.

wcfs/wcfs_test.py

@@ -379,6 +379,7 @@ class tDB:
     # buf if head/<zf>[blk] was accessed again after change, and was no longer
     # changed, the answer is "yes"
     # XXX text
+    # XXX -> _blkLastRevAccessed ?  _blkRevLastAccessed ? _blkHeadRevAccessed ?
     """
     def _blkHeadAccessed(t, zf, blk):
         zfAccessed = t._accessed.get(zf, {})
@@ -885,14 +886,17 @@ class tSrvReq:
 
 # ---- watch setup/adjust ----
 
-# _pinAt returns which blocks needs to be pinned for zf@at.
+# _pinAt returns which blocks needs to be pinned for zf@at compared to zf@head
+# according to wcfs invalidation protocol.
 #
-# it does not take into account whether blocks are in cache or not and computes
-# pins for all changes.     XXX is it desired behaviour?
-@func(tWatchLink)
-def _pinAt(twlink, zf, at):  # -> pin = {} blk -> rev
-    t = twlink.tdb
-
+# It does not take into account whether blocks are in cache or not and computes
+# pins as if all blocks @head were accesses - i.e. considering all file changes
+# in (at, head] range.
+#
+# The caller has to take cached/not-cached effect into account on its own
+# (see tDB._accessed & friends)
+@func(tDB)
+def _pinAt(t, zf, at):  # -> pin = {} blk -> rev
     # XXX dup in _blkData
 
     # all changes to zf
@@ -950,10 +954,10 @@ def watch(twlink, zf, at, pinok=None):   # XXX -> ?
     pin_prev = {}
     if at_prev is not None:
         assert at_prev <= at, 'TODO %s -> %s' % (t.hat(at_prev), t.hat(at))
-        pin_prev = twlink._pinAt(zf, at_prev)
+        pin_prev = t._pinAt(zf, at_prev)
     assert w.pinned == pin_prev     # XXX & blkHeadAccessedRev > w.at
 
-    pin = twlink._pinAt(zf, at)
+    pin = t._pinAt(zf, at)
 
     if at_prev != at and at_prev is not None:
         print('# pin@old: %s\n# pin@new: %s' % (pinstr(pin_prev), pinstr(pin)))
@@ -991,7 +995,7 @@ def watch(twlink, zf, at, pinok=None):   # XXX -> ?
     twlink._watch(zf, at, pinok, "ok")
 
     w.at = at
-    assert w.pinned == twlink._pinAt(zf, at)
+    assert w.pinned == t._pinAt(zf, at)
 
 
 # stop_watch instructs wlink to stop watching the file.