From 97b53e0b89281d33d0a37cc268a634715812dafb Mon Sep 17 00:00:00 2001
From: sanket1729 <sanket1729@gmail.com>
Date: Tue, 17 Aug 2021 20:38:16 +0000
Subject: [PATCH] Cache Input/Output ScriptPubkeys sha256

---
 src/script/interpreter.cpp | 31 +++++++++++++++++++++++++++++++
 src/script/interpreter.h   |  6 +++++-
 2 files changed, 36 insertions(+), 1 deletion(-)

diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp
index dd9bcdb0e2..a793e5be08 100644
--- a/src/script/interpreter.cpp
+++ b/src/script/interpreter.cpp
@@ -1941,6 +1941,35 @@ uint256 GetSpentScriptsSHA256(const std::vector<CTxOut>& outputs_spent)
     return ss.GetSHA256();
 }
 
+/** Compute the vector where each element is SHA256 of scriptPubKeys spent by a tx. */
+std::vector<uint256> GetSpentScriptPubKeysSHA256(const std::vector<CTxOut>& outputs_spent)
+{
+    std::vector<uint256> spent_spk_single_hashes;
+    spent_spk_single_hashes.reserve(outputs_spent.size());
+    for (const auto& txout : outputs_spent) {
+        // Normal serialization using the << operater would also serialize the length, therefore we directly write using CSHA256
+        uint256 spent_spk_single_hash;
+        CSHA256().Write(txout.scriptPubKey.data(), txout.scriptPubKey.size()).Finalize(spent_spk_single_hash.data());
+        spent_spk_single_hashes.push_back(std::move(spent_spk_single_hash));
+    }
+    return spent_spk_single_hashes;
+}
+
+/** Compute the vector where each element is SHA256 of output scriptPubKey of a tx. */
+template <class T>
+std::vector<uint256> GetOutputScriptPubKeysSHA256(const T& txTo)
+{
+    std::vector<uint256> out_spk_single_hashes;
+    out_spk_single_hashes.reserve(txTo.vout.size());
+    for (const auto& txout : txTo.vout) {
+        // Normal serialization using the << operater would also serialize the length, therefore we directly write using CSHA256
+        uint256 out_spk_single_hash;
+        CSHA256().Write(txout.scriptPubKey.data(), txout.scriptPubKey.size()).Finalize(out_spk_single_hash.data());
+        out_spk_single_hashes.push_back(std::move(out_spk_single_hash));
+    }
+    return out_spk_single_hashes;
+}
+
 template <class T>
 uint256 GetRangeproofsHash(const T& txTo) {
     CHashWriter ss(SER_GETHASH, 0);
@@ -2012,6 +2041,8 @@ void PrecomputedTransactionData::Init(const T& txTo, std::vector<CTxOut>&& spent
         m_issuance_rangeproofs_single_hash = GetIssuanceRangeproofsSHA256(txTo);
         m_output_witnesses_single_hash = GetOutputWitnessesSHA256(txTo);
         m_spent_scripts_single_hash = GetSpentScriptsSHA256(m_spent_outputs);
+        m_spent_output_spk_single_hashes = GetSpentScriptPubKeysSHA256(m_spent_outputs);
+        m_output_spk_single_hashes = GetOutputScriptPubKeysSHA256(txTo);
         m_bip341_taproot_ready = true;
     }
 }
diff --git a/src/script/interpreter.h b/src/script/interpreter.h
index c452c5dc29..e30ebe0ce5 100644
--- a/src/script/interpreter.h
+++ b/src/script/interpreter.h
@@ -173,7 +173,9 @@ struct PrecomputedTransactionData
     uint256 m_issuances_single_hash;
     uint256 m_output_witnesses_single_hash;
     uint256 m_issuance_rangeproofs_single_hash;
-    //! Whether the 10 fields above are initialized.
+    //! transaction outputs scriptpubkey sha single hash
+    std::vector<uint256> m_output_spk_single_hashes;
+    //! Whether the 11 fields above are initialized.
     bool m_bip341_taproot_ready = false;
 
     // BIP143 precomputed data (double-SHA256).
@@ -182,6 +184,8 @@ struct PrecomputedTransactionData
     bool m_bip143_segwit_ready = false;
 
     std::vector<CTxOut> m_spent_outputs;
+    //! ELEMENTS: spent outputs scriptpubkey sha single hash
+    std::vector<uint256> m_spent_output_spk_single_hashes;
     //! Whether m_spent_outputs is initialized.
     bool m_spent_outputs_ready = false;