Merge #12762: Make CKeyStore an interface

f381299 Move CKeyStore::cs_KeyStore to CBasicKeyStore (João Barbosa)
25eb9f5 Inline CKeyStore::AddKey(const CKey &) in CBasicKeyStore (João Barbosa)

Pull request description:

  Made these simplifications while reviewing #12714. This aims to make `CKeyStore` a *pure* interface:
   - no variable members - the mutex is moved to `CBasicKeyStore` which is where it is used;
   - no method implementations - `AddKey(const CKey &)` is moved to `CBasicKeyStore` which is where it is needed.

Tree-SHA512: 84e44f4390c59600e5cefa599b5464e1771c31dd4abc678ef50db8e06ffac778d692860a352918444f8bcd66430634637b6277a818a658721ffc4f381c1c6a90

doc/developer-notes.md

@@ -219,7 +219,7 @@ inconsistencies reported in the debug.log file.
 
 Re-architecting the core code so there are better-defined interfaces
 between the various components is a goal, with any necessary locking
-done by the components (e.g. see the self-contained CKeyStore class
+done by the components (e.g. see the self-contained CBasicKeyStore class
 and its cs_KeyStore lock for example).
 
 Threads

src/keystore.cpp

@@ -7,10 +7,6 @@
 
 #include <util.h>
 
-bool CKeyStore::AddKey(const CKey &key) {
-    return AddKeyPubKey(key, key.GetPubKey());
-}
-
 void CBasicKeyStore::ImplicitlyLearnRelatedKeyScripts(const CPubKey& pubkey)
 {
     AssertLockHeld(cs_KeyStore);

src/keystore.h

@@ -18,13 +18,9 @@
 /** A virtual base class for key stores */
 class CKeyStore : public SigningProvider
 {
-protected:
-    mutable CCriticalSection cs_KeyStore;
-
 public:
     //! Add a key to the store.
     virtual bool AddKeyPubKey(const CKey &key, const CPubKey &pubkey) =0;
-    virtual bool AddKey(const CKey &key);
 
     //! Check whether a key corresponding to a given address is present in the store.
     virtual bool HaveKey(const CKeyID &address) const =0;
@@ -51,6 +47,8 @@ typedef std::set<CScript> WatchOnlySet;
 class CBasicKeyStore : public CKeyStore
 {
 protected:
+    mutable CCriticalSection cs_KeyStore;
+
     KeyMap mapKeys;
     WatchKeyMap mapWatchKeys;
     ScriptMap mapScripts;
@@ -60,6 +58,7 @@ protected:
 
 public:
     bool AddKeyPubKey(const CKey& key, const CPubKey &pubkey) override;
+    bool AddKey(const CKey &key) { return AddKeyPubKey(key, key.GetPubKey()); }
     bool GetPubKey(const CKeyID &address, CPubKey& vchPubKeyOut) const override;
     bool HaveKey(const CKeyID &address) const override;
     std::set<CKeyID> GetKeys() const override;