Merge "Add lock_with_prefix convenience utility"

2 files changed, 32 insertions, 0 deletions

diff --git a/oslo_concurrency/lockutils.py b/oslo_concurrency/lockutils.py
index 7169ee4..ba0d0a5 100644
--- a/oslo_concurrency/lockutils.py
+++ b/oslo_concurrency/lockutils.py
@@ -281,6 +281,29 @@ def lock(name, lock_file_prefix=None, external=False, lock_path=None,
                 LOG.debug('Releasing lock "%(lock)s"', {'lock': name})
 
 
+def lock_with_prefix(lock_file_prefix):
+    """Partial object generator for the lock context manager.
+
+    Redefine lock in each project like so::
+
+        (in nova/utils.py)
+        from oslo_concurrency import lockutils
+
+        lock = lockutils.lock_with_prefix('nova-')
+
+
+        (in nova/foo.py)
+        from nova import utils
+
+        with utils.lock('mylock'):
+           ...
+
+    The lock_file_prefix argument is used to provide lock files on disk with a
+    meaningful prefix.
+    """
+    return functools.partial(lock, lock_file_prefix=lock_file_prefix)
+
+
 def synchronized(name, lock_file_prefix=None, external=False, lock_path=None,
                  semaphores=None, delay=0.01, fair=False):
     """Synchronization decorator.
diff --git a/oslo_concurrency/tests/unit/test_lockutils.py b/oslo_concurrency/tests/unit/test_lockutils.py
index b124963..fee32bb 100644
--- a/oslo_concurrency/tests/unit/test_lockutils.py
+++ b/oslo_concurrency/tests/unit/test_lockutils.py
@@ -227,6 +227,15 @@ class LockTestCase(test_base.BaseTestCase):
 
         self._do_test_lock_externally()
 
+    def test_lock_with_prefix(self):
+        # TODO(efried): Embetter this test
+        self.config(lock_path=tempfile.mkdtemp(), group='oslo_concurrency')
+        foo = lockutils.lock_with_prefix('mypfix-')
+
+        with foo('mylock', external=True):
+            # We can't check much
+            pass
+
     def test_synchronized_with_prefix(self):
         lock_name = 'mylock'
         lock_pfix = 'mypfix-'