def mediacache_redirect(request, blob_urn, mime_type, additional_args, resource):
"""Redirect to a mediacache resource
This will issue a redirect to the mediacache url that serves this resource,
given by DUCTUS_MEDIACACHE_URL. If DUCTUS_MEDIACACHE_URL is not defined,
it will be assumed to be '/mediacache'.
"""
# as an additional layer of protection, make sure each mediacache module
# view doesn't allow the insertion of rogue characters into additional_args
if additional_args:
if not _legal_additional_args_re.match(additional_args):
raise Exception("illegal characters given in additional_args!")
hash_type, digest = split_urn(blob_urn)
pathname = "%s/%s%s.%s" % (hash_type, digest,
_dotstr(additional_args),
mime_to_ext[mime_type])
if request.is_secure() and getattr(settings, "DUCTUS_MEDIACACHE_URL_SECURE", None):
mediacache_url = settings.DUCTUS_MEDIACACHE_URL_SECURE
elif settings.DUCTUS_MEDIACACHE_URL:
mediacache_url = settings.DUCTUS_MEDIACACHE_URL
else:
mediacache_url = '/mediacache'
url = "%s/%s?%s" % (mediacache_url, pathname, resource.urn)
return HttpResponseRedirect(url)
def __to_filename(urn, mime_type, additional_args):
hash_type, digest = split_urn(urn)
extension = mime_to_ext[mime_type]
basename = "%s%s.%s" % (digest, _dotstr(additional_args), extension)
# fixme: assert that there are no illegal characters in filename
filename = os.path.join(settings.DUCTUS_MEDIACACHE_DIR, hash_type,
digest[0:2], (digest[2:4] or digest[0:2]), basename)
return filename
def resolve_relative_mediacache_url(resource, mime_type=None, additional_args=None, blob_urn=None):
hash_type, digest = split_urn(blob_urn or resource.blob.href)
ext = mime_to_ext[mime_type or resource.blob.mime_type]
return "%s/%s%s.%s?%s" % (hash_type, digest, _dotstr(additional_args),
ext, resource.urn)
def __storage_location(self, urn):
hash_type, digest = split_urn(urn)
return os.path.join(self.__storage_directory, hash_type,
digest[0:2], (digest[2:4] or digest[0:2]), digest)
