def test_png(self):
self.assertEqual(get_format("path/img.png"), 'PNG')
class LazyThumbRenderer(View):
"""
Perform requested image render operations and handle fs logic and caching
of 404s. Maps a requested action (currently 'thumbnail' and 'resize' are
supported) to a matching method named after the action prefixed with
'action_'. Once the argument signatures are relaxed one can implement new
image transformations simply by subclassing this view and adding "action_"
methods that return raw image data as a string.
"""
def __init__(self):
self.fs = FileSystemStorage()
self._allowed_actions = [
a.__name__ for a in (getattr(self, a, None) for a in dir(self))
if type(a) == types.MethodType and getattr(a, 'is_action', False)
]
def get(self, request, action, geometry, source_path):
"""
Perform action routing and handle sanitizing url input. Handles caching the path to a rendered image to
django.cache and saves the new image on the filesystem. 404s are cached to
save time the next time the missing image is requested.
:param request: HttpRequest
:param action: some action, eg thumbnail or resize
:param geometry: a string of either '\dx\d' or just '\d'
:param source_path: the fs path to the image to be manipulated
:returns: an HttpResponse with an image/{format} content_type
"""
# reject naughty paths and actions
if source_path.startswith('/'):
logger.info("%s: blocked bad path" % source_path)
return self.four_oh_four()
if re.match('\.\./', source_path):
logger.info("%s: blocked bad path" % source_path)
return self.four_oh_four()
if action not in self._allowed_actions:
logger.info("%s: bad action requested: %s" % (source_path, action))
return self.four_oh_four()
try:
width, height = geometry_parse(action, geometry, ValueError)
except ValueError, e:
logger.info('corrupted geometry "%s" for action "%s"' %
(geometry, action))
return self.four_oh_four()
width = int(width) if width is not None else None
height = int(height) if height is not None else None
rendered_path = request.path[1:]
cache_key = self.cache_key(source_path, action, width, height)
was_404 = cache.get(cache_key)
if was_404 == 1:
return self.four_oh_four()
img_format = get_format(rendered_path)
# TODO this tangled mess of try/except is hideous... but such is
# filesystem io? No it can be cleaned up by splitting it out
try:
# does rendered file already exist?
raw_data = self.fs.open(rendered_path).read()
except IOError:
if was_404 == 0:
# then it *was* here last time. if was_404 had been None then
# it makes sense for rendered image to not exist yet: we
# probably haven't seen it, or it dropped out of cache.
logger.info(
'rendered image previously on fs missing. regenerating')
try:
pil_img = getattr(self, action)(width=width,
height=height,
img_path=source_path)
# this code from sorl-thumbnail
buf = StringIO()
# TODO we need a better way of choosing options based on size and format
params = {
'format': get_format(rendered_path),
'quality': 80,
}
if params['format'] == "JPEG" and pil_img.mode == 'P':
# Cannot save mode 'P' image as JPEG without converting first
# (This can happen if we have a GIF file without an extension and don't scale it)
pil_img = pil_img.convert()
try:
pil_img.save(buf, **params)
except IOError:
logger.exception("pil_img.save(%r)" % params)
# TODO reevaluate this except when we make options smarter
logger.info(
"Failed to create new image %s . Trying without options"
% rendered_path)
pil_img.save(buf, format=img_format)
raw_data = buf.getvalue()
buf.close()
try:
self.fs.save(rendered_path, ContentFile(raw_data))
except OSError, e:
if e.errno == errno.EEXIST:
pass # race condition, another WSGI worker wrote file or directory first
else:
logger.exception("saving converted image")
raise
except (IOError, SuspiciousOperation, ValueError), e:
# we've now failed to find a rendered path as well as the
# original source path. this is a 404.
logger.info('404: %s' % e)
cache.set(cache_key, 1, settings.LAZYTHUMBS_404_CACHE_TIMEOUT)
return self.four_oh_four()
def test_jpeg(self):
self.assertEqual(get_format("path/img.jpeg"), 'JPEG')
self.assertEqual(get_format("path/img.jpg"), 'JPEG')
def test_gif(self):
self.assertEqual(get_format("path/img.gif"), 'GIF')
def test_notaformat(self):
""" get_format will assume JPEG for unknown formats """
self.assertEqual(get_format("path/img"), 'JPEG')
def test_png(self):
self.assertEqual(get_format("path/img.png"), "PNG")
def test_gif(self):
self.assertEqual(get_format("path/img.gif"), "GIF")
def test_jpeg(self):
self.assertEqual(get_format("path/img.jpeg"), "JPEG")
self.assertEqual(get_format("path/img.jpg"), "JPEG")
def test_notaformat(self):
""" get_format will assume JPEG for unknown formats """
self.assertEqual(get_format("path/img"), "JPEG")
