Struct MemoryIndex 

pub struct MemoryIndex { /* private fields */ }

Canonical in-memory IndexBackend: a flat map from block identity to residency. This is the reference backend and the baseline that persistent backends (Holt/ART, RocksDB/LSM, filesystem) are compared against in Experiment mode. It reports bytes_written = 0 because nothing is persisted.

Implementations

impl MemoryIndex

pub fn new() -> Self

Trait Implementations

impl Debug for MemoryIndex

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

Formats the value using the given formatter.

impl Default for MemoryIndex

fn default() -> MemoryIndex

Returns the “default value” for a type.

impl IndexBackend for MemoryIndex

fn name(&self) -> &str

Stable backend name for reports (for example “memory”, “holt”, “rocksdb”).

fn put(&mut self, residency: CacheResidency)

Insert or update a residency record for a block on a worker/tier.

fn locate(&self, key: &KvBlockKey) -> Vec<CacheResidency>

Every residency for an exact block identity. A block may be resident on several workers or tiers at once.

fn prefix_scan( &self, scope: &IdentityScope, prefix_hash: &str, ) -> Vec<CacheResidency>

Identity-aware prefix scan: residencies whose block belongs to scope and whose prefix_hash equals prefix_hash. This is the lookup where radix/ART backends are expected to beat flat maps and LSM stores.

fn remove_block( &mut self, scope: &IdentityScope, worker_id: &str, block_hash: &str, ) -> usize

Remove a single block (by content hash, within an identity scope) from a worker. Returns the number of residency records removed.

fn clear_worker(&mut self, worker_id: &str)

Drop everything resident on one worker/engine (for AllBlocksCleared or worker loss).

fn clear(&mut self)

Drop the entire index.

fn snapshot(&self) -> Vec<CacheResidency>

Full residency snapshot, for debugging and for routers that consume a slice of residency.

fn len(&self) -> usize

Number of residency records currently held.

fn metrics(&self) -> IndexMetrics

Comparable backend metrics (see IndexMetrics). The default derives resident_blocks/resident_bytes from a snapshot; persistent backends should override to also report bytes_written and counters.

fn is_empty(&self) -> bool

fn persistent(&self) -> bool

Whether this backend persists residency across process restarts. The in-memory reference backend returns false; Holt (ART), RocksDB (LSM), and filesystem backends return true. Drives recovery experiments and is surfaced in reports.