notedeck

notes_holder.rs (6697B)

---

 use std::collections::HashMap;
 
 use enostr::{Filter, RelayPool};
 use nostrdb::{Ndb, Transaction};
 use notedeck::{NoteCache, NoteRef, NoteRefsUnkIdAction};
 use tracing::{debug, info, warn};
 
 use crate::{
     actionbar::NotesHolderResult, multi_subscriber::MultiSubscriber, timeline::TimelineTab, Error,
     Result,
 };
 
 pub struct NotesHolderStorage<M: NotesHolder> {
     pub id_to_object: HashMap<[u8; 32], M>,
 }
 
 impl<M: NotesHolder> Default for NotesHolderStorage<M> {
     fn default() -> Self {
         NotesHolderStorage {
             id_to_object: HashMap::new(),
         }
     }
 }
 
 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<M: NotesHolder> NotesHolderStorage<M> {
     pub fn notes_holder_expected_mut(&mut self, id: &[u8; 32]) -> &mut M {
         self.id_to_object
             .get_mut(id)
             .expect("notes_holder_expected_mut used but there was no NotesHolder")
     }
 
     pub fn notes_holder_mutated<'a>(
         &'a mut self,
         ndb: &Ndb,
         note_cache: &mut NoteCache,
         txn: &Transaction,
         id: &[u8; 32],
     ) -> Vitality<'a, M> {
         // 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.id_to_object.contains_key(id) {
             return Vitality::Stale(self.notes_holder_expected_mut(id));
         }
 
         // we don't have the note holder, query for it!
         let filters = M::filters(id);
 
         let notes = if let Ok(results) = ndb.query(txn, &filters, 1000) {
             results
                 .into_iter()
                 .map(NoteRef::from_query_result)
                 .collect()
         } else {
             debug!(
                 "got no results from NotesHolder lookup for {}",
                 hex::encode(id)
             );
             vec![]
         };
 
         if notes.is_empty() {
             warn!("NotesHolder query returned 0 notes? ")
         } else {
             info!("found NotesHolder with {} notes", notes.len());
         }
 
         self.id_to_object.insert(
             id.to_owned(),
             M::new_notes_holder(txn, ndb, note_cache, id, M::filters(id), notes),
         );
         Vitality::Fresh(self.id_to_object.get_mut(id).unwrap())
     }
 }
 
 pub trait NotesHolder {
     fn get_multi_subscriber(&mut self) -> Option<&mut MultiSubscriber>;
     fn set_multi_subscriber(&mut self, subscriber: MultiSubscriber);
     fn get_view(&mut self) -> &mut TimelineTab;
     fn filters(for_id: &[u8; 32]) -> Vec<Filter>;
     fn filters_since(for_id: &[u8; 32], since: u64) -> Vec<Filter>;
     fn new_notes_holder(
         txn: &Transaction,
         ndb: &Ndb,
         note_cache: &mut NoteCache,
         id: &[u8; 32],
         filters: Vec<Filter>,
         notes: Vec<NoteRef>,
     ) -> Self;
 
     #[must_use = "process_action must be handled in the Ok(action) case"]
     fn poll_notes_into_view(
         &mut self,
         txn: &Transaction,
         ndb: &Ndb,
     ) -> Result<NoteRefsUnkIdAction> {
         if let Some(multi_subscriber) = self.get_multi_subscriber() {
             let reversed = true;
             let note_refs: Vec<NoteRef> = multi_subscriber.poll_for_notes(ndb, txn)?;
             self.get_view().insert(&note_refs, reversed);
             Ok(NoteRefsUnkIdAction::new(note_refs))
         } else {
             Err(Error::Generic(
                 "NotesHolder unexpectedly has no MultiSubscriber".to_owned(),
             ))
         }
     }
 
     /// Look for new thread notes since our last fetch
     fn new_notes(notes: &[NoteRef], id: &[u8; 32], txn: &Transaction, ndb: &Ndb) -> Vec<NoteRef> {
         if notes.is_empty() {
             return vec![];
         }
 
         let last_note = notes[0];
         let filters = Self::filters_since(id, 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![]
         }
     }
 
     /// Local NotesHolder unsubscribe
     fn unsubscribe_locally<M: NotesHolder>(
         txn: &Transaction,
         ndb: &mut Ndb,
         note_cache: &mut NoteCache,
         notes_holder_storage: &mut NotesHolderStorage<M>,
         pool: &mut RelayPool,
         id: &[u8; 32],
     ) {
         let notes_holder = notes_holder_storage
             .notes_holder_mutated(ndb, note_cache, txn, id)
             .get_ptr();
 
         if let Some(multi_subscriber) = notes_holder.get_multi_subscriber() {
             multi_subscriber.unsubscribe(ndb, pool);
         }
     }
 
     fn open<M: NotesHolder>(
         ndb: &Ndb,
         note_cache: &mut NoteCache,
         txn: &Transaction,
         pool: &mut RelayPool,
         storage: &mut NotesHolderStorage<M>,
         id: &[u8; 32],
     ) -> Option<NotesHolderResult> {
         let vitality = storage.notes_holder_mutated(ndb, note_cache, txn, id);
 
         let (holder, result) = match vitality {
             Vitality::Stale(holder) => {
                 // The NotesHolder is stale, let's update it
                 let notes = M::new_notes(&holder.get_view().notes, id, txn, ndb);
                 let holder_result = if notes.is_empty() {
                     None
                 } else {
                     Some(NotesHolderResult::new_notes(notes, id.to_owned()))
                 };
 
                 //
                 // 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
                 //
                 (holder, holder_result)
             }
 
             Vitality::Fresh(thread) => (thread, None),
         };
 
         let multi_subscriber = if let Some(multi_subscriber) = holder.get_multi_subscriber() {
             multi_subscriber
         } else {
             let filters = M::filters(id);
             holder.set_multi_subscriber(MultiSubscriber::new(filters));
             holder.get_multi_subscriber().unwrap()
         };
 
         multi_subscriber.subscribe(ndb, pool);
 
         result
     }
 }