Files
edx-platform/common/djangoapps/util/models.py
Usman Khalid 6cb62f2697 Rebase upgrade Django to v1.8.5
Please note that this is a squshed commit and the work of:
Symbolist, macdiesel, nedbat, doctoryes, muzaffaryousaf and muhammad-ammar
2015-11-10 15:00:19 -05:00

65 lines
1.9 KiB
Python

"""Models for the util app. """
import cStringIO
import gzip
import logging
from django.db import models
from django.utils.text import compress_string
from config_models.models import ConfigurationModel
logger = logging.getLogger(__name__) # pylint: disable=invalid-name
class RateLimitConfiguration(ConfigurationModel):
"""Configuration flag to enable/disable rate limiting.
Applies to Django Rest Framework views.
This is useful for disabling rate limiting for performance tests.
When enabled, it will disable rate limiting on any view decorated
with the `can_disable_rate_limit` class decorator.
"""
class Meta(ConfigurationModel.Meta):
app_label = "util"
def decompress_string(value):
"""
Helper function to reverse CompressedTextField.get_prep_value.
"""
try:
val = value.encode('utf').decode('base64')
zbuf = cStringIO.StringIO(val)
zfile = gzip.GzipFile(fileobj=zbuf)
ret = zfile.read()
zfile.close()
except Exception as e:
logger.error('String decompression failed. There may be corrupted data in the database: %s', e)
ret = value
return ret
class CompressedTextField(models.TextField):
""" TextField that transparently compresses data when saving to the database, and decompresses the data
when retrieving it from the database. """
__metaclass__ = models.SubfieldBase
def get_prep_value(self, value):
""" Compress the text data. """
if value is not None:
if isinstance(value, unicode):
value = value.encode('utf8')
value = compress_string(value)
value = value.encode('base64').decode('utf8')
return value
def to_python(self, value):
""" Decompresses the value from the database. """
if isinstance(value, unicode):
value = decompress_string(value)
return value