Struct DiffModeBridge 

pub struct DiffModeBridge { /* private fields */ }

Host-side bridge between [DiffSubsystem] session lifecycle and the per-buffer ActiveModes set. See module docs for the why.

Implementations

impl DiffModeBridge

pub fn new() -> DiffModeBridge

pub fn note_session_opened( &self, session_key: BufferId, participants: &[BufferId], )

Record that session_key opened with participants as the user-visible diff sides. For each participant whose refcount transitions 0 → 1, queue an Activate change. Idempotent on re-open of the same session_key (subsystem register_with_sources is itself idempotent on session identity).

pub fn note_session_closed(&self, session_key: BufferId)

Record that session_key closed. For each participant whose refcount drops to 0, queue a Deactivate change. No-op on unknown session keys (close-before-open or double-close from auto-drop racing the user’s :diffoff).

pub fn note_session_extended(&self, session_key: BufferId, buf: BufferId)

D.8.d (2026-05-31): record that an existing session gained a new participant buf. Increments the refcount + appends buf to the session’s participant list so subsequent Self::note_session_closed decrements every participant including this one.

Idempotent: re-adding a buffer that’s already a participant of session_key is a no-op (the refcount bucket dedupes by session-key, mirroring Self::note_session_opened).

No-op on unknown session_key — the caller has either already torn the session down or the bridge was never notified of the open. Defensive against races between :diffthis (which goes through the membership API) and drop_session (which goes through note_session_closed).

pub fn note_session_shrunk(&self, session_key: BufferId, buf: BufferId)

D.8.d (2026-05-31): record that a participant buf was removed from session_key. Decrements the refcount; if buf no longer participates in any session, queues a Deactivate change so the dispatch tail flips ActiveModes.diff-mode off on that buffer. Removes buf from the session’s participant list so a subsequent note_session_closed doesn’t double-decrement it.

No-op on unknown session_key or unknown participant.

pub fn drain_pending(&self) -> Vec<DiffModeChange>

Drain every pending change. Callers (the dispatch tail) apply them via the mode registry, which mutates the per-buffer ActiveModes.

pub fn refcount(&self, buffer: BufferId) -> usize

Test-only / introspection: current refcount for buffer. Returns 0 if no session activated diff-mode on it.

pub fn note_conflict_state( &self, session_key: BufferId, participants: &[BufferId], has_conflicts: bool, )

CR.3 (2026-06-24): reconcile diff-conflict-mode activation for session_key against its latest sign map. has_conflicts comes from sign_map_has_conflicts; the host calls this each cycle off the active session’s published sign map. Idempotent on an unchanged state (no transition → nothing queued), so per-cycle calls are cheap. On the false → true transition it queues a Conflict Activate for each participant (refcounted, so a buffer shared by two conflict sessions stays active until the last clears); on true → false it queues a Deactivate for each whose conflict refcount hits zero.

Trait Implementations

impl Debug for DiffModeBridge

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

Formats the value using the given formatter.

impl Default for DiffModeBridge

fn default() -> DiffModeBridge

Returns the “default value” for a type.