Struct holochain::prelude::kitsune_p2p::dependencies::kitsune_p2p_types::dependencies::lair_keystore_api::dependencies::tokio::io::Error

pub struct Error { /* private fields */ }

The error type for I/O operations of the Read, Write, Seek, and associated traits.

Errors mostly originate from the underlying OS, but custom instances of Error can be created with crafted error messages and a particular value of ErrorKind.

Implementations

impl Error

pub fn new<E>(kind: ErrorKind, error: E) -> Errorwhere E: Into<Box<dyn Error + Sync + Send + 'static, Global>>,

Creates a new I/O error from a known kind of error as well as an arbitrary error payload.

This function is used to generically create I/O errors which do not originate from the OS itself. The error argument is an arbitrary payload which will be contained in this Error.

Note that this function allocates memory on the heap. If no extra payload is required, use the From conversion from ErrorKind.

Examples

use std::io::{Error, ErrorKind};

// errors can be created from strings
let custom_error = Error::new(ErrorKind::Other, "oh no!");

// errors can also be created from other errors
let custom_error2 = Error::new(ErrorKind::Interrupted, custom_error);

// creating an error without payload (and without memory allocation)
let eof_error = Error::from(ErrorKind::UnexpectedEof);

pub fn other<E>(error: E) -> Errorwhere E: Into<Box<dyn Error + Sync + Send + 'static, Global>>,

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

Creates a new I/O error from an arbitrary error payload.

This function is used to generically create I/O errors which do not originate from the OS itself. It is a shortcut for Error::new with ErrorKind::Other.

Examples

#![feature(io_error_other)]

use std::io::Error;

// errors can be created from strings
let custom_error = Error::other("oh no!");

// errors can also be created from other errors
let custom_error2 = Error::other(custom_error);

pub fn last_os_error() -> Error

Returns an error representing the last OS error which occurred.

This function reads the value of errno for the target platform (e.g. GetLastError on Windows) and will return a corresponding instance of Error for the error code.

This should be called immediately after a call to a platform function, otherwise the state of the error value is indeterminate. In particular, other standard library functions may call platform functions that may (or may not) reset the error value even if they succeed.

Examples

use std::io::Error;

let os_error = Error::last_os_error();
println!("last OS error: {os_error:?}");

pub fn from_raw_os_error(code: i32) -> Error

Creates a new instance of an Error from a particular OS error code.

Examples

On Linux:

use std::io;

let error = io::Error::from_raw_os_error(22);
assert_eq!(error.kind(), io::ErrorKind::InvalidInput);

On Windows:

use std::io;

let error = io::Error::from_raw_os_error(10022);
assert_eq!(error.kind(), io::ErrorKind::InvalidInput);

pub fn raw_os_error(&self) -> Option<i32>

Returns the OS error that this error represents (if any).

If this Error was constructed via last_os_error or from_raw_os_error, then this function will return Some, otherwise it will return None.

Examples

use std::io::{Error, ErrorKind};

fn print_os_error(err: &Error) {
    if let Some(raw_os_err) = err.raw_os_error() {
        println!("raw OS error: {raw_os_err:?}");
    } else {
        println!("Not an OS error");
    }
}

fn main() {
    // Will print "raw OS error: ...".
    print_os_error(&Error::last_os_error());
    // Will print "Not an OS error".
    print_os_error(&Error::new(ErrorKind::Other, "oh no!"));
}

pub fn get_ref(&self) -> Option<&(dyn Error + Sync + Send + 'static)>

Returns a reference to the inner error wrapped by this error (if any).

If this Error was constructed via new then this function will return Some, otherwise it will return None.

Examples

use std::io::{Error, ErrorKind};

fn print_error(err: &Error) {
    if let Some(inner_err) = err.get_ref() {
        println!("Inner error: {inner_err:?}");
    } else {
        println!("No inner error");
    }
}

fn main() {
    // Will print "No inner error".
    print_error(&Error::last_os_error());
    // Will print "Inner error: ...".
    print_error(&Error::new(ErrorKind::Other, "oh no!"));
}

pub fn get_mut(&mut self) -> Option<&mut (dyn Error + Sync + Send + 'static)>

Returns a mutable reference to the inner error wrapped by this error (if any).

If this Error was constructed via new then this function will return Some, otherwise it will return None.

Examples

use std::io::{Error, ErrorKind};
use std::{error, fmt};
use std::fmt::Display;

#[derive(Debug)]
struct MyError {
    v: String,
}

impl MyError {
    fn new() -> MyError {
        MyError {
            v: "oh no!".to_string()
        }
    }

    fn change_message(&mut self, new_message: &str) {
        self.v = new_message.to_string();
    }
}

impl error::Error for MyError {}

impl Display for MyError {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        write!(f, "MyError: {}", &self.v)
    }
}

fn change_error(mut err: Error) -> Error {
    if let Some(inner_err) = err.get_mut() {
        inner_err.downcast_mut::<MyError>().unwrap().change_message("I've been changed!");
    }
    err
}

fn print_error(err: &Error) {
    if let Some(inner_err) = err.get_ref() {
        println!("Inner error: {inner_err}");
    } else {
        println!("No inner error");
    }
}

fn main() {
    // Will print "No inner error".
    print_error(&change_error(Error::last_os_error()));
    // Will print "Inner error: ...".
    print_error(&change_error(Error::new(ErrorKind::Other, MyError::new())));
}

pub fn into_inner( self ) -> Option<Box<dyn Error + Sync + Send + 'static, Global>>

Consumes the Error, returning its inner error (if any).

If this Error was constructed via new then this function will return Some, otherwise it will return None.

Examples

use std::io::{Error, ErrorKind};

fn print_error(err: Error) {
    if let Some(inner_err) = err.into_inner() {
        println!("Inner error: {inner_err}");
    } else {
        println!("No inner error");
    }
}

fn main() {
    // Will print "No inner error".
    print_error(Error::last_os_error());
    // Will print "Inner error: ...".
    print_error(Error::new(ErrorKind::Other, "oh no!"));
}

pub fn downcast<E>(self) -> Result<Box<E, Global>, Error>where E: Error + Send + Sync + 'static,

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

Attempt to downgrade the inner error to E if any.

If this Error was constructed via new then this function will attempt to perform downgrade on it, otherwise it will return Err.

If downgrade succeeds, it will return Ok, otherwise it will also return Err.

Examples

#![feature(io_error_downcast)]

use std::fmt;
use std::io;
use std::error::Error;

#[derive(Debug)]
enum E {
    Io(io::Error),
    SomeOtherVariant,
}

impl fmt::Display for E {
   // ...
}
impl Error for E {}

impl From<io::Error> for E {
    fn from(err: io::Error) -> E {
        err.downcast::<E>()
            .map(|b| *b)
            .unwrap_or_else(E::Io)
    }
}

pub fn kind(&self) -> ErrorKind

Returns the corresponding ErrorKind for this error.

This may be a value set by Rust code constructing custom io::Errors, or if this io::Error was sourced from the operating system, it will be a value inferred from the system’s error encoding. See last_os_error for more details.

Examples

use std::io::{Error, ErrorKind};

fn print_error(err: Error) {
    println!("{:?}", err.kind());
}

fn main() {
    // As no error has (visibly) occurred, this may print anything!
    // It likely prints a placeholder for unidentified (non-)errors.
    print_error(Error::last_os_error());
    // Will print "AddrInUse".
    print_error(Error::new(ErrorKind::AddrInUse, "oh no!"));
}

Trait Implementations

impl AsRef<Error> for OneErr

fn as_ref(&self) -> &Error

Converts this type into a shared reference of the (usually inferred) input type.

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Error for Error

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

The lower-level source of this error, if any.

fn provide<'a>(&'a self, demand: &mut Demand<'a>)

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

Provides type based access to context intended for error reports.

impl ErrorExt for Error

fn id(&self) -> Cow<'_, str>

Get the identifier of this error type, or the string representation.

fn err_clone(&self) -> Error

Clone the error maintaining any meta info is available if we are a tx5 error type.

impl From<&Error> for Error

fn from(e: &Error) -> Error

Converts to this type from the input type.

impl From<&OneErr> for Error

fn from(e: &OneErr) -> Error

Converts to this type from the input type.

impl From<ASN1Error> for Error

fn from(e: ASN1Error) -> Error

Converts to this type from the input type.

impl From<CompressError> for Error

fn from(data: CompressError) -> Error

Converts to this type from the input type.

impl From<ConnectionError> for Error

fn from(x: ConnectionError) -> Error

Converts to this type from the input type.

impl From<DecompressError> for Error

fn from(data: DecompressError) -> Error

Converts to this type from the input type.

impl From<Elapsed> for Error

fn from(_err: Elapsed) -> Error

Converts to this type from the input type.

impl From<Elapsed> for Error

fn from(_err: Elapsed) -> Error

Converts to this type from the input type.

impl From<Errno> for Error

fn from(err: Errno) -> Error

Converts to this type from the input type.

impl From<Errno> for Error

fn from(err: Errno) -> Error

Converts to this type from the input type.

impl From<Error> for AnyDelimiterCodecError

fn from(e: Error) -> AnyDelimiterCodecError

Converts to this type from the input type.

impl From<Error> for ConductorApiError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Error> for ConductorConfigError

fn from(source: Error) -> ConductorConfigError

Converts to this type from the input type.

impl From<Error> for ConductorError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Error> for DatabaseError

fn from(source: Error) -> DatabaseError

Converts to this type from the input type.

impl From<Error> for DeserializeError

fn from(source: Error) -> DeserializeError

Converts to this type from the input type.

impl From<Error> for DnaError

fn from(error: Error) -> DnaError

Converts to this type from the input type.

impl From<Error> for Error

fn from(j: Error) -> Error

Convert a serde_json::Error into an io::Error.

JSON syntax and data errors are turned into InvalidData IO errors. EOF errors are turned into UnexpectedEof IO errors.

use std::io;

enum MyError {
    Io(io::Error),
    Json(serde_json::Error),
}

impl From<serde_json::Error> for MyError {
    fn from(err: serde_json::Error) -> MyError {
        use serde_json::error::Category;
        match err.classify() {
            Category::Io => {
                MyError::Io(err.into())
            }
            Category::Syntax | Category::Data | Category::Eof => {
                MyError::Json(err)
            }
        }
    }
}

impl<F> From<Error> for Error<F>where F: ErrorFormatter,

fn from(e: Error) -> Error<F>

Converts to this type from the input type.

impl From<Error> for Error

fn from(err: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(from: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(e: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(e: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(source: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(source: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(e: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(err: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(error: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(err: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(e: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(_: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(error: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(_err: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(e: Error) -> Error

Converts to this type from the input type.

impl From<Error> for Error

fn from(error: Error) -> Error

Creates a new Error::Io from the given error

impl From<Error> for Format

fn from(err: Error) -> Format

Converts to this type from the input type.

impl From<Error> for GetTimezoneError

fn from(orig: Error) -> GetTimezoneError

Converts to this type from the input type.

impl From<Error> for KitsuneP2pError

fn from(source: Error) -> KitsuneP2pError

Converts to this type from the input type.

impl From<Error> for LinesCodecError

fn from(e: Error) -> LinesCodecError

Converts to this type from the input type.

impl From<Error> for ManagedTaskError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<Error> for MrBundleError

fn from(source: Error) -> MrBundleError

Converts to this type from the input type.

impl From<Error> for OneErr

fn from(e: Error) -> OneErr

Converts to this type from the input type.

impl From<Error> for ProtobufError

fn from(err: Error) -> ProtobufError

Converts to this type from the input type.

impl From<Error> for SerializeError

fn from(source: Error) -> SerializeError

Converts to this type from the input type.

impl From<Error> for UnpackingError

fn from(source: Error) -> UnpackingError

Converts to this type from the input type.

impl From<Error> for WebsocketError

fn from(source: Error) -> WebsocketError

Converts to this type from the input type.

impl From<ErrorKind> for Error

Intended for use for errors not exposed to the user, where allocating onto the heap (for normal construction via Error::new) is too costly.

fn from(kind: ErrorKind) -> Error

Converts an ErrorKind into an Error.

This conversion creates a new error with a simple representation of error kind.

Examples

use std::io::{Error, ErrorKind};

let not_found = ErrorKind::NotFound;
let error = Error::from(not_found);
assert_eq!("entity not found", format!("{error}"));

impl From<ErrorStack> for Error

fn from(e: ErrorStack) -> Error

Converts to this type from the input type.

impl<W> From<IntoInnerError<W>> for Error

fn from(iie: IntoInnerError<W>) -> Error

Converts to this type from the input type.

impl From<JoinError> for Error

fn from(src: JoinError) -> Error

Converts to this type from the input type.

impl From<NulError> for Error

fn from(_: NulError) -> Error

Converts a alloc::ffi::NulError into a Error.

impl From<OneErr> for Error

fn from(e: OneErr) -> Error

Converts to this type from the input type.

impl From<PathPersistError> for Error

fn from(error: PathPersistError) -> Error

Converts to this type from the input type.

impl<F> From<PersistError<F>> for Error

fn from(error: PersistError<F>) -> Error

Converts to this type from the input type.

impl From<ProtobufError> for Error

fn from(err: ProtobufError) -> Error

Converts to this type from the input type.

impl From<ReadError> for Error

fn from(x: ReadError) -> Error

Converts to this type from the input type.

impl From<SpawnError> for Error

fn from(e: SpawnError) -> Error

Converts to this type from the input type.

impl From<ValueWriteError<Error>> for Error

fn from(err: ValueWriteError<Error>) -> Error

Converts to this type from the input type.

impl From<WriteError> for Error

fn from(x: WriteError) -> Error

Converts to this type from the input type.

impl Into<Error> for Error

fn into(self) -> Error

Converts this type into the (usually inferred) input type.

impl NonBlockingError for Error

fn into_non_blocking(self) -> Option<Error>

Convert WouldBlock to None and don’t touch other errors.

impl NonBlockingError for Error

fn into_non_blocking(self) -> Option<Error>

Convert WouldBlock to None and don’t touch other errors.

impl TryFrom<Error> for Errno

type Error = Error

The type returned in the event of a conversion error.

fn try_from(ioerror: Error) -> Result<Errno, Error>

Performs the conversion.

impl TryFrom<Format> for Error

type Error = DifferentVariant

The type returned in the event of a conversion error.

fn try_from(err: Format) -> Result<Error, <Error as TryFrom<Format>>::Error>

Performs the conversion.

impl RmpReadErr for Error

impl RmpWriteErr for Error