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19773e0d70
git-svn-id: http://code.djangoproject.com/svn/django/branches/boulder-oracle-sprint@4066 bcc190cf-cafb-0310-a4f2-bffc1f526a37
58 lines
2.4 KiB
Python
58 lines
2.4 KiB
Python
from django.conf import settings
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from django.core import signals
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from django.dispatch import dispatcher
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__all__ = ('backend', 'connection', 'DatabaseError')
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if not settings.DATABASE_ENGINE:
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settings.DATABASE_ENGINE = 'dummy'
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try:
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backend = __import__('django.db.backends.%s.base' % settings.DATABASE_ENGINE, {}, {}, [''])
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except ImportError, e:
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# The database backend wasn't found. Display a helpful error message
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# listing all possible database backends.
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from django.core.exceptions import ImproperlyConfigured
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import os
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backend_dir = os.path.join(__path__[0], 'backends')
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available_backends = [f for f in os.listdir(backend_dir) if not f.startswith('_') and not f.startswith('.') and not f.endswith('.py') and not f.endswith('.pyc')]
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available_backends.sort()
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if settings.DATABASE_ENGINE not in available_backends:
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raise ImproperlyConfigured, "%r isn't an available database backend. vailable options are: %s" % \
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(settings.DATABASE_ENGINE, ", ".join(map(repr, available_backends)))
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else:
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raise # If there's some other error, this must be an error in Django itself.
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def backend_module_accessor(module_name):
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def accessor():
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full_name = 'django.db.backends.%s.%s' % (settings.DATABASE_ENGINE, module_name)
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return __import__(full_name, {}, {}, [''])
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return accessor
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get_introspection_module = backend_module_accessor("introspection")
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get_creation_module = backend_module_accessor("creation")
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get_query_module = backend_module_accessor("query")
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get_client_module = backend_module_accessor("client")
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runshell = lambda: get_client_module().runshell()
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connection = backend.DatabaseWrapper(**settings.DATABASE_OPTIONS)
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DatabaseError = backend.DatabaseError
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# Register an event that closes the database connection
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# when a Django request is finished.
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dispatcher.connect(connection.close, signal=signals.request_finished)
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# Register an event that resets connection.queries
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# when a Django request is started.
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def reset_queries():
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connection.queries = []
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dispatcher.connect(reset_queries, signal=signals.request_started)
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# Register an event that rolls back the connection
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# when a Django request has an exception.
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def _rollback_on_exception():
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from django.db import transaction
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transaction.rollback_unless_managed()
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dispatcher.connect(_rollback_on_exception, signal=signals.got_request_exception)
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