Struct Error

pub struct Error { /* private fields */ }

Error is the error struct returned by all opendal functions.

Display

Error can be displayed in two ways:

• Via Display: like err.to_string() or format!("{err}")

Error will be printed in a single line:

Unexpected, context: { path: /path/to/file, called: send_async } => something wrong happened, source: networking error"

• Via Debug: like format!("{err:?}")

Error will be printed in multi lines with more details and backtraces (if captured):

Unexpected => something wrong happened

Context:
   path: /path/to/file
   called: send_async

Source: networking error

Backtrace:
   0: opendal::error::Error::new
             at ./src/error.rs:197:24
   1: opendal::error::tests::generate_error
             at ./src/error.rs:241:9
   2: opendal::error::tests::test_error_debug_with_backtrace::{{closure}}
             at ./src/error.rs:305:41
   ...

• For conventional struct-style Debug representation, like format!("{err:#?}"):

Error {
    kind: Unexpected,
    message: "something wrong happened",
    status: Permanent,
    operation: "Read",
    context: [
        (
            "path",
            "/path/to/file",
        ),
        (
            "called",
            "send_async",
        ),
    ],
    source: Some(
        "networking error",
    ),
}

Implementations

impl Error

pub fn new(kind: ErrorKind, message: impl Into<String>) -> Self

Create a new Error with error kind and message.

pub fn with_operation(self, operation: impl Into<&'static str>) -> Self

Update error’s operation.

Notes

If the error already carries an operation, we will push a new context (called, operation).

pub fn with_context(self, key: &'static str, value: impl ToString) -> Self

Add more context in error.

pub fn set_source(self, src: impl Into<Error>) -> Self

Set source for error.

Notes

If the source has been set, we will raise a panic here.

pub fn map<F>(self, f: F) -> Self

where F: FnOnce(Self) -> Self,

Operate on error with map.

pub fn set_permanent(self) -> Self

Set permanent status for error.

pub fn set_temporary(self) -> Self

Set temporary status for error.

By set temporary, we indicate this error is retryable.

pub fn set_persistent(self) -> Self

Set persistent status for error.

By setting persistent, we indicate the retry should be stopped.

pub fn kind(&self) -> ErrorKind

Return error’s kind.

pub fn is_temporary(&self) -> bool

Check if this error is temporary.

pub fn backtrace(&self) -> Option<&Backtrace>

Return error’s backtrace.

Note: the standard way of exposing backtrace is the unstable feature error_generic_member_access. We don’t provide it as it requires nightly rust.

If you just want to print error with backtrace, use Debug, like format!("{err:?}").

If you use nightly rust, and want to access opendal::Error’s backtrace in the standard way, you can implement a newtype like this:

// assume you already have `#![feature(error_generic_member_access)]` on the top of your crate

#[derive(::std::fmt::Debug)]
pub struct OpendalError(opendal::Error);

impl std::fmt::Display for OpendalError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        self.0.fmt(f)
    }
}

impl std::error::Error for OpendalError {
    fn provide<'a>(&'a self, request: &mut std::error::Request<'a>) {
        if let Some(bt) = self.0.backtrace() {
            request.provide_ref::<std::backtrace::Backtrace>(bt);
        }
    }

    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        self.0.source()
    }
}

Additionally, you can add a clippy lint to prevent usage of the original opendal::Error type.

disallowed-types = [
    { path = "opendal::Error", reason = "Please use `my_crate::OpendalError` instead." },
]

Trait Implementations

impl Debug for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for Error

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Error for Error

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0: use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0: replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl From<Error> for Error

fn from(err: Error) -> Self

Converts to this type from the input type.