[pal] Cache geos area and length calculation results

src/core/pal/feature.cpp

@@ -167,25 +167,20 @@ std::size_t FeaturePart::maximumLineCandidates() const
   if ( mCachedMaxLineCandidates > 0 )
     return mCachedMaxLineCandidates;
 
-  GEOSContextHandle_t geosctxt = QgsGeos::getGEOSHandler();
-  try
+  const double l = length();
+  if ( l > 0 )
   {
-    double length = 0;
-    if ( GEOSLength_r( geosctxt, geos(), &length ) == 1 )
-    {
-      const std::size_t candidatesForLineLength = static_cast< std::size_t >( std::ceil( mLF->layer()->mPal->maximumLineCandidatesPerMapUnit() * length ) );
-      const std::size_t maxForLayer = mLF->layer()->maximumLineLabelCandidates();
-      if ( maxForLayer == 0 )
-        mCachedMaxLineCandidates = candidatesForLineLength;
-      else
-        mCachedMaxLineCandidates = std::min( candidatesForLineLength, maxForLayer );
-      return mCachedMaxLineCandidates;
-    }
+    const std::size_t candidatesForLineLength = static_cast< std::size_t >( std::ceil( mLF->layer()->mPal->maximumLineCandidatesPerMapUnit() * l ) );
+    const std::size_t maxForLayer = mLF->layer()->maximumLineLabelCandidates();
+    if ( maxForLayer == 0 )
+      mCachedMaxLineCandidates = candidatesForLineLength;
+    else
+      mCachedMaxLineCandidates = std::min( candidatesForLineLength, maxForLayer );
   }
-  catch ( GEOSException & )
+  else
   {
+    mCachedMaxLineCandidates = 1;
   }
-  mCachedMaxLineCandidates = 1;
   return mCachedMaxLineCandidates;
 }
 
@@ -194,25 +189,20 @@ std::size_t FeaturePart::maximumPolygonCandidates() const
   if ( mCachedMaxPolygonCandidates > 0 )
     return mCachedMaxPolygonCandidates;
 
-  GEOSContextHandle_t geosctxt = QgsGeos::getGEOSHandler();
-  try
+  const double a = area();
+  if ( a > 0 )
   {
-    double area = 0;
-    if ( GEOSArea_r( geosctxt, geos(), &area ) == 1 )
-    {
-      const std::size_t candidatesForArea = static_cast< std::size_t >( std::ceil( mLF->layer()->mPal->maximumPolygonCandidatesPerMapUnitSquared() * area ) );
-      const std::size_t maxForLayer = mLF->layer()->maximumPolygonLabelCandidates();
-      if ( maxForLayer == 0 )
-        mCachedMaxPolygonCandidates = candidatesForArea;
-      else
-        mCachedMaxPolygonCandidates = std::min( candidatesForArea, maxForLayer );
-      return mCachedMaxPolygonCandidates;
-    }
+    const std::size_t candidatesForArea = static_cast< std::size_t >( std::ceil( mLF->layer()->mPal->maximumPolygonCandidatesPerMapUnitSquared() * a ) );
+    const std::size_t maxForLayer = mLF->layer()->maximumPolygonLabelCandidates();
+    if ( maxForLayer == 0 )
+      mCachedMaxPolygonCandidates = candidatesForArea;
+    else
+      mCachedMaxPolygonCandidates = std::min( candidatesForArea, maxForLayer );
   }
-  catch ( GEOSException & )
+  else
   {
+    mCachedMaxPolygonCandidates = 1;
   }
-  mCachedMaxPolygonCandidates = 1;
   return mCachedMaxPolygonCandidates;
 }
 
@@ -1778,46 +1768,30 @@ void FeaturePart::addSizePenalty( std::vector< std::unique_ptr< LabelPosition >
   double sizeCost = 0;
   if ( geomType == GEOS_LINESTRING )
   {
-    double length;
-    try
-    {
-      if ( GEOSLength_r( ctxt, mGeos, &length ) != 1 )
-        return; // failed to calculate length
-    }
-    catch ( GEOSException &e )
-    {
-      QgsMessageLog::logMessage( QObject::tr( "Exception: %1" ).arg( e.what() ), QObject::tr( "GEOS" ) );
-      return;
-    }
+    const double l = length();
+    if ( l <= 0 )
+      return; // failed to calculate length
     double bbox_length = std::max( bbx[2] - bbx[0], bby[2] - bby[0] );
-    if ( length >= bbox_length / 4 )
+    if ( l >= bbox_length / 4 )
       return; // the line is longer than quarter of height or width - don't penalize it
 
-    sizeCost = 1 - ( length / ( bbox_length / 4 ) ); // < 0,1 >
+    sizeCost = 1 - ( l / ( bbox_length / 4 ) ); // < 0,1 >
   }
   else if ( geomType == GEOS_POLYGON )
   {
-    double area;
-    try
-    {
-      if ( GEOSArea_r( ctxt, mGeos, &area ) != 1 )
-        return;
-    }
-    catch ( GEOSException &e )
-    {
-      QgsMessageLog::logMessage( QObject::tr( "Exception: %1" ).arg( e.what() ), QObject::tr( "GEOS" ) );
+    const double a = area();
+    if ( a <= 0 )
       return;
-    }
     double bbox_area = ( bbx[2] - bbx[0] ) * ( bby[2] - bby[0] );
-    if ( area >= bbox_area / 16 )
+    if ( a >= bbox_area / 16 )
       return; // covers more than 1/16 of our view - don't penalize it
 
-    sizeCost = 1 - ( area / ( bbox_area / 16 ) ); // < 0, 1 >
+    sizeCost = 1 - ( a / ( bbox_area / 16 ) ); // < 0, 1 >
   }
   else
     return; // no size penalty for points
 
-  // apply the penalty
+// apply the penalty
   for ( std::unique_ptr< LabelPosition > &pos : lPos )
   {
     pos->setCost( pos->cost() + sizeCost / 100 );

src/core/pal/layer.cpp

@@ -175,21 +175,23 @@ bool Layer::registerFeature( QgsLabelFeature *lf )
     if ( !lf->labelAllParts() && ( type == GEOS_POLYGON || type == GEOS_LINESTRING ) )
     {
       if ( type == GEOS_LINESTRING )
-        GEOSLength_r( geosctxt, geom, &geom_size );
+        geom_size = fpart->length();
       else if ( type == GEOS_POLYGON )
-        GEOSArea_r( geosctxt, geom, &geom_size );
+        geom_size = fpart->area();
 
       if ( geom_size > biggest_size )
       {
         biggest_size = geom_size;
         biggest_part.reset( fpart.release() );
       }
-      continue; // don't add the feature part now, do it later
+      // don't add the feature part now, do it later
+    }
+    else
+    {
+      // feature part is ready!
+      addFeaturePart( fpart.release(), lf->labelText() );
+      addedFeature = true;
     }
-
-    // feature part is ready!
-    addFeaturePart( fpart.release(), lf->labelText() );
-    addedFeature = true;
   }
 
   if ( lf->obstacleSettings().isObstacle() && !featureGeomIsObstacleGeom )
@@ -349,7 +351,7 @@ void Layer::chopFeaturesAtRepeatDistance()
     double featureLen = 0;
     if ( chopInterval != 0. && GEOSGeomTypeId_r( geosctxt, geom ) == GEOS_LINESTRING )
     {
-      ( void )GEOSLength_r( geosctxt, geom, &featureLen );
+      featureLen = fpart->length();
       if ( featureLen > chopInterval )
         canChop = true;
     }

src/core/pal/pointset.cpp

@@ -185,6 +185,8 @@ void PointSet::invalidateGeos()
   mOwnsGeom = false;
   mGeos = nullptr;
   mPreparedGeom = nullptr;
+  mLength = -1;
+  mArea = -1;
 }
 
 PointSet::~PointSet()
@@ -944,6 +946,9 @@ const GEOSGeometry *PointSet::geos() const
 
 double PointSet::length() const
 {
+  if ( mLength >= 0 )
+    return mLength;
+
   if ( !mGeos )
     createGeosGeom();
 
@@ -954,9 +959,8 @@ double PointSet::length() const
 
   try
   {
-    double len = 0;
-    ( void )GEOSLength_r( geosctxt, mGeos, &len );
-    return len;
+    ( void )GEOSLength_r( geosctxt, mGeos, &mLength );
+    return mLength;
   }
   catch ( GEOSException &e )
   {
@@ -967,6 +971,9 @@ double PointSet::length() const
 
 double PointSet::area() const
 {
+  if ( mArea >= 0 )
+    return mArea;
+
   if ( !mGeos )
     createGeosGeom();
 
@@ -977,9 +984,9 @@ double PointSet::area() const
 
   try
   {
-    double area = 0;
-    ( void )GEOSArea_r( geosctxt, mGeos, &area );
-    return area;
+    ( void )GEOSArea_r( geosctxt, mGeos, &mArea );
+    mArea = std::fabs( mArea );
+    return mArea;
   }
   catch ( GEOSException &e )
   {

src/core/pal/pointset.h

@@ -213,6 +213,10 @@ namespace pal
       PointSet *holeOf = nullptr;
       PointSet *parent = nullptr;
 
+      mutable double mArea = -1;
+      mutable double mLength = -1;
+
+
       PointSet( double x, double y );
 
       PointSet( const PointSet &ps );