refactored append and fixed tests

src/lib.rs

@@ -48,9 +48,13 @@ pub struct MMRNode {
 
 impl MMRNode {
     fn complete(&self) -> bool {
-        let leaves = self.data.end_height - self.data.start_height + 1;
+        let leaves = self.leaf_count();
         leaves & (leaves - 1) == 0
     }
+
+    fn leaf_count(&self) -> u32 {
+        self.data.end_height - self.data.start_height + 1
+    }
 }
 
 impl From<NodeData> for MMRNode {

src/tree.rs

@@ -141,7 +141,7 @@ impl Tree {
     pub fn append_leaf(&mut self, root: NodeLink, new_leaf: NodeData) -> AppendTransaction {
         let is_complete= self.resolve_link(root).node.complete();
 
-        let (new_root_node, mut appended) = if is_complete {
+        let (new_root, mut appended) = if is_complete {
             let new_leaf_link = self.push(new_leaf.into());
 
             let mut appended = Vec::new();
@@ -153,35 +153,77 @@ impl Tree {
                 self.resolve_link(new_leaf_link),
             );
 
-            (new_root_node, appended)
+            (self.push_generated(new_root_node), appended)
         } else {
-            let (root_left_child, root_right_child) = {
-                let root = self.resolve_link(root).node;
-                (
-                    root.left.expect("Root should always have left child"),
-                    root.right.expect("Root should always have right child"),
+//            let (root_left_child, root_right_child) = {
+//                let root = self.resolve_link(root).node;
+//                (
+//                    root.left.expect("Root should always have left child"),
+//                    root.right.expect("Root should always have right child"),
+//                )
+//            };
+//
+//            let nested_append = self.append_leaf(root_right_child, new_leaf);
+//            let appended = nested_append.appended;
+//            let subtree_root = nested_append.new_root;
+//
+//            let new_root_node = combine_nodes(
+//                self.resolve_link(root_left_child),
+//                self.resolve_link(subtree_root),
+//            );
+//
+//            (new_root_node, appended)
+
+            let new_leaf_link = self.push(new_leaf.into());
+            let mut appended = Vec::new();
+            appended.push(new_leaf_link);
+
+            let mut peaks = self.get_peaks(root);
+
+            let mut merge_stack = Vec::new();
+            merge_stack.push(new_leaf_link);
+
+            while let Some(next_peak) = peaks.pop() {
+                dbg!(next_peak);
+                let next_merge = merge_stack.pop().expect("there should be at least one, checked below");
+
+                if let Some(stored) = {
+                    let peak = self.resolve_link(next_peak);
+                    let m = self.resolve_link(next_merge);
+                    if peak.node.leaf_count() == m.node.leaf_count() {
+                        Some(combine_nodes(peak, m))
+                    } else { None }
+                } {
+                    let link = self.push(stored);
+                    merge_stack.push(link);
+                    appended.push(link);
+                    dbg!(link);
+                    continue;
+                }
+                merge_stack.push(next_merge);
+                merge_stack.push(next_peak);
+            }
+
+            let mut root = merge_stack.pop().expect("There should be at least one node in stack");
+            while let Some(next_child) = merge_stack.pop() {
+                root = self.push_generated(
+                    combine_nodes(
+                        self.resolve_link(root),
+                        self.resolve_link(next_child),
+                    )
                 )
-            };
+            }
 
-            let nested_append = self.append_leaf(root_right_child, new_leaf);
-            let appended = nested_append.appended;
-            let subtree_root = nested_append.new_root;
-
-            let new_root_node = combine_nodes(
-                self.resolve_link(root_left_child),
-                self.resolve_link(subtree_root),
-            );
-
-            (new_root_node, appended)
+            (root, appended)
         };
 
-        let new_root = if new_root_node.complete() {
-            let new_root= self.push(new_root_node);
-            appended.push(new_root);
-            new_root
-        } else {
-            self.push_generated(new_root_node)
-        };
+//        let new_root = if new_root_node.complete() {
+//            let new_root= self.push(new_root_node);
+//            appended.push(new_root);
+//            new_root
+//        } else {
+//            self.push_generated(new_root_node)
+//        };
 
         AppendTransaction {
             new_root,
@@ -448,7 +490,7 @@ mod tests {
         });
 
         // *** APPEND #6 ***
-
+        dbg!("go");
         let append_tx = tree.append_leaf(new_root_link, leaf(6));
         let new_root_link = append_tx.new_root;
         let new_root = tree.resolve_link(new_root_link).node;
@@ -620,5 +662,18 @@ mod tests {
                 TestResult::from_bool(if let NodeLink::Stored(2) = root { true } else { false })
             }
         }
+
+        fn leaf_count(number: u32) -> TestResult {
+            if (number > 1024 * 1024 || number < 3) {
+                TestResult::discard()
+            } else {
+                let (mut root, mut tree) = initial();
+                for i in 0..(number-2) {
+                    root = tree.append_leaf(root, leaf(i+3)).new_root;
+                }
+
+                TestResult::from_bool(tree.resolve_link(root).node.leaf_count() == number)
+            }
+        }
     }
 }