Switch over media processor to use the get_workbench decorator (#565)

This makes workbench getting more convenient by eliminating some
boilerplate and more robust by cleaning the workbench up even if processing
ends with an Exception.

Finally, this fixes the bugs in the ascii and video backends to never call
workbench.destroy, so those workbenches were never cleaned up.

Signed-off-by: Sebastian Spaeth <Sebastian@SSpaeth.de>

5 files changed, 37 insertions, 29 deletions

diff --git a/mediagoblin/media_types/ascii/processing.py b/mediagoblin/media_types/ascii/processing.py
index 04d1166c..254717eb 100644
--- a/mediagoblin/media_types/ascii/processing.py
+++ b/mediagoblin/media_types/ascii/processing.py
@@ -19,6 +19,7 @@ import Image
 import logging
 
 from mediagoblin import mg_globals as mgg
+from mediagoblin.decorators import get_workbench
 from mediagoblin.processing import create_pub_filepath
 from mediagoblin.media_types.ascii import asciitoimage
 
@@ -38,12 +39,14 @@ def sniff_handler(media_file, **kw):
     return False
 
 
-def process_ascii(entry):
-    '''
-    Code to process a txt file
-    '''
+@get_workbench
+def process_ascii(entry, workbench=None):
+    """Code to process a txt file. Will be run by celery.
+
+    A Workbench() represents a local tempory dir. It is automatically
+    cleaned up when this function exits. 
+    """
     ascii_config = mgg.global_config['media_type:mediagoblin.media_types.ascii']
-    workbench = mgg.workbench_manager.create_workbench()
     # Conversions subdirectory to avoid collisions
     conversions_subdir = os.path.join(
         workbench.dir, 'conversions')
diff --git a/mediagoblin/media_types/audio/processing.py b/mediagoblin/media_types/audio/processing.py
index c4ccad49..e12cefe6 100644
--- a/mediagoblin/media_types/audio/processing.py
+++ b/mediagoblin/media_types/audio/processing.py
@@ -19,6 +19,7 @@ from tempfile import NamedTemporaryFile
 import os
 
 from mediagoblin import mg_globals as mgg
+from mediagoblin.decorators import get_workbench
 from mediagoblin.processing import (create_pub_filepath, BadMediaFail,
     FilenameBuilder, ProgressCallback)
 
@@ -42,10 +43,14 @@ def sniff_handler(media_file, **kw):
     return False
 
 
-def process_audio(entry):
-    audio_config = mgg.global_config['media_type:mediagoblin.media_types.audio']
+@get_workbench
+def process_audio(entry, workbench=None):
+    """Code to process uploaded audio. Will be run by celery.
 
-    workbench = mgg.workbench_manager.create_workbench()
+    A Workbench() represents a local tempory dir. It is automatically
+    cleaned up when this function exits.
+    """
+    audio_config = mgg.global_config['media_type:mediagoblin.media_types.audio']
 
     queued_filepath = entry.queued_media_file
     queued_filename = workbench.localized_file(
@@ -143,6 +148,3 @@ def process_audio(entry):
         entry.media_files['thumb'] = ['fake', 'thumb', 'path.jpg']
 
     mgg.queue_store.delete_file(queued_filepath)
-
-    # clean up workbench
-    workbench.destroy_self()
diff --git a/mediagoblin/media_types/image/processing.py b/mediagoblin/media_types/image/processing.py
index bf464069..e6a34ca0 100644
--- a/mediagoblin/media_types/image/processing.py
+++ b/mediagoblin/media_types/image/processing.py
@@ -19,6 +19,7 @@ import os
 import logging
 
 from mediagoblin import mg_globals as mgg
+from mediagoblin.decorators import get_workbench
 from mediagoblin.processing import BadMediaFail, \
     create_pub_filepath, FilenameBuilder
 from mediagoblin.tools.exif import exif_fix_image_orientation, \
@@ -76,11 +77,13 @@ def sniff_handler(media_file, **kw):
     return False
 
 
-def process_image(entry):
-    """
-    Code to process an image
+@get_workbench
+def process_image(entry, workbench=None):
+    """Code to process an image. Will be run by celery.
+
+    A Workbench() represents a local tempory dir. It is automatically
+    cleaned up when this function exits.
     """
-    workbench = mgg.workbench_manager.create_workbench()
     # Conversions subdirectory to avoid collisions
     conversions_subdir = os.path.join(
         workbench.dir, 'conversions')
@@ -147,8 +150,6 @@ def process_image(entry):
             gps_data['gps_' + key] = gps_data.pop(key)
         entry.media_data_init(**gps_data)
 
-    # clean up workbench
-    workbench.destroy_self()
 
 if __name__ == '__main__':
     import sys
diff --git a/mediagoblin/media_types/stl/processing.py b/mediagoblin/media_types/stl/processing.py
index cd949e2a..3089f295 100644
--- a/mediagoblin/media_types/stl/processing.py
+++ b/mediagoblin/media_types/stl/processing.py
@@ -21,6 +21,7 @@ import subprocess
 import pkg_resources
 
 from mediagoblin import mg_globals as mgg
+from mediagoblin.decorators import get_workbench
 from mediagoblin.processing import create_pub_filepath, \
     FilenameBuilder
 
@@ -75,11 +76,13 @@ def blender_render(config):
         env=env)
 
 
-def process_stl(entry):
-    """
-    Code to process an stl or obj model.
+@get_workbench
+def process_stl(entry, workbench=None):
+    """Code to process an stl or obj model. Will be run by celery.
+
+    A Workbench() represents a local tempory dir. It is automatically
+    cleaned up when this function exits.
     """
-    workbench = mgg.workbench_manager.create_workbench()
     queued_filepath = entry.queued_media_file
     queued_filename = workbench.localized_file(
         mgg.queue_store, queued_filepath, 'source')
@@ -164,7 +167,7 @@ def process_stl(entry):
     # Remove queued media file from storage and database
     mgg.queue_store.delete_file(queued_filepath)
     entry.queued_media_file = []
-        
+
     # Insert media file information into database
     media_files_dict = entry.setdefault('media_files', {})
     media_files_dict[u'original'] = model_filepath
@@ -185,6 +188,3 @@ def process_stl(entry):
         "file_type" : ext,
         }
     entry.media_data_init(**dimensions)
-
-    # clean up workbench
-    workbench.destroy_self()
diff --git a/mediagoblin/media_types/video/processing.py b/mediagoblin/media_types/video/processing.py
index 703c4681..22c4355d 100644
--- a/mediagoblin/media_types/video/processing.py
+++ b/mediagoblin/media_types/video/processing.py
@@ -18,6 +18,7 @@ from tempfile import NamedTemporaryFile
 import logging
 
 from mediagoblin import mg_globals as mgg
+from mediagoblin.decorators import get_workbench
 from mediagoblin.processing import \
     create_pub_filepath, FilenameBuilder, BaseProcessingFail, ProgressCallback
 from mediagoblin.tools.translate import lazy_pass_to_ugettext as _
@@ -51,16 +52,17 @@ def sniff_handler(media_file, **kw):
 
     return False
 
-
-def process_video(entry):
+@get_workbench
+def process_video(entry, workbench=None):
     """
     Process a video entry, transcode the queued media files (originals) and
     create a thumbnail for the entry.
+
+    A Workbench() represents a local tempory dir. It is automatically
+    cleaned up when this function exits.
     """
     video_config = mgg.global_config['media_type:mediagoblin.media_types.video']
 
-    workbench = mgg.workbench_manager.create_workbench()
-
     queued_filepath = entry.queued_media_file
     queued_filename = workbench.localized_file(
         mgg.queue_store, queued_filepath,