From 8db7a071a0b79687d79ffc6894fe573944b16008 Mon Sep 17 00:00:00 2001
From: Jack Grigg <jack@electriccoin.co>
Date: Wed, 26 Apr 2023 15:33:48 +0000
Subject: [PATCH] zcash_primitives: `impl DynamicUsage for
 sapling::Bundle<Authorized>`

---
 zcash_primitives/CHANGELOG.md                 |  4 +++
 .../src/transaction/components/sapling.rs     | 28 +++++++++++++++++++
 2 files changed, 32 insertions(+)

diff --git a/zcash_primitives/CHANGELOG.md b/zcash_primitives/CHANGELOG.md
index dbc7d8fe1..001a41fc5 100644
--- a/zcash_primitives/CHANGELOG.md
+++ b/zcash_primitives/CHANGELOG.md
@@ -10,6 +10,10 @@ and this library adheres to Rust's notion of
 - `zcash_primitives::transaction`:
   - `Transaction::temporary_zcashd_read_v5_sapling`
   - `Transaction::temporary_zcashd_write_v5_sapling`
+- Implementations of `memuse::DynamicUsage` for the following types:
+  - `zcash_primitives::transaction::components::sapling`:
+    - `Bundle<Authorized>`
+    - `SpendDescription<Authorized>`
 
 ### Changed
 - Bumped dependencies to `secp256k1 0.26`, `hdwallet 0.4`.
diff --git a/zcash_primitives/src/transaction/components/sapling.rs b/zcash_primitives/src/transaction/components/sapling.rs
index dc1b66380..149bfdbd4 100644
--- a/zcash_primitives/src/transaction/components/sapling.rs
+++ b/zcash_primitives/src/transaction/components/sapling.rs
@@ -192,6 +192,24 @@ impl<A: Authorization> Bundle<A> {
     }
 }
 
+impl DynamicUsage for Bundle<Authorized> {
+    fn dynamic_usage(&self) -> usize {
+        self.shielded_spends.dynamic_usage() + self.shielded_outputs.dynamic_usage()
+    }
+
+    fn dynamic_usage_bounds(&self) -> (usize, Option<usize>) {
+        let bounds = (
+            self.shielded_spends.dynamic_usage_bounds(),
+            self.shielded_outputs.dynamic_usage_bounds(),
+        );
+
+        (
+            bounds.0 .0 + bounds.1 .0,
+            bounds.0 .1.zip(bounds.1 .1).map(|(a, b)| a + b),
+        )
+    }
+}
+
 #[derive(Clone)]
 pub struct SpendDescription<A: Authorization> {
     cv: ValueCommitment,
@@ -263,6 +281,16 @@ impl<A: Authorization> SpendDescription<A> {
     }
 }
 
+impl DynamicUsage for SpendDescription<Authorized> {
+    fn dynamic_usage(&self) -> usize {
+        self.zkproof.dynamic_usage()
+    }
+
+    fn dynamic_usage_bounds(&self) -> (usize, Option<usize>) {
+        self.zkproof.dynamic_usage_bounds()
+    }
+}
+
 /// Consensus rules (§4.4) & (§4.5):
 /// - Canonical encoding is enforced here.
 /// - "Not small order" is enforced here.