Enum BackendChangesError 

#[non_exhaustive]
pub enum BackendChangesError<E> {
    TooManyChanges {
        limit: u64,
    },
    Other(E),
}

Error type returned by JmapBackend::get_changes and JmapBackend::query_changes.

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.

TooManyChanges

The server cannot supply incremental changes for the given sinceState.

Two sub-cases share this variant:

• limit > 0 — maps to tooManyChanges in the JMAP response, with limit as the suggested maximum. The client may retry with a smaller window.

• limit: 0 — maps to cannotCalculateChanges. This signals a full state reset: the client MUST discard ALL locally cached objects for the affected type, reset its local state token to the empty string, and perform a full resync (/get with ids: null). Partial recovery is not permitted — the server has no usable change log for this state window. (Source: RFC 8620 §5.6; authoritative behavior documented in jmapio/jmap-js mail-model.js.)

Fields

limit: u64

Maximum window size the server can supply in a single /changes response. A value of 0 signals a full state reset is required per RFC 8620 §5.6; any non-zero value is the suggested maximum the client may retry with.

Other(E)

An unexpected storage-layer error.

Trait Implementations

impl<E: Debug> Debug for BackendChangesError<E>

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

Formats the value using the given formatter.

impl<E: Display> Display for BackendChangesError<E>

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

Formats the value using the given formatter.

impl<E: Error + 'static> Error for BackendChangesError<E>

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<E: Error> From<BackendChangesError<E>> for JmapError

fn from(e: BackendChangesError<E>) -> Self

Converts to this type from the input type.

impl<E> From<E> for BackendChangesError<E>

fn from(e: E) -> Self

Converts to this type from the input type.