Merge branch 'stable-2.6'

[ganeti-local] / lib / runtime.py

diff --git a/lib/runtime.py b/lib/runtime.py
index 5180486..883b2e5 100644 (file)
--- a/lib/runtime.py
+++ b/lib/runtime.py
@@ -26,6 +26,7 @@
 import grp
 import pwd
 import threading
 import grp
 import pwd
 import threading

+import platform

 
 from ganeti import constants
 from ganeti import errors
 
 from ganeti import constants
 from ganeti import errors

@@ -35,6 +36,9 @@ from ganeti import utils
 _priv = None
 _priv_lock = threading.Lock()
 
 _priv = None
 _priv_lock = threading.Lock()
 

+#: Architecture information
+_arch = None
+

 
 def GetUid(user, _getpwnam):
   """Retrieve the uid from the database.
 
 def GetUid(user, _getpwnam):
   """Retrieve the uid from the database.

@@ -171,7 +175,7 @@ def GetEnts(resolver=GetentResolver):
   """Singleton wrapper around resolver instance.
 
   As this method is accessed by multiple threads at the same time
   """Singleton wrapper around resolver instance.
 
   As this method is accessed by multiple threads at the same time

-  we need to take thread-safty carefully
+  we need to take thread-safety carefully.

 
   """
   # We need to use the global keyword here
 
   """
   # We need to use the global keyword here

@@ -187,3 +191,35 @@ def GetEnts(resolver=GetentResolver):
       _priv_lock.release()
 
   return _priv
       _priv_lock.release()
 
   return _priv

+
+
+def InitArchInfo():
+  """Initialize architecture information.
+
+  We can assume this information never changes during the lifetime of a
+  process, therefore the information can easily be cached.
+
+  @note: This function uses C{platform.architecture} to retrieve the Python
+    binary architecture and does so by forking to run C{file} (see Python
+    documentation for more information). Therefore it must not be used in a
+    multi-threaded environment.
+
+  """
+  global _arch # pylint: disable=W0603
+
+  if _arch is not None:
+    raise errors.ProgrammerError("Architecture information can only be"
+                                 " initialized once")
+
+  _arch = (platform.architecture()[0], platform.machine())
+
+
+def GetArchInfo():
+  """Returns previsouly initialized architecture information.
+
+  """
+  if _arch is None:
+    raise errors.ProgrammerError("Architecture information hasn't been"
+                                 " initialized")
+
+  return _arch