notedeck

cache.rs (7156B)

---

 use crate::{
     actionbar::TimelineOpenResult,
     error::Error,
     multi_subscriber::MultiSubscriber,
     //subscriptions::SubRefs,
     timeline::{Timeline, TimelineKind},
 };
 
 use notedeck::{filter, FilterState, NoteCache, NoteRef};
 
 use enostr::RelayPool;
 use nostrdb::{Filter, Ndb, Transaction};
 use std::collections::HashMap;
 use tracing::{debug, error, info, warn};
 
 #[derive(Default)]
 pub struct TimelineCache {
     pub timelines: HashMap<TimelineKind, Timeline>,
 }
 
 pub enum Vitality<'a, M> {
     Fresh(&'a mut M),
     Stale(&'a mut M),
 }
 
 impl<'a, M> Vitality<'a, M> {
     pub fn get_ptr(self) -> &'a mut M {
         match self {
             Self::Fresh(ptr) => ptr,
             Self::Stale(ptr) => ptr,
         }
     }
 
     pub fn is_stale(&self) -> bool {
         match self {
             Self::Fresh(_ptr) => false,
             Self::Stale(_ptr) => true,
         }
     }
 }
 
 impl TimelineCache {
     /// Pop a timeline from the timeline cache. This only removes the timeline
     /// if it has reached 0 subscribers, meaning it was the last one to be
     /// removed
     pub fn pop(
         &mut self,
         id: &TimelineKind,
         ndb: &mut Ndb,
         pool: &mut RelayPool,
     ) -> Result<(), Error> {
         let timeline = if let Some(timeline) = self.timelines.get_mut(id) {
             timeline
         } else {
             return Err(Error::TimelineNotFound);
         };
 
         if let Some(sub) = &mut timeline.subscription {
             // if this is the last subscriber, remove the timeline from cache
             if sub.unsubscribe(ndb, pool) {
                 debug!(
                     "popped last timeline {:?}, removing from timeline cache",
                     id
                 );
                 self.timelines.remove(id);
             }
 
             Ok(())
         } else {
             Err(Error::MissingSubscription)
         }
     }
 
     fn get_expected_mut(&mut self, key: &TimelineKind) -> &mut Timeline {
         self.timelines
             .get_mut(key)
             .expect("expected notes in timline cache")
     }
 
     /// Insert a new timeline into the cache, based on the TimelineKind
     #[allow(clippy::too_many_arguments)]
     fn insert_new(
         &mut self,
         id: TimelineKind,
         txn: &Transaction,
         ndb: &Ndb,
         notes: &[NoteRef],
         note_cache: &mut NoteCache,
     ) {
         let mut timeline = if let Some(timeline) = id.clone().into_timeline(txn, ndb) {
             timeline
         } else {
             error!("Error creating timeline from {:?}", &id);
             return;
         };
 
         // insert initial notes into timeline
         timeline.insert_new(txn, ndb, note_cache, notes);
         self.timelines.insert(id, timeline);
     }
 
     /// Get and/or update the notes associated with this timeline
     pub fn notes<'a>(
         &'a mut self,
         ndb: &Ndb,
         note_cache: &mut NoteCache,
         txn: &Transaction,
         id: &TimelineKind,
     ) -> Vitality<'a, Timeline> {
         // we can't use the naive hashmap entry API here because lookups
         // require a copy, wait until we have a raw entry api. We could
         // also use hashbrown?
 
         if self.timelines.contains_key(id) {
             return Vitality::Stale(self.get_expected_mut(id));
         }
 
         let notes = if let FilterState::Ready(filters) = id.filters(txn, ndb) {
             if let Ok(results) = ndb.query(txn, &filters, 1000) {
                 results
                     .into_iter()
                     .map(NoteRef::from_query_result)
                     .collect()
             } else {
                 debug!("got no results from TimelineCache lookup for {:?}", id);
                 vec![]
             }
         } else {
             // filter is not ready yet
             vec![]
         };
 
         if notes.is_empty() {
             warn!("NotesHolder query returned 0 notes? ")
         } else {
             info!("found NotesHolder with {} notes", notes.len());
         }
 
         self.insert_new(id.to_owned(), txn, ndb, &notes, note_cache);
 
         Vitality::Fresh(self.get_expected_mut(id))
     }
 
     /// Open a timeline, this is another way of saying insert a timeline
     /// into the timeline cache. If there exists a timeline already, we
     /// bump its subscription reference count. If it's new we start a new
     /// subscription
     pub fn open(
         &mut self,
         ndb: &Ndb,
         note_cache: &mut NoteCache,
         txn: &Transaction,
         pool: &mut RelayPool,
         id: &TimelineKind,
     ) -> Option<TimelineOpenResult> {
         let (open_result, timeline) = match self.notes(ndb, note_cache, txn, id) {
             Vitality::Stale(timeline) => {
                 // The timeline cache is stale, let's update it
                 let notes = find_new_notes(
                     timeline.all_or_any_notes(),
                     timeline.subscription.as_ref().map(|s| &s.filters)?,
                     txn,
                     ndb,
                 );
                 let open_result = if notes.is_empty() {
                     None
                 } else {
                     let new_notes = notes.iter().map(|n| n.key).collect();
                     Some(TimelineOpenResult::new_notes(new_notes, id.clone()))
                 };
 
                 // we can't insert and update the VirtualList now, because we
                 // are already borrowing it mutably. Let's pass it as a
                 // result instead
                 //
                 // holder.get_view().insert(&notes); <-- no
                 (open_result, timeline)
             }
 
             Vitality::Fresh(timeline) => (None, timeline),
         };
 
         if let Some(multi_sub) = &mut timeline.subscription {
             debug!("got open with *old* subscription for {:?}", &timeline.kind);
             multi_sub.subscribe(ndb, pool);
         } else if let Some(filter) = timeline.filter.get_any_ready() {
             debug!("got open with *new* subscription for {:?}", &timeline.kind);
             let mut multi_sub = MultiSubscriber::new(filter.clone());
             multi_sub.subscribe(ndb, pool);
             timeline.subscription = Some(multi_sub);
         } else {
             // This should never happen reasoning, self.notes would have
             // failed above if the filter wasn't ready
             error!(
                 "open: filter not ready, so could not setup subscription. this should never happen"
             );
         };
 
         open_result
     }
 }
 
 /// Look for new thread notes since our last fetch
 fn find_new_notes(
     notes: &[NoteRef],
     filters: &[Filter],
     txn: &Transaction,
     ndb: &Ndb,
 ) -> Vec<NoteRef> {
     if notes.is_empty() {
         return vec![];
     }
 
     let last_note = notes[0];
     let filters = filter::make_filters_since(filters, last_note.created_at + 1);
 
     if let Ok(results) = ndb.query(txn, &filters, 1000) {
         debug!("got {} results from NotesHolder update", results.len());
         results
             .into_iter()
             .map(NoteRef::from_query_result)
             .collect()
     } else {
         debug!("got no results from NotesHolder update",);
         vec![]
     }
 }