92ca64fa2a
- Added tests - Updated model field specification - Fixed issue of multiple event emission - Updated admin page - Added management command to manually generate course structures
88 lines
2.7 KiB
Python
88 lines
2.7 KiB
Python
"""Models for the util app. """
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import cStringIO
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import gzip
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import logging
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from django.db import models
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from django.db.models.signals import post_init
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from django.utils.text import compress_string
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from config_models.models import ConfigurationModel
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logger = logging.getLogger(__name__) # pylint: disable=invalid-name
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class RateLimitConfiguration(ConfigurationModel):
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"""Configuration flag to enable/disable rate limiting.
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Applies to Django Rest Framework views.
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This is useful for disabling rate limiting for performance tests.
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When enabled, it will disable rate limiting on any view decorated
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with the `can_disable_rate_limit` class decorator.
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"""
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pass
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def uncompress_string(s):
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"""
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Helper function to reverse CompressedTextField.get_prep_value.
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"""
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try:
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val = s.encode('utf').decode('base64')
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zbuf = cStringIO.StringIO(val)
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zfile = gzip.GzipFile(fileobj=zbuf)
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ret = zfile.read()
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zfile.close()
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except Exception as e:
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logger.error('String decompression failed. There may be corrupted data in the database: %s', e)
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ret = s
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return ret
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class CompressedTextField(models.TextField):
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"""transparently compress data before hitting the db and uncompress after fetching"""
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def get_prep_value(self, value):
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if value is not None:
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if isinstance(value, unicode):
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value = value.encode('utf8')
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value = compress_string(value)
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value = value.encode('base64').decode('utf8')
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return value
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def post_init(self, instance=None, **kwargs): # pylint: disable=unused-argument
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value = self._get_val_from_obj(instance)
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if value:
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setattr(instance, self.attname, value)
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def contribute_to_class(self, cls, name):
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super(CompressedTextField, self).contribute_to_class(cls, name)
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post_init.connect(self.post_init, sender=cls)
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def _get_val_from_obj(self, obj):
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if obj:
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value = uncompress_string(getattr(obj, self.attname))
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if value is not None:
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try:
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value = value.decode('utf8')
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except UnicodeDecodeError:
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pass
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return value
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else:
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return self.get_default()
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else:
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return self.get_default()
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def south_field_triple(self):
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"""Returns a suitable description of this field for South."""
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# We'll just introspect the _actual_ field.
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from south.modelsinspector import introspector
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field_class = "django.db.models.fields.TextField"
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args, kwargs = introspector(self)
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# That's our definition!
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return field_class, args, kwargs
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