Method alloc_node

nodedb/src/engine/kv/sorted_index/tree.rs:149–166

(&mut self, sort_key: Vec<u8>, primary_key: Vec<u8>)

    // ── AVL internal methods ───────────────────────────────────────────

    fn alloc_node(&mut self, sort_key: Vec<u8>, primary_key: Vec<u8>) -> u32 {
        let node = Node {
            sort_key,
            primary_key,
            left: NULL,
            right: NULL,
            height: 1,
            count: 1,
        };
        if let Some(idx) = self.free_list.pop() {
            self.nodes[idx as usize] = node;
            idx
        } else {
            let idx = self.nodes.len() as u32;
            self.nodes.push(node);
            idx
        }
    }

    fn free_node(&mut self, idx: u32) {
        self.free_list.push(idx);