diff options
Diffstat (limited to 'rand/rand_core/src/error.rs')
| -rw-r--r-- | rand/rand_core/src/error.rs | 177 |
1 files changed, 0 insertions, 177 deletions
diff --git a/rand/rand_core/src/error.rs b/rand/rand_core/src/error.rs deleted file mode 100644 index 5a8459e..0000000 --- a/rand/rand_core/src/error.rs +++ /dev/null @@ -1,177 +0,0 @@ -// Copyright 2018 Developers of the Rand project. -// -// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or -// https://www.apache.org/licenses/LICENSE-2.0> or the MIT license -// <LICENSE-MIT or https://opensource.org/licenses/MIT>, at your -// option. This file may not be copied, modified, or distributed -// except according to those terms. - -//! Error types - -use core::fmt; - -#[cfg(feature="std")] -use std::error::Error as stdError; -#[cfg(feature="std")] -use std::io; - -/// Error kind which can be matched over. -#[derive(PartialEq, Eq, Debug, Copy, Clone)] -pub enum ErrorKind { - /// Feature is not available; not recoverable. - /// - /// This is the most permanent failure type and implies the error cannot be - /// resolved simply by retrying (e.g. the feature may not exist in this - /// build of the application or on the current platform). - Unavailable, - /// General failure; there may be a chance of recovery on retry. - /// - /// This is the catch-all kind for errors from known and unknown sources - /// which do not have a more specific kind / handling method. - /// - /// It is suggested to retry a couple of times or retry later when - /// handling; some error sources may be able to resolve themselves, - /// although this is not likely. - Unexpected, - /// A transient failure which likely can be resolved or worked around. - /// - /// This error kind exists for a few specific cases where it is known that - /// the error likely can be resolved internally, but is reported anyway. - Transient, - /// Not ready yet: recommended to try again a little later. - /// - /// This error kind implies the generator needs more time or needs some - /// other part of the application to do something else first before it is - /// ready for use; for example this may be used by external generators - /// which require time for initialization. - NotReady, - #[doc(hidden)] - __Nonexhaustive, -} - -impl ErrorKind { - /// True if this kind of error may resolve itself on retry. - /// - /// See also `should_wait()`. - pub fn should_retry(self) -> bool { - self != ErrorKind::Unavailable - } - - /// True if we should retry but wait before retrying - /// - /// This implies `should_retry()` is true. - pub fn should_wait(self) -> bool { - self == ErrorKind::NotReady - } - - /// A description of this error kind - pub fn description(self) -> &'static str { - match self { - ErrorKind::Unavailable => "permanently unavailable", - ErrorKind::Unexpected => "unexpected failure", - ErrorKind::Transient => "transient failure", - ErrorKind::NotReady => "not ready yet", - ErrorKind::__Nonexhaustive => unreachable!(), - } - } -} - - -/// Error type of random number generators -/// -/// This is a relatively simple error type, designed for compatibility with and -/// without the Rust `std` library. It embeds a "kind" code, a message (static -/// string only), and an optional chained cause (`std` only). The `kind` and -/// `msg` fields can be accessed directly; cause can be accessed via -/// `std::error::Error::cause` or `Error::take_cause`. Construction can only be -/// done via `Error::new` or `Error::with_cause`. -#[derive(Debug)] -pub struct Error { - /// The error kind - pub kind: ErrorKind, - /// The error message - pub msg: &'static str, - #[cfg(feature="std")] - cause: Option<Box<stdError + Send + Sync>>, -} - -impl Error { - /// Create a new instance, with specified kind and a message. - pub fn new(kind: ErrorKind, msg: &'static str) -> Self { - #[cfg(feature="std")] { - Error { kind, msg, cause: None } - } - #[cfg(not(feature="std"))] { - Error { kind, msg } - } - } - - /// Create a new instance, with specified kind, message, and a - /// chained cause. - /// - /// Note: `stdError` is an alias for `std::error::Error`. - /// - /// If not targetting `std` (i.e. `no_std`), this function is replaced by - /// another with the same prototype, except that there are no bounds on the - /// type `E` (because both `Box` and `stdError` are unavailable), and the - /// `cause` is ignored. - #[cfg(feature="std")] - pub fn with_cause<E>(kind: ErrorKind, msg: &'static str, cause: E) -> Self - where E: Into<Box<stdError + Send + Sync>> - { - Error { kind, msg, cause: Some(cause.into()) } - } - - /// Create a new instance, with specified kind, message, and a - /// chained cause. - /// - /// In `no_std` mode the *cause* is ignored. - #[cfg(not(feature="std"))] - pub fn with_cause<E>(kind: ErrorKind, msg: &'static str, _cause: E) -> Self { - Error { kind, msg } - } - - /// Take the cause, if any. This allows the embedded cause to be extracted. - /// This uses `Option::take`, leaving `self` with no cause. - #[cfg(feature="std")] - pub fn take_cause(&mut self) -> Option<Box<stdError + Send + Sync>> { - self.cause.take() - } -} - -impl fmt::Display for Error { - fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { - #[cfg(feature="std")] { - if let Some(ref cause) = self.cause { - return write!(f, "{} ({}); cause: {}", - self.msg, self.kind.description(), cause); - } - } - write!(f, "{} ({})", self.msg, self.kind.description()) - } -} - -#[cfg(feature="std")] -impl stdError for Error { - fn description(&self) -> &str { - self.msg - } - - fn cause(&self) -> Option<&stdError> { - self.cause.as_ref().map(|e| e.as_ref() as &stdError) - } -} - -#[cfg(feature="std")] -impl From<Error> for io::Error { - fn from(error: Error) -> Self { - use std::io::ErrorKind::*; - match error.kind { - ErrorKind::Unavailable => io::Error::new(NotFound, error), - ErrorKind::Unexpected | - ErrorKind::Transient => io::Error::new(Other, error), - ErrorKind::NotReady => io::Error::new(WouldBlock, error), - ErrorKind::__Nonexhaustive => unreachable!(), - } - } -} |