Enum HostError 

#[non_exhaustive]
pub enum HostError {
    Locked {
        path: PathBuf,
    },
    Io {
        path: PathBuf,
        source: Error,
    },
    NeedsCheckpoint {
        path: PathBuf,
    },
    Engine(Error),
    Embed(String),
}

Every way the host layer can fail. Engine failures pass through as HostError::Engine; everything filesystem- or network-shaped is typed here.

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.

Locked

The database file is exclusively locked by another process (or another handle in this process). One local database has one owner — open a different file, or drop the other handle.

Fields

path: PathBuf

The database base path.

Io

A filesystem operation failed.

Fields

path: PathBuf

The file the operation touched.

source: Error

The underlying error.

NeedsCheckpoint

There is no published snapshot generation to map: the database has never been checkpointed, so a read-only open ([crate::Database:: open_readonly]) or a crate::Database::scrub has nothing to point at. Open it read-write once and checkpoint, then retry.

A dirty journal is not this error. A reader maps the published generation and never reads the journal, which is snapshot isolation: it answers as of the last checkpoint rather than refusing until you take one.

Fields

path: PathBuf

The database base path.

Engine(Error)

The engine returned a typed error.

Embed(String)

The embedder transport or response was unusable (the message names what exactly: status, dimension mismatch, malformed JSON).

Implementations

impl HostError

pub fn capacity_hint(&self) -> Option<&'static str>

The follow-up line for a pool that ran out of room, or None when this error is something else.

The number in the message is a setting; the setting has a name and one specific trade-off. Callers that talk to a person should print this after the error itself.

Trait Implementations

impl Debug for HostError

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

Formats the value using the given formatter.

impl Display for HostError

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

Formats the value using the given formatter.

impl Error for HostError

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 HostError

fn from(source: Error) -> Self

Converts to this type from the input type.

impl From<HostError> for WorkspaceError

fn from(source: HostError) -> Self

Converts to this type from the input type.