Struct DerivedCache 

pub struct DerivedCache { /* private fields */ }

A disposable, closure-keyed derived observation cache rooted under a field store’s cache/ directory.

Implementations

impl DerivedCache

pub fn open(root: impl AsRef<Path>) -> Result<Self>

Open (creating if needed) a derived cache rooted at root.

pub fn root(&self) -> &Path

The cache root directory.

pub fn get(&self, id: &NodeId) -> Result<Option<Vec<u8>>>

Fetch a cached output, verifying the sidecar digest.

• absent bytes or absent sidecar -> Ok(None) (a miss; disposable).
• sidecar present but BLAKE3(bytes) != sidecar -> crate::ErrorClass::IntegrityMismatch (fail closed; never return wrong bytes).

pub fn put(&mut self, id: &NodeId, bytes: &[u8]) -> Result<u64>

Store an output atomically with its sidecar digest. Returns the number of output bytes written.

pub fn contains(&self, id: &NodeId) -> Result<bool>

Whether an output file exists for id (the sidecar is not checked).

pub fn total_bytes(&self) -> Result<u64>

Total physical cache bytes (outputs plus sidecars), excluding temp files.

pub fn clear(&self) -> Result<u64>

Remove every cache entry, returning the bytes reclaimed. Idempotent.

Trait Implementations

impl Debug for DerivedCache

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

Formats the value using the given formatter.

impl OutputCache for DerivedCache

fn get(&self, id: &NodeId) -> Result<Option<Vec<u8>>>

Fetch a cached node output, or None on a miss. A get error is treated as a miss by the caller (the cache is disposable, never authority).

fn put(&mut self, id: &NodeId, bytes: &[u8]) -> Result<()>

Store a node output. Best-effort: a put error does not fail the materialization.

fn note(&mut self, _note: CacheNote<'_>)

Phase 15.6. Advisory, best-effort reuse/store event, reported for every cache hit and store. The default is a no-op, so NoCache and DerivedCache are byte-identical to a build without this method; it is never on the exactness path and can never change an output.