[afs] Support interruption requests on feature iterator

Results in a huge increase in responsiveness when working with
large AFS layers

src/providers/arcgisrest/qgsafsfeatureiterator.cpp

@@ -19,6 +19,7 @@
 #include "geometry/qgsgeometry.h"
 #include "qgsexception.h"
 #include "qgsarcgisrestutils.h"
+#include "qgsfeedback.h"
 
 QgsAfsFeatureSource::QgsAfsFeatureSource( const std::shared_ptr<QgsAfsSharedData> &sharedData )
   : mSharedData( sharedData )
@@ -72,20 +73,11 @@ QgsAfsFeatureIterator::QgsAfsFeatureIterator( QgsAfsFeatureSource *source, bool
 
   if ( !mFilterRect.isNull() )
   {
-    QgsFeatureIds featuresInRect = mSource->sharedData()->getFeatureIdsInExtent( mFilterRect );
-    if ( !requestIds.isEmpty() )
-    {
-      requestIds.intersect( featuresInRect );
-    }
-    else
-    {
-      requestIds = featuresInRect;
-    }
-    if ( requestIds.empty() )
-    {
-      close();
-      return;
-    }
+    // defer request to find features in filter rect until first feature is requested
+    // this allows time for a interruption checker to be installed on the iterator
+    // and avoids performing this expensive check in the main thread when just
+    // preparing iterators
+    mDeferredFeaturesInFilterRectCheck = true;
   }
 
   mFeatureIdList = requestIds.toList();
@@ -107,9 +99,38 @@ bool QgsAfsFeatureIterator::fetchFeature( QgsFeature &f )
   if ( mClosed )
     return false;
 
+  if ( mInterruptionChecker && mInterruptionChecker->isCanceled() )
+    return false;
+
   if ( mFeatureIterator >= mSource->sharedData()->featureCount() )
     return false;
 
+  if ( mDeferredFeaturesInFilterRectCheck )
+  {
+    QgsFeatureIds featuresInRect = mSource->sharedData()->getFeatureIdsInExtent( mFilterRect, mInterruptionChecker );
+    if ( !mFeatureIdList.isEmpty() )
+    {
+      QgsFeatureIds requestIds = mFeatureIdList.toSet();
+      requestIds.intersect( featuresInRect );
+      mFeatureIdList = requestIds.toList();
+    }
+    else
+    {
+      mFeatureIdList = featuresInRect.toList();
+    }
+    if ( mFeatureIdList.empty() )
+    {
+      return false;
+    }
+
+    std::sort( mFeatureIdList.begin(), mFeatureIdList.end() );
+    mRemainingFeatureIds = mFeatureIdList;
+    if ( !mRemainingFeatureIds.empty() )
+      mFeatureIterator = mRemainingFeatureIds.at( 0 );
+
+    mDeferredFeaturesInFilterRectCheck = false;
+  }
+
   if ( !mFeatureIdList.empty() && mRemainingFeatureIds.empty() )
     return false;
 
@@ -133,10 +154,13 @@ bool QgsAfsFeatureIterator::fetchFeature( QgsFeature &f )
     {
       while ( mFeatureIterator < mSource->sharedData()->featureCount() )
       {
+        if ( mInterruptionChecker && mInterruptionChecker->isCanceled() )
+          return false;
+
         if ( !mFeatureIdList.empty() && mRemainingFeatureIds.empty() )
           return false;
 
-        bool success = mSource->sharedData()->getFeature( mFeatureIterator, f );
+        bool success = mSource->sharedData()->getFeature( mFeatureIterator, f, QgsRectangle(), mInterruptionChecker );
         if ( !mFeatureIdList.empty() )
         {
           mRemainingFeatureIds.removeAll( mFeatureIterator );
@@ -178,3 +202,8 @@ bool QgsAfsFeatureIterator::close()
   mClosed = true;
   return true;
 }
+
+void QgsAfsFeatureIterator::setInterruptionChecker( QgsFeedback *interruptionChecker )
+{
+  mInterruptionChecker = interruptionChecker;
+}

src/providers/arcgisrest/qgsafsfeatureiterator.h

@@ -45,6 +45,8 @@ class QgsAfsFeatureIterator : public QgsAbstractFeatureIteratorFromSource<QgsAfs
     bool rewind() override;
     bool close() override;
 
+    void setInterruptionChecker( QgsFeedback *interruptionChecker ) override;
+
   protected:
     bool fetchFeature( QgsFeature &f ) override;
 
@@ -56,6 +58,9 @@ class QgsAfsFeatureIterator : public QgsAbstractFeatureIteratorFromSource<QgsAfs
 
     QgsCoordinateTransform mTransform;
     QgsRectangle mFilterRect;
+
+    QgsFeedback *mInterruptionChecker = nullptr;
+    bool mDeferredFeaturesInFilterRectCheck = false;
 };
 
 #endif // QGSAFSFEATUREITERATOR_H

src/providers/arcgisrest/qgsafsshareddata.cpp

@@ -23,7 +23,7 @@ void QgsAfsSharedData::clearCache()
   mCache.clear();
 }
 
-bool QgsAfsSharedData::getFeature( QgsFeatureId id, QgsFeature &f, const QgsRectangle &filterRect )
+bool QgsAfsSharedData::getFeature( QgsFeatureId id, QgsFeature &f, const QgsRectangle &filterRect, QgsFeedback *feedback )
 {
   QMutexLocker locker( &mMutex );
 
@@ -70,7 +70,8 @@ bool QgsAfsSharedData::getFeature( QgsFeatureId id, QgsFeature &f, const QgsRect
   const QVariantMap queryData = QgsArcGisRestUtils::getObjects(
                                   mDataSource.param( QStringLiteral( "url" ) ), objectIds, mDataSource.param( QStringLiteral( "crs" ) ), true,
                                   fetchAttribNames, QgsWkbTypes::hasM( mGeometryType ), QgsWkbTypes::hasZ( mGeometryType ),
-                                  filterRect, errorTitle, errorMessage );
+                                  filterRect, errorTitle, errorMessage, feedback );
+
   if ( queryData.isEmpty() )
   {
 //    const_cast<QgsAfsProvider *>( this )->pushError( errorTitle + ": " + errorMessage );
@@ -141,15 +142,15 @@ bool QgsAfsSharedData::getFeature( QgsFeatureId id, QgsFeature &f, const QgsRect
   return false;
 }
 
-QgsFeatureIds QgsAfsSharedData::getFeatureIdsInExtent( const QgsRectangle &extent )
+QgsFeatureIds QgsAfsSharedData::getFeatureIdsInExtent( const QgsRectangle &extent, QgsFeedback *feedback )
 {
   QString errorTitle;
   QString errorText;
 
 
   const QList<quint32> featuresInRect = QgsArcGisRestUtils::getObjectIdsByExtent( mDataSource.param( QStringLiteral( "url" ) ),
                                         mObjectIdFieldName,
-                                        extent, errorTitle, errorText );
+                                        extent, errorTitle, errorText, feedback );
 
   QgsFeatureIds ids;
   for ( quint32 id : featuresInRect )

src/providers/arcgisrest/qgsafsshareddata.h

@@ -22,6 +22,8 @@
 #include "qgsfeature.h"
 #include "qgsdatasourceuri.h"
 
+class QgsFeedback;
+
 /**
  * \brief This class holds data, shared between QgsAfsProvider and QgsAfsFeatureIterator
  **/
@@ -36,8 +38,8 @@ class QgsAfsSharedData : public QObject
     QgsCoordinateReferenceSystem crs() const { return mSourceCRS; }
     void clearCache();
 
-    bool getFeature( QgsFeatureId id, QgsFeature &f, const QgsRectangle &filterRect = QgsRectangle() );
-    QgsFeatureIds getFeatureIdsInExtent( const QgsRectangle &extent );
+    bool getFeature( QgsFeatureId id, QgsFeature &f, const QgsRectangle &filterRect = QgsRectangle(), QgsFeedback *feedback = nullptr );
+    QgsFeatureIds getFeatureIdsInExtent( const QgsRectangle &extent, QgsFeedback *feedback );
 
   private:
     friend class QgsAfsProvider;

src/providers/arcgisrest/qgsarcgisrestutils.cpp

@@ -27,6 +27,7 @@
 #include "geometry/qgsmulticurve.h"
 #include "geometry/qgspolygon.h"
 #include "geometry/qgspoint.h"
+#include "qgsfeedback.h"
 
 #include <QEventLoop>
 #include <QNetworkRequest>
@@ -370,7 +371,7 @@ QVariantMap QgsArcGisRestUtils::getObjects( const QString &layerurl, const QList
     bool fetchGeometry, const QStringList &fetchAttributes,
     bool fetchM, bool fetchZ,
     const QgsRectangle &filterRect,
-    QString &errorTitle, QString &errorText )
+    QString &errorTitle, QString &errorText, QgsFeedback *feedback )
 {
   QStringList ids;
   foreach ( int id, objectIds )
@@ -404,10 +405,10 @@ QVariantMap QgsArcGisRestUtils::getObjects( const QString &layerurl, const QList
     queryUrl.addQueryItem( QStringLiteral( "geometryType" ), QStringLiteral( "esriGeometryEnvelope" ) );
     queryUrl.addQueryItem( QStringLiteral( "spatialRel" ), QStringLiteral( "esriSpatialRelEnvelopeIntersects" ) );
   }
-  return queryServiceJSON( queryUrl, errorTitle, errorText );
+  return queryServiceJSON( queryUrl, errorTitle, errorText, feedback );
 }
 
-QList<quint32> QgsArcGisRestUtils::getObjectIdsByExtent( const QString &layerurl, const QString &objectIdField, const QgsRectangle &filterRect, QString &errorTitle, QString &errorText )
+QList<quint32> QgsArcGisRestUtils::getObjectIdsByExtent( const QString &layerurl, const QString &objectIdField, const QgsRectangle &filterRect, QString &errorTitle, QString &errorText, QgsFeedback *feedback )
 {
   QUrl queryUrl( layerurl + "/query" );
   queryUrl.addQueryItem( QStringLiteral( "f" ), QStringLiteral( "json" ) );
@@ -418,7 +419,7 @@ QList<quint32> QgsArcGisRestUtils::getObjectIdsByExtent( const QString &layerurl
                          .arg( filterRect.xMaximum(), 0, 'f', -1 ).arg( filterRect.yMaximum(), 0, 'f', -1 ) );
   queryUrl.addQueryItem( QStringLiteral( "geometryType" ), QStringLiteral( "esriGeometryEnvelope" ) );
   queryUrl.addQueryItem( QStringLiteral( "spatialRel" ), QStringLiteral( "esriSpatialRelEnvelopeIntersects" ) );
-  const QVariantMap objectIdData = queryServiceJSON( queryUrl, errorTitle, errorText );
+  const QVariantMap objectIdData = queryServiceJSON( queryUrl, errorTitle, errorText, feedback );
 
   if ( objectIdData.isEmpty() )
   {
@@ -433,7 +434,7 @@ QList<quint32> QgsArcGisRestUtils::getObjectIdsByExtent( const QString &layerurl
   return ids;
 }
 
-QByteArray QgsArcGisRestUtils::queryService( const QUrl &u, QString &errorTitle, QString &errorText )
+QByteArray QgsArcGisRestUtils::queryService( const QUrl &u, QString &errorTitle, QString &errorText, QgsFeedback *feedback )
 {
   QEventLoop loop;
   QUrl url = parseUrl( u );
@@ -447,11 +448,18 @@ QByteArray QgsArcGisRestUtils::queryService( const QUrl &u, QString &errorTitle,
   {
     reply = nam->get( request );
     QObject::connect( reply, &QNetworkReply::finished, &loop, &QEventLoop::quit );
+    if ( feedback )
+    {
+      QObject::connect( feedback, &QgsFeedback::canceled, reply, &QNetworkReply::abort );
+    }
 
     loop.exec( QEventLoop::ExcludeUserInputEvents );
 
     reply->deleteLater();
 
+    if ( feedback && feedback->isCanceled() )
+      return QByteArray();
+
     // Handle network errors
     if ( reply->error() != QNetworkReply::NoError )
     {
@@ -475,9 +483,9 @@ QByteArray QgsArcGisRestUtils::queryService( const QUrl &u, QString &errorTitle,
   return result;
 }
 
-QVariantMap QgsArcGisRestUtils::queryServiceJSON( const QUrl &url, QString &errorTitle, QString &errorText )
+QVariantMap QgsArcGisRestUtils::queryServiceJSON( const QUrl &url, QString &errorTitle, QString &errorText, QgsFeedback *feedback )
 {
-  QByteArray reply = queryService( url, errorTitle, errorText );
+  QByteArray reply = queryService( url, errorTitle, errorText, feedback );
   if ( !errorTitle.isEmpty() )
   {
     return QVariantMap();

src/providers/arcgisrest/qgsarcgisrestutils.h

@@ -26,6 +26,7 @@ class QgsFields;
 class QgsRectangle;
 class QgsAbstractGeometry;
 class QgsCoordinateReferenceSystem;
+class QgsFeedback;
 
 class QgsArcGisRestUtils
 {
@@ -40,10 +41,10 @@ class QgsArcGisRestUtils
     static QVariantMap getObjectIds( const QString &layerurl, const QString &objectIdFieldName, QString &errorTitle, QString &errorText );
     static QVariantMap getObjects( const QString &layerurl, const QList<quint32> &objectIds, const QString &crs,
                                    bool fetchGeometry, const QStringList &fetchAttributes, bool fetchM, bool fetchZ,
-                                   const QgsRectangle &filterRect, QString &errorTitle, QString &errorText );
-    static QList<quint32> getObjectIdsByExtent( const QString &layerurl, const QString &objectIdField, const QgsRectangle &filterRect, QString &errorTitle, QString &errorText );
-    static QByteArray queryService( const QUrl &url, QString &errorTitle, QString &errorText );
-    static QVariantMap queryServiceJSON( const QUrl &url, QString &errorTitle, QString &errorText );
+                                   const QgsRectangle &filterRect, QString &errorTitle, QString &errorText, QgsFeedback *feedback = nullptr );
+    static QList<quint32> getObjectIdsByExtent( const QString &layerurl, const QString &objectIdField, const QgsRectangle &filterRect, QString &errorTitle, QString &errorText, QgsFeedback *feedback = nullptr );
+    static QByteArray queryService( const QUrl &url, QString &errorTitle, QString &errorText, QgsFeedback *feedback = nullptr );
+    static QVariantMap queryServiceJSON( const QUrl &url, QString &errorTitle, QString &errorText, QgsFeedback *feedback = nullptr );
 
     static QUrl parseUrl( const QUrl &url );
 };