Revert "Define a new interface for storages that support the new commit protocol."

This reverts commit 7901868a.

src/ZODB/interfaces.py

@@ -811,92 +811,6 @@ class IStorage(Interface):
         either from tpc_vote or store for objects passed to store.
         """
 
-class IMultiCommitStorage(IStorage):
-    """A multi-commit storage can commit multiple transactions at once.
-
-    It's lilely that future versions of ZODB will require all storages
-    to provide this interface.
-    """
-
-    def store(oid, serial, data, version, transaction):
-        """Store data for the object id, oid.
-
-        Arguments:
-
-        oid
-            The object identifier.  This is either a string
-            consisting of 8 nulls or a string previously returned by
-            new_oid.
-
-        serial
-            The serial of the data that was read when the object was
-            loaded from the database.  If the object was created in
-            the current transaction this will be a string consisting
-            of 8 nulls.
-
-        data
-            The data record. This is opaque to the storage.
-
-        version
-            This must be an empty string. It exists for backward compatibility.
-
-        transaction
-            A transaction object.  This should match the current
-            transaction for the storage, set by tpc_begin.
-
-        None is returned.
-
-        Several different exceptions may be raised when an error occurs.
-
-        ConflictError
-          is raised when serial does not match the most recent serial
-          number for object oid and the conflict was not resolved by
-          the storage.
-
-        StorageTransactionError
-          is raised when transaction does not match the current
-          transaction.
-
-        StorageError or, more often, a subclass of it
-          is raised when an internal error occurs while the storage is
-          handling the store() call.
-
-        """
-
-    def tpc_finish(transaction, func = lambda tid: None):
-        """Finish the transaction, making any transaction changes permanent.
-
-        Changes must be made permanent at this point.
-
-        This call raises a StorageTransactionError if the storage
-        isn't participating in two-phase commit.  Failure of this
-        method is extremely serious.
-
-        The second argument is a call-back function that must be
-        called while the storage transaction lock is held.  It takes
-        the new transaction id generated by the transaction.
-
-        The return value must be the committed tid. It is used to set the
-        serial for objects whose ids were passed to previous store calls
-        in the same transaction.
-        """
-
-    def tpc_vote(transaction):
-        """Provide a storage with an opportunity to veto a transaction
-
-        This call raises a StorageTransactionError if the storage
-        isn't participating in two-phase commit or if it is commiting
-        a different transaction.
-
-        If a transaction can be committed by a storage, then the
-        method should return.  If a transaction cannot be committed,
-        then an exception should be raised.  If this method returns
-        without an error, then there must not be an error if
-        tpc_finish or tpc_abort is called subsequently.
-
-        The return value can be either None or a sequence of oids for which
-        a conflict was resolved.
-        """
 
 class IStorageRestoreable(IStorage):
     """Copying Transactions
@@ -1034,8 +948,8 @@ class IStorageUndoable(IStorage):
         This method must only be called in the first phase of
         two-phase commit (after tpc_begin but before tpc_vote). It
         returns a serial (transaction id) and a sequence of object ids
-        for objects affected by the transaction. The serial is ignored
-        and may be None.
+        for objects affected by the transaction.
+
         """
         # Used by DB (Actually, by TransactionalUndo)