feat: add cow btree

surrealdb · Dec 20, 2024 · 67735ba · 67735ba
1 parent fe3ae95
commit 67735ba
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Showing 2 changed files with 54 additions and 28 deletions.
diff --git a/src/node.rs b/src/node.rs
@@ -154,21 +154,13 @@ impl<K: KeyTrait + Clone, V: Clone> TwigNode<K, V> {
 
     #[inline]
     pub(crate) fn get_leaf_by_ts(&self, ts: u64) -> Option<&Arc<LeafValue<V>>> {
-        // self.values
-        //     .iter()
-        //     .filter(|value| value.ts <= ts)
-        //     .max_by_key(|value| value.ts)
-
         self.values
-        .iter()
-        .filter(|value| {
-            let should_include = value.ts <= ts;
-            if should_include {
-                println!("Version: {:?}, Key: {:?}, TS: {}", value.version, self.key, value.ts);
-            }
-            should_include
-        })
-        .max_by_key(|value| value.ts)
+            .iter()
+            .filter(|value| value.ts <= ts)
+            .max_by(|a, b| {
+                a.ts.cmp(&b.ts)
+                    .then_with(|| Arc::as_ptr(a).cmp(&Arc::as_ptr(b)))
+            })
     }
 
     #[inline]

diff --git a/src/version.rs b/src/version.rs
@@ -93,7 +93,14 @@ impl<V: Clone> BTree<V> {
             {
                 i -= 1;
             }
-            node.entries.insert(i, leaf_value);
+            // Check for duplicate version and replace if the new one has the same or later timestamp
+            if i > 0 && node.entries[i - 1].version == leaf_value.version {
+                if node.entries[i - 1].ts <= leaf_value.ts {
+                    node.entries[i - 1] = leaf_value;
+                }
+            } else {
+                node.entries.insert(i, leaf_value);
+            }
         } else {
             while i > 0
                 && !self.should_go_right(&node.entries[i - 1], leaf_value.version, leaf_value.ts)
@@ -115,6 +122,37 @@ impl<V: Clone> BTree<V> {
         }
     }
 
+    // fn insert_non_full(&self, node: &mut BNode<V>, leaf_value: Arc<LeafValue<V>>) {
+    //     let mut i = node.entries.len();
+
+    //     if node.is_leaf {
+    //         while i > 0
+    //             && !self.should_go_right(&node.entries[i - 1], leaf_value.version, leaf_value.ts)
+    //         {
+    //             i -= 1;
+    //         }
+    //         node.entries.insert(i, leaf_value);
+    //     } else {
+    //         while i > 0
+    //             && !self.should_go_right(&node.entries[i - 1], leaf_value.version, leaf_value.ts)
+    //         {
+    //             i -= 1;
+    //         }
+
+    //         let child = Arc::clone(&node.children[i]);
+    //         if child.is_full() {
+    //             self.split_child(node, i);
+    //             if self.should_go_right(&node.entries[i], leaf_value.version, leaf_value.ts) {
+    //                 i += 1;
+    //             }
+    //         }
+
+    //         let mut child = (*node.children[i]).clone();
+    //         self.insert_non_full(&mut child, leaf_value);
+    //         node.children[i] = Arc::new(child);
+    //     }
+    // }
+
     fn should_go_right(&self, entry: &LeafValue<V>, version: u64, ts: u64) -> bool {
         if version != entry.version {
             version > entry.version
@@ -460,20 +498,16 @@ mod tests {
         tree.insert(10, 1, ts);
         tree.insert(20, 1, ts);
 
-        let val = tree
-        .iter()
-        .filter(|value| {
-            let should_include = value.ts <= ts;
-            if should_include {
-                println!("Version: {:?}, TS: {}", value.version, value.ts);
-            }
-            should_include
-        })
-        .max_by_key(|value| value.ts).unwrap();
-        println!("Max value: {:?}", val.value);
-
+        let max_val = tree
+            .iter()
+            .filter(|value| value.ts <= ts)
+            .max_by(|a, b| {
+                a.ts.cmp(&b.ts)
+                    .then_with(|| Arc::as_ptr(a).cmp(&Arc::as_ptr(b)))
+            })
+            .unwrap();
 
+        assert_eq!(max_val.value, 20);
         assert_eq!(tree.search(1, ts).map(|leaf| &leaf.value), Some(&20));
     }
-
 }