Files
oak-editor/crates/oakstorage/README.md
T
Mike-Solar b36cbd6b6f refactor: purge CHandle from module internals (M14 R5)
Module-internal object references are Rust types now (values, Arc,
Mutex); CHandle remains only at the oakengine C-ABI boundary:

- oakundo: the global stack holds UndoStack/UndoCommand values
  directly (stack token is the static's address)
- oaktimeline: marker/workarea boxes carry Arc<Mutex<T>>; commands
  share the same allocation through Arc clones (readers in oakengine
  stubs and the app's graphops updated to lock)
- oaktask/oakstorage: sessions, write-through bindings and the
  database backend pass ProjectArc; the Session drops its manual
  release bookkeeping; nodeutil keeps the CHandle<->Arc boundary
  conversion (release_project restored for the app)
- oakcodec: handle.rs deleted outright (no facade entry needed it);
  texture/block placeholders are unit structs
- oakrender: copier's project handle is an identity u64; alive-count
  machinery removed; handle.rs is make_owned/get/get_mut only
- oakplugin: the instance registry is gone (its unregister key never
  matched, leaking weak entries); handle.rs is the RefBox boundary type
- oaknode/oakcommon: only dead guard/borrow helpers removed; external
  payload handles (texture/processor) documented as the boundary

Flake hunts landed along the way: the audio recording test serializes
on the shared manager lock with a normalized state; the autocacher
cancel test uses a slow producer so cancellation is deterministic.
2026-08-17 16:40:15 +08:00

78 lines
3.5 KiB
Markdown

# oakstorage Rust crate — project persistence
> Status: **implemented** (file backends). Manual:
> docs/zh/plans/riir/M10-oakstorage.md.
## Scope
Project persistence — the single module that knows where projects come
from and where they are saved to. Backends are pluggable via a manual
vtable; shipping in this pass: `ove-xml` (the XML project format) and
`otio` (the `.otio` / `.fcpxml` interchange, via the native oakotio
crate). The **database** backend (PostgreSQL + SQLite, SeaORM) is a
declared stub for a later proxy — not registered, `todo!()` bodies.
Consumers never branch on backend.
## Architectural decisions
1. **URI dispatch, not file paths.** Every entry point takes a URI:
`file:///…proj.ove` / `file:///…proj.otio` / `oakdb://…`. Bare
paths are normalized to `file://`. The core resolves scheme +
backend `can_handle` arbitration (M10 §2.3).
2. **Manual vtable backends** (`backend.rs` `StorageBackend` trait =
the M10 C vtable's Rust shape). The public C ABI vtable
(`oakstorage_backend_register`) accepts foreign (C-side) backends —
the database-swap interface proof — and in-crate backends implement
the Rust trait directly.
3. **The graph (de)serialization itself stays in oaknode** — every
backend calls the oaknode serializer (`oaknode::serializer::load` /
`save`) through `bridge::node` (direct Rust calls, single-lib
unification) to fetch/rebuild the in-memory graph; backends own
framing: container bytes, schema, versioning (TOO_OLD/TOO_NEW/
UNKNOWN_VERSION), sessions. `OAKSTORAGE_SAVE_COMPRESS` is accepted
but not implemented (the oaknode serializer emits plain XML only).
4. **Database backend shares one logical schema** across PostgreSQL
and SQLite via **SeaORM**: a private current-thread tokio runtime
drives the async API behind the synchronous C ABI; the entity set is
minimal (projects table: id, name, payload blob, version,
timestamps). The graph payload is the same serialized form the
ove-xml backend uses — one serialization truth, two containers.
5. **No callbacks/events** (M10: synchronous commands only; the caller
— oaktask/facade — owns progress reporting).
6. **Errors** follow the project -MMCCCC scheme, module 10
(`-100001` …); the M10 positive info codes (TOO_OLD/TOO_NEW/…) are
kept verbatim.
7. **Interchange is lossy.** The otio backend's export/import mapping
preserves sequences/tracks/clips/gaps/transitions; effect chains,
keyframes, project bins/settings and exact rational timebases are
not carried (see the module docs in `backends/otio.rs`).
## Layout
```
src/
lib.rs crate doc + module map
error.rs error/info codes (M10 §2.1, -MMCCCC module 10)
handle.rs shared CHandle re-export (boxes live in oaknode's handle.rs)
uri.rs URI parsing/classification
session.rs StorageProject session (open/take/uri)
registry.rs backend registry (register/unregister/arbitrate)
backend.rs StorageBackend trait + LoadResult
backends/
ove_xml.rs built-in .ove XML backend (via bridge::node)
otio.rs built-in .otio/.fcpxml backend (via oakotio)
database.rs declared stub (later proxy)
bridge/
node.rs oaknode calls (project + serializer + sequence builder)
ffi.rs export layer (M10 §2.2/§2.3 verbatim)
tests/ contract tests incl. the pluggability proof
```
## Build / test
A workspace member (not a default member); build and test explicitly:
```
cargo test -p oakstorage
```