Make ValidationInterface signals-type-agnostic

(by hiding boost::signals stuff in the .cpp)

This allows us to give it a bit more intelligence as we move
forward, including routing some signals through CScheduler. While
the introduction of a "internals" pointer in the class is pretty
ugly, the fact that we no longer need to include boost/signals
directly from validationinterface.h is very much worth the loss.

2 files changed, 117 insertions, 53 deletions

diff --git a/src/validationinterface.cpp b/src/validationinterface.cpp
index be2f20b863..7d0ab756e8 100644
--- a/src/validationinterface.cpp
+++ b/src/validationinterface.cpp
@@ -5,45 +5,99 @@
 
 #include "validationinterface.h"
 
+#include <boost/signals2/signal.hpp>
+
+struct MainSignalsInstance {
+    boost::signals2::signal<void (const CBlockIndex *, const CBlockIndex *, bool fInitialDownload)> UpdatedBlockTip;
+    boost::signals2::signal<void (const CTransactionRef &)> TransactionAddedToMempool;
+    boost::signals2::signal<void (const std::shared_ptr<const CBlock> &, const CBlockIndex *pindex, const std::vector<CTransactionRef>&)> BlockConnected;
+    boost::signals2::signal<void (const std::shared_ptr<const CBlock> &)> BlockDisconnected;
+    boost::signals2::signal<void (const CBlockLocator &)> SetBestChain;
+    boost::signals2::signal<void (const uint256 &)> Inventory;
+    boost::signals2::signal<void (int64_t nBestBlockTime, CConnman* connman)> Broadcast;
+    boost::signals2::signal<void (const CBlock&, const CValidationState&)> BlockChecked;
+    boost::signals2::signal<void (const CBlockIndex *, const std::shared_ptr<const CBlock>&)> NewPoWValidBlock;
+};
+
 static CMainSignals g_signals;
 
+CMainSignals::CMainSignals() {
+    m_internals.reset(new MainSignalsInstance());
+}
+
 CMainSignals& GetMainSignals()
 {
     return g_signals;
 }
 
 void RegisterValidationInterface(CValidationInterface* pwalletIn) {
-    g_signals.UpdatedBlockTip.connect(boost::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, _1, _2, _3));
-    g_signals.TransactionAddedToMempool.connect(boost::bind(&CValidationInterface::TransactionAddedToMempool, pwalletIn, _1));
-    g_signals.BlockConnected.connect(boost::bind(&CValidationInterface::BlockConnected, pwalletIn, _1, _2, _3));
-    g_signals.BlockDisconnected.connect(boost::bind(&CValidationInterface::BlockDisconnected, pwalletIn, _1));
-    g_signals.SetBestChain.connect(boost::bind(&CValidationInterface::SetBestChain, pwalletIn, _1));
-    g_signals.Inventory.connect(boost::bind(&CValidationInterface::Inventory, pwalletIn, _1));
-    g_signals.Broadcast.connect(boost::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, _1, _2));
-    g_signals.BlockChecked.connect(boost::bind(&CValidationInterface::BlockChecked, pwalletIn, _1, _2));
-    g_signals.NewPoWValidBlock.connect(boost::bind(&CValidationInterface::NewPoWValidBlock, pwalletIn, _1, _2));
+    g_signals.m_internals->UpdatedBlockTip.connect(boost::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, _1, _2, _3));
+    g_signals.m_internals->TransactionAddedToMempool.connect(boost::bind(&CValidationInterface::TransactionAddedToMempool, pwalletIn, _1));
+    g_signals.m_internals->BlockConnected.connect(boost::bind(&CValidationInterface::BlockConnected, pwalletIn, _1, _2, _3));
+    g_signals.m_internals->BlockDisconnected.connect(boost::bind(&CValidationInterface::BlockDisconnected, pwalletIn, _1));
+    g_signals.m_internals->SetBestChain.connect(boost::bind(&CValidationInterface::SetBestChain, pwalletIn, _1));
+    g_signals.m_internals->Inventory.connect(boost::bind(&CValidationInterface::Inventory, pwalletIn, _1));
+    g_signals.m_internals->Broadcast.connect(boost::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, _1, _2));
+    g_signals.m_internals->BlockChecked.connect(boost::bind(&CValidationInterface::BlockChecked, pwalletIn, _1, _2));
+    g_signals.m_internals->NewPoWValidBlock.connect(boost::bind(&CValidationInterface::NewPoWValidBlock, pwalletIn, _1, _2));
 }
 
 void UnregisterValidationInterface(CValidationInterface* pwalletIn) {
-    g_signals.BlockChecked.disconnect(boost::bind(&CValidationInterface::BlockChecked, pwalletIn, _1, _2));
-    g_signals.Broadcast.disconnect(boost::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, _1, _2));
-    g_signals.Inventory.disconnect(boost::bind(&CValidationInterface::Inventory, pwalletIn, _1));
-    g_signals.SetBestChain.disconnect(boost::bind(&CValidationInterface::SetBestChain, pwalletIn, _1));
-    g_signals.TransactionAddedToMempool.disconnect(boost::bind(&CValidationInterface::TransactionAddedToMempool, pwalletIn, _1));
-    g_signals.BlockConnected.disconnect(boost::bind(&CValidationInterface::BlockConnected, pwalletIn, _1, _2, _3));
-    g_signals.BlockDisconnected.disconnect(boost::bind(&CValidationInterface::BlockDisconnected, pwalletIn, _1));
-    g_signals.UpdatedBlockTip.disconnect(boost::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, _1, _2, _3));
-    g_signals.NewPoWValidBlock.disconnect(boost::bind(&CValidationInterface::NewPoWValidBlock, pwalletIn, _1, _2));
+    g_signals.m_internals->BlockChecked.disconnect(boost::bind(&CValidationInterface::BlockChecked, pwalletIn, _1, _2));
+    g_signals.m_internals->Broadcast.disconnect(boost::bind(&CValidationInterface::ResendWalletTransactions, pwalletIn, _1, _2));
+    g_signals.m_internals->Inventory.disconnect(boost::bind(&CValidationInterface::Inventory, pwalletIn, _1));
+    g_signals.m_internals->SetBestChain.disconnect(boost::bind(&CValidationInterface::SetBestChain, pwalletIn, _1));
+    g_signals.m_internals->TransactionAddedToMempool.disconnect(boost::bind(&CValidationInterface::TransactionAddedToMempool, pwalletIn, _1));
+    g_signals.m_internals->BlockConnected.disconnect(boost::bind(&CValidationInterface::BlockConnected, pwalletIn, _1, _2, _3));
+    g_signals.m_internals->BlockDisconnected.disconnect(boost::bind(&CValidationInterface::BlockDisconnected, pwalletIn, _1));
+    g_signals.m_internals->UpdatedBlockTip.disconnect(boost::bind(&CValidationInterface::UpdatedBlockTip, pwalletIn, _1, _2, _3));
+    g_signals.m_internals->NewPoWValidBlock.disconnect(boost::bind(&CValidationInterface::NewPoWValidBlock, pwalletIn, _1, _2));
 }
 
 void UnregisterAllValidationInterfaces() {
-    g_signals.BlockChecked.disconnect_all_slots();
-    g_signals.Broadcast.disconnect_all_slots();
-    g_signals.Inventory.disconnect_all_slots();
-    g_signals.SetBestChain.disconnect_all_slots();
-    g_signals.TransactionAddedToMempool.disconnect_all_slots();
-    g_signals.BlockConnected.disconnect_all_slots();
-    g_signals.BlockDisconnected.disconnect_all_slots();
-    g_signals.UpdatedBlockTip.disconnect_all_slots();
-    g_signals.NewPoWValidBlock.disconnect_all_slots();
+    g_signals.m_internals->BlockChecked.disconnect_all_slots();
+    g_signals.m_internals->Broadcast.disconnect_all_slots();
+    g_signals.m_internals->Inventory.disconnect_all_slots();
+    g_signals.m_internals->SetBestChain.disconnect_all_slots();
+    g_signals.m_internals->TransactionAddedToMempool.disconnect_all_slots();
+    g_signals.m_internals->BlockConnected.disconnect_all_slots();
+    g_signals.m_internals->BlockDisconnected.disconnect_all_slots();
+    g_signals.m_internals->UpdatedBlockTip.disconnect_all_slots();
+    g_signals.m_internals->NewPoWValidBlock.disconnect_all_slots();
+}
+
+void CMainSignals::UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) {
+    m_internals->UpdatedBlockTip(pindexNew, pindexFork, fInitialDownload);
+}
+
+void CMainSignals::TransactionAddedToMempool(const CTransactionRef &ptx) {
+    m_internals->TransactionAddedToMempool(ptx);
+}
+
+void CMainSignals::BlockConnected(const std::shared_ptr<const CBlock> &pblock, const CBlockIndex *pindex, const std::vector<CTransactionRef>& vtxConflicted) {
+    m_internals->BlockConnected(pblock, pindex, vtxConflicted);
+}
+
+void CMainSignals::BlockDisconnected(const std::shared_ptr<const CBlock> &pblock) {
+    m_internals->BlockDisconnected(pblock);
+}
+
+void CMainSignals::SetBestChain(const CBlockLocator &locator) {
+    m_internals->SetBestChain(locator);
+}
+
+void CMainSignals::Inventory(const uint256 &hash) {
+    m_internals->Inventory(hash);
+}
+
+void CMainSignals::Broadcast(int64_t nBestBlockTime, CConnman* connman) {
+    m_internals->Broadcast(nBestBlockTime, connman);
+}
+
+void CMainSignals::BlockChecked(const CBlock& block, const CValidationState& state) {
+    m_internals->BlockChecked(block, state);
+}
+
+void CMainSignals::NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock> &block) {
+    m_internals->NewPoWValidBlock(pindex, block);
 }
diff --git a/src/validationinterface.h b/src/validationinterface.h
index 17545018df..c248781a48 100644
--- a/src/validationinterface.h
+++ b/src/validationinterface.h
@@ -6,7 +6,6 @@
 #ifndef BITCOIN_VALIDATIONINTERFACE_H
 #define BITCOIN_VALIDATIONINTERFACE_H
 
-#include <boost/signals2/signal.hpp>
 #include <memory>
 
 #include "primitives/transaction.h" // CTransaction(Ref)
@@ -32,49 +31,60 @@ void UnregisterAllValidationInterfaces();
 
 class CValidationInterface {
 protected:
-    virtual void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) {}
-    virtual void TransactionAddedToMempool(const CTransactionRef &ptxn) {}
-    virtual void BlockConnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex *pindex, const std::vector<CTransactionRef> &txnConflicted) {}
-    virtual void BlockDisconnected(const std::shared_ptr<const CBlock> &block) {}
-    virtual void SetBestChain(const CBlockLocator &locator) {}
-    virtual void Inventory(const uint256 &hash) {}
-    virtual void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) {}
-    virtual void BlockChecked(const CBlock&, const CValidationState&) {}
-    virtual void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& block) {};
-    friend void ::RegisterValidationInterface(CValidationInterface*);
-    friend void ::UnregisterValidationInterface(CValidationInterface*);
-    friend void ::UnregisterAllValidationInterfaces();
-};
-
-struct CMainSignals {
     /** Notifies listeners of updated block chain tip */
-    boost::signals2::signal<void (const CBlockIndex *, const CBlockIndex *, bool fInitialDownload)> UpdatedBlockTip;
+    virtual void UpdatedBlockTip(const CBlockIndex *pindexNew, const CBlockIndex *pindexFork, bool fInitialDownload) {}
     /** Notifies listeners of a transaction having been added to mempool. */
-    boost::signals2::signal<void (const CTransactionRef &)> TransactionAddedToMempool;
+    virtual void TransactionAddedToMempool(const CTransactionRef &ptxn) {}
     /**
      * Notifies listeners of a block being connected.
      * Provides a vector of transactions evicted from the mempool as a result.
      */
-    boost::signals2::signal<void (const std::shared_ptr<const CBlock> &, const CBlockIndex *pindex, const std::vector<CTransactionRef> &)> BlockConnected;
+    virtual void BlockConnected(const std::shared_ptr<const CBlock> &block, const CBlockIndex *pindex, const std::vector<CTransactionRef> &txnConflicted) {}
     /** Notifies listeners of a block being disconnected */
-    boost::signals2::signal<void (const std::shared_ptr<const CBlock> &)> BlockDisconnected;
-    /** Notifies listeners of a new active block chain. */
-    boost::signals2::signal<void (const CBlockLocator &)> SetBestChain;
+    virtual void BlockDisconnected(const std::shared_ptr<const CBlock> &block) {}
+    /** Notifies listeners of the new active block chain on-disk. */
+    virtual void SetBestChain(const CBlockLocator &locator) {}
     /** Notifies listeners about an inventory item being seen on the network. */
-    boost::signals2::signal<void (const uint256 &)> Inventory;
+    virtual void Inventory(const uint256 &hash) {}
     /** Tells listeners to broadcast their data. */
-    boost::signals2::signal<void (int64_t nBestBlockTime, CConnman* connman)> Broadcast;
+    virtual void ResendWalletTransactions(int64_t nBestBlockTime, CConnman* connman) {}
     /**
      * Notifies listeners of a block validation result.
      * If the provided CValidationState IsValid, the provided block
      * is guaranteed to be the current best block at the time the
      * callback was generated (not necessarily now)
      */
-    boost::signals2::signal<void (const CBlock&, const CValidationState&)> BlockChecked;
+    virtual void BlockChecked(const CBlock&, const CValidationState&) {}
     /**
      * Notifies listeners that a block which builds directly on our current tip
      * has been received and connected to the headers tree, though not validated yet */
-    boost::signals2::signal<void (const CBlockIndex *, const std::shared_ptr<const CBlock>&)> NewPoWValidBlock;
+    virtual void NewPoWValidBlock(const CBlockIndex *pindex, const std::shared_ptr<const CBlock>& block) {};
+    friend void ::RegisterValidationInterface(CValidationInterface*);
+    friend void ::UnregisterValidationInterface(CValidationInterface*);
+    friend void ::UnregisterAllValidationInterfaces();
+};
+
+struct MainSignalsInstance;
+class CMainSignals {
+private:
+    std::unique_ptr<MainSignalsInstance> m_internals;
+
+    friend void ::RegisterValidationInterface(CValidationInterface*);
+    friend void ::UnregisterValidationInterface(CValidationInterface*);
+    friend void ::UnregisterAllValidationInterfaces();
+public:
+    CMainSignals();
+
+    void UpdatedBlockTip(const CBlockIndex *, const CBlockIndex *, bool fInitialDownload);
+    void TransactionAddedToMempool(const CTransactionRef &);
+    void BlockConnected(const std::shared_ptr<const CBlock> &, const CBlockIndex *pindex, const std::vector<CTransactionRef> &);
+    void BlockDisconnected(const std::shared_ptr<const CBlock> &);
+    void UpdatedTransaction(const uint256 &);
+    void SetBestChain(const CBlockLocator &);
+    void Inventory(const uint256 &);
+    void Broadcast(int64_t nBestBlockTime, CConnman* connman);
+    void BlockChecked(const CBlock&, const CValidationState&);
+    void NewPoWValidBlock(const CBlockIndex *, const std::shared_ptr<const CBlock>&);
 };
 
 CMainSignals& GetMainSignals();