wallet: Cache SigningProviders

In order to avoid constantly re-deriving the same keys in
DescriptorScriptPubKeyMan, cache the SigningProviders generated inside
of GetSigningProvider.

1 files changed, 14 insertions, 3 deletions

diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index bba31dfe0b..a0efc4c063 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -2075,10 +2075,21 @@ std::unique_ptr<FlatSigningProvider> DescriptorScriptPubKeyMan::GetSigningProvid
 std::unique_ptr<FlatSigningProvider> DescriptorScriptPubKeyMan::GetSigningProvider(int32_t index, bool include_private) const
 {
     AssertLockHeld(cs_desc_man);
-    // Get the scripts, keys, and key origins for this script
+
     std::unique_ptr<FlatSigningProvider> out_keys = std::make_unique<FlatSigningProvider>();
-    std::vector<CScript> scripts_temp;
-    if (!m_wallet_descriptor.descriptor->ExpandFromCache(index, m_wallet_descriptor.cache, scripts_temp, *out_keys)) return nullptr;
+
+    // Fetch SigningProvider from cache to avoid re-deriving
+    auto it = m_map_signing_providers.find(index);
+    if (it != m_map_signing_providers.end()) {
+        *out_keys = Merge(*out_keys, it->second);
+    } else {
+        // Get the scripts, keys, and key origins for this script
+        std::vector<CScript> scripts_temp;
+        if (!m_wallet_descriptor.descriptor->ExpandFromCache(index, m_wallet_descriptor.cache, scripts_temp, *out_keys)) return nullptr;
+
+        // Cache SigningProvider so we don't need to re-derive if we need this SigningProvider again
+        m_map_signing_providers[index] = *out_keys;
+    }
 
     if (HavePrivateKeys() && include_private) {
         FlatSigningProvider master_provider;