QGIS_PROVIDER_FILE: provider regexp pattern environment variable

blazek · blazek · commit 3b00dc12583e · 2015-05-16T12:56:51.000+02:00
diff --git a/src/core/qgsproviderregistry.cpp b/src/core/qgsproviderregistry.cpp
@@ -94,11 +94,28 @@ QgsProviderRegistry::QgsProviderRegistry( QString pluginPath )
     return;
   }
 
+  // provider file regex pattern, only files matching the pattern are loaded if the variable is defined
+  QString filePattern = getenv( "QGIS_PROVIDER_FILE" );
+  QRegExp fileRegexp;
+  if ( !filePattern.isEmpty() )
+  {
+    fileRegexp.setPattern( filePattern );
+  }
+
   QListIterator<QFileInfo> it( mLibraryDirectory.entryInfoList() );
   while ( it.hasNext() )
   {
     QFileInfo fi( it.next() );
 
+    if ( !fileRegexp.isEmpty() )
+    {
+      if ( fileRegexp.indexIn( fi.fileName() ) == -1 )
+      {
+        QgsDebugMsg( "provider " + fi.fileName() + " skipped because doesn't match pattern " + filePattern );
+        continue;
+      }
+    }
+
     QLibrary myLib( fi.filePath() );
     if ( !myLib.load() )
     {
diff --git a/src/core/qgsproviderregistry.h b/src/core/qgsproviderregistry.h
@@ -36,6 +36,11 @@ class QgsCoordinateReferenceSystem;
   * A registry / canonical manager of data providers.
 
   This is a Singleton class that manages data provider access.
+
+  Loaded providers may be restricted using QGIS_PROVIDER_FILE environment variable.
+  QGIS_PROVIDER_FILE is regexp pattern applied to provider file name (not provider key).
+  For example, if the variable is set to gdal|ogr|postgres it will load only providers gdal,
+  ogr and postgres.
 */
 class CORE_EXPORT QgsProviderRegistry
 {
