Two-part change:
1) Submodule split of src/cache/ (was a single ~150-line mod.rs)
- src/cache/config.rs: CacheConfig, defaults, default_cache_dir(),
DEFAULT_NAME / DEFAULT_MEMORY_CAPACITY_BYTES /
DEFAULT_DISK_CAPACITY_BYTES constants
- src/cache/key.rs: CacheKey / CacheValue type aliases and key
derivation helpers (rev -> oid, blob-exists negatives)
- src/cache/store.rs: CacheStore — the foyer HybridCache wrapper
(open / close / get / insert / remove / contains), all errors
mapped to BabyError::Cache with op-tagged source
- src/cache/pools.rs: CachePools — multi-store aggregator used by
the global singleton; replaces the old monolithic CacheStore
- src/cache/stats.rs: CacheStats + counter accessors
- src/cache/invalidation.rs: hook_ref_updated / hook_blob_written
(single-process invalidation hooks, fired from usecase impls)
- src/cache/mod.rs: now just submodule re-exports of
(config, global, invalidation, key, pools, stats, store)
- src/cache/global.rs: GITBABY_CACHE singleton + init / try /
shutdown now operate on Arc<CachePools> instead of Arc<CacheStore>
2) Cache integration in usecase modules
- src/blob/usecase.rs: read paths go through cache.get / insert;
invalidation hooks fire on write
- src/commit/usecase.rs: commit-list results cached, invalidated on
commit write
- src/branch/usecase.rs: branch-list results cached, invalidated on
ref update
- src/refs/usecase.rs: lookup-cache + ref-update hook
- src/tags/usecase.rs: tag-info cache + write hook
3) AGENTS.md
- Document that cached serde payloads (CommitInfo, Vec<TreeEntry>,
etc.) follow additive-only compatibility: never rename/remove a
field, every new field gets #[serde(default)] so stale payloads
still deserialize.
- Note that the foyer cache is single-process: fixed on-disk dir
per config + in-process invalidation hooks. Sharing across
processes on the same repo can leave stale metadata; do not do
that.
CI: cargo build + cargo test (61 passed) green.
BREAKING: the public cache surface moved. Anyone reaching into
cache::CacheStore directly should switch to cache::CachePools (or
cache::global::try_global_cache). The high-level helpers in
cache::global keep the same name; only the inner type changed.
Introduce a two-tier cache for blob payloads backed by the foyer crate
(memory + disk). The cache is configured via CacheConfig and exposed
through src/cache/{mod,global}.rs.
Why foyer:
- HybridCache gives us bounded RAM plus disk overflow without bringing
in our own eviction / spill logic.
- The runtime-tokio feature plays cleanly with the existing tokio stack.
Touches:
- src/cache/mod.rs: CacheConfig, CacheStore, CacheKey/Value aliases,
default-into-disk fallback (CacheConfig::default)
- src/cache/global.rs: process-wide singleton accessor for the default
cache
- src/error.rs: new BabyError::Cache { op, source } variant wrapping
foyer::Error so cache failures share the existing error pipeline
- Cargo.toml: add foyer = "0.22.3" with runtime-tokio feature
- src/lib.rs: pub mod cache; (wiring only — no public API on GitBaby
changes yet)
- src/tree/types.rs: drive-by import reorder (serde before std::path)
to match rustfmt
CI: cargo build + cargo test (38 passed) green.
Skipped intentionally: no git/lfs protocol logic is added here; this
commit is purely the storage substrate.
