Merge branch 'master' into jwandborg-f482_media_attachments

Conflicts:
	mediagoblin/config_spec.ini
	mediagoblin/edit/forms.py
	mediagoblin/edit/views.py
	mediagoblin/submit/views.py
	mediagoblin/templates/mediagoblin/user_pages/media.html

1 files changed, 105 insertions, 18 deletions

diff --git a/mediagoblin/process_media/__init__.py b/mediagoblin/process_media/__init__.py
index 125b24e0..e1289a4c 100644
--- a/mediagoblin/process_media/__init__.py
+++ b/mediagoblin/process_media/__init__.py
@@ -15,10 +15,14 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import Image
-from mediagoblin.db.util import ObjectId
-from celery.task import task
 
+from contextlib import contextmanager
+from celery.task import Task
+from celery import registry
+
+from mediagoblin.db.util import ObjectId
 from mediagoblin import mg_globals as mgg
+from mediagoblin.process_media.errors import BaseProcessingFail, BadMediaFail
 
 
 THUMB_SIZE = 180, 180
@@ -32,19 +36,106 @@ def create_pub_filepath(entry, filename):
              filename])
 
 
-@task
-def process_media_initial(media_id):
-    workbench = mgg.workbench_manager.create_workbench()
+@contextmanager
+def closing(callback):
+    try:
+        yield callback
+    finally:
+        pass
+
+
+################################
+# Media processing initial steps
+################################
+
+class ProcessMedia(Task):
+    """
+    Pass this entry off for processing.
+    """
+    def run(self, media_id):
+        """
+        Pass the media entry off to the appropriate processing function
+        (for now just process_image...)
+        """
+        entry = mgg.database.MediaEntry.one(
+            {'_id': ObjectId(media_id)})
+
+        # Try to process, and handle expected errors.
+        try:
+            process_image(entry)
+        except BaseProcessingFail, exc:
+            mark_entry_failed(entry[u'_id'], exc)
+            return
+            
+        entry['state'] = u'processed'
+        entry.save()
+
+    def on_failure(self, exc, task_id, args, kwargs, einfo):
+        """
+        If the processing failed we should mark that in the database.
+
+        Assuming that the exception raised is a subclass of BaseProcessingFail,
+        we can use that to get more information about the failure and store that
+        for conveying information to users about the failure, etc.
+        """
+        entry_id = args[0]
+        mark_entry_failed(entry_id, exc)
+
+
+process_media = registry.tasks[ProcessMedia.name]
+
+
+def mark_entry_failed(entry_id, exc):
+    """
+    Mark a media entry as having failed in its conversion.
 
-    entry = mgg.database.MediaEntry.one(
-        {'_id': ObjectId(media_id)})
+    Uses the exception that was raised to mark more information.  If the
+    exception is a derivative of BaseProcessingFail then we can store extra
+    information that can be useful for users telling them why their media failed
+    to process.
+
+    Args:
+     - entry_id: The id of the media entry
+
+    """
+    # Was this a BaseProcessingFail?  In other words, was this a
+    # type of error that we know how to handle?
+    if isinstance(exc, BaseProcessingFail):
+        # Looks like yes, so record information about that failure and any
+        # metadata the user might have supplied.
+        mgg.database['media_entries'].update(
+            {'_id': entry_id},
+            {'$set': {u'state': u'failed',
+                      u'fail_error': exc.exception_path,
+                      u'fail_metadata': exc.metadata}})
+    else:
+        # Looks like no, so just mark it as failed and don't record a
+        # failure_error (we'll assume it wasn't handled) and don't record
+        # metadata (in fact overwrite it if somehow it had previous info
+        # here)
+        mgg.database['media_entries'].update(
+            {'_id': entry_id},
+            {'$set': {u'state': u'failed',
+                      u'fail_error': None,
+                      u'fail_metadata': {}}})
+
+
+def process_image(entry):
+    """
+    Code to process an image
+    """
+    workbench = mgg.workbench_manager.create_workbench()
 
     queued_filepath = entry['queued_media_file']
     queued_filename = workbench.localized_file(
         mgg.queue_store, queued_filepath,
         'source')
 
-    thumb = Image.open(queued_filename)
+    try:
+        thumb = Image.open(queued_filename)
+    except IOError:
+        raise BadMediaFail()
+
     thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
     # ensure color mode is compatible with jpg
     if thumb.mode != "RGB":
@@ -53,14 +144,12 @@ def process_media_initial(media_id):
     thumb_filepath = create_pub_filepath(entry, 'thumbnail.jpg')
 
     thumb_file = mgg.public_store.get_file(thumb_filepath, 'w')
-    with thumb_file:
+    with closing(thumb_file):
         thumb.save(thumb_file, "JPEG", quality=90)
 
-    """
-    If the size of the original file exceeds the specified size of a `medium`
-    file, a `medium.jpg` files is created and later associated with the media
-    entry.
-    """
+    # If the size of the original file exceeds the specified size of a `medium`
+    # file, a `medium.jpg` files is created and later associated with the media
+    # entry.
     medium = Image.open(queued_filename)
     medium_processed = False
 
@@ -73,7 +162,7 @@ def process_media_initial(media_id):
         medium_filepath = create_pub_filepath(entry, 'medium.jpg')
 
         medium_file = mgg.public_store.get_file(medium_filepath, 'w')
-        with medium_file:
+        with closing(medium_file):
             medium.save(medium_file, "JPEG", quality=90)
             medium_processed = True
 
@@ -84,7 +173,7 @@ def process_media_initial(media_id):
     with queued_file:
         original_filepath = create_pub_filepath(entry, queued_filepath[-1])
         
-        with mgg.public_store.get_file(original_filepath, 'wb') as original_file:
+        with closing(mgg.public_store.get_file(original_filepath, 'wb')) as original_file:
             original_file.write(queued_file.read())
 
     mgg.queue_store.delete_file(queued_filepath)
@@ -94,8 +183,6 @@ def process_media_initial(media_id):
     media_files_dict['original'] = original_filepath
     if medium_processed:
         media_files_dict['medium'] = medium_filepath
-    entry['state'] = u'processed'
-    entry.save()
 
     # clean up workbench
     workbench.destroy_self()