.

wcfs/wcfs_test.py

@@ -220,7 +220,7 @@ class tDB:
 
     # change schedules zf to be changed according changeDelta at commit.
     #
-    # changeDelta is {} blk -> data.
+    # changeDelta: {} blk -> data.
     # data can be both bytes and unicode.
     def change(t, zf, changeDelta):
         assert isinstance(zf, ZBigFile)
@@ -233,7 +233,7 @@ class tDB:
 
     # commit commits transaction and makes sure wcfs is synchronized to it.
     #
-    # It remembers/returns committed transaction ID.
+    # It updates .dFtail and returns committed transaction ID.
     def commit(t):
         # perform modifications scheduled by change.
         # use !wcfs mode so that we prepare data independently of wcfs code paths.
@@ -248,11 +248,10 @@ class tDB:
                 memcpy(vma, data)
             dF.byfile[zf] = dfile
 
-        # NOTE there is no clean way to retrieve tid of just committed transaction
-        #      we use last._p_serial as workaround.
+        # perform the commit. NOTE there is no clean way to retrieve tid of
+        # just committed transaction - we use last._p_serial as workaround.
         t.root['_last'] = last = Persistent()
         last._p_changed = 1
-
         transaction.commit()
         head = last._p_serial
 
@@ -260,15 +259,15 @@ class tDB:
         for dfile in dF.byfile.values():
             dfile.rev = head
         t.dFtail.append(dF)
+        assert t.head == head   # self-check
 
         print('\nM: commit -> %s' % t.hat(head))
         for zf, zfDelta in t._changed.items():
             print('M:      f<%s>\t%s' % (h(zf._p_oid), sorted(zfDelta.keys())))
         t._changed = {}
 
-        # synchronize wcfs to db
+        # synchronize wcfs to db, and we are done
         t._wcsync()
-
         return head
 
     # _blkaccess marks head/zf[blk] accessed.