descriptors: Cache last hardened xpub

Cache the last hardenex xpub in the DescriptorCache

1 files changed, 16 insertions, 0 deletions

diff --git a/src/script/descriptor.h b/src/script/descriptor.h
index 7e422332a0..9ec2a766b1 100644
--- a/src/script/descriptor.h
+++ b/src/script/descriptor.h
@@ -22,6 +22,8 @@ private:
     std::unordered_map<uint32_t, ExtPubKeyMap> m_derived_xpubs;
     /** Map key expression index -> parent xpub */
     ExtPubKeyMap m_parent_xpubs;
+    /** Map key expression index -> last hardened xpub */
+    ExtPubKeyMap m_last_hardened_xpubs;
 
 public:
     /** Cache a parent xpub
@@ -50,11 +52,25 @@ public:
      * @param[in] xpub The CExtPubKey to get from cache
      */
     bool GetCachedDerivedExtPubKey(uint32_t key_exp_pos, uint32_t der_index, CExtPubKey& xpub) const;
+    /** Cache a last hardened xpub
+     *
+     * @param[in] key_exp_pos Position of the key expression within the descriptor
+     * @param[in] xpub The CExtPubKey to cache
+     */
+    void CacheLastHardenedExtPubKey(uint32_t key_exp_pos, const CExtPubKey& xpub);
+    /** Retrieve a cached last hardened xpub
+     *
+     * @param[in] key_exp_pos Position of the key expression within the descriptor
+     * @param[in] xpub The CExtPubKey to get from cache
+     */
+    bool GetCachedLastHardenedExtPubKey(uint32_t key_exp_pos, CExtPubKey& xpub) const;
 
     /** Retrieve all cached parent xpubs */
     const ExtPubKeyMap GetCachedParentExtPubKeys() const;
     /** Retrieve all cached derived xpubs */
     const std::unordered_map<uint32_t, ExtPubKeyMap> GetCachedDerivedExtPubKeys() const;
+    /** Retrieve all cached last hardened xpubs */
+    const ExtPubKeyMap GetCachedLastHardenedExtPubKeys() const;
 
     /** Combine another DescriptorCache into this one.
      * Returns a cache containing the items from the other cache unknown to current cache