Struct ImageRegistry 

pub struct ImageRegistry { /* private fields */ }

Persistent LRU cache mapping opaque keys to SnapshotIds.

Backed by a single SQLite table with WAL journaling. The registry tracks the last-access timestamp for every entry and evicts the oldest entries when the configured capacity is exceeded.

The inner Connection is wrapped in a Mutex so that the registry (and any struct containing it, e.g. crate::vm::HmVm) satisfies Send + Sync for safe sharing across async tasks.

Implementations

impl ImageRegistry

pub fn open(path: &Path, capacity: NonZeroU64) -> Result<Self>

Open or create the registry database at path.

The parent directory is created if it does not exist. The database uses WAL mode and NORMAL synchronous for a good balance of durability and performance.

Errors

Returns an error if the database cannot be opened or the schema cannot be applied.

pub fn get(&self, key: &str) -> Option<SnapshotId>

Look up a cached snapshot and update its access time.

Returns None if no entry exists for key.

pub fn put(&self, key: &str, snapshot: &SnapshotId) -> Vec<SnapshotId>

Insert or update a cache entry.

Returns the SnapshotIds of any entries evicted to keep the registry within its configured capacity. The caller is responsible for cleaning up the backend resources associated with evicted snapshots.

pub fn invalidate(&self, key: &str) -> Option<SnapshotId>

Remove a specific entry.

Returns the removed snapshot’s ID so the caller can clean up backend resources, or None if the key was not present.

pub fn all_snapshot_ids(&self) -> Vec<SnapshotId>

Return every stored snapshot ID.

Used by hm cache clean to remove the backing backend images before the registry DB is deleted — without this the images orphan beyond recovery by key. Order is unspecified.

pub fn len(&self) -> u64

Returns the number of cached entries.

pub fn is_empty(&self) -> bool

Returns true if the registry contains no entries.

Trait Implementations

impl Debug for ImageRegistry

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

Formats the value using the given formatter.