From 353db2efa207d1f520be72ff9a45cc332e6a969b Mon Sep 17 00:00:00 2001
From: Kris Nuttycombe <kris@nutty.land>
Date: Sat, 9 Mar 2024 11:22:50 -0700
Subject: [PATCH] incrementalmerkletree: Add `Frontier::tree_size`

---
 incrementalmerkletree/CHANGELOG.md    | 3 +++
 incrementalmerkletree/src/frontier.rs | 7 +++++++
 2 files changed, 10 insertions(+)

diff --git a/incrementalmerkletree/CHANGELOG.md b/incrementalmerkletree/CHANGELOG.md
index 3d7e08c0..03010bca 100644
--- a/incrementalmerkletree/CHANGELOG.md
+++ b/incrementalmerkletree/CHANGELOG.md
@@ -7,6 +7,9 @@ and this project adheres to Rust's notion of
 
 ## Unreleased
 
+### Added
+- `incrementalmerkletree::Frontier::tree_size`
+
 ## [0.5.0] - 2023-09-08
 
 ### Added
diff --git a/incrementalmerkletree/src/frontier.rs b/incrementalmerkletree/src/frontier.rs
index 9a28afda..e2342c6b 100644
--- a/incrementalmerkletree/src/frontier.rs
+++ b/incrementalmerkletree/src/frontier.rs
@@ -225,6 +225,13 @@ impl<H, const DEPTH: u8> Frontier<H, DEPTH> {
             size_of::<usize>() + (f.ommers.capacity() + 1) * size_of::<H>()
         })
     }
+
+    /// Returns the size of the Merkle tree that this frontier corresponds to.
+    pub fn tree_size(&self) -> u64 {
+        self.frontier
+            .as_ref()
+            .map_or(0, |f| u64::from(f.position()) + 1)
+    }
 }
 
 impl<H: Hashable + Clone, const DEPTH: u8> Frontier<H, DEPTH> {