Do N SVG->PNG conversions with inkscape before shutting down the inkscape server and starting a new one to prevent memory leaks in Inkscape from becoming problematic.

mdboom · mdboom · commit 9086ef1a1c86 · 2011-04-27T15:41:03.000-04:00
diff --git a/lib/matplotlib/testing/compare.py b/lib/matplotlib/testing/compare.py
@@ -112,8 +112,34 @@ def convert(*args):
    converter['eps'] = make_external_conversion_command(cmd)
 
 if matplotlib.checkdep_inkscape() is not None:
-   def make_svg_converter():
-      def read_to_end(buf):
+   class SVGConverter:
+      def __init__(self):
+         self._count = 0
+         self._process = None
+
+      def get_process(self):
+         # Since Inkscape can leak a little memory, we run X
+         # conversions and then shut it down and start up a new
+         # Inkscape.
+         if self._count == 0:
+            if self._process is not None:
+               self._process.communicate('quit\n')
+            self._process = subprocess.Popen(['inkscape', '-z', '--shell'],
+                                             stdin=subprocess.PIPE,
+                                             stdout=subprocess.PIPE,
+                                             stderr=subprocess.STDOUT)
+            self.read_to_end(self._process.stdout)
+            self._count = 10
+         self._count -= 1
+         return self._process
+
+      def __call__(self, old, new):
+         process = self.get_process()
+         process.stdin.write('%s --export-png=%s\n' % (old, new))
+         process.stdin.flush()
+         self.read_to_end(process.stdout)
+
+      def read_to_end(self, buf):
          ret = ''
          lastchar = ''
          while True:
@@ -124,20 +150,7 @@ def read_to_end(buf):
             lastchar = char
          return ret
 
-      p = subprocess.Popen(['inkscape', '--shell'],
-                           stdin=subprocess.PIPE,
-                           stdout=subprocess.PIPE,
-                           stderr=subprocess.STDOUT)
-      read_to_end(p.stdout)
-
-      def convert_svg(old, new):
-         p.stdin.write('%s --export-png=%s\n' % (old, new))
-         p.stdin.flush()
-         read_to_end(p.stdout)
-
-      return convert_svg
-
-   converter['svg'] = make_svg_converter()
+   converter['svg'] = SVGConverter()
 
 def comparable_formats():
    '''Returns the list of file formats that compare_images can compare
