Disable VSI cache before GDALGetOverviewCount, workaround for GDAL ti…

…cket 5170, hopefully fixes #8356
qgis · Aug 18, 2013 · 6a1a4be · 6a1a4be
1 parent 2a29483
commit 6a1a4be
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Showing 3 changed files with 27 additions and 1 deletion.
diff --git a/src/providers/gdal/qgsgdalprovider.cpp b/src/providers/gdal/qgsgdalprovider.cpp
@@ -2353,7 +2353,7 @@ void QgsGdalProvider::initBaseDataset()
   }
 
   // check if this file has pyramids
-  mHasPyramids = GDALGetOverviewCount( myGDALBand ) > 0;
+  mHasPyramids = gdalGetOverviewCount( myGDALBand ) > 0;
 
   // Get the layer's projection info and set up the
   // QgsCoordinateTransform for this layer

diff --git a/src/providers/gdal/qgsgdalproviderbase.cpp b/src/providers/gdal/qgsgdalproviderbase.cpp
@@ -283,13 +283,15 @@ GDALDatasetH QgsGdalProviderBase::gdalOpen( const char *pszFilename, GDALAccess
 #if GDAL_VERSION_MAJOR == 1 && ( (GDAL_VERSION_MINOR == 9 && GDAL_VERSION_REV <= 2) || (GDAL_VERSION_MINOR == 10 && GDAL_VERSION_REV <= 0) )
   char* pszOldVal = CPLStrdup( CPLGetConfigOption( "VSI_CACHE", "FALSE" ) );
   CPLSetThreadLocalConfigOption( "VSI_CACHE", "FALSE" );
+  QgsDebugMsg( "Disabled VSI_CACHE" );
 #endif
 
   GDALDatasetH hDS = GDALOpen( pszFilename, eAccess );
 
 #if GDAL_VERSION_MAJOR == 1 && ( (GDAL_VERSION_MINOR == 9 && GDAL_VERSION_REV <= 2) || (GDAL_VERSION_MINOR == 10 && GDAL_VERSION_REV <= 0) )
   CPLSetThreadLocalConfigOption( "VSI_CACHE", pszOldVal );
   CPLFree( pszOldVal );
+  QgsDebugMsg( "Reset VSI_CACHE" );
 #endif
 
   return hDS;
@@ -301,14 +303,36 @@ CPLErr QgsGdalProviderBase::gdalRasterIO( GDALRasterBandH hBand, GDALRWFlag eRWF
 #if GDAL_VERSION_MAJOR == 1 && ( (GDAL_VERSION_MINOR == 9 && GDAL_VERSION_REV <= 2) || (GDAL_VERSION_MINOR == 10 && GDAL_VERSION_REV <= 0) )
   char* pszOldVal = CPLStrdup( CPLGetConfigOption( "VSI_CACHE", "FALSE" ) );
   CPLSetThreadLocalConfigOption( "VSI_CACHE", "FALSE" );
+  QgsDebugMsg( "Disabled VSI_CACHE" );
 #endif
 
   CPLErr err = GDALRasterIO( hBand, eRWFlag, nXOff, nYOff, nXSize, nYSize, pData, nBufXSize, nBufYSize, eBufType, nPixelSpace, nLineSpace );
 
 #if GDAL_VERSION_MAJOR == 1 && ( (GDAL_VERSION_MINOR == 9 && GDAL_VERSION_REV <= 2) || (GDAL_VERSION_MINOR == 10 && GDAL_VERSION_REV <= 0) )
   CPLSetThreadLocalConfigOption( "VSI_CACHE", pszOldVal );
   CPLFree( pszOldVal );
+  QgsDebugMsg( "Reset VSI_CACHE" );
 #endif
 
   return err;
 }
+
+int QgsGdalProviderBase::gdalGetOverviewCount( GDALRasterBandH hBand )
+{
+  // See http://hub.qgis.org/issues/8356 and http://trac.osgeo.org/gdal/ticket/5170
+#if GDAL_VERSION_MAJOR == 1 && ( (GDAL_VERSION_MINOR == 9 && GDAL_VERSION_REV <= 2) || (GDAL_VERSION_MINOR == 10 && GDAL_VERSION_REV <= 0) )
+  char* pszOldVal = CPLStrdup( CPLGetConfigOption( "VSI_CACHE", "FALSE" ) );
+  CPLSetThreadLocalConfigOption( "VSI_CACHE", "FALSE" );
+  QgsDebugMsg( "Disabled VSI_CACHE" );
+#endif
+
+  int count = GDALGetOverviewCount( hBand );
+
+#if GDAL_VERSION_MAJOR == 1 && ( (GDAL_VERSION_MINOR == 9 && GDAL_VERSION_REV <= 2) || (GDAL_VERSION_MINOR == 10 && GDAL_VERSION_REV <= 0) )
+  CPLSetThreadLocalConfigOption( "VSI_CACHE", pszOldVal );
+  CPLFree( pszOldVal );
+  QgsDebugMsg( "Reset VSI_CACHE" );
+#endif
+
+  return count;
+}
diff --git a/src/providers/gdal/qgsgdalproviderbase.h b/src/providers/gdal/qgsgdalproviderbase.h
@@ -53,6 +53,8 @@ class QgsGdalProviderBase
     /** Wrapper function for GDALRasterIO to get around possible bugs in GDAL */
     static CPLErr gdalRasterIO( GDALRasterBandH hBand, GDALRWFlag eRWFlag, int nXOff, int nYOff, int nXSize, int nYSize, void * pData, int nBufXSize, int nBufYSize, GDALDataType eBufType, int nPixelSpace, int nLineSpace );
 
+    /** Wrapper function for GDALRasterIO to get around possible bugs in GDAL */
+    static int gdalGetOverviewCount( GDALRasterBandH hBand );
   protected:
 
     QGis::DataType dataTypeFromGdal( int theGdalDataType ) const;