Struct MultipartStateStore 

pub struct MultipartStateStore { /* private fields */ }

In-memory side-table mapping upload_id → context. One of these hangs off S4Service (always-on, no flag — the per-upload state is gateway-internal).

Implementations

impl MultipartStateStore

pub fn new() -> Self

Empty store. Use Arc<MultipartStateStore> so S4Service’s async handlers can borrow it across &self calls without requiring Clone.

pub fn put(&self, upload_id: &str, ctx: MultipartUploadContext)

Register a new upload under upload_id. If upload_id is already present (extremely unlikely — backend issues fresh ids) the previous entry is overwritten silently to mirror HashMap::insert’s replace-on-collision semantics.

pub fn get(&self, upload_id: &str) -> Option<MultipartUploadContext>

Snapshot the context for upload_id. None when no entry was registered (e.g. Complete arrived for an upload that the gateway has no record of — passes through to the backend untouched, which in turn surfaces NoSuchUpload).

pub fn remove(&self, upload_id: &str)

Drop the entry. Called by Complete / Abort to release the SSE-C key bytes and the tag-set memory promptly.

pub fn completion_lock(&self, bucket: &str, key: &str) -> Arc<Mutex<()>>

v0.8.1 #59: get-or-create the per-(bucket, key) Mutex used to serialise complete_multipart_upload invocations on the same logical key. Caller does lock.lock().await and holds the guard for the duration of its critical section (GET assembled body → encrypt → PUT encrypted body → version-id mint → object- lock apply → tagging persist → replication enqueue).

Returns an Arc<Mutex<()>> so the caller can drop the DashMap shard’s read lock immediately and only retain the mutex itself across the await point — DashMap’s shard guard is !Send, so we must not hold it through an await.

pub fn prune_completion_locks(&self)

v0.8.1 #59: best-effort cleanup of stale completion-lock entries. A (bucket, key) entry is “stale” once no concurrent Complete is referencing its Arc<Mutex<()>> — we detect that by Arc::strong_count == 1 (only the DashMap itself holds a reference). Called from complete_multipart_upload after the guarded section returns, so a steady-state workload of unique keys never accumulates locks.

The retain predicate is > 1 (keep entries with outstanding borrowers), so prune is safe to invoke concurrently with other completion_lock callers — at worst the prune sees the entry during a brief window where the borrower has cloned but not yet taken lock(), and the entry survives until the next sweep.

Trait Implementations

impl Default for MultipartStateStore

fn default() -> Self

Returns the “default value” for a type.