[Qt] Add option to pause/resume block downloads

src/net_processing.cpp

@@ -60,6 +60,8 @@ static std::vector<std::pair<uint256, CTransactionRef>> vExtraTxnForCompact GUAR
 
 static const uint64_t RANDOMIZER_ID_ADDRESS_RELAY = 0x3cac0035b5866b90ULL; // SHA256("main address relay")[0:8]
 
+static std::atomic<bool> fAutoRequestBlocks(DEFAULT_AUTOMATIC_BLOCK_REQUESTS);
+
 // Internal stuff
 namespace {
     /** Number of nodes with fSyncStarted. */
@@ -105,6 +107,7 @@ namespace {
         std::unique_ptr<PartiallyDownloadedBlock> partialBlock;  //!< Optional, used for CMPCTBLOCK downloads
     };
     std::map<uint256, std::pair<NodeId, std::list<QueuedBlock>::iterator> > mapBlocksInFlight;
+    std::atomic<unsigned int> nBlocksInFlight; //!< lock free counter on how many block are in flight
 
     /** Stack of nodes which we have set to announce using compact blocks */
     std::list<NodeId> lNodesAnnouncingHeaderAndIDs;
@@ -291,6 +294,7 @@ void FinalizeNode(NodeId nodeid, bool& fUpdateConnectionTime) {
     for (const QueuedBlock& entry : state->vBlocksInFlight) {
         mapBlocksInFlight.erase(entry.hash);
     }
+    nBlocksInFlight = mapBlocksInFlight.size();
     EraseOrphansFor(nodeid);
     nPreferredDownload -= state->fPreferredDownload;
     nPeersWithValidatedDownloads -= (state->nBlocksInFlightValidHeaders != 0);
@@ -327,6 +331,7 @@ bool MarkBlockAsReceived(const uint256& hash) {
         state->nBlocksInFlight--;
         state->nStallingSince = 0;
         mapBlocksInFlight.erase(itInFlight);
+        nBlocksInFlight = mapBlocksInFlight.size();
         return true;
     }
     return false;
@@ -363,6 +368,7 @@ bool MarkBlockAsInFlight(NodeId nodeid, const uint256& hash, const CBlockIndex*
         nPeersWithValidatedDownloads++;
     }
     itInFlight = mapBlocksInFlight.insert(std::make_pair(hash, std::make_pair(nodeid, it))).first;
+    nBlocksInFlight = mapBlocksInFlight.size();
     if (pit)
         *pit = &itInFlight->second.second;
     return true;
@@ -465,6 +471,10 @@ void FindNextBlocksToDownload(NodeId nodeid, unsigned int count, std::vector<con
     // Make sure pindexBestKnownBlock is up to date, we'll need it.
     ProcessBlockAvailability(nodeid);
 
+    if (!fAutoRequestBlocks) {
+        return;
+    }
+
     if (state->pindexBestKnownBlock == NULL || state->pindexBestKnownBlock->nChainWork < chainActive.Tip()->nChainWork || state->pindexBestKnownBlock->nChainWork < UintToArith256(consensusParams.nMinimumChainWork)) {
         // This peer has nothing interesting.
         return;
@@ -3301,6 +3311,18 @@ bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interr
     return true;
 }
 
+void SetAutoRequestBlocks(bool state) {
+    fAutoRequestBlocks = state;
+}
+
+bool isAutoRequestingBlocks() {
+    return fAutoRequestBlocks;
+}
+
+unsigned int getAmountOfBlocksInFlight() {
+    return nBlocksInFlight;
+}
+
 class CNetProcessingCleanup
 {
 public:

src/net_processing.h

@@ -27,6 +27,9 @@ void RegisterNodeSignals(CNodeSignals& nodeSignals);
 /** Unregister a network node */
 void UnregisterNodeSignals(CNodeSignals& nodeSignals);
 
+/** if disabled, blocks will not be requested automatically, useful for low-resources-available mode */
+static const bool DEFAULT_AUTOMATIC_BLOCK_REQUESTS = true;
+
 class PeerLogicValidation : public CValidationInterface {
 private:
     CConnman* connman;
@@ -64,4 +67,10 @@ bool ProcessMessages(CNode* pfrom, CConnman& connman, const std::atomic<bool>& i
  */
 bool SendMessages(CNode* pto, CConnman& connman, const std::atomic<bool>& interrupt);
 
+void SetAutoRequestBlocks(bool);
+bool isAutoRequestingBlocks();
+
+/** retruns the amount of blocks in flight (in total) */
+unsigned int getAmountOfBlocksInFlight();
+
 #endif // BITCOIN_NET_PROCESSING_H

src/qt/bitcoingui.cpp

@@ -479,6 +479,10 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel)
         connect(_clientModel, SIGNAL(networkActiveChanged(bool)), this, SLOT(setNetworkActive(bool)));
 
         modalOverlay->setKnownBestHeight(_clientModel->getHeaderTipHeight(), QDateTime::fromTime_t(_clientModel->getHeaderTipTime()));
+        modalOverlay->setPauseResumeState(!_clientModel->isAutoRequestingBlocks());
+        connect(modalOverlay, SIGNAL(requestVerificationPauseOrResume()), _clientModel, SLOT(toggleAutoRequestBlocks()));
+        connect(_clientModel, SIGNAL(verificationProgressPauseStateHasChanged(bool)), modalOverlay, SLOT(setPauseResumeState(bool)));
+
         setNumBlocks(_clientModel->getNumBlocks(), _clientModel->getLastBlockDate(), _clientModel->getVerificationProgress(NULL), false);
         connect(_clientModel, SIGNAL(numBlocksChanged(int,QDateTime,double,bool)), this, SLOT(setNumBlocks(int,QDateTime,double,bool)));
 
@@ -506,6 +510,7 @@ void BitcoinGUI::setClientModel(ClientModel *_clientModel)
             // initialize the disable state of the tray icon with the current value in the model.
             setTrayIconVisible(optionsModel->getHideTrayIcon());
         }
+
     } else {
         // Disable possibility to show main window via action
         toggleHideAction->setEnabled(false);

src/qt/clientmodel.cpp

@@ -15,6 +15,7 @@
 #include "clientversion.h"
 #include "validation.h"
 #include "net.h"
+#include "net_processing.h"
 #include "txmempool.h"
 #include "ui_interface.h"
 #include "util.h"
@@ -245,6 +246,22 @@ QString ClientModel::dataDir() const
     return GUIUtil::boostPathToQString(GetDataDir());
 }
 
+bool ClientModel::isAutoRequestingBlocks() const
+{
+    return ::isAutoRequestingBlocks();
+}
+
+void ClientModel::setAutoRequestBlocks(bool state)
+{
+    ::SetAutoRequestBlocks(state);
+    Q_EMIT verificationProgressPauseStateHasChanged(!::isAutoRequestingBlocks());
+}
+
+void ClientModel::toggleAutoRequestBlocks()
+{
+    setAutoRequestBlocks(!::isAutoRequestingBlocks());
+}
+
 void ClientModel::updateBanlist()
 {
     banTableModel->refresh();

src/qt/clientmodel.h

@@ -84,6 +84,10 @@ class ClientModel : public QObject
     mutable std::atomic<int> cachedBestHeaderHeight;
     mutable std::atomic<int64_t> cachedBestHeaderTime;
 
+    // get/set state about autorequesting-blocks during IBD
+    bool isAutoRequestingBlocks() const;
+    void setAutoRequestBlocks(bool state);
+
 private:
     OptionsModel *optionsModel;
     PeerTableModel *peerTableModel;
@@ -108,12 +112,15 @@ class ClientModel : public QObject
     // Show progress dialog e.g. for verifychain
     void showProgress(const QString &title, int nProgress);
 
+    void verificationProgressPauseStateHasChanged(bool pauseActive);
+
 public Q_SLOTS:
     void updateTimer();
     void updateNumConnections(int numConnections);
     void updateNetworkActive(bool networkActive);
     void updateAlert();
     void updateBanlist();
+    void toggleAutoRequestBlocks();
 };
 
 #endif // BITCOIN_QT_CLIENTMODEL_H

src/qt/forms/modaloverlay.ui

@@ -224,6 +224,26 @@ QLabel { color: rgb(40,40,40);  }</string>
             </widget>
            </item>
            <item row="1" column="0">
+            <widget class="QLabel" name="labelNumberBlocksRequested">
+             <property name="font">
+              <font>
+               <weight>75</weight>
+               <bold>true</bold>
+              </font>
+             </property>
+             <property name="text">
+              <string>Blocks requested from peers</string>
+             </property>
+            </widget>
+           </item>
+           <item row="1" column="1">
+            <widget class="QLabel" name="numberBlocksRequested">
+             <property name="text">
+              <string>Unknown...</string>
+             </property>
+            </widget>
+           </item>
+           <item row="2" column="0">
             <widget class="QLabel" name="labelLastBlockTime">
              <property name="font">
               <font>
@@ -236,7 +256,7 @@ QLabel { color: rgb(40,40,40);  }</string>
              </property>
             </widget>
            </item>
-           <item row="1" column="1">
+           <item row="2" column="1">
             <widget class="QLabel" name="newestBlockDate">
              <property name="sizePolicy">
               <sizepolicy hsizetype="Maximum" vsizetype="Preferred">
@@ -249,7 +269,7 @@ QLabel { color: rgb(40,40,40);  }</string>
              </property>
             </widget>
            </item>
-           <item row="2" column="0">
+           <item row="3" column="0">
             <widget class="QLabel" name="labelSyncDone">
              <property name="font">
               <font>
@@ -262,7 +282,7 @@ QLabel { color: rgb(40,40,40);  }</string>
              </property>
             </widget>
            </item>
-           <item row="2" column="1">
+           <item row="3" column="1">
             <layout class="QHBoxLayout" name="horizontalLayoutSync" stretch="0,1">
              <item>
               <widget class="QLabel" name="percentageProgress">
@@ -283,7 +303,7 @@ QLabel { color: rgb(40,40,40);  }</string>
              </item>
             </layout>
            </item>
-           <item row="4" column="0">
+           <item row="5" column="0">
             <widget class="QLabel" name="labelProgressIncrease">
              <property name="font">
               <font>
@@ -296,14 +316,14 @@ QLabel { color: rgb(40,40,40);  }</string>
              </property>
             </widget>
            </item>
-           <item row="4" column="1">
+           <item row="5" column="1">
             <widget class="QLabel" name="progressIncreasePerH">
              <property name="text">
               <string>calculating...</string>
              </property>
             </widget>
            </item>
-           <item row="5" column="0">
+           <item row="6" column="0">
             <widget class="QLabel" name="labelEstimatedTimeLeft">
              <property name="font">
               <font>
@@ -316,7 +336,7 @@ QLabel { color: rgb(40,40,40);  }</string>
              </property>
             </widget>
            </item>
-           <item row="5" column="1">
+           <item row="6" column="1">
             <widget class="QLabel" name="expectedTimeLeft">
              <property name="text">
               <string>calculating...</string>
@@ -334,6 +354,33 @@ QLabel { color: rgb(40,40,40);  }</string>
             <number>10</number>
            </property>
            <item>
+            <widget class="QPushButton" name="pauseResumeVerification">
+             <property name="text">
+              <string>Pause downloading blocks</string>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <spacer name="horizontalSpacer_2">
+             <property name="orientation">
+              <enum>Qt::Horizontal</enum>
+             </property>
+             <property name="sizeHint" stdset="0">
+              <size>
+               <width>40</width>
+               <height>20</height>
+              </size>
+             </property>
+            </spacer>
+           </item>
+           <item>
+            <widget class="QLabel" name="infoLabel">
+             <property name="text">
+              <string/>
+             </property>
+            </widget>
+           </item>
+           <item>
             <spacer name="horizontalSpacer">
              <property name="orientation">
               <enum>Qt::Horizontal</enum>

src/qt/modaloverlay.cpp

@@ -8,6 +8,7 @@
 #include "guiutil.h"
 
 #include "chainparams.h"
+#include "net_processing.h"
 
 #include <QResizeEvent>
 #include <QPropertyAnimation>
@@ -18,10 +19,12 @@ ui(new Ui::ModalOverlay),
 bestHeaderHeight(0),
 bestHeaderDate(QDateTime()),
 layerIsVisible(false),
-userClosed(false)
+userClosed(false),
+verificationPauseActive(false)
 {
     ui->setupUi(this);
     connect(ui->closeButton, SIGNAL(clicked()), this, SLOT(closeClicked()));
+    connect(ui->pauseResumeVerification, SIGNAL(clicked()), this, SLOT(pauseClicked()));
     if (parent) {
         parent->installEventFilter(this);
         raise();
@@ -71,6 +74,7 @@ void ModalOverlay::setKnownBestHeight(int count, const QDateTime& blockDate)
     if (count > bestHeaderHeight) {
         bestHeaderHeight = count;
         bestHeaderDate = blockDate;
+        eventuallyShowHeaderSyncing(count);
     }
 }
 
@@ -125,15 +129,30 @@ void ModalOverlay::tipUpdate(int count, const QDateTime& blockDate, double nVeri
         // not syncing
         return;
 
+    // show remaining number of blocks
+    ui->numberOfBlocksLeft->setText(QString::number(bestHeaderHeight - count));
+
+    // show already requested blocks (in total)
+    ui->numberBlocksRequested->setText(QString::number(getAmountOfBlocksInFlight()));
+    eventuallyShowHeaderSyncing(count);
+    updatePauseState(verificationPauseActive);
+
+    // disable pause button when we we can fetch directly
+    // avoid using the core-layer's existing CanFetchDirectly()
+    bool canFetchDirecly = (blockDate.toTime_t() > GetAdjustedTime() - Params().GetConsensus().nPowTargetSpacing * 20);
+    ui->pauseResumeVerification->setEnabled(!canFetchDirecly);
+    ui->infoLabel->setVisible(!canFetchDirecly);
+}
+
+void ModalOverlay::eventuallyShowHeaderSyncing(int count)
+{
     // estimate the number of headers left based on nPowTargetSpacing
     // and check if the gui is not aware of the best header (happens rarely)
-    int estimateNumHeadersLeft = bestHeaderDate.secsTo(currentDate) / Params().GetConsensus().nPowTargetSpacing;
+    int estimateNumHeadersLeft = bestHeaderDate.secsTo(QDateTime::currentDateTime()) / Params().GetConsensus().nPowTargetSpacing;
     bool hasBestHeader = bestHeaderHeight >= count;
 
-    // show remaining number of blocks
-    if (estimateNumHeadersLeft < HEADER_HEIGHT_DELTA_SYNC && hasBestHeader) {
-        ui->numberOfBlocksLeft->setText(QString::number(bestHeaderHeight - count));
-    } else {
+    // show headers-syncing progress if we still sync headers
+    if (estimateNumHeadersLeft >= HEADER_HEIGHT_DELTA_SYNC || !hasBestHeader) {
         ui->numberOfBlocksLeft->setText(tr("Unknown. Syncing Headers (%1)...").arg(bestHeaderHeight));
         ui->expectedTimeLeft->setText(tr("Unknown..."));
     }
@@ -170,3 +189,21 @@ void ModalOverlay::closeClicked()
     showHide(true);
     userClosed = true;
 }
+
+void ModalOverlay::pauseClicked()
+{
+    Q_EMIT requestVerificationPauseOrResume();
+}
+
+void ModalOverlay::setPauseResumeState(bool pauseActive)
+{
+    verificationPauseActive = pauseActive;
+    updatePauseState(pauseActive);
+}
+
+void ModalOverlay::updatePauseState(bool pauseActive)
+{
+    ui->labelNumberBlocksRequested->setText((pauseActive ? "Finish downloading blocks": "Blocks requested from peers"));
+    ui->pauseResumeVerification->setText((pauseActive ? "Resume downloading blocks ": "Pause downloading blocks"));
+    ui->infoLabel->setText((pauseActive && getAmountOfBlocksInFlight() > 0 ? "Wait to finish current downloads...": ""));
+}