def shorten_url(self, original_url):
"""
:raises: ImproperlyConfigured, django.core.exceptions.ValidationError
:raises: brevisurl.backends.local.TokensExhaustedError
"""
if self.kwargs.get('domain') is not None:
# Domain is present in keyword arguments supplied by constructor.
domain = self.kwargs.get('domain')
elif brevisurl.settings.LOCAL_BACKEND_DOMAIN is not None:
# Domain is defined in settings.
domain = brevisurl.settings.LOCAL_BACKEND_DOMAIN
else:
# Domain is taken from django site framework.
domain = Site.objects.get_current().domain
try:
shortened_url = self.__generate_shortened_url(domain)
try:
short_url, created = ShortUrl.objects.get_or_create(
backend=self.class_path,
original_url=original_url,
original_url_hash=ShortUrl.url_hash(original_url),
defaults={'shortened_url': shortened_url})
if created:
log.info('Url "%s" shortened to "%s"', original_url,
shortened_url)
else:
log.info('Url "%s" already shortened to "%s"',
original_url, short_url.shortened_url)
return short_url
except (IntegrityError, ValidationError) as e:
# Check if the error is an URL validation error.
if isinstance(e, ValidationError) and e.message_dict.has_key(
'original_url'):
raise
# Generate another token.
self.__check_tokens_exhausted()
while True:
shortened_url = self.__generate_shortened_url(domain)
sid = transaction.savepoint()
try:
short_url = ShortUrl.objects.create(
backend=self.class_path,
original_url=original_url,
shortened_url=shortened_url)
log.info('Url "%s" shortened to "%s"', original_url,
shortened_url)
transaction.savepoint_commit(sid)
return short_url
except (IntegrityError, ValidationError) as e:
transaction.savepoint_rollback(sid)
self.__check_tokens_exhausted()
except Exception:
if self.fail_silently:
return None
else:
log.exception(
'Unknown exception raised while shortening url "%s"',
original_url)
raise
