Files
signed/crates/signed_core/src/deletions.rs
T

81 lines
2.8 KiB
Rust

use std::collections::HashSet;
use nostr::prelude::*;
/// NIP-09 deletion requests and NIP-62 vanish requests,
/// built from the kind-5 and kind-62 events in the local database.
///
/// Deleted events are hidden before they reach the UI.
///
/// Pass any event through [`Deletions::is_deleted`] before showing it.
pub struct Deletions {
/// `(deleted event id, expected author)` from `e` tags of kind-5 events.
ids: HashSet<(EventId, PublicKey)>,
/// `(coordinate, expected author, cutoff)` from `a` tags of kind-5 events.
///
/// All versions of the addressable event up to `cutoff` are deleted.
coords: Vec<(Coordinate, PublicKey, Timestamp)>,
/// `(author, cutoff)` from kind-62 vanish requests.
vanished: Vec<(PublicKey, Timestamp)>,
}
impl Deletions {
/// Build the deletion index from raw kind-5 and kind-62 events.
pub fn from_events(events: impl IntoIterator<Item = Event>) -> Self {
let mut ids = HashSet::new();
let mut coords = Vec::new();
let mut vanished = Vec::new();
for event in events {
if event.kind == Kind::EventDeletion {
ids.extend(event.tags.event_ids().map(|id| (id, event.pubkey)));
coords.extend(
event
.tags
.coordinates()
.map(|c| (c, event.pubkey, event.created_at)),
);
} else if event.kind == Kind::RequestToVanish {
// Client-side we can't verify which relay the request targeted.
// Any vanish request is then honored for the author's events.
vanished.push((event.pubkey, event.created_at));
}
}
Self {
ids,
coords,
vanished,
}
}
/// Whether the event is covered by a valid deletion or vanish request.
/// A request is valid when its author matches the deleted event's author, per NIP-09.
///
/// Addressable events are deleted up to the request's `created_at`.
pub fn is_deleted(&self, event: &Event) -> bool {
if self
.vanished
.iter()
.any(|(pk, cutoff)| *pk == event.pubkey && event.created_at <= *cutoff)
{
return true;
}
if self.ids.contains(&(event.id, event.pubkey)) {
return true;
}
if event.kind.is_addressable()
&& let Some(identifier) = event.tags.identifier()
{
let coordinate = Coordinate::new(event.kind, event.pubkey).identifier(identifier);
return self.coords.iter().any(|(c, pk, cutoff)| {
*c == coordinate && *pk == event.pubkey && event.created_at <= *cutoff
});
}
false
}
}