descending value sort

2 files changed, 17 insertions, 2 deletions

diff --git a/database/src/kv/index.rs b/database/src/kv/index.rs
index c8f9259..7a3a5b1 100644
--- a/database/src/kv/index.rs
+++ b/database/src/kv/index.rs
@@ -93,10 +93,12 @@ pub fn iter_index<'a>(
         ),
         Sort::Value(value_sort) => {
             assert!(value_sort.offset.is_none(), "TODO");
-            assert_eq!(value_sort.order, SortOrder::Ascending, "TODO");
             Box::new(
                 PrefixIterator {
-                    inner: txn.iter(&prefix, false)?,
+                    inner: match value_sort.order {
+                        SortOrder::Ascending => txn.iter(&prefix, false)?,
+                        SortOrder::Descending => txn.iter(&prefix_end(prefix.clone()), true)?,
+                    },
                     prefix: prefix.into(),
                 }
                 .map(|k| {
@@ -112,3 +114,14 @@ pub fn iter_index<'a>(
         Sort::TextSearch(path, _) => todo!(),
     })
 }
+
+fn prefix_end(mut prefix: Vec<u8>) -> Vec<u8> {
+    for v in prefix.iter_mut().rev() {
+        let (nv, carry) = v.overflowing_add(1);
+        *v = nv;
+        if !carry {
+            break;
+        }
+    }
+    prefix
+}
diff --git a/database/src/kv/mod.rs b/database/src/kv/mod.rs
index 87af3fa..90b6686 100644
--- a/database/src/kv/mod.rs
+++ b/database/src/kv/mod.rs
@@ -69,6 +69,7 @@ impl Transaction for &mut dyn jellykv::Transaction {
         Ok(row)
     }
     fn remove(&mut self, row: RowNum) -> Result<()> {
+        debug!("remove {row}");
         let entry = self.get(row)?.ok_or(anyhow!("row did not exist"))?;
         let ob = entry.as_object();
         for (is, ik) in list_indices(*self)? {
@@ -77,6 +78,7 @@ impl Transaction for &mut dyn jellykv::Transaction {
         jellykv::Transaction::del(*self, &row_key(row))
     }
     fn update(&mut self, row: RowNum, entry: ObjectBuffer) -> Result<()> {
+        debug!("update {row}");
         let before = self.get(row)?.ok_or(anyhow!("row to update missing"))?;
         let before = before.as_object();
         let after = entry.as_object();