Struct AppContext 

pub struct AppContext {
    pub db_context: DbContext,
    pub event_hub: Arc<EventHub>,
    pub shutdown_rx: Receiver<()>,
    pub undo_redo_manager: Arc<Mutex<UndoRedoManager>>,
    pub long_operation_manager: Arc<Mutex<LongOperationManager>>,
    /* private fields */
}

Application context that holds all shared state.

Shutdown lifecycle: when AppContext::shutdown is called the shared shutdown_tx is dropped, which makes every cloned shutdown_rx (held by EventHubClient::start threads) see Disconnected on its next recv() and exit. No polling and no atomic flag needed.

Fields

db_context: DbContext

event_hub: Arc<EventHub>

shutdown_rx: Receiver<()>

Receiver clones are handed to background event-hub threads. Threads exit when the matching sender is dropped via AppContext::shutdown.

undo_redo_manager: Arc<Mutex<UndoRedoManager>>

long_operation_manager: Arc<Mutex<LongOperationManager>>

Implementations

impl AppContext

pub fn new() -> Self

pub fn new_sharing(other: &AppContext) -> Self

A context that shares another’s event hub, shutdown channel and long-operation manager, with a private store and undo stack.

What may be shared and what may not is decided by undo. Every repository’s snapshot/restore takes and puts back the whole store (see Transaction::snapshot_store), so two documents in one store would undo and roll each other back. The store and the undo manager therefore stay private to each document.

The event hub can be shared, and that is where the cost is: draining one costs an OS thread, so a hub per document is a thread per document. A stream over a book-length manuscript opens more than a hundred.

Because the hub is shared, so is the shutdown channel: a document that stopped the pump on its own way out would stop it for every sibling. The owner of the shared context is what decides when the pump ends.

pub fn shutdown(&self)

Signal background event-hub threads to stop. Idempotent: the second call is a no-op because the sender has already been taken.

Trait Implementations

impl Clone for AppContext

fn clone(&self) -> AppContext

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for AppContext

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

Formats the value using the given formatter.

impl Default for AppContext

fn default() -> Self

Returns the “default value” for a type.