interval sorting

rslib/src/scheduler/queue/builder/mod.rs

@@ -26,8 +26,8 @@ pub(crate) struct DueCard {
     pub note_id: NoteID,
     pub mtime: TimestampSecs,
     pub due: i32,
-    /// Used to store interval, and for shuffling
-    pub extra: u64,
+    pub interval: u32,
+    pub hash: u64,
 }
 
 /// Temporary holder for new cards that will be built into a queue.

rslib/src/scheduler/queue/builder/sorting.rs

@@ -10,7 +10,7 @@ impl QueueBuilder {
         match self.new_order {
             NewCardOrder::Random => {
                 self.new.iter_mut().for_each(NewCard::hash_id_and_mtime);
-                self.new.sort_unstable_by(|a, b| a.extra.cmp(&b.extra));
+                self.new.sort_unstable_by(shuffle_new_card);
             }
             NewCardOrder::Due => {
                 self.new.sort_unstable_by(|a, b| a.due.cmp(&b.due));
@@ -30,30 +30,48 @@ impl QueueBuilder {
                 self.day_learning.sort_unstable_by(shuffle_by_day);
             }
             ReviewCardOrder::Shuffled => {
-                self.review.sort_unstable_by(|a, b| a.extra.cmp(&b.extra));
-                self.day_learning
-                    .sort_unstable_by(|a, b| a.extra.cmp(&b.extra));
+                self.review.sort_unstable_by(shuffle_due_card);
+                self.day_learning.sort_unstable_by(shuffle_due_card);
             }
             ReviewCardOrder::IntervalsAscending => {
-                // fixme: implement; may require separate field if we want
-                // to shuffle cards that share an interval
+                self.review.sort_unstable_by(intervals_ascending);
+                self.day_learning.sort_unstable_by(shuffle_due_card);
             }
             ReviewCardOrder::IntervalsDescending => {
-                // fixme: implement; may require separate field if we want
-                // to shuffle cards that share an interval
+                self.review
+                    .sort_unstable_by(|a, b| intervals_ascending(b, a));
+                self.day_learning.sort_unstable_by(shuffle_due_card);
             }
         }
     }
 }
 
+fn shuffle_new_card(a: &NewCard, b: &NewCard) -> Ordering {
+    a.extra.cmp(&b.extra)
+}
+
+fn shuffle_by_day(a: &DueCard, b: &DueCard) -> Ordering {
+    (a.due, a.hash).cmp(&(b.due, b.hash))
+}
+
+fn shuffle_due_card(a: &DueCard, b: &DueCard) -> Ordering {
+    a.hash.cmp(&b.hash)
+}
+
+fn intervals_ascending(a: &DueCard, b: &DueCard) -> Ordering {
+    (a.interval, a.hash).cmp(&(a.interval, b.hash))
+}
+
 // We sort based on a hash so that if the queue is rebuilt, remaining
-// cards come back in the same order.
+// cards come back in the same approximate order (mixing + due learning cards
+// may still result in a different card)
+
 impl DueCard {
     fn hash_id_and_mtime(&mut self) {
         let mut hasher = FnvHasher::default();
         hasher.write_i64(self.id.0);
         hasher.write_i64(self.mtime.0);
-        self.extra = hasher.finish();
+        self.hash = hasher.finish();
     }
 }
 
@@ -65,7 +83,3 @@ impl NewCard {
         self.extra = hasher.finish();
     }
 }
-
-fn shuffle_by_day(a: &DueCard, b: &DueCard) -> Ordering {
-    (a.due, a.extra).cmp(&(b.due, b.extra))
-}

rslib/src/storage/card/mod.rs

@@ -189,8 +189,9 @@ impl super::SqliteStorage {
                     id: row.get(1)?,
                     note_id: row.get(2)?,
                     due: row.get(3).ok().unwrap_or_default(),
-                    extra: row.get::<_, u32>(4)? as u64,
+                    interval: row.get(4)?,
                     mtime: row.get(5)?,
+                    hash: 0,
                 },
             ) {
                 break;