Convert/package faster!

libqfieldsync/offline_converter.py

@@ -26,6 +26,7 @@
 from typing import Dict, List, Optional, Union
 
 from qgis.core import (
+    Qgis,
     QgsApplication,
     QgsBilinearRasterResampler,
     QgsCoordinateReferenceSystem,
@@ -125,7 +126,7 @@ def __init__(
         self.project_configuration = ProjectConfiguration(project)
 
     # flake8: noqa: max-complexity: 33
-    def convert(self) -> None:
+    def convert(self, reload_original_project: bool = True) -> None:
         """
         Convert the project to a portable project.
         """
@@ -136,34 +137,50 @@ def convert(self) -> None:
         try:
             self._convert(project)
         finally:
-            QCoreApplication.processEvents()
-            QgsProject.instance().clear()
-            QCoreApplication.processEvents()
+            if reload_original_project:
+                QCoreApplication.processEvents()
+                QgsProject.instance().clear()
+                QCoreApplication.processEvents()
 
-            open_project(str(self.original_filename), self.backup_filename)
+                open_project(str(self.original_filename), self.backup_filename)
 
             self.total_progress_updated.emit(100, 100, self.tr("Finished"))
 
     def _convert(self, project: QgsProject) -> None:
         xml_elements_to_preserve = {}
-        on_original_project_read = self._on_original_project_read_wrapper(
-            xml_elements_to_preserve
-        )
-        project.readProject.connect(on_original_project_read)
+        tmp_project_filename = ""
 
         if self.export_type == ExportType.Cable:
             # the `backup_filename` is copied right after packaging is requested. It has all the unsaved
             # project settings, which means they will be available in the packaged project too.
-            project.read(self.backup_filename)
+            tmp_project_filename = self.backup_filename
         elif self.export_type == ExportType.Cloud:
             # if you save the project without QGIS GUI, the project no longer has `theMapCanvas` canvas
             # so we should use the original project file that already has `theMapCanvas`. There is no
             # gain using the `backup_filename`, since there is no user to modify the project.
-            project.read(project.fileName())
+            tmp_project_filename = project.fileName()
         else:
             raise NotImplementedError(f"Unknown package type: {self.export_type}")
 
-        project.readProject.disconnect(on_original_project_read)
+        # Set flags that usually significantly speed-up project file read
+        read_flags = QgsProject.ReadFlags()
+        read_flags |= QgsProject.FlagDontResolveLayers
+        read_flags |= QgsProject.FlagDontLoadLayouts
+        if Qgis.versionInt() >= 32600:
+            read_flags |= QgsProject.FlagDontLoad3DViews
+
+        # Make a new function object that we can connect and disconnect easily
+        on_original_project_read = self._on_original_project_read_wrapper(
+            xml_elements_to_preserve
+        )
+
+        # Create a new temporary `QgsProject` instance just to make sure that `theMapCanvas`
+        # XML object is properly set within the XML document. Using a new `QgsProject`
+        # instead of the singleton `QgsProject.instance()` allows using the read flags.
+        tmp_project = QgsProject()
+        tmp_project.readProject.connect(on_original_project_read)
+        tmp_project.read(tmp_project_filename, read_flags)
+        tmp_project.readProject.disconnect(on_original_project_read)
 
         self.export_folder.mkdir(parents=True, exist_ok=True)
         self.total_progress_updated.emit(0, 100, self.trUtf8("Converting project…"))