Run the item page's count and the feed list's queries together (#346)

entry_page awaited the page's query and then its count, about 40 and
24 ms on /api/entries, the busiest route; feed_list awaited five
independent queries in turn (entries, downloaded, unread, blocked,
feeds), 59 ms of a 67 ms /api/feeds, with the pool's connections idle.
Both now use tokio::try_join!. On SQLite they queue on its connection
as before.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

crates/ipx/CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 - Traces show more of where a request's time goes: a page of items' query and its files apart, artwork's cache, check and fetch, the status counts, and each part of changing or leaving a feed (#350).
 - A page of items finds its files by feed as well as item: it read every file's row in the database, about a quarter of a second a page (#344).
+- A page of items asks for its count beside the items, and the feed list asks its five questions at once, where each waited for the one before (#346).
 
 ### Fixed
 

crates/ipx/src/db.rs

@@ -521,22 +521,22 @@ impl Db {
         // Of this person's feeds only, as the unread count is: counting every item of every feed on
         // the server, 1534 feeds for someone reading 146, was 184-316 ms, 70% of the feed list's
         // time (#165). The Directory reads this for every feed's title and artwork, not a count.
+        // Five queries that need nothing of each other, run at once: one after another they were
+        // 59 ms of a 67 ms feed list, on a pool of idle connections (#346).
         let entries = counts(
             "entries",
             "SELECT e.feed_id, count(*) AS n FROM entries e
                JOIN subscriptions sub ON sub.user_id = $1 AND sub.feed_id = e.feed_id
               WHERE (CAST($2 AS TEXT) IS NULL OR e.feed_id = $2) GROUP BY e.feed_id",
             vec![user_id.into(), one()],
-        )
+        );
-        .await?;
         let downloaded = counts(
             "downloaded",
             "SELECT x.feed_id, count(*) AS n FROM enclosures x
                JOIN subscriptions sub ON sub.user_id = $1 AND sub.feed_id = x.feed_id
               WHERE x.path IS NOT NULL AND (CAST($2 AS TEXT) IS NULL OR x.feed_id = $2) GROUP BY x.feed_id",
             vec![user_id.into(), one()],
-        )
+        );
-        .await?;
         let unread = counts(
             "unread",
             "SELECT e.feed_id, count(*) AS n FROM entries e
@@ -549,22 +549,26 @@ impl Db {
                                  WHERE h.user_id = $1 AND h.feed_id = e.feed_id AND h.guid = e.guid)
               GROUP BY e.feed_id",
             vec![user_id.into(), one()],
-        )
+        );
-        .await?;
+        let blocked = tracing::Instrument::instrument(
-        let mut blocked: HashMap<String, Vec<String>> = tracing::Instrument::instrument(
             blocklists::Entity::find().filter(blocklists::Column::UserId.eq(user_id)).all(&self.orm),
             step("blocked"),
-        )
+        );
-        .await?
-        .into_iter()
-        .map(|b| (b.feed_id, keywords(Some(b.words)).unwrap_or_default()))
-        .collect();
         let mut rows = feeds::Entity::find();
         if let Some(id) = only {
             rows = rows.filter(feeds::Column::Id.eq(id));
         }
-        Ok(tracing::Instrument::instrument(rows.all(&self.orm), step("feeds"))
+        let rows = tracing::Instrument::instrument(rows.all(&self.orm), step("feeds"));
-            .await?
+        let (entries, downloaded, unread, blocked, rows) = tokio::try_join!(
+            entries,
+            downloaded,
+            unread,
+            async { blocked.await.map_err(anyhow::Error::from) },
+            async { rows.await.map_err(anyhow::Error::from) },
+        )?;
+        let mut blocked: HashMap<String, Vec<String>> =
+            blocked.into_iter().map(|b| (b.feed_id, keywords(Some(b.words)).unwrap_or_default())).collect();
+        Ok(rows
             .into_iter()
             .map(|f| {
                 let id = f.id.clone();

crates/ipx/src/web.rs

@@ -1596,12 +1596,23 @@ async fn entry_page(
         limit,
         search = search.is_some(),
     );
-    let mut rows = match signal {
+    let list = async {
-        Some(id) => {
+        match signal {
-            db.signal_entries(user_id, id, filter, search, page.offset, limit, &order).instrument(in_list).await?
+            Some(id) => {
+                db.signal_entries(user_id, id, filter, search, page.offset, limit, &order).instrument(in_list).await
+            }
+            None => db.entries_of(user_id, feeds, filter, search, page.offset, limit, &order).instrument(in_list).await,
         }
-        None => db.entries_of(user_id, feeds, filter, search, page.offset, limit, &order).instrument(in_list).await?,
     };
+    let count = async {
+        match signal {
+            Some(id) => db.signal_count(user_id, id, filter, search).instrument(step("count_in")).await,
+            None => db.count_of(user_id, feeds, filter, search).instrument(step("count_in")).await,
+        }
+    };
+    // The count beside the list, not after it: each waited on the other, about 40 and 24 ms on the
+    // busiest route (#346).
+    let (mut rows, total) = tokio::try_join!(list, count)?;
     step("sanitize").in_scope(|| {
         let mut sanitizer = feed_sanitizer();
         for row in &mut rows {
@@ -1609,10 +1620,6 @@ async fn entry_page(
         }
     });
     crate::deadair::for_reader(&state.ctx, user_id, &mut rows).instrument(step("deadair")).await?;
-    let total = match signal {
-        Some(id) => db.signal_count(user_id, id, filter, search).instrument(step("count_in")).await?,
-        None => db.count_of(user_id, feeds, filter, search).instrument(step("count_in")).await?,
-    };
     Ok(Json(EntryPage { total, entries: rows }))
 }