.

wcfs/wcfs_test.py

@@ -17,7 +17,7 @@
 #
 # See COPYING file for full licensing terms.
 # See https://www.nexedi.com/licensing for rationale and options.
-"""test wcfs filesystem from outside as python client process"""
+"""wcfs_test tests wcfs filesystem from outside as python client process"""
 
 from __future__ import print_function
 
@@ -116,7 +116,11 @@ def test_join_autostart():
     assert os.path.isdir(wc.mountpoint + "/head/bigfile")
 
 
-# tDB is database/wcfs testing environment.
+# tDB provides database/wcfs testing environment.
+#
+# XXX link -> tFile + tWatch.
+#
+# XXX print -> t.trace/debug() + t.verbose depending on py.test -v -v ?
 class tDB:
     def __init__(t):
         t.root  = testdb.dbopen()
@@ -126,6 +130,7 @@ class tDB:
         t._changed = {} # ZBigFile -> {} blk -> data
 
         # committed: head + head history
+        # XXX -> vδF (committed changes to files)
         t.head   = None
         t._headv = []
 
@@ -157,7 +162,9 @@ class tDB:
             assert len(data) <= zf.blksize
             zfDelta[blk] = data
 
-    # commit commits transaction and remembers/returns committed transaction ID.
+    # commit commits transaction and makes sure wcfs is synchronized to it.
+    #
+    # It remembers/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.
@@ -171,7 +178,7 @@ class tDB:
         t._changed = {}
 
         # NOTE there is no clean way to retrieve tid of just committed transaction
-        #      we are using last._p_serial as workaround.
+        #      we use last._p_serial as workaround.
         t.root['_last'] = last = Persistent()
         last._p_changed = 1
 
@@ -181,10 +188,14 @@ class tDB:
         t.ncommit += 1
         t.head = head
         t._headv.append(head)
+
+        # sync wcfs
+        t._wcsync()
+
         return head
 
-    # wcsync makes sure wcfs synchronized to latest committed transaction.
-    def wcsync(t):
+    # _wcsync makes sure wcfs is synchronized to latest committed transaction.
+    def _wcsync(t):
         while len(t._wc_zheadv) < len(t._headv):
             l = t._wc_zheadfh.readline()
             #print('> zhead read: %r' % l)
@@ -239,7 +250,7 @@ class tDB:
         return tWatch(t)
 
 
-# tFile is testing environment for one bigfile on wcfs.
+# tFile provides testing environment for one bigfile on wcfs.
 class tFile:
     # maximum number of pages we mmap for 1 file.
     # this should be not big not to exceed mlock limit.
@@ -251,10 +262,10 @@ class tFile:
         t.f   = tdb._open(zf, at=at)
         t.blksize = zf.blksize
 
-        # mmap the file past the end up to XXX pages and lock the pages with
-        # MLOCK_ONFAULT. This way when a page is read by mmap access we have
-        # the guarantee from kernel that the page will stay in pagecache. We
-        # rely on this to verify OS cache state.
+        # mmap the file past the end up to _max_tracked pages and lock the
+        # pages with MLOCK_ONFAULT. This way when a page is read by mmap access
+        # we have the guarantee from kernel that the page will stay in
+        # pagecache. We rely on this to verify OS cache state.
         assert t.blksize % mm.PAGE_SIZE == 0
         t.fmmap = mm.map_ro(t.f.fileno(), 0, t._max_tracked*t.blksize)
         mm.lock(t.fmmap, mm.MLOCK_ONFAULT)
@@ -302,7 +313,7 @@ class tFile:
         assert t.cached() == incorev
 
 
-    # blk returns bytearray connected to view of file[blk].
+    # blk returns bytearray view of file[blk].
     def blk(t, blk):
         assert blk <= t._max_tracked
         return bytearray(t.fmmap[blk*t.blksize:(blk+1)*t.blksize])
@@ -348,9 +359,7 @@ class tFile:
     # Expected blocks may be given with size < zf.blksize. In such case they
     # are implicitly appended with trailing zeros.
     #
-    # It also check file size and optionally mtime.
-    #
-    # XXX also check pagecache state?
+    # It also checks file size and optionally mtime.
     def assertData(t, datav, mtime=None):
         st = os.fstat(t.f.fileno())
         assert st.st_size == len(datav)*t.blksize
@@ -364,7 +373,7 @@ class tFile:
         t.assertCache([1]*len(datav))
 
 
-# tWatch is testing environment for /head/watch opened on wcfs.
+# tWatch provides testing environment for /head/watch opened on wcfs.
 class tWatch:
 
     def __init__(t, tdb):
@@ -540,7 +549,6 @@ def test_wcfs():
     t.ncommit = 0   # so that atX in the code correspond with debug output
     at0_ = t.commit()
     assert tidtime(at0_) > tidtime(at0)
-    t.wcsync()
 
     # >>> lookup non-BigFile -> must be rejected
     with raises(OSError) as exc:
@@ -556,7 +564,6 @@ def test_wcfs():
     t.change(zf, {2: b'alpha'})
     at1 = t.commit()
 
-    t.wcsync()
     f.assertCache([0,0,0])  # initially not cached
     f.assertData ([b'',b'',b'alpha'], mtime=t.head)
 
@@ -564,8 +571,6 @@ def test_wcfs():
     t.change(zf, {2: b'beta', 3: b'gamma'})
     at2 = t.commit()
 
-    t.wcsync()
-
     # f @head
     f.assertCache([1,1,0,0])
     f.assertData ([b'',b'', b'beta', b'gamma'], mtime=t.head)
@@ -581,7 +586,6 @@ def test_wcfs():
     t.change(zf, {2: b'kitty'})
     at3 = t.commit()
 
-    t.wcsync()
     f.assertCache([1,1,0,1])
 
     # f @head is opened again -> cache must not be lost