# HG changeset patch
# User cl349@xxxxxxxxxxxxxxxxxxxx
# Node ID 47dca2f335de3493e9bcef04459a7d37ccc5ebf0
# Parent 4856f000d35d6be0bfb6f5c822e91e9ef7fc885e
Add simple transactional read/write python xenstore interface.
Signed-off-by: Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>
diff -r 4856f000d35d -r 47dca2f335de
tools/python/xen/xend/xenstore/xstransact.py
--- /dev/null Fri Sep 9 13:08:25 2005
+++ b/tools/python/xen/xend/xenstore/xstransact.py Fri Sep 9 13:20:51 2005
@@ -0,0 +1,113 @@
+# Copyright (C) 2005 Christian Limpach <Christian.Limpach@xxxxxxxxxxxx>
+
+# This file is subject to the terms and conditions of the GNU General
+# Public License. See the file "COPYING" in the main directory of
+# this archive for more details.
+
+import threading
+from xen.lowlevel import xs
+
+handles = {}
+
+# XXX need to g/c handles from dead threads
+def xshandle():
+ if not handles.has_key(threading.currentThread()):
+ handles[threading.currentThread()] = xs.open()
+ return handles[threading.currentThread()]
+
+class xstransact:
+
+ def __init__(self, path):
+ self.path = path.rstrip("/")
+ xshandle().transaction_start(path)
+ self.in_transaction = True
+
+ def __del__(self):
+ if self.in_transaction:
+ xshandle().transaction_end(True)
+
+ def commit(self):
+ if not self.in_transaction:
+ raise RuntimeError
+ self.in_transaction = False
+ return xshandle().transaction_end(False)
+
+ def abort(self):
+ if not self.in_transaction:
+ raise RuntimeError
+ self.in_transaction = False
+ return xshandle().transaction_end(True)
+
+ def _read(self, key):
+ path = "%s/%s" % (self.path, key)
+ return xshandle().read(path)
+
+ def read(self, *args):
+ if len(args) == 0:
+ raise TypeError
+ if len(args) == 1:
+ return self._read(args[0])
+ ret = []
+ for key in args:
+ ret.append(self._read(key))
+ return ret
+
+ def _write(self, key, data, create=True, excl=False):
+ path = "%s/%s" % (self.path, key)
+ xshandle().write(path, data, create=create, excl=excl)
+
+ def write(self, *args, **opts):
+ create = opts.get('create') or True
+ excl = opts.get('excl') or False
+ if len(args) == 0:
+ raise TypeError
+ if isinstance(args[0], dict):
+ for d in args:
+ if not isinstance(d, dict):
+ raise TypeError
+ for key in d.keys():
+ self._write(key, d[key], create, excl)
+ elif isinstance(args[0], list):
+ for l in args:
+ if not len(l) == 2:
+ raise TypeError
+ self._write(l[0], l[1], create, excl)
+ elif len(args) % 2 == 0:
+ for i in range(len(args) / 2):
+ self._write(args[i * 2], args[i * 2 + 1], create, excl)
+ else:
+ raise TypeError
+
+ def Read(cls, path, *args):
+ t = cls(path)
+ v = t.read(*args)
+ t.commit()
+ return v
+
+ Read = classmethod(Read)
+
+ def Write(cls, path, *args, **opts):
+ t = cls(path)
+ t.write(*args, **opts)
+ t.commit()
+
+ Write = classmethod(Write)
+
+ def SafeRead(cls, path, *args):
+ while True:
+ try:
+ return cls.Read(path, *args)
+ except RuntimeError, ex:
+ pass
+
+ SafeRead = classmethod(SafeRead)
+
+ def SafeWrite(cls, path, *args, **opts):
+ while True:
+ try:
+ cls.Write(path, *args, **opts)
+ return
+ except RuntimeError, ex:
+ pass
+
+ SafeWrite = classmethod(SafeWrite)
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