Prepare for removal of QgsCoordinateTransformCache

python/core/qgscoordinatetransform.sip

@@ -71,6 +71,18 @@ Default constructor, creates an invalid QgsCoordinateTransform.
  No reference to ``project`` is stored or utilised outside of the constructor,
  and it is used to retrieve the project's transform context only.
 
+.. versionadded:: 3.0
+%End
+
+    explicit QgsCoordinateTransform( const QgsCoordinateReferenceSystem &source,
+                                     const QgsCoordinateReferenceSystem &destination,
+                                     int sourceDatumTransform,
+                                     int destinationDatumTransform );
+%Docstring
+ Constructs a QgsCoordinateTransform to transform from the ``source``
+ to ``destination`` coordinate reference system, with the specified
+ datum transforms.
+
 .. versionadded:: 3.0
 %End
 
@@ -282,6 +294,14 @@ Default constructor, creates an invalid QgsCoordinateTransform.
     void initialize();
 %Docstring
 initialize is used to actually create the Transformer instance
+%End
+
+    static void invalidateCache();
+%Docstring
+ Clears the internal cache used to initialize QgsCoordinateTransform objects.
+ This should be called whenever the srs database has
+ been modified in order to ensure that outdated CRS transforms are not created.
+.. versionadded:: 3.0
 %End
 
 };

src/analysis/vector/geometry_checker/qgsgeometrycheck.cpp

@@ -18,7 +18,7 @@
 #include "qgsgeometrycheck.h"
 #include "qgsfeaturepool.h"
 
-QgsGeometryCheckerContext::QgsGeometryCheckerContext( int _precision, const QString &_mapCrs, const QMap<QString, QgsFeaturePool *> &_featurePools )
+QgsGeometryCheckerContext::QgsGeometryCheckerContext( int _precision, const QgsCoordinateReferenceSystem &_mapCrs, const QMap<QString, QgsFeaturePool *> &_featurePools )
   : tolerance( std::pow( 10, -_precision ) )
   , reducedTolerance( std::pow( 10, -_precision / 2 ) )
   , mapCrs( _mapCrs )

src/analysis/vector/geometry_checker/qgsgeometrycheck.h

@@ -35,10 +35,10 @@ class QgsFeaturePool;
 
 struct ANALYSIS_EXPORT QgsGeometryCheckerContext
 {
-  QgsGeometryCheckerContext( int _precision, const QString &_mapCrs, const QMap<QString, QgsFeaturePool *> &_featurePools );
+  QgsGeometryCheckerContext( int _precision, const QgsCoordinateReferenceSystem &_mapCrs, const QMap<QString, QgsFeaturePool *> &_featurePools );
   const double tolerance;
   const double reducedTolerance;
-  const QString mapCrs;
+  const QgsCoordinateReferenceSystem mapCrs;
   const QMap<QString, QgsFeaturePool *> featurePools;
 };
 

src/analysis/vector/geometry_checker/qgsgeometrychecker.cpp

@@ -18,6 +18,7 @@
 #include "qgsgeometrychecker.h"
 #include "qgsgeometrycheck.h"
 #include "qgsfeaturepool.h"
+#include "qgsproject.h"
 
 #include <QtConcurrentMap>
 #include <QFutureWatcher>
@@ -144,7 +145,7 @@ bool QgsGeometryChecker::fixError( QgsGeometryCheckError *error, int method, boo
   {
     const QMap<QgsFeatureId, QList<QgsGeometryCheck::Change>> &layerChanges = changes[layerId];
     QgsFeaturePool *featurePool = mContext->featurePools[layerId];
-    QgsCoordinateTransform t = QgsCoordinateTransformCache::instance()->transform( featurePool->getLayer()->crs().authid(), mContext->mapCrs );
+    QgsCoordinateTransform t( featurePool->getLayer()->crs(), mContext->mapCrs, QgsProject::instance() );
     for ( QgsFeatureId id : layerChanges.keys() )
     {
       bool removed = false;
@@ -183,7 +184,7 @@ bool QgsGeometryChecker::fixError( QgsGeometryCheckError *error, int method, boo
   for ( const QString &layerId : mContext->featurePools.keys() )
   {
     QgsFeaturePool *featurePool = mContext->featurePools[layerId];
-    QgsCoordinateTransform t = QgsCoordinateTransformCache::instance()->transform( mContext->mapCrs, featurePool->getLayer()->crs().authid() );
+    QgsCoordinateTransform t( mContext->mapCrs, featurePool->getLayer()->crs(), QgsProject::instance() );
     recheckAreaFeatures[layerId] = featurePool->getIntersects( t.transform( recheckArea ) );
   }
 

src/analysis/vector/geometry_checker/qgsgeometryfollowboundariescheck.cpp

@@ -16,6 +16,7 @@
 #include "qgscrscache.h"
 #include "qgsgeometryfollowboundariescheck.h"
 #include "qgsgeometryengine.h"
+#include "qgsproject.h"
 #include "../qgsgeometrysnapper.h"
 
 
@@ -49,7 +50,7 @@ void QgsGeometryFollowBoundariesCheck::collectErrors( QList<QgsGeometryCheckErro
     const QgsAbstractGeometry *geom = layerFeature.geometry();
 
     // The geometry to crs of the check layer
-    QgsCoordinateTransform crst = QgsCoordinateTransformCache::instance()->transform( layerFeature.layer().crs().authid(), mCheckLayer->crs().authid() );
+    QgsCoordinateTransform crst( layerFeature.layer().crs(), mCheckLayer->crs(), QgsProject::instance() );
     QgsGeometry geomt( geom->clone() );
     geomt.transform( crst );
 

src/app/qgscustomprojectiondialog.cpp

@@ -174,7 +174,7 @@ bool  QgsCustomProjectionDialog::deleteCrs( const QString &id )
   sqlite3_close( myDatabase );
 
   QgsCoordinateReferenceSystem::invalidateCache();
-  QgsCoordinateTransformCache::instance()->invalidateCrs( QStringLiteral( "USER:%1" ).arg( id ) );
+  QgsCoordinateTransform::invalidateCache();
 
   return myResult == SQLITE_OK;
 }
@@ -300,7 +300,7 @@ bool QgsCustomProjectionDialog::saveCrs( QgsCoordinateReferenceSystem myCRS, con
   existingCRSnames[myId] = myName;
 
   QgsCoordinateReferenceSystem::invalidateCache();
-  QgsCoordinateTransformCache::instance()->invalidateCrs( QStringLiteral( "USER:%1" ).arg( myId ) );
+  QgsCoordinateTransform::invalidateCache();
 
   // If we have a projection acronym not in the user db previously, add it.
   // This is a must, or else we can't select it from the vw_srs table.

src/core/composer/qgsatlascomposition.cpp

@@ -815,7 +815,7 @@ QgsGeometry QgsAtlasComposition::currentGeometry( const QgsCoordinateReferenceSy
   }
 
   QgsGeometry transformed = mCurrentFeature.geometry();
-  transformed.transform( QgsCoordinateTransformCache::instance()->transform( mCoverageLayer->crs().authid(), crs.authid() ) );
+  transformed.transform( QgsCoordinateTransform( mCoverageLayer->crs(), crs, mComposition->project() ) );
   mGeometryCache[crs.srsid()] = transformed;
   return transformed;
 }

src/core/qgscoordinatetransform.cpp

@@ -41,6 +41,9 @@ extern "C"
 // if defined shows all information about transform to stdout
 // #define COORDINATE_TRANSFORM_VERBOSE
 
+QReadWriteLock QgsCoordinateTransform::sCacheLock;
+QMultiHash< QPair< QString, QString >, QgsCoordinateTransform > QgsCoordinateTransform::sTransforms;
+
 QgsCoordinateTransform::QgsCoordinateTransform()
 {
   d = new QgsCoordinateTransformPrivate();
@@ -67,6 +70,14 @@ QgsCoordinateTransform::QgsCoordinateTransform( const QgsCoordinateReferenceSyst
 #endif
 }
 
+QgsCoordinateTransform::QgsCoordinateTransform( const QgsCoordinateReferenceSystem &source, const QgsCoordinateReferenceSystem &destination, int sourceDatumTransform, int destinationDatumTransform )
+{
+  d = new QgsCoordinateTransformPrivate( source, destination, sourceDatumTransform, destinationDatumTransform );
+#ifdef QGISDEBUG
+  d->mHasContext = true; // not strictly true, but we don't need to worry if datums have been explicitly set
+#endif
+}
+
 QgsCoordinateTransform::QgsCoordinateTransform( const QgsCoordinateTransform &o )
 {
   d = o.d;
@@ -792,3 +803,10 @@ void QgsCoordinateTransform::initialize()
   d.detach();
   d->initialize();
 }
+
+void QgsCoordinateTransform::invalidateCache()
+{
+  sCacheLock.lockForWrite();
+  sTransforms.clear();
+  sCacheLock.unlock();
+}

src/core/qgscoordinatetransform.h

@@ -101,6 +101,18 @@ class CORE_EXPORT QgsCoordinateTransform
                                      const QgsCoordinateReferenceSystem &destination,
                                      const QgsProject *project );
 
+    /**
+     * Constructs a QgsCoordinateTransform to transform from the \a source
+     * to \a destination coordinate reference system, with the specified
+     * datum transforms.
+     *
+     * \since QGIS 3.0
+     */
+    explicit QgsCoordinateTransform( const QgsCoordinateReferenceSystem &source,
+                                     const QgsCoordinateReferenceSystem &destination,
+                                     int sourceDatumTransform,
+                                     int destinationDatumTransform );
+
     /**
      * Copy constructor
      */
@@ -364,11 +376,24 @@ class CORE_EXPORT QgsCoordinateTransform
     //!initialize is used to actually create the Transformer instance
     void initialize();
 
+    /**
+     * Clears the internal cache used to initialize QgsCoordinateTransform objects.
+     * This should be called whenever the srs database has
+     * been modified in order to ensure that outdated CRS transforms are not created.
+     * \since QGIS 3.0
+     */
+    static void invalidateCache();
+
   private:
 
     static void searchDatumTransform( const QString &sql, QList< int > &transforms );
 
     mutable QExplicitlySharedDataPointer<QgsCoordinateTransformPrivate> d;
+
+    // cache
+    static QReadWriteLock sCacheLock;
+    static QMultiHash< QPair< QString, QString >, QgsCoordinateTransform > sTransforms; //same auth_id pairs might have different datum transformations
+
 };
 
 //! Output stream operator

src/core/qgscoordinatetransform_p.cpp

@@ -58,6 +58,16 @@ QgsCoordinateTransformPrivate::QgsCoordinateTransformPrivate( const QgsCoordinat
   initialize();
 }
 
+QgsCoordinateTransformPrivate::QgsCoordinateTransformPrivate( const QgsCoordinateReferenceSystem &source, const QgsCoordinateReferenceSystem &destination, int sourceDatumTransform, int destDatumTransform )
+  : mSourceCRS( source )
+  , mDestCRS( destination )
+  , mSourceDatumTransform( sourceDatumTransform )
+  , mDestinationDatumTransform( destDatumTransform )
+{
+  setFinder();
+  initialize();
+}
+
 QgsCoordinateTransformPrivate::QgsCoordinateTransformPrivate( const QgsCoordinateTransformPrivate &other )
   : QSharedData( other )
   , mIsValid( other.mIsValid )

src/core/qgscoordinatetransform_p.h

@@ -66,6 +66,11 @@ class QgsCoordinateTransformPrivate : public QSharedData
                                    const QgsCoordinateReferenceSystem &destination,
                                    const QgsCoordinateTransformContext &context );
 
+    QgsCoordinateTransformPrivate( const QgsCoordinateReferenceSystem &source,
+                                   const QgsCoordinateReferenceSystem &destination,
+                                   int sourceDatumTransform,
+                                   int destDatumTransform );
+
     QgsCoordinateTransformPrivate( const QgsCoordinateTransformPrivate &other );
 
     ~QgsCoordinateTransformPrivate();

src/core/qgsmaphittest.cpp

@@ -115,7 +115,7 @@ void QgsMapHitTest::runHitTestLayer( QgsVectorLayer *vl, SymbolSet &usedSymbols,
   {
     if ( mSettings.destinationCrs() != vl->crs() )
     {
-      QgsCoordinateTransform ct = QgsCoordinateTransformCache::instance()->transform( mSettings.destinationCrs().authid(), vl->crs().authid() );
+      QgsCoordinateTransform ct( mSettings.destinationCrs(), vl->crs(), mSettings.transformContext() );
       transformedPolygon.transform( ct );
     }
   }

src/core/raster/qgsrasterprojector.cpp

@@ -754,7 +754,7 @@ QgsRasterBlock *QgsRasterProjector::block( int bandNo, QgsRectangle  const &exte
     return mInput->block( bandNo, extent, width, height, feedback );
   }
 
-  QgsCoordinateTransform inverseCt = QgsCoordinateTransformCache::instance()->transform( mDestCRS.authid(), mSrcCRS.authid(), mDestDatumTransform, mSrcDatumTransform );
+  QgsCoordinateTransform inverseCt( mDestCRS, mSrcCRS, mDestDatumTransform, mSrcDatumTransform );
 
   ProjectorData pd( extent, width, height, mInput, inverseCt, mPrecision );
 
@@ -852,7 +852,7 @@ bool QgsRasterProjector::destExtentSize( const QgsRectangle &srcExtent, int srcX
   {
     return false;
   }
-  QgsCoordinateTransform ct = QgsCoordinateTransformCache::instance()->transform( mSrcCRS.authid(), mDestCRS.authid(), mSrcDatumTransform, mDestDatumTransform );
+  QgsCoordinateTransform ct( mSrcCRS, mDestCRS, mSrcDatumTransform, mDestDatumTransform );
 
   return extentSize( ct, srcExtent, srcXSize, srcYSize, destExtent, destXSize, destYSize );
 }

src/plugins/geometry_checker/qgsgeometrycheckerresulttab.cpp

@@ -256,7 +256,7 @@ bool QgsGeometryCheckerResultTab::exportErrorsDo( const QString &file )
   {
     return false;
   }
-  if ( !createEmptyDataSource( file, QStringLiteral( "ESRI Shapefile" ), "UTF-8", QgsWkbTypes::Point, attributes, mIface->mapCanvas()->mapSettings().destinationCrs() ) )
+  if ( !createEmptyDataSource( file, QStringLiteral( "ESRI Shapefile" ), "UTF-8", QgsWkbTypes::Point, attributes, QgsProject::instance()->crs() ) )
   {
     return false;
   }

src/plugins/geometry_checker/qgsgeometrycheckersetuptab.cpp

@@ -178,7 +178,7 @@ QList<QgsVectorLayer *> QgsGeometryCheckerSetupTab::getSelectedLayers()
 
 void QgsGeometryCheckerSetupTab::validateInput()
 {
-  QStringList layerCrs = QStringList() << mIface->mapCanvas()->mapSettings().destinationCrs().authid();
+  QStringList layerCrs = QStringList() << QgsProject::instance()->crs().authid();
   QList<QgsVectorLayer *> layers = getSelectedLayers();
   int nApplicable = 0;
   int nPoint = 0;
@@ -431,7 +431,7 @@ void QgsGeometryCheckerSetupTab::runChecks()
   for ( QgsVectorLayer *layer : processLayers )
   {
     double layerToMapUntis = mIface->mapCanvas()->mapSettings().layerToMapUnits( layer );
-    QgsCoordinateTransform layerToMapTransform = QgsCoordinateTransformCache::instance()->transform( layer->crs().authid(), mIface->mapCanvas()->mapSettings().destinationCrs().authid() );
+    QgsCoordinateTransform layerToMapTransform( layer->crs(), QgsProject::instance()->crs(), QgsProject::instance() );
     featurePools.insert( layer->id(), new QgsFeaturePool( layer, layerToMapUntis, layerToMapTransform, selectedOnly ) );
   }
   // LineLayerIntersection check is enabled, make sure there is also a feature pool for that layer
@@ -440,11 +440,11 @@ void QgsGeometryCheckerSetupTab::runChecks()
     QgsVectorLayer *layer = dynamic_cast<QgsVectorLayer *>( QgsProject::instance()->mapLayer( ui.comboLineLayerIntersection->currentData().toString() ) );
     Q_ASSERT( layer );
     double layerToMapUntis = mIface->mapCanvas()->mapSettings().layerToMapUnits( layer );
-    QgsCoordinateTransform layerToMapTransform = QgsCoordinateTransformCache::instance()->transform( layer->crs().authid(), mIface->mapCanvas()->mapSettings().destinationCrs().authid() );
+    QgsCoordinateTransform layerToMapTransform( layer->crs(), QgsProject::instance()->crs(), QgsProject::instance() );
     featurePools.insert( layer->id(), new QgsFeaturePool( layer, layerToMapUntis, layerToMapTransform, selectedOnly ) );
   }
 
-  QgsGeometryCheckerContext *context = new QgsGeometryCheckerContext( ui.spinBoxTolerance->value(), mIface->mapCanvas()->mapSettings().destinationCrs().authid(), featurePools );
+  QgsGeometryCheckerContext *context = new QgsGeometryCheckerContext( ui.spinBoxTolerance->value(), QgsProject::instance()->crs(), featurePools );
 
   QList<QgsGeometryCheck *> checks;
   for ( const QgsGeometryCheckFactory *factory : QgsGeometryCheckFactoryRegistry::getCheckFactories() )

tests/src/geometry_checker/testqgsgeometrychecks.cpp

@@ -39,6 +39,7 @@
 #include "qgsgeometryselfcontactcheck.h"
 #include "qgsgeometryselfintersectioncheck.h"
 #include "qgsgeometrysliverpolygoncheck.h"
+#include "qgsproject.h"
 
 #include "qgsgeometrytypecheck.h"
 
@@ -55,9 +56,9 @@ class TestQgsGeometryChecks: public QObject
       QgsGeometryCheck::ChangeType type;
       QgsVertexId vidx;
     };
-    double layerToMapUnits( const QgsMapLayer *layer, const QString &mapCrs ) const;
-    QgsFeaturePool *createFeaturePool( QgsVectorLayer *layer, const QString &mapCrs, bool selectedOnly = false ) const;
-    QgsGeometryCheckerContext *createTestContext( QTemporaryDir &tempDir, QMap<QString, QString> &layers, const QString &mapCrs = "EPSG:4326", double prec = 8 ) const;
+    double layerToMapUnits( const QgsMapLayer *layer, const QgsCoordinateReferenceSystem &mapCrs ) const;
+    QgsFeaturePool *createFeaturePool( QgsVectorLayer *layer, const QgsCoordinateReferenceSystem &mapCrs, bool selectedOnly = false ) const;
+    QgsGeometryCheckerContext *createTestContext( QTemporaryDir &tempDir, QMap<QString, QString> &layers, const QgsCoordinateReferenceSystem &mapCrs = QgsCoordinateReferenceSystem( "EPSG:4326" ), double prec = 8 ) const;
     void cleanupTestContext( QgsGeometryCheckerContext *ctx ) const;
     void listErrors( const QList<QgsGeometryCheckError *> &checkErrors, const QStringList &messages ) const;
     QList<QgsGeometryCheckError *> searchCheckErrors( const QList<QgsGeometryCheckError *> &checkErrors, const QString &layerId, const QgsFeatureId &featureId = -1, const QgsPointXY &pos = QgsPointXY(), const QgsVertexId &vid = QgsVertexId(), const QVariant &value = QVariant(), double tol = 1E-4 ) const;
@@ -958,9 +959,9 @@ void TestQgsGeometryChecks::testSliverPolygonCheck()
 
 ///////////////////////////////////////////////////////////////////////////////
 
-double TestQgsGeometryChecks::layerToMapUnits( const QgsMapLayer *layer, const QString &mapCrs ) const
+double TestQgsGeometryChecks::layerToMapUnits( const QgsMapLayer *layer, const QgsCoordinateReferenceSystem &mapCrs ) const
 {
-  QgsCoordinateTransform crst = QgsCoordinateTransformCache::instance()->transform( layer->crs().authid(), mapCrs );
+  QgsCoordinateTransform crst = QgsCoordinateTransform( layer->crs(), mapCrs, QgsProject::instance() );
   QgsRectangle extent = layer->extent();
   QgsPointXY l1( extent.xMinimum(), extent.yMinimum() );
   QgsPointXY l2( extent.xMaximum(), extent.yMaximum() );
@@ -971,14 +972,14 @@ double TestQgsGeometryChecks::layerToMapUnits( const QgsMapLayer *layer, const Q
   return distMapUnits / distLayerUnits;
 }
 
-QgsFeaturePool *TestQgsGeometryChecks::createFeaturePool( QgsVectorLayer *layer, const QString &mapCrs, bool selectedOnly ) const
+QgsFeaturePool *TestQgsGeometryChecks::createFeaturePool( QgsVectorLayer *layer, const QgsCoordinateReferenceSystem &mapCrs, bool selectedOnly ) const
 {
   double layerToMapUntis = layerToMapUnits( layer, mapCrs );
-  QgsCoordinateTransform layerToMapTransform = QgsCoordinateTransformCache::instance()->transform( layer->crs().authid(), mapCrs );
+  QgsCoordinateTransform layerToMapTransform = QgsCoordinateTransform( layer->crs(), mapCrs, QgsProject::instance() );
   return new QgsFeaturePool( layer, layerToMapUntis, layerToMapTransform, selectedOnly );
 }
 
-QgsGeometryCheckerContext *TestQgsGeometryChecks::createTestContext( QTemporaryDir &tempDir, QMap<QString, QString> &layers, const QString &mapCrs, double prec ) const
+QgsGeometryCheckerContext *TestQgsGeometryChecks::createTestContext( QTemporaryDir &tempDir, QMap<QString, QString> &layers, const QgsCoordinateReferenceSystem &mapCrs, double prec ) const
 {
   QDir testDataDir( QDir( TEST_DATA_DIR ).absoluteFilePath( "geometry_checker" ) );
   QDir tmpDir( tempDir.path() );