Enum CacheEntryProblem 

#[non_exhaustive]
pub enum CacheEntryProblem {
    Metadata(ThumbnailMetadataProblem),
    UnreadableEntry,
    UnverifiableOriginal,
    InvalidPngStructure,
    NonconformingPngFormat,
    DimensionsExceedNamespace,
    ResourceLimitExceeded,
    NonstandardFilename,
    UriFilenameMismatch,
}

Policy-neutral problem found while validating or inspecting a cache entry.

This is a compact fact vocabulary for caller policy branching, not a detailed diagnostic surface that carries expected and actual values for every failure class. Metadata problems carry typed detail through ThumbnailMetadataProblem; future non-metadata detail should be exposed separately instead of changing existing variant payloads.

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.

Metadata(ThumbnailMetadataProblem)

A standard thumbnail metadata key is missing, malformed, or does not match.

UnreadableEntry

The cache entry itself could not be read well enough to validate.

UnverifiableOriginal

The original cannot be verified in this validation context.

InvalidPngStructure

PNG structure could not be decoded.

NonconformingPngFormat

PNG encoding does not conform to the successful-thumbnail requirements.

DimensionsExceedNamespace

PNG dimensions exceed the requested namespace.

ResourceLimitExceeded

PNG decoding would exceed configured resource limits.

NonstandardFilename

The cache directory entry is not a standard thumbnail filename.

UriFilenameMismatch

The standard cache filename does not match the stored thumbnail URI identity.

Trait Implementations

impl Clone for CacheEntryProblem

fn clone(&self) -> CacheEntryProblem

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for CacheEntryProblem

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

Formats the value using the given formatter.

impl Hash for CacheEntryProblem

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl PartialEq for CacheEntryProblem

fn eq(&self, other: &CacheEntryProblem) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for CacheEntryProblem

impl Eq for CacheEntryProblem

impl StructuralPartialEq for CacheEntryProblem