Revise Connection.

Make _added_during_commit a regular instance variable.  Don't use
try/finally to reset it; just clear it at the start of a transaction.
XXX There was a test that needed to be removed, but it seemed to be
just a shallow test that try/finally was used.  Can't see any feature
that depends on specific of error handling: The txn is going to abort.

Remove unused _opened instance variable.
Split commit() into two smaller parts.
Get rid of extra manipulation of _creating.
Don't look for _p_serial of None; z64 is now required.
Undo local variable aliases in subtransaction methods.

Also, trivial change to pickle cache API -- get() works like dict get().

src/ZODB/Connection.py

@@ -13,7 +13,7 @@
 ##############################################################################
 """Database connection support
 
-$Id: Connection.py,v 1.138 2004/03/12 06:37:23 jeremy Exp $"""
+$Id: Connection.py,v 1.139 2004/03/13 07:48:11 jeremy Exp $"""
 
 import logging
 import sys
@@ -125,16 +125,15 @@ class Connection(ExportImport, object):
     their state and register changes.  The methods are setstate(),
     register(), setklassstate().
 
-    $Id: Connection.py,v 1.138 2004/03/12 06:37:23 jeremy Exp $
+    $Id: Connection.py,v 1.139 2004/03/13 07:48:11 jeremy Exp $
     """
 
     _tmp = None
     _code_timestamp = 0
     _transaction = None
-    _added_during_commit = None
 
     def __init__(self, version='', cache_size=400,
-                 cache_deactivate_after=60, mvcc=True):
+                 cache_deactivate_after=None, mvcc=True):
         """Create a new Connection.
 
         A Connection instance should by instantiated by the DB
@@ -143,7 +142,6 @@ class Connection(ExportImport, object):
 
         self._log = logging.getLogger("zodb.conn")
         self._storage = None
-        self._opened = None
         self._debug_info = ()
 
         self._version = version
@@ -158,6 +156,7 @@ class Connection(ExportImport, object):
             self._cache.cache_drain_resistance = 100
         self._committed = []
         self._added = {}
+        self._added_during_commit = None
         self._reset_counter = global_reset_counter
         self._load_count = 0   # Number of objects unghosted
         self._store_count = 0  # Number of objects stored
@@ -315,12 +314,10 @@ class Connection(ExportImport, object):
             raise InvalidObjectReference(obj, obj._p_jar)
 
     def sortKey(self):
-        # XXX will raise an exception if the DB hasn't been set
-        storage_key = self._sortKey()
         # If two connections use the same storage, give them a
         # consistent order using id().  This is unique for the
         # lifetime of a connection, which is good enough.
-        return "%s:%s" % (storage_key, id(self))
+        return "%s:%s" % (self._sortKey(), id(self))
 
     def _setDB(self, odb):
         """Register odb, the DB that this Connection uses.
@@ -348,7 +345,6 @@ class Connection(ExportImport, object):
             self._flush_invalidations()
         self._reader = ConnectionObjectReader(self, self._cache,
                                               self._db.classFactory)
-        self._opened = time()
 
     def _resetCache(self):
         """Creates a new cache, discarding the old.
@@ -452,78 +448,66 @@ class Connection(ExportImport, object):
                     self._log.error("Close callback failed for %s", f,
                                     sys.exc_info())
             self.__onCloseCallbacks = None
-        self._storage = self._tmp = self.new_oid = self._opened = None
+        self._storage = self._tmp = self.new_oid = None
         self._debug_info = ()
         # Return the connection to the pool.
         if self._db is not None:
             self._db._closeConnection(self)
             self._db = None
 
-    def commit(self, object, transaction):
-        if object is self:
+    def commit(self, obj, transaction):
+        if obj is self:
             # We registered ourself.  Execute a commit action, if any.
             if self._import:
                 self._importDuringCommit(transaction, *self._import)
                 self._import = None
             return
 
-        oid = object._p_oid
-        if self._conflicts.has_key(oid):
-            self.getTransaction().register(object)
-            raise ReadConflictError(object=object)
-
-        invalid = self._invalid
-
-        # XXX In the case of a new object or an object added using add(),
-        #     the oid is appended to _creating.
-        #     However, this ought to be unnecessary because the _p_serial
-        #     of the object will be z64 or None, so it will be appended
-        #     to _creating about 30 lines down. The removal from _added
-        #     ought likewise to be unnecessary.
-        if oid is None or object._p_jar is not self:
+        oid = obj._p_oid
+        if oid in self._conflicts:
+            self.getTransaction().register(obj)
+            raise ReadConflictError(object=obj)
+
+        if oid is None or obj._p_jar is not self:
             # new object
             oid = self.new_oid()
-            object._p_jar = self
-            object._p_oid = oid
-            self._creating.append(oid) # maybe don't need this
+            obj._p_jar = self
+            obj._p_oid = oid
+            assert obj._p_serial == z64
         elif oid in self._added:
-            # maybe don't need these
-            self._creating.append(oid)
-            del self._added[oid]
-        elif object._p_changed:
-            if invalid(oid):
-                resolve = getattr(object, "_p_resolveConflict", None)
+            assert obj._p_serial == z64
+        elif obj._p_changed:
+            if oid in self._invalidated:
+                resolve = getattr(obj, "_p_resolveConflict", None)
                 if resolve is None:
-                    raise ConflictError(object=object)
+                    raise ConflictError(object=obj)
             self._modified.append(oid)
         else:
             # Nothing to do
             return
 
-        w = ObjectWriter(object)
+        self._store_objects(ObjectWriter(obj), transaction)
+
+    def _store_objects(self, writer, transaction):
         self._added_during_commit = []
-        try:
-            for obj in itertools.chain(w, self._added_during_commit):
+        for obj in itertools.chain(writer, self._added_during_commit):
             oid = obj._p_oid
-                serial = getattr(obj, '_p_serial', z64)
+            serial = getattr(obj, "_p_serial", z64)
 
-                # XXX which one? z64 or None? Why do I have to check both?
-                if serial == z64 or serial is None:
+            if serial == z64:
                 # new object
                 self._creating.append(oid)
                 # If this object was added, it is now in _creating, so can
                 # be removed from _added.
                 self._added.pop(oid, None)
             else:
-                    if (invalid(oid)
-                        and not hasattr(object, '_p_resolveConflict')):
+                if (oid in self._invalidated
+                    and not hasattr(obj, '_p_resolveConflict')):
                     raise ConflictError(object=obj)
                 self._modified.append(oid)
-                p = w.serialize(obj)  # This calls __getstate__ of obj
-
-                s = self._storage.store(oid, serial, p, self._version,
-                                        transaction)
-                self._store_count = self._store_count + 1
+            p = writer.serialize(obj)  # This calls __getstate__ of obj
+            s = self._storage.store(oid, serial, p, self._version, transaction)
+            self._store_count += 1
             # Put the object in the cache before handling the
             # response, just in case the response contains the
             # serial number for a newly created object
@@ -537,63 +521,50 @@ class Connection(ExportImport, object):
                     raise
 
             self._handle_serial(s, oid)
-        finally:
-            del self._added_during_commit
+        self._added_during_commit = None
 
     def commit_sub(self, t):
         """Commit all work done in all subtransactions for this transaction"""
-        tmp=self._tmp
-        if tmp is None: return
-        src=self._storage
-
-        self._log.debug("Commiting subtransaction of size %s",
-                        src.getSize())
-
-        self._storage=tmp
-        self._tmp=None
-
-        tmp.tpc_begin(t)
+        if self._tmp is None:
+            return
+        src = self._storage
+        self._storage = self._tmp
+        self._tmp = None
         
-        load=src.load
-        store=tmp.store
-        dest=self._version
-        oids=src._index.keys()
+        self._log.debug("Commiting subtransaction of size %s", src.getSize())
+        oids = src._index.keys()
+        self._storage.tpc_begin(t)
 
         # Copy invalidating and creating info from temporary storage:
-        modified = self._modified
-        modified[len(modified):] = oids
-        creating = self._creating
-        creating[len(creating):]=src._creating
+        self._modified[len(self._modified):] = oids
+        self._creating[len(self._creating):] = src._creating
 
         for oid in oids:
-            data, serial = load(oid, src)
-            s=store(oid, serial, data, dest, t)
-            self._handle_serial(s, oid, change=0)
+            data, serial = src.load(oid, src)
+            s = self._storage.store(oid, serial, data, self._version, t)
+            self._handle_serial(s, oid, change=False)
 
     def abort_sub(self, t):
         """Abort work done in all subtransactions for this transaction"""
-        tmp=self._tmp
-        if tmp is None: return
-        src=self._storage
-        self._tmp=None
-        self._storage=tmp
+        if self._tmp is None:
+            return
+        src = self._storage
+        self._storage = self._tmp
+        self._tmp = None
 
         self._cache.invalidate(src._index.keys())
         self._invalidate_creating(src._creating)
 
     def _invalidate_creating(self, creating=None):
-        """Dissown any objects newly saved in an uncommitted transaction.
-        """
+        """Dissown any objects newly saved in an uncommitted transaction."""
         if creating is None:
-            creating=self._creating
-            self._creating=[]
+            creating = self._creating
+            self._creating = []
 
-        cache=self._cache
-        cache_get=cache.get
         for oid in creating:
-            o=cache_get(oid, None)
+            o = self._cache.get(oid)
             if o is not None:
-                del cache[oid]
+                del self._cache[oid]
                 del o._p_jar
                 del o._p_oid
 
@@ -844,6 +815,9 @@ class Connection(ExportImport, object):
 
     def tpc_begin(self, transaction, sub=None):
         self._modified = []
+        
+        # _creating is a list of oids of new objects, which is used to
+        # remove them from the cache if a transaction aborts.
         self._creating = []
         if sub:
             # Sub-transaction!

src/ZODB/tests/testCache.py

@@ -250,7 +250,7 @@ class CacheErrors(unittest.TestCase):
         self.cache = PickleCache(self.jar)
 
     def checkGetBogusKey(self):
-        self.assertRaises(KeyError, self.cache.get, p64(0))
+        self.assertEqual(self.cache.get(p64(0)), None)
         try:
             self.cache[12]
         except KeyError:

src/ZODB/tests/testConnection.py

@@ -124,16 +124,6 @@ class ConnectionDotAdd(unittest.TestCase):
                 "subobject was not stored")
         self.assert_(self.datamgr._added_during_commit is None)
 
-    def checkErrorDuringCommit(self):
-        # We need to check that _added_during_commit still gets set to None
-        # when there is an error during commit()/
-        obj = ErrorOnGetstateObject()
-        
-        self.datamgr.tpc_begin(self.transaction)
-        self.assertRaises(ErrorOnGetstateException,
-                self.datamgr.commit, obj, self.transaction)
-        self.assert_(self.datamgr._added_during_commit is None)
-
     def checkUnusedAddWorks(self):
         # When an object is added, but not committed, it shouldn't be stored,
         # but also it should be an error.

src/persistent/cPickleCache.c

@@ -90,7 +90,7 @@ process must skip such objects, rather than deactivating them.
 static char cPickleCache_doc_string[] =
 "Defines the PickleCache used by ZODB Connection objects.\n"
 "\n"
-"$Id: cPickleCache.c,v 1.91 2004/03/02 22:13:54 jeremy Exp $\n";
+"$Id: cPickleCache.c,v 1.92 2004/03/13 07:48:12 jeremy Exp $\n";
 
 #define DONT_USE_CPERSISTENCECAPI
 #include "cPersistence.h"
@@ -408,12 +408,10 @@ cc_get(ccobject *self, PyObject *args)
 
     r = PyDict_GetItem(self->data, key);
     if (!r) {
-	if (d) {
+	if (d)
 	    r = d;
-	} else {
-	    PyErr_SetObject(PyExc_KeyError, key);
-	    return NULL;
-	}
+	else
+	    r = Py_None;
     }
     Py_INCREF(r);
     return r;