[Kimchi-devel] [kimchi-devel][PATCH 3/5] Add utils to support file lock

From: Royce Lv <lvroyce(a)linux.vnet.ibm.com&gt; Wrap posix file lock with contextlib so that file sections can be protected by lock. Signed-off-by: Royce Lv <lvroyce(a)linux.vnet.ibm.com&gt; --- src/kimchi/model/utils.py | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/src/kimchi/model/utils.py b/src/kimchi/model/utils.py index 9896289..1188b19 100644 --- a/src/kimchi/model/utils.py +++ b/src/kimchi/model/utils.py @@ -18,8 +18,10 @@ # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA import libvirt +import posixfile import socket import urlparse +from contextlib import contextmanager from lxml import etree, objectify from lxml.builder import E, ElementMaker @@ -161,3 +163,17 @@ def get_metadata_node(dom, tag, metadata_support, mode="current"): if node is not None: return etree.tostring(node) return "" + + +@contextmanager +def flock(fp, pos, len): + fp.lock('w|', len, pos) + yield + fp.lock('u', len, pos) + + +@contextmanager +def f_open(path, mod): + file = posixfile.open(path, mod) + yield file + file.close() -- 1.9.3