# 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 mediagoblin import globals as mg_globals
+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 = 200, 200
+THUMB_SIZE = 180, 180
+MEDIUM_SIZE = 640, 640
-@task
-def process_media_initial(media_id):
- workbench = mg_globals.workbench_manager.create_workbench()
- entry = mg_globals.database.MediaEntry.one(
- {'_id': ObjectId(media_id)})
+def create_pub_filepath(entry, filename):
+ return mgg.public_store.get_unique_filepath(
+ ['media_entries',
+ unicode(entry['_id']),
+ filename])
+
+
+@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.
+
+ 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 = mg_globals.workbench_manager.localized_file(
- workbench, mg_globals.queue_store, queued_filepath,
+ queued_filename = workbench.localized_file(
+ mgg.queue_store, queued_filepath,
'source')
- queued_file = file(queued_filename, 'r')
+ try:
+ thumb = Image.open(queued_filename)
+ except IOError:
+ raise BadMediaFail()
- with queued_file:
- thumb = Image.open(queued_file)
- thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
+ thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
+ # ensure color mode is compatible with jpg
+ if thumb.mode != "RGB":
+ thumb = thumb.convert("RGB")
- thumb_filepath = mg_globals.public_store.get_unique_filepath(
- ['media_entries',
- unicode(entry['_id']),
- 'thumbnail.jpg'])
+ thumb_filepath = create_pub_filepath(entry, 'thumbnail.jpg')
- thumb_file = mg_globals.public_store.get_file(thumb_filepath, 'w')
- with thumb_file:
- thumb.save(thumb_file, "JPEG")
+ thumb_file = mgg.public_store.get_file(thumb_filepath, 'w')
+ 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.
+ medium = Image.open(queued_filename)
+ medium_processed = False
+
+ if medium.size[0] > MEDIUM_SIZE[0] or medium.size[1] > MEDIUM_SIZE[1]:
+ medium.thumbnail(MEDIUM_SIZE, Image.ANTIALIAS)
+
+ if medium.mode != "RGB":
+ medium = medium.convert("RGB")
+
+ medium_filepath = create_pub_filepath(entry, 'medium.jpg')
+
+ medium_file = mgg.public_store.get_file(medium_filepath, 'w')
+ with closing(medium_file):
+ medium.save(medium_file, "JPEG", quality=90)
+ medium_processed = True
# we have to re-read because unlike PIL, not everything reads
# things in string representation :)
queued_file = file(queued_filename, 'rb')
with queued_file:
- main_filepath = mg_globals.public_store.get_unique_filepath(
- ['media_entries',
- unicode(entry['_id']),
- queued_filepath[-1]])
+ original_filepath = create_pub_filepath(entry, queued_filepath[-1])
- with mg_globals.public_store.get_file(main_filepath, 'wb') as main_file:
- main_file.write(queued_file.read())
+ with closing(mgg.public_store.get_file(original_filepath, 'wb')) as original_file:
+ original_file.write(queued_file.read())
- mg_globals.queue_store.delete_file(queued_filepath)
+ mgg.queue_store.delete_file(queued_filepath)
+ entry['queued_media_file'] = []
media_files_dict = entry.setdefault('media_files', {})
media_files_dict['thumb'] = thumb_filepath
- media_files_dict['main'] = main_filepath
- entry['state'] = u'processed'
- entry.save()
+ media_files_dict['original'] = original_filepath
+ if medium_processed:
+ media_files_dict['medium'] = medium_filepath
# clean up workbench
- mg_globals.workbench_manager.destroy_workbench(workbench)
+ workbench.destroy_self()