// Copyright (c) 2022-2023 Yuki Kishimoto
// Copyright (c) 2023-2025 Rust Nostr Developers
// Distributed under the MIT software license
use std::collections::btree_set::IntoIter;
use std::collections::hash_map::DefaultHasher;
use std::hash::{Hash, Hasher};
use std::num::NonZeroUsize;
use btreecap::{BTreeCapSet, Capacity, OverCapacityPolicy};
use nostr::{Event, Filter};
// Lookup ID: EVENT_ORD_IMPL
const POLICY: OverCapacityPolicy = OverCapacityPolicy::Last;
/// Descending sorted collection of events
#[derive(Debug, Clone)]
pub struct Events {
set: BTreeCapSet<Event>,
hash: u64,
prev_not_match: bool,
}
impl Default for Events {
fn default() -> Self {
Self {
set: BTreeCapSet::unbounded(),
hash: 0,
prev_not_match: false,
}
}
}
impl PartialEq for Events {
fn eq(&self, other: &Self) -> bool {
self.set == other.set
}
}
impl Eq for Events {}
impl Events {
/// New collection
#[inline]
pub fn new(filter: &Filter) -> Self {
let mut hasher = DefaultHasher::new();
filter.hash(&mut hasher);
let hash: u64 = hasher.finish();
let set: BTreeCapSet<Event> = match filter.limit {
Some(limit) => match NonZeroUsize::new(limit) {
Some(max) => BTreeCapSet::with_capacity(Capacity::Bounded {
max,
policy: POLICY,
}),
None => BTreeCapSet::unbounded(),
},
None => BTreeCapSet::unbounded(),
};
Self {
set,
hash,
prev_not_match: false,
}
}
/// Returns the number of events in the collection.
#[inline]
pub fn len(&self) -> usize {
self.set.len()
}
/// Checks if there are no events.
#[inline]
pub fn is_empty(&self) -> bool {
self.set.is_empty()
}
/// Check if contains [`Event`]
#[inline]
pub fn contains(&self, event: &Event) -> bool {
self.set.contains(event)
}
/// Insert [`Event`]
///
/// If the set did not previously contain an equal value, `true` is returned.
/// If the collection is full, the older events will be discarded.
/// Use [`Events::force_insert`] to always make sure the event is inserted.
#[inline]
pub fn insert(&mut self, event: Event) -> bool {
self.set.insert(event).inserted
}
/// Force insert [`Event`]
///
/// Use [`Events::insert`] to respect the max collection capacity (if any).
/// If the collection capacity is full, this method will increase it.
#[inline]
pub fn force_insert(&mut self, event: Event) -> bool {
self.set.force_insert(event).inserted
}
/// Insert events
#[inline]
pub fn extend<I>(&mut self, events: I)
where
I: IntoIterator<Item = Event>,
{
self.set.extend(events);
}
/// Merge events collections into a single one.
///
/// Collection is converted to unbounded if one of the merge [`Events`] have a different hash.
/// In other words, the filters limit is respected only if the [`Events`] are related to the same
/// list of filters.
pub fn merge(mut self, other: Self) -> Self {
// Hash not match -> change capacity to unbounded
if self.hash != other.hash || self.prev_not_match || other.prev_not_match {
self.set.change_capacity(Capacity::Unbounded);
self.hash = 0;
self.prev_not_match = true;
}
// Extend
self.extend(other.set);
self
}
/// Get first [`Event`] (descending order)
#[inline]
pub fn first(&self) -> Option<&Event> {
// Lookup ID: EVENT_ORD_IMPL
self.set.first()
}
/// Get first [`Event`] (descending order)
#[inline]
pub fn first_owned(self) -> Option<Event> {
// Lookup ID: EVENT_ORD_IMPL
self.into_iter().next()
}
/// Get last [`Event`] (descending order)
#[inline]
pub fn last(&self) -> Option<&Event> {
// Lookup ID: EVENT_ORD_IMPL
self.set.last()
}
/// Get last [`Event`] (descending order)
#[inline]
pub fn last_owned(self) -> Option<Event> {
// Lookup ID: EVENT_ORD_IMPL
self.into_iter().next_back()
}
/// Iterate events in descending order
#[inline]
pub fn iter(&self) -> impl Iterator<Item = &Event> {
// Lookup ID: EVENT_ORD_IMPL
self.set.iter()
}
/// Convert the collection to vector of events.
#[inline]
pub fn to_vec(self) -> Vec<Event> {
self.into_iter().collect()
}
}
impl IntoIterator for Events {
type Item = Event;
type IntoIter = IntoIter<Self::Item>;
fn into_iter(self) -> Self::IntoIter {
// Lookup ID: EVENT_ORD_IMPL
self.set.into_iter()
}
}
impl FromIterator<Event> for Events {
fn from_iter<T>(iter: T) -> Self
where
T: IntoIterator<Item = Event>,
{
let mut events: Self = Self::default();
events.extend(iter);
events
}
}
#[cfg(test)]
mod tests {
use nostr::Kind;
use super::*;
#[test]
fn test_events_equality() {
// Match
{
let event1 = Event::from_json(r#"{"content":"Kind 10050 is for DMs, kind 10002 for the other stuff. But both have the same aim. So IMO both have to be under the `gossip` option.","created_at":1732738371,"id":"f2d71a515ce3576d238aaaeaa48fde97388162d08208f729b540a4c3f9723e6b","kind":1,"pubkey":"68d81165918100b7da43fc28f7d1fc12554466e1115886b9e7bb326f65ec4272","sig":"d88d3ac21036cfb541809288c12844747dbf1d20a246133dbd37374254b281808c5582bade27c880477759491b2b964d7235142c8b80d233dfb9ae8a50252119","tags":[["e","8262a50cf7832351ae3f21c429e111bb31be0cf754ec437e015534bf5cc2eee8","","root"],["e","0f4bcc83ef2af2febbc7eb9aea5d615a29084ed9e65c467ef2a9387ff79b57e8"],["e","94469431e367b2c16e6d224a4ac2c369c18718a1abdf42759ff591d9816b5ff3","","reply"],["p","68d81165918100b7da43fc28f7d1fc12554466e1115886b9e7bb326f65ec4272"],["p","1739d937dc8c0c7370aa27585938c119e25c41f6c441a5d34c6d38503e3136ef"],["p","03f9cfd948e95aeb04f780382344f7c1cfc0210d9af3f4006bb6d451c7b08692"],["p","126103bfddc8df256b6e0abfd7f3797c80dcc4ea88f7c2f87dd4104220b4d65f"],["p","13a665157257e79d9dcc960deeb367fd79383be2d0babb3d861679a5701d463b"],["p","ee0d20b47fb298e8a9ed3609108fe7f2296bd71e8b82fb4f9ff8f61f62bbc7a6"],["p","1c71312fb45273956b078e27981dcc15b178db8d55bffd7ad57a8cfaed6b5ab4"],["p","800e0fe3d8638ce3f75a56ed865df9d96fc9d9cd2f75550df0d7f5c1d8468b0b"]]}"#).unwrap();
let mut events1 = Events::new(&Filter::new().kind(Kind::TextNote).limit(1));
events1.insert(event1);
let event2 = Event::from_json(r#"{"content":"Kind 10050 is for DMs, kind 10002 for the other stuff. But both have the same aim. So IMO both have to be under the `gossip` option.","created_at":1732738371,"id":"f2d71a515ce3576d238aaaeaa48fde97388162d08208f729b540a4c3f9723e6b","kind":1,"pubkey":"68d81165918100b7da43fc28f7d1fc12554466e1115886b9e7bb326f65ec4272","sig":"d88d3ac21036cfb541809288c12844747dbf1d20a246133dbd37374254b281808c5582bade27c880477759491b2b964d7235142c8b80d233dfb9ae8a50252119","tags":[["e","8262a50cf7832351ae3f21c429e111bb31be0cf754ec437e015534bf5cc2eee8","","root"],["e","0f4bcc83ef2af2febbc7eb9aea5d615a29084ed9e65c467ef2a9387ff79b57e8"],["e","94469431e367b2c16e6d224a4ac2c369c18718a1abdf42759ff591d9816b5ff3","","reply"],["p","68d81165918100b7da43fc28f7d1fc12554466e1115886b9e7bb326f65ec4272"],["p","1739d937dc8c0c7370aa27585938c119e25c41f6c441a5d34c6d38503e3136ef"],["p","03f9cfd948e95aeb04f780382344f7c1cfc0210d9af3f4006bb6d451c7b08692"],["p","126103bfddc8df256b6e0abfd7f3797c80dcc4ea88f7c2f87dd4104220b4d65f"],["p","13a665157257e79d9dcc960deeb367fd79383be2d0babb3d861679a5701d463b"],["p","ee0d20b47fb298e8a9ed3609108fe7f2296bd71e8b82fb4f9ff8f61f62bbc7a6"],["p","1c71312fb45273956b078e27981dcc15b178db8d55bffd7ad57a8cfaed6b5ab4"],["p","800e0fe3d8638ce3f75a56ed865df9d96fc9d9cd2f75550df0d7f5c1d8468b0b"]]}"#).unwrap();
let mut events2 = Events::new(&Filter::new().kind(Kind::TextNote).limit(2)); // Different filter from above
events2.insert(event2);
assert_eq!(events1, events2);
}
// NOT match
{
let event1 = Event::from_json(r#"{"content":"Kind 10050 is for DMs, kind 10002 for the other stuff. But both have the same aim. So IMO both have to be under the `gossip` option.","created_at":1732738371,"id":"f2d71a515ce3576d238aaaeaa48fde97388162d08208f729b540a4c3f9723e6b","kind":1,"pubkey":"68d81165918100b7da43fc28f7d1fc12554466e1115886b9e7bb326f65ec4272","sig":"d88d3ac21036cfb541809288c12844747dbf1d20a246133dbd37374254b281808c5582bade27c880477759491b2b964d7235142c8b80d233dfb9ae8a50252119","tags":[["e","8262a50cf7832351ae3f21c429e111bb31be0cf754ec437e015534bf5cc2eee8","","root"],["e","0f4bcc83ef2af2febbc7eb9aea5d615a29084ed9e65c467ef2a9387ff79b57e8"],["e","94469431e367b2c16e6d224a4ac2c369c18718a1abdf42759ff591d9816b5ff3","","reply"],["p","68d81165918100b7da43fc28f7d1fc12554466e1115886b9e7bb326f65ec4272"],["p","1739d937dc8c0c7370aa27585938c119e25c41f6c441a5d34c6d38503e3136ef"],["p","03f9cfd948e95aeb04f780382344f7c1cfc0210d9af3f4006bb6d451c7b08692"],["p","126103bfddc8df256b6e0abfd7f3797c80dcc4ea88f7c2f87dd4104220b4d65f"],["p","13a665157257e79d9dcc960deeb367fd79383be2d0babb3d861679a5701d463b"],["p","ee0d20b47fb298e8a9ed3609108fe7f2296bd71e8b82fb4f9ff8f61f62bbc7a6"],["p","1c71312fb45273956b078e27981dcc15b178db8d55bffd7ad57a8cfaed6b5ab4"],["p","800e0fe3d8638ce3f75a56ed865df9d96fc9d9cd2f75550df0d7f5c1d8468b0b"]]}"#).unwrap();
let mut events1 = Events::new(&Filter::new().kind(Kind::TextNote).limit(1));
events1.insert(event1);
let event2 = Event::from_json(r#"{"content":"Thank you !","created_at":1732738224,"id":"035a18ba52a9b40137c0c60ed955eb1f1f93e12423082f6d8a83f62726462d21","kind":1,"pubkey":"1c71312fb45273956b078e27981dcc15b178db8d55bffd7ad57a8cfaed6b5ab4","sig":"54921c7a4f972428c67267a0d99df7d5094c7ca4d26fe9c08221de88ffafb0cab347939ff77129ecfdebad6b18cd2c4c229bf67ce8914fe778d24e19bc22be43","tags":[["p","68d81165918100b7da43fc28f7d1fc12554466e1115886b9e7bb326f65ec4272"],["p","1739d937dc8c0c7370aa27585938c119e25c41f6c441a5d34c6d38503e3136ef"],["p","03f9cfd948e95aeb04f780382344f7c1cfc0210d9af3f4006bb6d451c7b08692"],["p","126103bfddc8df256b6e0abfd7f3797c80dcc4ea88f7c2f87dd4104220b4d65f"],["p","13a665157257e79d9dcc960deeb367fd79383be2d0babb3d861679a5701d463b"],["p","ee0d20b47fb298e8a9ed3609108fe7f2296bd71e8b82fb4f9ff8f61f62bbc7a6"],["e","8262a50cf7832351ae3f21c429e111bb31be0cf754ec437e015534bf5cc2eee8","wss://nos.lol/","root"],["e","670303f9cbb24568c705b545c277be1f5172ad84795cc9e700aeea5bb248fd74","wss://n.ok0.org/","reply"]]}"#).unwrap();
let mut events2 = Events::new(&Filter::new().kind(Kind::TextNote).limit(2)); // Different filter from above
events2.insert(event2);
assert_ne!(events1, events2);
}
}
#[test]
fn test_merge() {
// Same filter
let filter = Filter::new().kind(Kind::TextNote).limit(100);
let events1 = Events::new(&filter);
assert_eq!(
events1.set.capacity(),
Capacity::Bounded {
max: NonZeroUsize::new(100).unwrap(),
policy: POLICY
}
);
let events2 = Events::new(&filter);
assert_eq!(
events2.set.capacity(),
Capacity::Bounded {
max: NonZeroUsize::new(100).unwrap(),
policy: POLICY
}
);
let hash1 = events1.hash;
assert_eq!(events1.hash, events2.hash);
let events = events1.merge(events2);
assert_eq!(events.hash, hash1);
assert!(!events.prev_not_match);
assert_eq!(
events.set.capacity(),
Capacity::Bounded {
max: NonZeroUsize::new(100).unwrap(),
policy: POLICY
}
);
// Different filters
let filter1 = Filter::new().kind(Kind::TextNote).limit(100);
let filter2 = Filter::new().kind(Kind::Metadata).limit(10);
let filter3 = Filter::new().kind(Kind::ContactList).limit(1);
let events1 = Events::new(&filter1);
assert_eq!(
events1.set.capacity(),
Capacity::Bounded {
max: NonZeroUsize::new(100).unwrap(),
policy: POLICY
}
);
let events2 = Events::new(&filter2);
assert_eq!(
events2.set.capacity(),
Capacity::Bounded {
max: NonZeroUsize::new(10).unwrap(),
policy: POLICY
}
);
let events3 = Events::new(&filter3);
assert_eq!(
events3.set.capacity(),
Capacity::Bounded {
max: NonZeroUsize::new(1).unwrap(),
policy: POLICY
}
);
assert_ne!(events1.hash, events2.hash);
let events = events1.merge(events2);
assert_eq!(events.hash, 0);
assert!(events.prev_not_match);
assert_eq!(events.set.capacity(), Capacity::Unbounded);
let events = events.merge(events3);
assert_eq!(events.hash, 0);
assert!(events.prev_not_match);
assert_eq!(events.set.capacity(), Capacity::Unbounded);
}
}