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use std::fmt::{Debug, Display, Formatter};
use std::rc::Rc;
use backtrace::Backtrace;
#[derive(Clone)]
pub struct BacktraceError<E>
where
E: Debug + Display + 'static
{
value: Rc<BacktraceErrorImpl<E>>
}
struct BacktraceErrorImpl<E>
where
E: Debug + Display
{
error: E,
backtrace: Backtrace,
cause: Option<Box<dyn std::error::Error>>
}
impl<E: Debug + Display> std::error::Error for BacktraceError<E> {}
impl<E: Debug + Display> Display for BacktraceError<E>
{
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result
{
Display::fmt(self.error(), f)
}
}
impl<E: Debug + Display> Debug for BacktraceError<E>
{
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result
{
f.debug_struct("BacktraceError")
.field("error", self.error())
.field("backtrace", self.get_backtrace())
.field("cause", self.cause())
.finish()
}
}
impl<E: Debug + Display> BacktraceError<E>
{
#[must_use]
pub(crate) fn new_with_cause<Cause: std::error::Error + 'static>(
error: E,
cause: Cause
) -> Self
{
BacktraceError {
value: Rc::new(BacktraceErrorImpl {
backtrace: Backtrace::new(),
error,
cause: Some(Box::new(cause))
})
}
}
#[must_use]
pub(crate) fn new(error: E) -> Self
{
BacktraceError {
value: Rc::new(BacktraceErrorImpl {
backtrace: Backtrace::new(),
error,
cause: None
})
}
}
#[must_use]
pub fn get_backtrace(&self) -> &Backtrace
{
&self.value.backtrace
}
#[must_use]
pub fn error(&self) -> &E
{
&self.value.error
}
#[must_use]
pub fn cause(&self) -> &Option<Box<dyn std::error::Error>>
{
&self.value.cause
}
#[must_use]
pub(crate) fn context<S: AsRef<str>>(
self,
description: S
) -> BacktraceError<ErrorMessage>
{
BacktraceError::new_with_cause(
ErrorMessage {
description: description.as_ref().to_string()
},
self
)
}
}
#[derive(Clone, Debug)]
pub struct ErrorMessage
{
description: String
}
impl ErrorMessage
{
pub(crate) fn msg<S: AsRef<str>>(description: S) -> BacktraceError<Self>
{
BacktraceError::new(Self {
description: description.as_ref().to_string()
})
}
pub(crate) fn msg_with_cause<S, Cause>(
description: S,
cause: Cause
) -> BacktraceError<Self>
where
S: AsRef<str>,
Cause: std::error::Error + 'static
{
BacktraceError::new_with_cause(
Self {
description: description.as_ref().to_string()
},
cause
)
}
}
impl Display for ErrorMessage
{
fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result
{
Display::fmt(&self.description, f)
}
}
pub(crate) trait Context<R>
{
fn context<S: AsRef<str>>(
self,
description: S
) -> Result<R, BacktraceError<ErrorMessage>>;
}
impl<R, E: std::error::Error + 'static> Context<R> for Result<R, E>
{
fn context<S: AsRef<str>>(
self,
description: S
) -> Result<R, BacktraceError<ErrorMessage>>
{
match self {
Ok(result) => Ok(result),
Err(err) => Err(BacktraceError::new_with_cause(
ErrorMessage {
description: description.as_ref().to_string()
},
err
))
}
}
}