qt: Move transaction notification to transaction table model

Move transaction new/update notification to TransactionTableModel.
This moves the concerns to where they're actually handled.
No need to bounce this through wallet model.

- Do wallet transaction preprocessing on signal handler side;
  avoids locking cs_main/cs_wallet on notification in GUI thread
  (except for new transactions)

5 files changed, 159 insertions, 110 deletions

diff --git a/src/qt/transactiontablemodel.cpp b/src/qt/transactiontablemodel.cpp
index e34d776818..79cb4a6296 100644
--- a/src/qt/transactiontablemodel.cpp
+++ b/src/qt/transactiontablemodel.cpp
@@ -91,87 +91,80 @@ public:
 
        Call with transaction that was added, removed or changed.
      */
-    void updateWallet(const uint256 &hash, int status)
+    void updateWallet(const uint256 &hash, int status, bool showTransaction)
     {
         qDebug() << "TransactionTablePriv::updateWallet : " + QString::fromStdString(hash.ToString()) + " " + QString::number(status);
-        {
-            LOCK2(cs_main, wallet->cs_wallet);
 
-            // Find transaction in wallet
-            std::map<uint256, CWalletTx>::iterator mi = wallet->mapWallet.find(hash);
-            bool inWallet = mi != wallet->mapWallet.end();
+        // Find bounds of this transaction in model
+        QList<TransactionRecord>::iterator lower = qLowerBound(
+            cachedWallet.begin(), cachedWallet.end(), hash, TxLessThan());
+        QList<TransactionRecord>::iterator upper = qUpperBound(
+            cachedWallet.begin(), cachedWallet.end(), hash, TxLessThan());
+        int lowerIndex = (lower - cachedWallet.begin());
+        int upperIndex = (upper - cachedWallet.begin());
+        bool inModel = (lower != upper);
 
-            // Find bounds of this transaction in model
-            QList<TransactionRecord>::iterator lower = qLowerBound(
-                cachedWallet.begin(), cachedWallet.end(), hash, TxLessThan());
-            QList<TransactionRecord>::iterator upper = qUpperBound(
-                cachedWallet.begin(), cachedWallet.end(), hash, TxLessThan());
-            int lowerIndex = (lower - cachedWallet.begin());
-            int upperIndex = (upper - cachedWallet.begin());
-            bool inModel = (lower != upper);
+        if(status == CT_UPDATED)
+        {
+            if(showTransaction && !inModel)
+                status = CT_NEW; /* Not in model, but want to show, treat as new */
+            if(!showTransaction && inModel)
+                status = CT_DELETED; /* In model, but want to hide, treat as deleted */
+        }
 
-            // Determine whether to show transaction or not
-            bool showTransaction = (inWallet && TransactionRecord::showTransaction(mi->second));
+        qDebug() << "    inModel=" + QString::number(inModel) +
+                    " Index=" + QString::number(lowerIndex) + "-" + QString::number(upperIndex) +
+                    " showTransaction=" + QString::number(showTransaction) + " derivedStatus=" + QString::number(status);
 
-            if(status == CT_UPDATED)
+        switch(status)
+        {
+        case CT_NEW:
+            if(inModel)
             {
-                if(showTransaction && !inModel)
-                    status = CT_NEW; /* Not in model, but want to show, treat as new */
-                if(!showTransaction && inModel)
-                    status = CT_DELETED; /* In model, but want to hide, treat as deleted */
+                qWarning() << "TransactionTablePriv::updateWallet : Warning: Got CT_NEW, but transaction is already in model";
+                break;
             }
-
-            qDebug() << "   inWallet=" + QString::number(inWallet) + " inModel=" + QString::number(inModel) +
-                        " Index=" + QString::number(lowerIndex) + "-" + QString::number(upperIndex) +
-                        " showTransaction=" + QString::number(showTransaction) + " derivedStatus=" + QString::number(status);
-
-            switch(status)
+            if(showTransaction)
             {
-            case CT_NEW:
-                if(inModel)
-                {
-                    qWarning() << "TransactionTablePriv::updateWallet : Warning: Got CT_NEW, but transaction is already in model";
-                    break;
-                }
-                if(!inWallet)
+                LOCK2(cs_main, wallet->cs_wallet);
+                // Find transaction in wallet
+                std::map<uint256, CWalletTx>::iterator mi = wallet->mapWallet.find(hash);
+                if(mi == wallet->mapWallet.end())
                 {
                     qWarning() << "TransactionTablePriv::updateWallet : Warning: Got CT_NEW, but transaction is not in wallet";
                     break;
                 }
-                if(showTransaction)
+                // Added -- insert at the right position
+                QList<TransactionRecord> toInsert =
+                        TransactionRecord::decomposeTransaction(wallet, mi->second);
+                if(!toInsert.isEmpty()) /* only if something to insert */
                 {
-                    // Added -- insert at the right position
-                    QList<TransactionRecord> toInsert =
-                            TransactionRecord::decomposeTransaction(wallet, mi->second);
-                    if(!toInsert.isEmpty()) /* only if something to insert */
+                    parent->beginInsertRows(QModelIndex(), lowerIndex, lowerIndex+toInsert.size()-1);
+                    int insert_idx = lowerIndex;
+                    foreach(const TransactionRecord &rec, toInsert)
                     {
-                        parent->beginInsertRows(QModelIndex(), lowerIndex, lowerIndex+toInsert.size()-1);
-                        int insert_idx = lowerIndex;
-                        foreach(const TransactionRecord &rec, toInsert)
-                        {
-                            cachedWallet.insert(insert_idx, rec);
-                            insert_idx += 1;
-                        }
-                        parent->endInsertRows();
+                        cachedWallet.insert(insert_idx, rec);
+                        insert_idx += 1;
                     }
+                    parent->endInsertRows();
                 }
-                break;
-            case CT_DELETED:
-                if(!inModel)
-                {
-                    qWarning() << "TransactionTablePriv::updateWallet : Warning: Got CT_DELETED, but transaction is not in model";
-                    break;
-                }
-                // Removed -- remove entire transaction from table
-                parent->beginRemoveRows(QModelIndex(), lowerIndex, upperIndex-1);
-                cachedWallet.erase(lower, upper);
-                parent->endRemoveRows();
-                break;
-            case CT_UPDATED:
-                // Miscellaneous updates -- nothing to do, status update will take care of this, and is only computed for
-                // visible transactions.
+            }
+            break;
+        case CT_DELETED:
+            if(!inModel)
+            {
+                qWarning() << "TransactionTablePriv::updateWallet : Warning: Got CT_DELETED, but transaction is not in model";
                 break;
             }
+            // Removed -- remove entire transaction from table
+            parent->beginRemoveRows(QModelIndex(), lowerIndex, upperIndex-1);
+            cachedWallet.erase(lower, upper);
+            parent->endRemoveRows();
+            break;
+        case CT_UPDATED:
+            // Miscellaneous updates -- nothing to do, status update will take care of this, and is only computed for
+            // visible transactions.
+            break;
         }
     }
 
@@ -230,16 +223,20 @@ TransactionTableModel::TransactionTableModel(CWallet* wallet, WalletModel *paren
         QAbstractTableModel(parent),
         wallet(wallet),
         walletModel(parent),
-        priv(new TransactionTablePriv(wallet, this))
+        priv(new TransactionTablePriv(wallet, this)),
+        fProcessingQueuedTransactions(false)
 {
     columns << QString() << QString() << tr("Date") << tr("Type") << tr("Address") << BitcoinUnits::getAmountColumnTitle(walletModel->getOptionsModel()->getDisplayUnit());
     priv->refreshWallet();
 
     connect(walletModel->getOptionsModel(), SIGNAL(displayUnitChanged(int)), this, SLOT(updateDisplayUnit()));
+
+    subscribeToCoreSignals();
 }
 
 TransactionTableModel::~TransactionTableModel()
 {
+    unsubscribeFromCoreSignals();
     delete priv;
 }
 
@@ -250,12 +247,12 @@ void TransactionTableModel::updateAmountColumnTitle()
     emit headerDataChanged(Qt::Horizontal,Amount,Amount);
 }
 
-void TransactionTableModel::updateTransaction(const QString &hash, int status)
+void TransactionTableModel::updateTransaction(const QString &hash, int status, bool showTransaction)
 {
     uint256 updated;
     updated.SetHex(hash.toStdString());
 
-    priv->updateWallet(updated, status);
+    priv->updateWallet(updated, status, showTransaction);
 }
 
 void TransactionTableModel::updateConfirmations()
@@ -649,3 +646,82 @@ void TransactionTableModel::updateDisplayUnit()
     updateAmountColumnTitle();
     emit dataChanged(index(0, Amount), index(priv->size()-1, Amount));
 }
+
+// queue notifications to show a non freezing progress dialog e.g. for rescan
+struct TransactionNotification
+{
+public:
+    TransactionNotification() {}
+    TransactionNotification(uint256 hash, ChangeType status, bool showTransaction):
+        hash(hash), status(status), showTransaction(showTransaction) {}
+
+    void invoke(QObject *ttm)
+    {
+        QString strHash = QString::fromStdString(hash.GetHex());
+        qDebug() << "NotifyTransactionChanged : " + strHash + " status= " + QString::number(status);
+        QMetaObject::invokeMethod(ttm, "updateTransaction", Qt::QueuedConnection,
+                                  Q_ARG(QString, strHash),
+                                  Q_ARG(int, status),
+                                  Q_ARG(bool, showTransaction));
+    }
+private:
+    uint256 hash;
+    ChangeType status;
+    bool showTransaction;
+};
+
+static bool fQueueNotifications = false;
+static std::vector< TransactionNotification > vQueueNotifications;
+
+static void NotifyTransactionChanged(TransactionTableModel *ttm, CWallet *wallet, const uint256 &hash, ChangeType status)
+{
+    // Find transaction in wallet
+    std::map<uint256, CWalletTx>::iterator mi = wallet->mapWallet.find(hash);
+    // Determine whether to show transaction or not (determine this here so that no relocking is needed in GUI thread)
+    bool inWallet = mi != wallet->mapWallet.end();
+    bool showTransaction = (inWallet && TransactionRecord::showTransaction(mi->second));
+
+    TransactionNotification notification(hash, status, showTransaction);
+
+    if (fQueueNotifications)
+    {
+        vQueueNotifications.push_back(notification);
+        return;
+    }
+    notification.invoke(ttm);
+}
+
+static void ShowProgress(TransactionTableModel *ttm, const std::string &title, int nProgress)
+{
+    if (nProgress == 0)
+        fQueueNotifications = true;
+
+    if (nProgress == 100)
+    {
+        fQueueNotifications = false;
+        if (vQueueNotifications.size() > 10) // prevent balloon spam, show maximum 10 balloons
+            QMetaObject::invokeMethod(ttm, "setProcessingQueuedTransactions", Qt::QueuedConnection, Q_ARG(bool, true));
+        for (unsigned int i = 0; i < vQueueNotifications.size(); ++i)
+        {
+            if (vQueueNotifications.size() - i <= 10)
+                QMetaObject::invokeMethod(ttm, "setProcessingQueuedTransactions", Qt::QueuedConnection, Q_ARG(bool, false));
+
+            vQueueNotifications[i].invoke(ttm);
+        }
+        std::vector<TransactionNotification >().swap(vQueueNotifications); // clear
+    }
+}
+
+void TransactionTableModel::subscribeToCoreSignals()
+{
+    // Connect signals to wallet
+    wallet->NotifyTransactionChanged.connect(boost::bind(NotifyTransactionChanged, this, _1, _2, _3));
+    wallet->ShowProgress.connect(boost::bind(ShowProgress, this, _1, _2));
+}
+
+void TransactionTableModel::unsubscribeFromCoreSignals()
+{
+    // Disconnect signals from wallet
+    wallet->NotifyTransactionChanged.disconnect(boost::bind(NotifyTransactionChanged, this, _1, _2, _3));
+    wallet->ShowProgress.disconnect(boost::bind(ShowProgress, this, _1, _2));
+}
diff --git a/src/qt/transactiontablemodel.h b/src/qt/transactiontablemodel.h
index 413f3f9bf1..bb517a969c 100644
--- a/src/qt/transactiontablemodel.h
+++ b/src/qt/transactiontablemodel.h
@@ -72,12 +72,17 @@ public:
     QVariant data(const QModelIndex &index, int role) const;
     QVariant headerData(int section, Qt::Orientation orientation, int role) const;
     QModelIndex index(int row, int column, const QModelIndex & parent = QModelIndex()) const;
+    bool processingQueuedTransactions() { return fProcessingQueuedTransactions; }
 
 private:
     CWallet* wallet;
     WalletModel *walletModel;
     QStringList columns;
     TransactionTablePriv *priv;
+    bool fProcessingQueuedTransactions;
+
+    void subscribeToCoreSignals();
+    void unsubscribeFromCoreSignals();
 
     QString lookupAddress(const std::string &address, bool tooltip) const;
     QVariant addressColor(const TransactionRecord *wtx) const;
@@ -92,11 +97,14 @@ private:
     QVariant txAddressDecoration(const TransactionRecord *wtx) const;
 
 public slots:
-    void updateTransaction(const QString &hash, int status);
+    /* New transaction, or transaction changed status */
+    void updateTransaction(const QString &hash, int status, bool showTransaction);
     void updateConfirmations();
     void updateDisplayUnit();
     /** Updates the column title to "Amount (DisplayUnit)" and emits headerDataChanged() signal for table headers to react. */
     void updateAmountColumnTitle();
+    /* Needed to update fProcessingQueuedTransactions through a QueuedConnection */
+    void setProcessingQueuedTransactions(bool value) { fProcessingQueuedTransactions = value; }
 
     friend class TransactionTablePriv;
 };
diff --git a/src/qt/walletmodel.cpp b/src/qt/walletmodel.cpp
index b4733d369e..f7b1552f3e 100644
--- a/src/qt/walletmodel.cpp
+++ b/src/qt/walletmodel.cpp
@@ -34,7 +34,6 @@ WalletModel::WalletModel(CWallet *wallet, OptionsModel *optionsModel, QObject *p
     cachedEncryptionStatus(Unencrypted),
     cachedNumBlocks(0)
 {
-    fProcessingQueuedTransactions = false;
     fHaveWatchOnly = wallet->HaveWatchOnly();
     fForceCheckBalanceChanged = false;
 
@@ -164,11 +163,8 @@ void WalletModel::checkBalanceChanged()
     }
 }
 
-void WalletModel::updateTransaction(const QString &hash, int status)
+void WalletModel::updateTransaction()
 {
-    if(transactionTableModel)
-        transactionTableModel->updateTransaction(hash, status);
-
     // Balance and number of transactions might have changed
     fForceCheckBalanceChanged = true;
 }
@@ -455,45 +451,16 @@ static void NotifyAddressBookChanged(WalletModel *walletmodel, CWallet *wallet,
                               Q_ARG(int, status));
 }
 
-// queue notifications to show a non freezing progress dialog e.g. for rescan
-static bool fQueueNotifications = false;
-static std::vector<std::pair<uint256, ChangeType> > vQueueNotifications;
 static void NotifyTransactionChanged(WalletModel *walletmodel, CWallet *wallet, const uint256 &hash, ChangeType status)
 {
-    if (fQueueNotifications)
-    {
-        vQueueNotifications.push_back(make_pair(hash, status));
-        return;
-    }
-
-    QString strHash = QString::fromStdString(hash.GetHex());
-
-    qDebug() << "NotifyTransactionChanged : " + strHash + " status= " + QString::number(status);
-    QMetaObject::invokeMethod(walletmodel, "updateTransaction", Qt::QueuedConnection,
-                              Q_ARG(QString, strHash),
-                              Q_ARG(int, status));
+    Q_UNUSED(wallet);
+    Q_UNUSED(hash);
+    Q_UNUSED(status);
+    QMetaObject::invokeMethod(walletmodel, "updateTransaction", Qt::QueuedConnection);
 }
 
 static void ShowProgress(WalletModel *walletmodel, const std::string &title, int nProgress)
 {
-    if (nProgress == 0)
-        fQueueNotifications = true;
-
-    if (nProgress == 100)
-    {
-        fQueueNotifications = false;
-        if (vQueueNotifications.size() > 10) // prevent balloon spam, show maximum 10 balloons
-            QMetaObject::invokeMethod(walletmodel, "setProcessingQueuedTransactions", Qt::QueuedConnection, Q_ARG(bool, true));
-        for (unsigned int i = 0; i < vQueueNotifications.size(); ++i)
-        {
-            if (vQueueNotifications.size() - i <= 10)
-                QMetaObject::invokeMethod(walletmodel, "setProcessingQueuedTransactions", Qt::QueuedConnection, Q_ARG(bool, false));
-
-            NotifyTransactionChanged(walletmodel, NULL, vQueueNotifications[i].first, vQueueNotifications[i].second);
-        }
-        std::vector<std::pair<uint256, ChangeType> >().swap(vQueueNotifications); // clear
-    }
-
     // emits signal "showProgress"
     QMetaObject::invokeMethod(walletmodel, "showProgress", Qt::QueuedConnection,
                               Q_ARG(QString, QString::fromStdString(title)),
diff --git a/src/qt/walletmodel.h b/src/qt/walletmodel.h
index b1d0f28f12..fe91e9d9fa 100644
--- a/src/qt/walletmodel.h
+++ b/src/qt/walletmodel.h
@@ -133,7 +133,6 @@ public:
     CAmount getWatchUnconfirmedBalance() const;
     CAmount getWatchImmatureBalance() const;
     EncryptionStatus getEncryptionStatus() const;
-    bool processingQueuedTransactions() { return fProcessingQueuedTransactions; }
 
     // Check address for validity
     bool validateAddress(const QString &address);
@@ -197,7 +196,6 @@ public:
 
 private:
     CWallet *wallet;
-    bool fProcessingQueuedTransactions;
     bool fHaveWatchOnly;
     bool fForceCheckBalanceChanged;
 
@@ -254,15 +252,13 @@ public slots:
     /* Wallet status might have changed */
     void updateStatus();
     /* New transaction, or transaction changed status */
-    void updateTransaction(const QString &hash, int status);
+    void updateTransaction();
     /* New, updated or removed address book entry */
     void updateAddressBook(const QString &address, const QString &label, bool isMine, const QString &purpose, int status);
     /* Watch-only added */
     void updateWatchOnlyFlag(bool fHaveWatchonly);
     /* Current, immature or unconfirmed balance might have changed - emit 'balanceChanged' if so */
     void pollBalanceChanged();
-    /* Needed to update fProcessingQueuedTransactions through a QueuedConnection */
-    void setProcessingQueuedTransactions(bool value) { fProcessingQueuedTransactions = value; }
 };
 
 #endif // WALLETMODEL_H
diff --git a/src/qt/walletview.cpp b/src/qt/walletview.cpp
index eff50593bd..3b8fdd7e5f 100644
--- a/src/qt/walletview.cpp
+++ b/src/qt/walletview.cpp
@@ -137,10 +137,12 @@ void WalletView::setWalletModel(WalletModel *walletModel)
 void WalletView::processNewTransaction(const QModelIndex& parent, int start, int /*end*/)
 {
     // Prevent balloon-spam when initial block download is in progress
-    if (!walletModel || walletModel->processingQueuedTransactions() || !clientModel || clientModel->inInitialBlockDownload())
+    if (!walletModel || !clientModel || clientModel->inInitialBlockDownload())
         return;
 
     TransactionTableModel *ttm = walletModel->getTransactionTableModel();
+    if (!ttm || ttm->processingQueuedTransactions())
+        return;
 
     QString date = ttm->index(start, TransactionTableModel::Date, parent).data().toString();
     qint64 amount = ttm->index(start, TransactionTableModel::Amount, parent).data(Qt::EditRole).toULongLong();