[minion-cvs] Answer question from roger by switching to more paranoi...

[nickm@seul.org (Nick Mathewson)]

Update of /home/minion/cvsroot/src/minion/lib/mixminion
In directory moria.mit.edu:/tmp/cvs-serv12013/lib/mixminion

Modified Files:
	Common.py 
Log Message:
Answer question from roger by switching to more paranoid implementation

Index: Common.py
===================================================================
RCS file: /home/minion/cvsroot/src/minion/lib/mixminion/Common.py,v
retrieving revision 1.74
retrieving revision 1.75
diff -u -d -r1.74 -r1.75
--- Common.py	17 May 2003 05:04:32 -0000	1.74
+++ Common.py	17 May 2003 05:40:42 -0000	1.75
@@ -254,15 +254,19 @@
 # File helpers
 class AtomicFile:
     """Wrapper around open/write/rename to encapsulate writing to a temporary
-       file, then moving to the final filename on close"""
+       file, then moving to the final filename on close.
+
+       NOTE 1: If you don't call 'close' or 'discard' on this object,
+       the temporary file it creates will stay around indefinitely.
+
+       NOTE 2: If multiple AtomicFiles are active for the same destination
+       file, the last one to close will win, and results for the others will
+       not be visible.
+       """
     def __init__(self, fname, mode='w'):
         self.fname = fname
         self.tmpname = fname + ".tmp"
-        # XXXX Put a note here saying we've thought about the security
-        # XXXX issues (eg having a file that ends in .tmp that gets
-        # XXXX overwritten by this thing).
-        fd = os.open(self.tmpname, os.O_WRONLY|os.O_CREAT|os.O_TRUNC, 0600)
-        self.f = os.fdopen(fd, mode)
+        self.f, self.tmpname = openUnique(self.tmpname)
 
     def write(self, s):
         self.f.write(s)
@@ -271,11 +275,17 @@
         """Close the underlying file and replace the destination file."""
         os.rename(self.tmpname, self.fname)
         self.f.close()
+        self.f = None
 
     def discard(self):
         """Discard changes to the temporary file."""
         self.f.close()
         os.unlink(self.tmpname)
+        self.f = None
+
+    def __del__(self):
+        if self.f:
+            LOG.error("Atomic file not closed/discarded: %s",self.tmpname)
 
 def readPickled(fn):
     """Given the name of a file containing a pickled object, return the pickled