add status message for output file writing/finishing

this can take significant amounts of time, too

ocitysmap/__init__.py

@@ -832,6 +832,7 @@ class OCitySMap:
         -------
         void
         """
+        tmp_output_filename = output_filename + ".tmp"
         config.output_format = output_format.upper()
         LOG.debug('Rendering to %s format...' % config.output_format)
         config.status_update(_("Rendering %s") % config.output_format)
@@ -872,15 +873,15 @@ class OCitySMap:
             surface = cairo.PDFSurface(None, w_px, h_px)
 
         elif output_format == 'svg':
-            surface = cairo.SVGSurface(output_filename,
+            surface = cairo.SVGSurface(tmp_output_filename,
                                        renderer.paper_width_pt, renderer.paper_height_pt)
             surface.restrict_to_version(cairo.SVGVersion.VERSION_1_2);
         elif output_format == 'svgz':
-            surface = cairo.SVGSurface(gzip.GzipFile(output_filename, 'wb'),
+            surface = cairo.SVGSurface(gzip.GzipFile(tmp_output_filename, 'wb'),
                                        renderer.paper_width_pt, renderer.paper_height_pt)
             surface.restrict_to_version(cairo.SVGVersion.VERSION_1_2);
         elif output_format == 'pdf':
-            surface = cairo.PDFSurface(output_filename,
+            surface = cairo.PDFSurface(tmp_output_filename,
                                        renderer.paper_width_pt, renderer.paper_height_pt)
             surface.restrict_to_version(cairo.PDFVersion.VERSION_1_5);
 
@@ -904,10 +905,10 @@ class OCitySMap:
               LOG.warning("Installed Cairo version does not support PDF annotations yet")
 
         elif output_format == 'ps':
-            surface = cairo.PSSurface(output_filename,
+            surface = cairo.PSSurface(tmp_output_filename,
                                       renderer.paper_width_pt, renderer.paper_height_pt)
         elif output_format == 'ps.gz':
-            surface = cairo.PSSurface(gzip.GzipFile(output_filename, 'wb'),
+            surface = cairo.PSSurface(gzip.GzipFile(tmp_output_filename, 'wb'),
                                       renderer.paper_width_pt, renderer.paper_height_pt)
         elif output_format == 'csv':
             # We don't render maps into CSV.
@@ -920,11 +921,15 @@ class OCitySMap:
 
         LOG.debug('Writing %s...' % output_filename)
 
+        config.status_update(_("%s: writing output file") % output_format.upper())
+
         if output_format == 'png':
-            surface.write_to_png(output_filename)
+            surface.write_to_png(tmp_output_filename)
 
         surface.finish()
 
+        os.rename(tmp_output_filename, output_filename)
+
 if __name__ == '__main__':
     logging.basicConfig(level=logging.DEBUG)
 

ocitysmap/layoutlib/multi_page_renderer.py

@@ -362,8 +362,6 @@ class MultiPageRenderer(Renderer):
         self.overview_overlay_effects  = {}
 
         for overlay in self._overlays:
-            self.rc.status_update(_("Preparing overview page: %s") % overlay.name)
-
             path = overlay.path.strip()
             if path.startswith('internal:'):
                 plugin_name = path.lstrip('internal:')
@@ -375,6 +373,7 @@ class MultiPageRenderer(Renderer):
                 else:
                     self.overview_overlay_effects[plugin_name] = self.get_plugin(plugin_name)
             else:
+                self.rc.status_update(_("Preparing overview page: %s") % overlay.name)
                 ov_canvas = MapCanvas(overlay,
                                       overview_bb,
                                       self._usable_area_width_pt,
@@ -1129,7 +1128,7 @@ class MultiPageRenderer(Renderer):
         self._render_overview_page(ctx, cairo_surface, dpi)
 
         for map_number, (canvas, grid, overlay_canvases, overlay_effects) in enumerate(self.pages):
-            self.rc.status_update(_("Rendering map page %(page)d of %(total)d: base map")
+            self.rc.status_update(_("Rendering map page %(page)d of %(total)d")
                                   % { 'page':  map_number + 1,
                                       'total': len(self.pages),
                                      })
@@ -1147,6 +1146,11 @@ class MultiPageRenderer(Renderer):
             dest_tag = "mypage%d" % (map_number + self._first_map_page_number)
             draw_utils.anchor(ctx, dest_tag)
 
+            self.rc.status_update(_("Rendering map page %(page)d of %(total)d: base map")
+                                  % { 'page':  map_number + 1,
+                                      'total': len(self.pages),
+                                     })
+
             mapnik.render(rendered_map, ctx)
 
             for overlay_canvas in overlay_canvases: