Update lock managet app

Add keyword arguments. Sort imports. Move settings and test
literals to their own module.

Signed-off-by: Roberto Rosario <Roberto.Rosario@mayan-edms.com>

mayan/apps/lock_manager/backends/file_lock.py

@@ -1,8 +1,8 @@
 from __future__ import unicode_literals
 
 import hashlib
-import logging
 import json
+import logging
 import os
 import threading
 import time
@@ -23,7 +23,9 @@ lock = threading.Lock()
 logger = logging.getLogger(__name__)
 
 lock_file = os.path.join(
-    setting_temporary_directory.value, hashlib.sha256(force_bytes(settings.SECRET_KEY)).hexdigest()
+    setting_temporary_directory.value, hashlib.sha256(
+        force_bytes(settings.SECRET_KEY)
+    ).hexdigest()
 )
 open(lock_file, 'a').close()
 logger.debug('lock_file: %s', lock_file)
@@ -76,7 +78,7 @@ class FileLock(LockingBackend):
             data = file_object.read()
 
             if data:
-                file_locks = json.loads(data)
+                file_locks = json.loads(s=data)
             else:
                 file_locks = {}
 
@@ -103,7 +105,7 @@ class FileLock(LockingBackend):
         with open(self.__class__.lock_file, 'r+') as file_object:
             locks.lock(f=file_object, flags=locks.LOCK_EX)
             try:
-                file_locks = json.loads(file_object.read())
+                file_locks = json.loads(s=file_object.read())
             except EOFError:
                 file_locks = {}
 

mayan/apps/lock_manager/decorators.py

@@ -1,7 +1,7 @@
 from __future__ import absolute_import, unicode_literals
 
-import time
 import random
+import time
 
 from .exceptions import LockError
 

mayan/apps/lock_manager/exceptions.py

@@ -1,2 +1,5 @@
+from __future__ import unicode_literals
+
+
 class LockError(Exception):
-    pass
+    """Raised when trying to acquire an existing lock"""

mayan/apps/lock_manager/literals.py

@@ -0,0 +1,4 @@
+from __future__ import unicode_literals
+
+DEFAULT_BACKEND = 'mayan.apps.lock_manager.backends.file_lock.FileLock'
+DEFAULT_LOCK_TIMEOUT_VALUE = 30

mayan/apps/lock_manager/migrations/0001_initial.py

@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):

mayan/apps/lock_manager/migrations/0002_auto_20150604_2219.py

@@ -1,6 +1,6 @@
 from __future__ import unicode_literals
 
-from django.db import models, migrations
+from django.db import migrations, models
 
 
 class Migration(migrations.Migration):

mayan/apps/lock_manager/models.py

@@ -38,7 +38,7 @@ class Lock(models.Model):
         """
         try:
             lock = Lock.objects.get(
-                name=self.name, creation_datetime=self.creation_datetime
+                creation_datetime=self.creation_datetime, name=self.name
             )
         except Lock.DoesNotExist:
             # Our lock has expired and was reassigned

mayan/apps/lock_manager/runtime.py

@@ -2,4 +2,4 @@ from django.utils.module_loading import import_string
 
 from .settings import setting_backend
 
-locking_backend = import_string(setting_backend.value)
+locking_backend = import_string(dotted_path=setting_backend.value)

mayan/apps/lock_manager/settings.py

@@ -4,10 +4,9 @@ from django.utils.translation import ugettext_lazy as _
 
 from mayan.apps.smart_settings import Namespace
 
-DEFAULT_BACKEND = 'mayan.apps.lock_manager.backends.file_lock.FileLock'
-DEFAULT_LOCK_TIMEOUT_VALUE = 30
+from .literals import DEFAULT_BACKEND, DEFAULT_LOCK_TIMEOUT_VALUE
 
-namespace = Namespace(name='lock_manager', label=_('Lock manager'))
+namespace = Namespace(label=_('Lock manager'), name='lock_manager')
 
 setting_backend = namespace.add_setting(
     default=DEFAULT_BACKEND,

mayan/apps/lock_manager/tests/literals.py

@@ -0,0 +1,3 @@
+from __future__ import unicode_literals
+
+TEST_LOCK_NAME = 'test lock name'

mayan/apps/lock_manager/tests/test_backends.py

@@ -7,51 +7,53 @@ from django.utils.module_loading import import_string
 
 from ..exceptions import LockError
 
-TEST_LOCK_1 = 'test lock 1'
+from .literals import TEST_LOCK_NAME
 
 
 class FileLockTestCase(TestCase):
     backend_string = 'mayan.apps.lock_manager.backends.file_lock.FileLock'
 
     def setUp(self):
-        self.locking_backend = import_string(self.backend_string)
+        self.locking_backend = import_string(dotted_path=self.backend_string)
 
     def test_exclusive(self):
-        lock_1 = self.locking_backend.acquire_lock(name=TEST_LOCK_1)
+        lock_1 = self.locking_backend.acquire_lock(name=TEST_LOCK_NAME)
         with self.assertRaises(LockError):
-            self.locking_backend.acquire_lock(name=TEST_LOCK_1)
+            self.locking_backend.acquire_lock(name=TEST_LOCK_NAME)
 
         # Cleanup
         lock_1.release()
 
     def test_release(self):
-        lock_1 = self.locking_backend.acquire_lock(name=TEST_LOCK_1)
+        lock_1 = self.locking_backend.acquire_lock(name=TEST_LOCK_NAME)
         lock_1.release()
-        lock_2 = self.locking_backend.acquire_lock(name=TEST_LOCK_1)
+        lock_2 = self.locking_backend.acquire_lock(name=TEST_LOCK_NAME)
 
         # Cleanup
         lock_2.release()
 
     def test_timeout_expired(self):
-        self.locking_backend.acquire_lock(name=TEST_LOCK_1, timeout=1)
+        self.locking_backend.acquire_lock(name=TEST_LOCK_NAME, timeout=1)
 
         # lock_1 not release and not expired, should raise LockError
         with self.assertRaises(LockError):
-            self.locking_backend.acquire_lock(name=TEST_LOCK_1)
+            self.locking_backend.acquire_lock(name=TEST_LOCK_NAME)
 
         time.sleep(1.01)
         # lock_1 not release but has expired, should not raise LockError
-        lock_2 = self.locking_backend.acquire_lock(name=TEST_LOCK_1)
+        lock_2 = self.locking_backend.acquire_lock(name=TEST_LOCK_NAME)
 
         # Cleanup
         lock_2.release()
 
     def test_double_release(self):
-        lock_1 = self.locking_backend.acquire_lock(name=TEST_LOCK_1)
+        lock_1 = self.locking_backend.acquire_lock(name=TEST_LOCK_NAME)
         lock_1.release()
 
     def test_release_expired(self):
-        lock_1 = self.locking_backend.acquire_lock(name=TEST_LOCK_1, timeout=1)
+        lock_1 = self.locking_backend.acquire_lock(
+            name=TEST_LOCK_NAME, timeout=1
+        )
         time.sleep(1.01)
         lock_1.release()
         # No exception is raised even though the lock has expired.
@@ -60,11 +62,13 @@ class FileLockTestCase(TestCase):
         # would be successfull, even after an extended lapse of time
 
     def test_release_expired_reaquired(self):
-        self.locking_backend.acquire_lock(name=TEST_LOCK_1, timeout=1)
+        self.locking_backend.acquire_lock(name=TEST_LOCK_NAME, timeout=1)
         time.sleep(1.01)
-        # TEST_LOCK_1 is expired so trying to acquire it should not return an
-        # error.
-        lock_2 = self.locking_backend.acquire_lock(name=TEST_LOCK_1, timeout=1)
+        # TEST_LOCK_NAME is expired so trying to acquire it should not return
+        # an error.
+        lock_2 = self.locking_backend.acquire_lock(
+            name=TEST_LOCK_NAME, timeout=1
+        )
 
         # Cleanup
         lock_2.release()