Enum Error 

#[non_exhaustive]
pub enum Error {
    Io(Error),
    BadMagic,
    UnsupportedVersion(u16),
    Corrupt(&'static str),
    ValueTooLarge,
}

The set of failures a bison-db operation can produce.

Variants are grouped by origin: I/O failures from the host filesystem, and format failures detected while decoding the on-disk log. A format failure always means the bytes on disk did not match the expectations encoded by the writer — never that the caller passed bad arguments to an in-memory type.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Io(Error)

Available on crate feature std only.

An underlying filesystem operation failed.

Wraps the originating std::io::Error so the caller can inspect the std::io::ErrorKind (for example, PermissionDenied when opening a read-only path, or NotFound for a missing parent directory).

BadMagic

The file does not begin with a valid bison-db header.

Returned by Db::open when the target path exists, is non-empty, but its magic bytes do not identify it as a bison-db store — the usual cause of opening the wrong file by mistake.

UnsupportedVersion(u16)

The on-disk format version is newer than this build understands.

The contained value is the version stamped in the file header. A binary built against an older release will refuse to read a file written by a newer one rather than risk misinterpreting it.

Corrupt(&'static str)

A stored record failed its integrity check or was structurally invalid.

This covers a CRC mismatch, an unknown value tag, a length field that overruns the record, or a non-UTF-8 string — any signal that the bytes were corrupted in place after being written. A clean torn write at the very end of the log is not reported here: it is recovered silently by truncating the partial tail (see Db::open).

The contained &'static str is a fixed diagnostic label, never a formatted message, so producing it allocates nothing.

ValueTooLarge

A value was too large to encode within the configured record limit.

Guards against a single document growing past MAX_RECORD_BYTES, which would otherwise force an unbounded allocation on the read path during recovery.

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

Available on crate feature std only.

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

Available on crate feature std only.

fn from(err: Error) -> Self

Converts to this type from the input type.