Enum CacheError 

pub enum CacheError {
    CreateShard(PathBuf, Error),
    Serialize(String, Error),
    Write(PathBuf, Error),
    Walk(Error),
    Remove(PathBuf, Error),
}

What can go wrong at write time.

Reads are infallible by design: a corrupt or missing entry is a miss, not an error, so get returns Option<Value>. The caller treats write failures as non-fatal (log and continue); only the path to disk, the serialisation, the directory creation, and eviction need error variants.

Variants

CreateShard(PathBuf, Error)

The shard directory could not be created on put.

Serialize(String, Error)

Serialising the value to JSON failed. Should be unreachable for values produced by serde_json itself, but the type permits any Value, so the error path exists.

Write(PathBuf, Error)

Writing the JSON file failed (disk full, permissions, race with concurrent eviction).

Walk(Error)

Reading the cache directory during eviction failed.

Remove(PathBuf, Error)

Removing an entry during eviction failed.

Trait Implementations

impl Debug for CacheError

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

Formats the value using the given formatter.

impl Display for CacheError

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

Formats the value using the given formatter.

impl Error for CacheError

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.