1 files changed, 32 insertions, 0 deletions
diff --git a/src/wallet/walletdb.h b/src/wallet/walletdb.h
index 00c10ea70f..71b0ff26db 100644
--- a/src/wallet/walletdb.h
+++ b/src/wallet/walletdb.h
@@ -40,6 +40,35 @@ enum DBErrors
     DB_NEED_REWRITE
 };
 
+/* simple hd chain data model */
+class CHDChain
+{
+public:
+    uint32_t nExternalChainCounter;
+    CKeyID masterKeyID; //!< master key hash160
+
+    static const int CURRENT_VERSION = 1;
+    int nVersion;
+
+    CHDChain() { SetNull(); }
+    ADD_SERIALIZE_METHODS;
+    template <typename Stream, typename Operation>
+    inline void SerializationOp(Stream& s, Operation ser_action, int nType, int nVersion)
+    {
+        READWRITE(this->nVersion);
+        nVersion = this->nVersion;
+        READWRITE(nExternalChainCounter);
+        READWRITE(masterKeyID);
+    }
+
+    void SetNull()
+    {
+        nVersion = CHDChain::CURRENT_VERSION;
+        nExternalChainCounter = 0;
+        masterKeyID.SetNull();
+    }
+};
+
 class CKeyMetadata
 {
 public:
@@ -134,6 +163,9 @@ public:
     static bool Recover(CDBEnv& dbenv, const std::string& filename, bool fOnlyKeys);
     static bool Recover(CDBEnv& dbenv, const std::string& filename);
 
+    //! write the hdchain model (external chain child index counter)
+    bool WriteHDChain(const CHDChain& chain);
+
 private:
     CWalletDB(const CWalletDB&);
     void operator=(const CWalletDB&);