MOBI Output: Do not keep all images in memory during the conversion. Fixes #810801 (Private bug)

src/calibre/ebooks/conversion/plumber.py

@@ -1055,6 +1055,7 @@ OptionRecommendation(name='sr3_replace',
         with self.output_plugin:
             self.output_plugin.convert(self.oeb, self.output, self.input_plugin,
                 self.opts, self.log)
+        self.oeb.clean_temp_files()
         self.ui_reporter(1.)
         run_plugins_on_postprocess(self.output, self.output_fmt)
 

src/calibre/ebooks/mobi/writer.py

@@ -1325,6 +1325,8 @@ class MobiWriter(object):
             except:
                 self._oeb.logger.warn('Bad image file %r' % item.href)
                 continue
+            finally:
+                item.unload_data_from_memory()
             self._records.append(data)
             if self._first_image_record is None:
                 self._first_image_record = len(self._records)-1

src/calibre/ebooks/oeb/base.py

@@ -1180,8 +1180,9 @@ class Manifest(object):
                 if memory is None:
                     from calibre.ptempfile import PersistentTemporaryFile
                     pt = PersistentTemporaryFile(suffix='_oeb_base_mem_unloader.img')
-                    pt.write(self._data)
-                    pt.close()
+                    with pt:
+                        pt.write(self._data)
+                    self.oeb._temp_files.append(pt.name)
                     def loader(*args):
                         with open(pt.name, 'rb') as f:
                             ans = f.read()
@@ -1196,8 +1197,6 @@ class Manifest(object):
                     self._loader = loader2
                 self._data = None
 
-
-
         def __str__(self):
             data = self.data
             if isinstance(data, etree._Element):
@@ -1913,6 +1912,14 @@ class OEBBook(object):
         self.toc = TOC()
         self.pages = PageList()
         self.auto_generated_toc = True
+        self._temp_files = []
+
+    def clean_temp_files(self):
+        for path in self._temp_files:
+            try:
+                os.remove(path)
+            except:
+                pass
 
     @classmethod
     def generate(cls, opts):