Struct FsBlobStore 

pub struct FsBlobStore { /* private fields */ }

On-disk content-addressed store, sharded by digest prefix.

Layout (rooted at <root>/blobs/sha256/):

blobs/sha256/
  ab/
    ab12cd34…ff.zst        (zstd-19 compressed payload)
  cd/
    cd56ef78…00.zst

The two-byte shard prefix keeps directory entry counts <65 536 even at large stores. Atomic write is temp file in same dir → fsync → rename.

Thread-safe (concurrent put/get ok). On a race two writers may both produce the same temp file path — we add a per-process counter to dodge.

Implementations

impl FsBlobStore

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

Open (or create) an on-disk store rooted at root.

Creates root/blobs/sha256/ if missing. Idempotent.

pub fn root(&self) -> &Path

The root directory passed to Self::open.

Trait Implementations

impl BlobStore for FsBlobStore

fn put(&self, bytes: &[u8]) -> Result<Digest256>

Insert bytes, return its content digest. Idempotent: storing the same payload twice produces the same digest and is a no-op the second time.

fn get(&self, digest: &Digest256) -> Result<Vec<u8>>

Retrieve the bytes for a previously-stored digest.

fn contains(&self, digest: &Digest256) -> Result<bool>

Cheap existence check.

fn physical_bytes(&self) -> Result<u64>

Total physical bytes stored on disk (compressed). Implementations may approximate; used for pf status and the storage-efficiency microbenchmark.

impl Debug for FsBlobStore

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

Formats the value using the given formatter.