() {
assert_eq!(size_of::<Error>(), 4);
assert_eq!(size_of::<Result<(), Error>>(), 4);
}
}