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DiffParticipantSource

lattice_host::diff::subsystem

Trait DiffParticipantSource 

Source 
pub trait DiffParticipantSource:
    Send
    + Sync
    + 'static
    + Debug {
    // Required method
    fn snapshot(&self) -> Rope;

    // Provided method
    fn buffer_id(&self) -> Option<BufferId> { ... }
}
Expand description

One participant in a diff session — produces the rope to diff for one slot in Hunk::ranges.

D.8.b (2026-05-31): collapses the previous BaselineSource + CurrentSource two-trait split into a single trait. The original split was structural sugar (made descriptor.baseline.snapshot() vs descriptor.current.snapshot() visually distinct) and stopped scaling once participants became an arity-agnostic Vec<Arc<dyn DiffParticipantSource>>. The slot index now carries the role.

Concrete impls in this module:

D.7’s GitSource (post-implementation) will land alongside these.

snapshot is called from inside the spawn_blocking body of DiffSubsystem::schedule_recompute, so impls may do cheap blocking I/O (a git cat-file for GitSource) but must not hold the host’s UI thread. Send + Sync + 'static is required so the trait object can cross the spawn_blocking boundary.

Required Methods§

Source

fn snapshot(&self) -> Rope

Produce this participant’s rope. Called once per recompute; the implementor decides whether to clone a cached rope or rematerialise from a backing store.

Provided Methods§

Source

fn buffer_id(&self) -> Option<BufferId>

D.8.d (2026-05-31): the buffer id this source is backed by, if any. Returns None for non-buffer sources (StaticSource, OnDiskSource, future GitSource); BufferSource overrides to return Some(buffer_id).

Load-bearing for the slot ↔ buffer mapping the subsystem’s membership API + the D.6.d pane_index_of helper rely on. Without it, compute_get_edit / compute_put_plan / remove_participant_buffer would need a sidecar map to find “the slot in Hunk::ranges for buffer X”. Default None means non-overriding impls continue to work — they just can’t be addressed by buffer id.

Dyn Compatibility§

This trait is dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors§