Merge bitcoin#10809: optim: mark a few classes final

40a0f9f Enable devirtualization opportunities by using the final specifier (C++11) (practicalswift)
9a1675e optim: mark a few classes final (Cory Fields)

Pull request description:

  Using gcc's ```-Wsuggest-final-types``` and lto, I identified a few easy devirtualization wins:

  > wallet/wallet.h:651:7: warning: Declaring type 'struct CWallet' final would enable devirtualization of 26 calls [-Wsuggest-final-types]

  >coins.h:201:7: warning: Declaring type 'struct CCoinsViewCache' final would enable devirtualization of 13 calls [-Wsuggest-final-types]

  >txdb.h:67:7: warning: Declaring type 'struct CCoinsViewDB' final would enable devirtualization of 5 calls [-Wsuggest-final-types]

  >zmq/zmqnotificationinterface.h:16:7: warning: Declaring type 'struct CZMQNotificationInterface' final would enable devirtualization of 4 calls [-Wsuggest-final-types]

  >httpserver.cpp:42:7: warning: Declaring type 'struct HTTPWorkItem' final would enable devirtualization of 2 calls [-Wsuggest-final-types]

Tree-SHA512: 2a825fd27121ccabaacff5cde2fc8a50d1b4cc846374606caa2a71b0cd8fcb0d3c9b5b3fd342d944998610e2168048601278f8a3709cc515191a0bb2d98ba782

src/httpserver.cpp

@@ -40,7 +40,7 @@
 static const size_t MAX_HEADERS_SIZE = 8192;
 
 /** HTTP request work item */
-class HTTPWorkItem : public HTTPClosure
+class HTTPWorkItem final : public HTTPClosure
 {
 public:
     HTTPWorkItem(std::unique_ptr<HTTPRequest> _req, const std::string &_path, const HTTPRequestHandler& _func):

src/init.cpp

@@ -133,7 +133,7 @@ bool ShutdownRequested()
  * chainstate, while keeping user interface out of the common library, which is shared
  * between bitcoind, and bitcoin-qt and non-server tools.
 */
-class CCoinsViewErrorCatcher : public CCoinsViewBacked
+class CCoinsViewErrorCatcher final : public CCoinsViewBacked
 {
 public:
     explicit CCoinsViewErrorCatcher(CCoinsView* view) : CCoinsViewBacked(view) {}

src/txdb.h

@@ -64,7 +64,7 @@ struct CDiskTxPos : public CDiskBlockPos
 };
 
 /** CCoinsView backed by the coin database (chainstate/) */
-class CCoinsViewDB : public CCoinsView
+class CCoinsViewDB final : public CCoinsView
 {
 protected:
     CDBWrapper db;

src/wallet/wallet.h

@@ -651,7 +651,7 @@ class CAccountingEntry
  * A CWallet is an extension of a keystore, which also maintains a set of transactions and balances,
  * and provides the ability to create new transactions.
  */
-class CWallet : public CCryptoKeyStore, public CValidationInterface
+class CWallet final : public CCryptoKeyStore, public CValidationInterface
 {
 private:
     static std::atomic<bool> fFlushScheduled;
@@ -1131,7 +1131,7 @@ class CWallet : public CCryptoKeyStore, public CValidationInterface
 };
 
 /** A key allocated from the key pool. */
-class CReserveKey : public CReserveScript
+class CReserveKey final : public CReserveScript
 {
 protected:
     CWallet* pwallet;

src/zmq/zmqnotificationinterface.h

@@ -13,7 +13,7 @@
 class CBlockIndex;
 class CZMQAbstractNotifier;
 
-class CZMQNotificationInterface : public CValidationInterface
+class CZMQNotificationInterface final : public CValidationInterface
 {
 public:
     virtual ~CZMQNotificationInterface();