Mike-Solar
013a175707
Single mechanical restructure commit: - root Cargo.toml = oakapp bin + workspace; one cargo build produces oakapp, oak-cli, oak-worker, liboakengine.dylib - app/rust/src -> src/ (app at repo root, no rust/ nesting) - src/<mod>/rust -> crates/oak<mod>; src/oakcore-rs -> crates/oakcore; src/bindings/oakotio -> crates/oakotio; src/engine/rust -> crates/oakengine (keeps cdylib+staticlib+rlib) - public C headers include/<mod>/ -> crates/oakengine/include/<mod>/ - OFX SDK headers vendored into crates/oakplugin/ofx/ (HostSupport gone) - legacy deleted: old src/ C++ modules, engine/, core/, ffmpeg_bridge/, app/ (Qt), cli/worker C++, root CMakeLists, third_party/KDDockWidgets submodule, otio-install, all build-* output (~40GB) - oakstorage kept but excluded from the workspace (skeleton w/ todos); gpui excluded (own workspace) - verified: cargo build green, cargo test --workspace 1845/0 (with the documented OCIO_RS_* env override for the homebrew OCIO)
65 lines
2.9 KiB
Markdown
65 lines
2.9 KiB
Markdown
# oakundo Rust crate
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> Status: **implemented**. Ports the C++ oakundo module
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> (`src/undo/src`) to Rust behind its frozen C ABI
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> (`include/undo/*.h`). Template follows `crates/oakplugin`.
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## Scope
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Replaces the C++ oakundo module (`src/undo/src`): undoable commands
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and the undo/redo history stack. Public contract: `include/undo/*.h`
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(3 headers: `error.h`, `undocommand.h`, `undostack.h`) — frozen,
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implemented verbatim by `src/ffi.rs`.
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## Architectural decisions
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1. **Vtable-command pattern is the centerpiece.** In C++ other modules
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*subclass* `olive::UndoCommand` (`redo()`/`undo()` overrides) and
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plug themselves in polymorphically. Rust has no inheritance, so the
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C ABI already models exactly this with
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`OakUndoCommandVtable { redo, undo, free_fn }` plus a caller-owned
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`userdata` pointer. The safe layer's [`undocommand::CommandKind`]
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is the direct analog: either a caller-defined vtable command
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(function pointers + userdata) or a [`undocommand::MultiUndoCommand`]
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composite. Domain logic dispatches on the vtable the same way the
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C++ virtual dispatch does.
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2. **Modified-state callbacks are intentionally not part of the C ABI.**
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The C++ `UndoCommand::redo_and_set_modified` pair records/restores a
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project dirty flag via `std::function` accessors. The public headers
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expose none of this; the stack drives state via `done_` on the safe
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type instead, and the flag callbacks are left as a documented future
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extension.
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3. **`UndoStack` state machine** is modeled directly on the C++:
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two deques — `commands_` (done, oldest at front) and
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`undone_commands_` (most-recently-undone at front); `push` clears any
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redoable tail, executes redo, and drops the oldest when the cap
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(200) is exceeded; `jump` clamps and walks via `undo`/`redo`. The
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fresh stack holds a single "New/Open Project" empty command so
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`can_undo` is false at the bottom (per `undostack.cpp`).
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4. **No merge semantics.** `include/undo/*.h` and `src/undo/src/*`
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define no `merge_with`/`can_merge`; commands are never coalesced.
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Tests reflect this (no merge tests).
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## Layout
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```
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src/
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lib.rs crate doc + module map
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error.rs error codes (include/undo/error.h)
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handle.rs refcounted-handle scaffolding (OAKUNDO_ABI_VERSION=1)
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undocommand.rs UndoCommand / vtable command / MultiUndoCommand
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undostack.rs UndoStack + empty bottom command
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ffi.rs export layer (one submodule per public header)
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tests/ contract tests per module
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```
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`error.h` exports macros only and is folded into `ffi.rs`'s preamble
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(no own submodule), matching the codec crate convention.
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## Dependency policy
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Prefer mature third-party crates (MIT/Apache-2.0/BSD, GPL-compatible)
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over hand-rolling; register each addition (name + reason) here. Large
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existing C++ libraries (OTIO, OCIO, OIIO, FFmpeg) are NEVER rewritten
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— they are consumed through their C ABI / bridge layers.
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