Enum BackendError 

#[non_exhaustive]
pub enum BackendError {
    StorageAlreadyOwned {
        namespace: String,
    },
    StoreStateStorageUnsupported,
    InvalidStoreStateStagingToken,
    InvalidStoreStateView,
    StoreStateNamespaceImmutable,
    RecordTooLarge {
        encoded_bytes: usize,
    },
    EntryNotFound {
        id: ID,
    },
    EntryValidationFailed {
        entry_id: ID,
        reason: String,
    },
    VerificationStatusNotFound {
        id: ID,
    },
    EntryNotInTree {
        entry_id: ID,
        tree_id: ID,
    },
    EntryNotInSubtree {
        entry_id: ID,
        tree_id: ID,
        subtree: String,
    },
    CycleDetected {
        entry_id: ID,
    },
    NoCommonAncestor {
        entry_ids: Vec<ID>,
    },
    EmptyEntryList {
        operation: String,
    },
    HeightCalculationCorruption {
        reason: String,
    },
    PrivateKeyNotFound {
        key_name: String,
    },
    SerializationFailed {
        source: Error,
    },
    DeserializationFailed {
        source: Error,
    },
    FileIo {
        source: Error,
    },
    CrdtCacheError {
        reason: String,
    },
    TreeIntegrityViolation {
        reason: String,
    },
    InvalidTreeReference {
        tree_id: ID,
    },
    StateInconsistency {
        reason: String,
    },
    CacheError {
        reason: String,
    },
    SqlxError {
        reason: String,
        source: Option<Error>,
    },
}

Errors that can occur during database operations.

Stability

• New variants may be added in minor versions (enum is #[non_exhaustive])
• Existing variants will not be removed in minor versions
• Field additions/changes require a major version bump
• Helper methods like is_*() provide stable APIs

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.

StorageAlreadyOwned

Another Eidetica backend already owns this storage namespace.

Fields

namespace: String

Credential-free description of the storage namespace.

StoreStateStorageUnsupported

The backend does not cache Store state as records.

InvalidStoreStateStagingToken

A staging token does not identify a private unpublished build.

InvalidStoreStateView

A Store-state view does not identify a published record set.

The record set was cleared after the view was minted, or the view never identified a published record set. This is never a missing key or an empty page: reads against a live view still report those as None and empty pages.

StoreStateNamespaceImmutable

A published record set cannot be changed after publication.

RecordTooLarge

One encoded record cannot fit in a protocol frame.

Fields

encoded_bytes: usize

Encoded record size rejected before transmission.

EntryNotFound

Entry not found by ID.

Fields

id: ID

The ID of the entry that was not found

EntryValidationFailed

Entry failed structural validation.

Fields

entry_id: ID

The ID of the entry that failed validation

reason: String

The reason for validation failure

VerificationStatusNotFound

Verification status not found for entry.

Fields

id: ID

The ID of the entry whose verification status was not found

EntryNotInTree

Entry is not part of the specified tree.

Fields

entry_id: ID

The ID of the entry

tree_id: ID

The ID of the tree

EntryNotInSubtree

Entry is not part of the specified subtree.

Fields

entry_id: ID

The ID of the entry

tree_id: ID

The ID of the tree

subtree: String

The name of the subtree

CycleDetected

Cycle detected in DAG structure.

Fields

entry_id: ID

The entry ID where cycle was detected

NoCommonAncestor

No common ancestor found for given entries.

This engine never produces this error: find_merge_base reports disjoint histories as Ok(None) (the empty-base merge) rather than failing. The variant is kept because peers running older versions still emit it over the service wire (see the decode table in service::error), and removing an existing variant is a breaking change.

Fields

entry_ids: Vec<ID>

The entry IDs that have no common ancestor

EmptyEntryList

Empty entry list provided where non-empty list required.

Fields

operation: String

The operation that required a non-empty list

HeightCalculationCorruption

Data corruption detected during height calculation.

Fields

reason: String

Description of the corruption detected

PrivateKeyNotFound

Private key not found.

Fields

key_name: String

The name of the private key that was not found

SerializationFailed

Serialization failed.

Fields

source: Error

The underlying serialization error

DeserializationFailed

Deserialization failed.

Fields

source: Error

The underlying deserialization error

FileIo

File I/O error.

Fields

source: Error

The underlying I/O error

CrdtCacheError

CRDT cache operation failed.

Fields

reason: String

Description of the cache operation failure

TreeIntegrityViolation

Database integrity violation detected.

Fields

reason: String

Description of the integrity violation

InvalidTreeReference

Invalid tree reference or tree ID.

Fields

tree_id: ID

The invalid tree ID

StateInconsistency

Database state inconsistency detected.

Fields

reason: String

Description of the state inconsistency

CacheError

Cache miss or cache corruption.

Fields

reason: String

Description of the cache error

SqlxError

SQL database error (sqlx).

Fields

reason: String

Description of the SQL error

source: Option<Error>

The underlying sqlx error, if available

Implementations

impl BackendError

pub fn is_not_found(&self) -> bool

Check if this error indicates a resource was not found.

pub fn is_integrity_error(&self) -> bool

Check if this error indicates a data integrity issue.

pub fn is_io_error(&self) -> bool

Check if this error is related to I/O operations.

pub fn is_sql_error(&self) -> bool

Check if this error is related to SQL database operations.

pub fn is_cache_error(&self) -> bool

Check if this error is related to cache operations.

pub fn is_logical_error(&self) -> bool

Check if this error indicates a logical inconsistency.

pub fn is_unsupported_store_state(&self) -> bool

Whether this error means the backend does not cache Store state as records.

Only BackendError::StoreStateStorageUnsupported reports this. Every other failure — invalid tokens, invalid views, storage I/O — is genuine and must propagate, never fall back.

pub fn is_invalid_store_state_view(&self) -> bool

Whether this error means a Store-state view no longer identifies a published record set (cleared after minting, or never published).

pub fn entry_id(&self) -> Option<&ID>

Get the entry ID if this error is about a specific entry.

pub fn tree_id(&self) -> Option<&ID>

Get the tree ID if this error is about a specific tree.

Trait Implementations

impl Debug for BackendError

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

Formats the value using the given formatter.

impl Display for BackendError

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

Formats the value using the given formatter.

impl Error for BackendError

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<BackendError> for Error

fn from(err: BackendError) -> Self

Converts to this type from the input type.