Module state_cache 

AG-2a: the protocol-neutral editor read-state cache.

Per mode-ownership ([[feedback_mode_owns_its_surface]]), the read state the agent read tools answer from belongs to this crate, not the host and not any one agent-protocol adapter. Adapters subscribe to the generic event bus (DocumentOpened / DocumentClosed / SelectionsChanged) and fold those events into an EditorStateCache. A dedicated updater task owns the writes; agent tasks read the cache off the editor thread. The editor thread pays nothing new — it already publishes these events.

On-demand text / path / dirty come from the generic BufferStore service at read time, not this cache — the cache only tracks the open-editor set and the active selection, which aren’t otherwise queryable off-thread.

Structs

ActiveSelection

The active buffer’s selection, tracked from SelectionsChanged.

EditorStateCache

Crate-owned snapshot of the editor state the read tools answer from. Holds no host types — only protocol-level ids / selections / paths. Mutated solely by the updater task (draining generic events); read by consumers under the EditorStateHandle mutex.

OpenBuffer

One open editor buffer, tracked from DocumentOpened.

Functions

spawn_read_cache

Subscribe to the generic event bus and spawn the cache-updater task. Returns the shared cache handle. Fully crate-owned: the host only publishes the (generic) events; this task + cache live here.

Type Aliases

EditorStateHandle

Thread-safe handle to the read cache, shared between the updater task (writer) and agent tasks (readers). A plain Mutex — updates are O(1) in-place (no per-event clone) and reads are rare (agent-initiated), so there’s no contention worth a wait-free structure.