feat(builder): add api for adding spentproof

src/builder.rs

@@ -195,7 +195,7 @@ pub struct DbcBuilder {
     pub revealed_commitments: Vec<RevealedCommitment>,
     pub output_owner_map: OutputOwnerMap,
     pub revealed_tx: RevealedTransaction,
-
+    pub spent_proofs: HashSet<SpentProof>,
     pub spent_proof_shares: BTreeMap<PublicKey, HashSet<SpentProofShare>>,
     pub spent_transactions: BTreeMap<Hash, DbcTransaction>,
 }
@@ -213,6 +213,7 @@ impl DbcBuilder {
             revealed_commitments,
             output_owner_map,
             revealed_tx,
+            spent_proofs: Default::default(),
             spent_proof_shares: Default::default(),
             spent_transactions: Default::default(),
         }
@@ -228,6 +229,12 @@ impl DbcBuilder {
             .collect()
     }
 
+    /// Add a SpentProof.
+    pub fn add_spent_proof(mut self, proof: SpentProof) -> Self {
+        let _ = self.spent_proofs.insert(proof);
+        self
+    }
+
     /// Add a SpentProofShare for the given input index
     pub fn add_spent_proof_share(mut self, share: SpentProofShare) -> Self {
         let shares = self
@@ -353,6 +360,7 @@ impl DbcBuilder {
             .map(|(key_image, shares)| {
                 SpentProof::try_from_proof_shares(*key_image, transaction_hash, shares.iter())
             })
+            .chain(self.spent_proofs.iter().cloned().map(Ok))
             .collect::<Result<_>>()?;
 
         Ok(spent_proofs)

src/spent_proof.rs

@@ -162,7 +162,7 @@ pub trait SpentProofKeyVerifier {
 
 /// SpentProof's are constructed when a DBC is logged to the spentbook.
 #[cfg_attr(feature = "serde", derive(Serialize, Deserialize))]
-#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
+#[derive(Debug, Clone, PartialOrd, Ord)]
 pub struct SpentProof {
     /// data to be signed
     pub content: SpentProofContent,
@@ -262,3 +262,21 @@ impl SpentProof {
             .map_err(|err| Error::FailedKnownKeyCheck(err.to_string()))
     }
 }
+
+// impl manually to avoid clippy complaint about Hash conflict.
+impl PartialEq for SpentProof {
+    fn eq(&self, other: &Self) -> bool {
+        self.content == other.content
+            && self.spentbook_pub_key == other.spentbook_pub_key
+            && self.spentbook_sig == other.spentbook_sig
+    }
+}
+
+impl Eq for SpentProof {}
+
+impl std::hash::Hash for SpentProof {
+    fn hash<H: std::hash::Hasher>(&self, state: &mut H) {
+        let bytes = self.to_bytes();
+        bytes.hash(state);
+    }
+}