wallet: Upgrade existing descriptor caches

Add functions to upgrade existing descriptor caches to support the use
of last hardened xpub caching.

1 files changed, 29 insertions, 0 deletions

diff --git a/src/wallet/scriptpubkeyman.cpp b/src/wallet/scriptpubkeyman.cpp
index ec38265216..4d29facc49 100644
--- a/src/wallet/scriptpubkeyman.cpp
+++ b/src/wallet/scriptpubkeyman.cpp
@@ -2278,3 +2278,32 @@ bool DescriptorScriptPubKeyMan::GetDescriptorString(std::string& out, bool priv)
 
     return m_wallet_descriptor.descriptor->ToNormalizedString(provider, out, priv);
 }
+
+void DescriptorScriptPubKeyMan::UpgradeDescriptorCache()
+{
+    LOCK(cs_desc_man);
+    if (m_storage.IsLocked() || m_storage.IsWalletFlagSet(WALLET_FLAG_LAST_HARDENED_XPUB_CACHED)) {
+        return;
+    }
+
+    // Skip if we have the last hardened xpub cache
+    if (m_wallet_descriptor.cache.GetCachedLastHardenedExtPubKeys().size() > 0) {
+        return;
+    }
+
+    // Expand the descriptor
+    FlatSigningProvider provider;
+    provider.keys = GetKeys();
+    FlatSigningProvider out_keys;
+    std::vector<CScript> scripts_temp;
+    DescriptorCache temp_cache;
+    if (!m_wallet_descriptor.descriptor->Expand(0, provider, scripts_temp, out_keys, &temp_cache)){
+        throw std::runtime_error("Unable to expand descriptor");
+    }
+
+    // Cache the last hardened xpubs
+    DescriptorCache diff = m_wallet_descriptor.cache.MergeAndDiff(temp_cache);
+    if (!WalletBatch(m_storage.GetDatabase()).WriteDescriptorCacheItems(GetID(), diff)) {
+        throw std::runtime_error(std::string(__func__) + ": writing cache items failed");
+    }
+}