Struct WriteEvent 

pub struct WriteEvent { /* private fields */ }

A cursor-advance notification delivered to a write callback.

A WriteEvent carries no entry payloads — only the cursor brackets (previous_tips → post_tips) and the WriteSource. Callbacks that only care that something changed (cache invalidation, UI wake-ups) can act on the event directly without touching the wire or the DAG. Callbacks that need to enumerate or fetch the new entries call Database::ids_added with the brackets:

// Enumerate the IDs added between the two cursors
let new_ids = db.ids_added(event.previous_tips(), event.post_tips()).await?;
for id in new_ids {
    // … fetch entry bodies via db.get_entry(id) if needed …
}

Cursor semantics: previous_tips is this callback’s frontier before this fire — the user-supplied initial tips on the first fire, then the preceding fire’s post_tips on each subsequent fire. The cursor advances to post_tips synchronously before the user closure is awaited, so the next fire is guaranteed to bracket against the latest observed frontier even if the closure is slow.

Triggered only by settled-state (Verified) writes, but the cursors are raw DAG frontiers — the bracket can span Unverified/Failed entries, which Database::ids_added will enumerate. See Notification::DatabaseWrite rustdoc for the full verification contract.

Implementations

impl WriteEvent

pub fn previous_tips(&self) -> &Snapshot

Get the database state at this callback’s cursor before this fire.

The first fire on a freshly-registered callback returns the initial snapshot passed at registration time. Subsequent fires return the previous fire’s post_tips.

pub fn post_tips(&self) -> &Snapshot

Get the database state at this callback’s cursor after this fire.

The cursor advances to this value before the callback is awaited, so the next fire on the same callback will have previous_tips() == this fire's post_tips().

pub fn source(&self) -> WriteSource

The source of this write (local commit or remote sync).

Trait Implementations

impl Clone for WriteEvent

fn clone(&self) -> WriteEvent

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for WriteEvent

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

Formats the value using the given formatter.