Merge lp:~soren/surveilr/driver-infrastructure into lp:surveilr

[Soren Hansen]

Add basic driver management infrastructure.

=== added file 'surveilr/drivers.py'
--- surveilr/drivers.py	1970-01-01 00:00:00 +0000
+++ surveilr/drivers.py	2011-11-22 09:03:23 +0000
@@ -0,0 +1,58 @@
+"""
+    Surveilr - Log aggregation, analysis and visualisation
+
+    Copyright (C) 2011  Linux2Go
+
+    This program is free software: you can redistribute it and/or
+    modify it under the terms of the GNU Affero General Public License
+    as published by the Free Software Foundation, either version 3 of
+    the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public
+    License along with this program.  If not, see
+    <http://www.gnu.org/licenses/>.
+
+    Driver infrastructure
+"""
+
+from surveilr import exceptions
+
+registry = {}
+
+
+def register_driver(driver_type, name, driver):
+    if driver_type not in registry:
+        registry[driver_type] = {}
+
+    if name in registry[driver_type]:
+        raise exceptions.DuplicateDriverError()
+
+    registry[driver_type][name] = driver
+
+
+def unregister_driver(driver_type, name):
+    if driver_type not in registry:
+        raise exceptions.UnknownDriverTypeError()
+
+    if name not in registry[driver_type]:
+        raise exceptions.UnknownDriverError()
+
+    del registry[driver_type][name]
+
+    if not registry[driver_type]:
+        del registry[driver_type]
+
+
+def get_driver(driver_type, name):
+    if driver_type not in registry:
+        raise exceptions.UnknownDriverTypeError()
+
+    if name not in registry[driver_type]:
+        raise exceptions.UnknownDriverError()
+
+    return registry[driver_type][name]

=== added file 'surveilr/exceptions.py'
--- surveilr/exceptions.py	1970-01-01 00:00:00 +0000
+++ surveilr/exceptions.py	2011-11-22 09:03:23 +0000
@@ -0,0 +1,33 @@
+"""
+    Surveilr - Log aggregation, analysis and visualisation
+
+    Copyright (C) 2011  Linux2Go
+
+    This program is free software: you can redistribute it and/or
+    modify it under the terms of the GNU Affero General Public License
+    as published by the Free Software Foundation, either version 3 of
+    the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public
+    License along with this program.  If not, see
+    <http://www.gnu.org/licenses/>.
+
+    Exception classes
+"""
+
+
+class DuplicateDriverError(Exception):
+    pass
+
+
+class UnknownDriverTypeError(Exception):
+    pass
+
+
+class UnknownDriverError(Exception):
+    pass

=== added file 'surveilr/tests/__init__.py'
--- surveilr/tests/__init__.py	1970-01-01 00:00:00 +0000
+++ surveilr/tests/__init__.py	2011-11-22 09:03:23 +0000
@@ -0,0 +1,19 @@
+"""
+    Surveilr - Log aggregation, analysis and visualisation
+
+    Copyright (C) 2011  Linux2Go
+
+    This program is free software: you can redistribute it and/or
+    modify it under the terms of the GNU Affero General Public License
+    as published by the Free Software Foundation, either version 3 of
+    the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public
+    License along with this program.  If not, see
+    <http://www.gnu.org/licenses/>.
+"""

=== added file 'surveilr/tests/test_drivers.py'
--- surveilr/tests/test_drivers.py	1970-01-01 00:00:00 +0000
+++ surveilr/tests/test_drivers.py	2011-11-22 09:03:23 +0000
@@ -0,0 +1,92 @@
+"""
+    Surveilr - Log aggregation, analysis and visualisation
+
+    Copyright (C) 2011  Linux2Go
+
+    This program is free software: you can redistribute it and/or
+    modify it under the terms of the GNU Affero General Public License
+    as published by the Free Software Foundation, either version 3 of
+    the License, or (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Affero General Public License for more details.
+
+    You should have received a copy of the GNU Affero General Public
+    License along with this program.  If not, see
+    <http://www.gnu.org/licenses/>.
+
+    Tests for driver infrastructure
+"""
+
+import unittest
+
+from surveilr import drivers
+from surveilr import exceptions
+
+
+class DriversTests(unittest.TestCase):
+    def register_empty_driver(self, driver_type, driver_name,
+                              add_cleanup=True):
+        class SomeDriver(object):
+            pass
+
+        driver = SomeDriver()
+        drivers.register_driver(driver_type, driver_name, driver)
+        if add_cleanup:
+            self.addCleanup(drivers.unregister_driver,
+                            driver_type, driver_name)
+        return driver
+
+    def test_register_retrieve_driver(self):
+        """Register driver and retrieve it again"""
+        driver = self.register_empty_driver('some_type', 'some_name')
+        self.assertTrue(drivers.get_driver('some_type', 'some_name') is driver)
+
+    def test_register_duplicate_driver(self):
+        """Registering duplicate driver fails"""
+        self.register_empty_driver('some_type', 'some_name')
+        self.assertRaises(exceptions.DuplicateDriverError,
+                          self.register_empty_driver,
+                          'some_type',
+                          'some_name')
+
+    def test_get_invalid_driver_type(self):
+        """Retrieve driver of unknown type fails"""
+        self.assertRaises(exceptions.UnknownDriverTypeError,
+                          drivers.get_driver,
+                          'unknown_type',
+                          'some_name')
+
+    def test_get_invalid_driver(self):
+        """Retrieve unknown driver of known type fails"""
+        self.register_empty_driver('some_type', 'some_name')
+        self.assertRaises(exceptions.UnknownDriverError,
+                          drivers.get_driver,
+                          'some_type',
+                          'unknown_name')
+
+    def test_unregister_unknown_driver_type(self):
+        """Unregister driver of unknown type fails"""
+        self.assertRaises(exceptions.UnknownDriverTypeError,
+                          drivers.unregister_driver,
+                          'unknown_type',
+                          'some_name')
+
+    def test_unregister_unknown_driver(self):
+        """Unregister unknown driver of known type fails"""
+        self.register_empty_driver('some_type', 'some_name')
+        self.assertRaises(exceptions.UnknownDriverError,
+                          drivers.unregister_driver,
+                          'some_type',
+                          'unknown_name')
+
+    def test_unregister_then_retrieve(self):
+        """When last driver of a type is removed, so it the type"""
+        self.register_empty_driver('some_type', 'some_name', add_cleanup=False)
+        drivers.unregister_driver('some_type', 'some_name')
+        self.assertRaises(exceptions.UnknownDriverTypeError,
+                          drivers.unregister_driver,
+                          'some_type',
+                          'some_name')