[minion-cvs] Maint branch: change Filestore to raise an exception on...

[nickm@seul.org (Nick Mathewson)]

Update of /home/minion/cvsroot/src/minion/lib/mixminion
In directory moria.mit.edu:/tmp/cvs-serv27233/lib/mixminion

Modified Files:
      Tag: mixminion-v0-0-5-patches
	ClientMain.py Filestore.py 
Log Message:
Maint branch: change Filestore to raise an exception on failed cPickle.load.

Change users of Filestore to respond appropriately.


Index: ClientMain.py
===================================================================
RCS file: /home/minion/cvsroot/src/minion/lib/mixminion/ClientMain.py,v
retrieving revision 1.112.2.1
retrieving revision 1.112.2.2
diff -u -d -r1.112.2.1 -r1.112.2.2
--- ClientMain.py	12 Sep 2003 15:35:47 -0000	1.112.2.1
+++ ClientMain.py	28 Sep 2003 03:57:32 -0000	1.112.2.2
@@ -1349,7 +1349,8 @@
     def getPacket(self, handle):
         """Given a handle, return a 3-tuple of the corresponding
            32K packet, IPV4Info, and time of first queueing.  (The time
-           is rounded down to the closest midnight GMT.)"""
+           is rounded down to the closest midnight GMT.)  May raise 
+           CorruptedFile."""
         obj = self.store.getObject(handle)
         try:
             magic, message, routing, when = obj
@@ -1381,7 +1382,10 @@
             return
         timesByServer = {}
         for h in handles:
-            _, routing, when = self.getPacket(h)
+            try:
+                _, routing, when = self.getPacket(h)
+            except mixminion.Filestore.CorruptedFile:
+                continue
             timesByServer.setdefault(routing, []).append(when)
         for s in timesByServer.keys():
             count = len(timesByServer[s])
@@ -1400,7 +1404,10 @@
         cutoff = now - maxAge
         remove = []
         for h in self.getHandles():
-            when = self.getPacket(h)[2]
+            try:
+                when = self.getPacket(h)[2]
+            except mixminion.Filestore.CorruptedFile:
+                continue
             if when < cutoff:
                 remove.append(h)
         LOG.info("Removing %s old messages from queue", len(remove))
@@ -1657,7 +1664,10 @@
             LOG.info("Flushing %s", len(handles))
             messagesByServer = {}
             for h in handles:
-                message, routing, _ = self.queue.getPacket(h)
+                try:
+                    message, routing, _ = self.queue.getPacket(h)
+                except mixminion.Filestore.CorruptedFile: 
+                    continue
                 messagesByServer.setdefault(routing, []).append((message, h))
         finally:
             clientUnlock()

Index: Filestore.py
===================================================================
RCS file: /home/minion/cvsroot/src/minion/lib/mixminion/Filestore.py,v
retrieving revision 1.9.2.2
retrieving revision 1.9.2.3
diff -u -d -r1.9.2.2 -r1.9.2.3
--- Filestore.py	26 Sep 2003 02:16:22 -0000	1.9.2.2
+++ Filestore.py	28 Sep 2003 03:57:32 -0000	1.9.2.3
@@ -23,16 +23,20 @@
 import threading
 import time
 
-from mixminion.Common import MixFatalError, secureDelete, LOG, \
+from mixminion.Common import MixError, MixFatalError, secureDelete, LOG, \
      createPrivateDir, readFile, tryUnlink
 from mixminion.Crypto import getCommonPRNG
 
 __all__ = [ "StringStore", "StringMetadataStore",
             "ObjectStore", "ObjectMetadataStore", 
             "MixedStore", "MixedMetadataStore",
-            "DBBase", "JournaledDBBase", "BooleanJournaledDBBase"
+            "DBBase", "JournaledDBBase", "BooleanJournaledDBBase",
+            "CorruptedFile",
             ]
 
+class CorruptedFile(MixError):
+    """Raised when a pickled object cannot be properly decoded."""
+    pass
 
 # ======================================================================
 # Filestores.
@@ -309,21 +313,22 @@
     """
     def __init__(self): pass
     def getObject(self, handle):
-        """Given a message handle, read and unpickle the contents of the
-           corresponding message.  In rare error cases, defaults to 'None'.
+        """Given a message handle, read and unpickle the contents of
+           the corresponding message.  In rare error cases, raises
+           CorruptedFile.
            """
         try:
             self._lock.acquire()
             f = open(os.path.join(self.dir, "msg_"+handle), 'rb')
             try:
                 res = cPickle.load(f)
+                f.close()
+                return res
             except cPickle.UnpicklingError, e:
                 LOG.error("Found damaged object %s in filestore %s: %s",
                           handle, self.dir, str(e))
                 self.removeMessage(handle)
-                res = None
-            f.close()
-            return res
+                raise CorruptedFile()
         finally:
             self._lock.release()
 
@@ -389,11 +394,15 @@
                 except KeyError:
                     LOG.warn("Missing metadata for file %s",h)
                     self.setMetadata(h, newDataFn(h))
+                except CorruptedFile:
+                    LOG.warn("Repairing metadata for file %s",h)
+                    self.setMetadata(h, newDataFn(h))
         finally:
             self._lock.release()
 
     def getMetadata(self, handle):
-        """Return the metadata associated with a given handle."""
+        """Return the metadata associated with a given handle.  If the
+           metadata is damaged, may raise CorruptedFile."""
         fname = os.path.join(self.dir, "meta_"+handle)
         if not os.path.exists(fname):
             raise KeyError(handle)
@@ -410,7 +419,7 @@
                 LOG.error("Found damaged metadata for %s in filestore %s: %s",
                           handle, self.dir, str(e))
                 self.removeMessage(handle)
-                return None
+                raise CorruptedFile()
             f.close()
             self._metadata_cache[handle] = res
             return res