Enum MnemoError 

pub enum MnemoError {
    Io(Error),
    BadMagic,
    UnsupportedVersion(u16),
    HeaderChecksum,
    WrongPassphrase,
    PageAuthFailed(u64),
    HeaderTampered,
    Crypto(String),
    Kdf(String),
    Serialize(String),
    NotFound(String),
    DimensionMismatch {
        expected: usize,
        got: usize,
    },
    Invalid(String),
    Locked {
        path: PathBuf,
    },
    ReadOnly,
    NeedsWriteOpen {
        reason: &'static str,
    },
}

All errors the Mnemo engine can produce.

Variants

Io(Error)

An underlying I/O failure.

BadMagic

The file does not begin with the Mnemo magic bytes.

UnsupportedVersion(u16)

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

HeaderChecksum

The header page failed its CRC check — a torn page-0 write or corruption. crate::Mnemo::open tries to repair this from the WAL.

WrongPassphrase

Returned when the supplied passphrase fails to unwrap the data key. The failure is an authenticated-decryption failure, so it is indistinguishable from a tampered key blob — both are rejected cleanly.

PageAuthFailed(u64)

AEAD authentication failed for a page: corruption or tampering.

HeaderTampered

The v7 header seal failed authentication — at least one mutable header field has been rewritten without the DEK. Open refuses to proceed so a silent rollback or pointer-rewrite attack can’t surface stale data.

Crypto(String)

A low-level cryptographic operation failed.

Kdf(String)

Argon2id key derivation failed.

Serialize(String)

A record failed to (de)serialize.

NotFound(String)

No memory exists with the requested ID.

DimensionMismatch

A vector did not match the database’s configured dimensionality.

Fields

expected: usize

Dimensionality the database was created with.

got: usize

Dimensionality of the offending vector.

Invalid(String)

A caller-supplied argument was invalid.

Locked

Another process (or another handle in this process) already holds a conflicting OS file lock on the target .mnemo file. Write handles take an exclusive lock; read-only handles take a shared lock. Two writers or a writer + reader will collide.

Fields

path: PathBuf

The path whose lock was requested and refused.

ReadOnly

A mutation was attempted on a handle opened via crate::Mnemo::open_read_only. Reopen read-write to mutate.

NeedsWriteOpen

A read-only open was requested but the file has pending on-disk work that requires a write handle to complete — a committed-but-unchecked WAL transaction, or a format-version migration older than the current VERSION. Open read-write once, close cleanly, then reopen read-only.

Fields

reason: &'static str

Human-readable reason (e.g. "pending WAL recovery").

Trait Implementations

impl Debug for MnemoError

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

Formats the value using the given formatter.

impl Display for MnemoError

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

Formats the value using the given formatter.

impl Error for MnemoError

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 MnemoError

fn from(source: Error) -> Self

Converts to this type from the input type.