.

wcfs/wcfs_test.py

@@ -118,6 +118,24 @@ def test_join_autostart():
 
 # --- test access to data ----
 
+# DF corresponds to ΔF in wcfs.
+# it represents a change in files space.
+class DF:
+    # .rev      tid
+    # .byfile   {} ZBigFile -> DFile
+    def __init__(dF):
+        # rev set from outside
+        dF.byfile = {}
+
+# DFile is similar to ΔFile in wcfs.
+# represents a change to one file.
+class DFile:
+    # .rev      tid
+    # .ddata    {} blk -> data      XXX name
+    def __init__(dfile):
+        # rev set from outside
+        dfile.ddata = {}
+
 # tDB provides database/wcfs testing environment.
 #
 # BigFiles opened under tDB are represented as tFile - see .open for details.
@@ -135,10 +153,10 @@ class tDB:
         # ZBigFile(s) scheduled for commit
         t._changed = {} # ZBigFile -> {} blk -> data
 
-        # committed: head + head history
-        # XXX -> vδF (committed changes to files)
+        # committed: head + δF history
         t.head   = None
-        t._headv = []
+        t._headv = [] # XXX -> just use dFtail[·].rev ?
+        t.dFtail = [] # of DF
 
         # number of commits made so far
         t.ncommit = 0
@@ -185,13 +203,17 @@ class tDB:
     def commit(t):
         # perform modifications scheduled by change.
         # use !wcfs mode so that we prepare data independently of wcfs code paths.
+        dF = DF()
         for zf, zfDelta in t._changed.iteritems():
+            dfile = DFile()
             zfh = zf.fileh_open(_use_wcfs=False)
             for blk, data in zfDelta.iteritems():
+                dfile.ddata[blk] = data
                 data += b'\0'*(zf.blksize - len(data))  # trailing \0
                 vma = zfh.mmap(blk, 1)
                 memcpy(vma, data)
             print('    δ f<%s>\t%s' % (h(zf._p_oid), sorted(zfDelta.keys())))
+            dF.byfile[zf] = dfile
         t._changed = {}
 
         # NOTE there is no clean way to retrieve tid of just committed transaction
@@ -206,6 +228,11 @@ class tDB:
         t.head = head
         t._headv.append(head)
 
+        dF.rev = head
+        for dfile in dF.byfile.values():
+            dfile.rev = head
+        t.dFtail.append(dF)
+
         # synchronize wcfs to db
         t._wcsync()
 
@@ -260,7 +287,7 @@ class tDB:
 # tFile provides testing environment for one bigfile on wcfs.
 #
 # .blk() provides access to data of a block. .cached() gives state of which
-# blocks are in OS pagecache.  .assertCache and .assertBlk/.assertData assert
+# blocks are in OS pagecache. .assertCache and .assertBlk/.assertData assert
 # on state of cache and data.
 class tFile:
     # maximum number of pages we mmap for 1 file.
@@ -366,8 +393,8 @@ class tWatch:
 
         # open new head/watch handle.
         #
-        # python/stdio lock file object on read/write
-        # however we need both read and write to be working simultaneously.
+        # python/stdio lock file object on read/write, however we need both
+        # read and write to be working simultaneously.
         # -> we use 2 separate file objects for rx and tx.
         #
         # fdopen takes ownership of file descriptor and closes it when file
@@ -623,7 +650,7 @@ def test_wcfs():
 
     # XXX test watch with all at variants
     # XXX both from scratch and going e.g. at1 -> at2 -> at3
-    # XXX going not only up, but also down at1 <- at2 <- at3
+    # XXX going not only up, but also down at1 <- at2 <- at3    ?
     w = t.watch(zf, at1)  # XXX <- pin @at2 @at3
     #t.watch(zf, at1, {2: at1, 3: at1})  # XXX <- pin @at2 @at3
 
@@ -655,14 +682,14 @@ def test_wcfs():
     # XXX pin message when blk data only first appeared after > w.at - pin
     # needs to pin to zero.
 
+    # XXX watch @at when file did not existed -> error
+
     # XXX ZBlk copied from blk1 -> blk2 ; for the same file and for file1 -> file2
     # XXX ZBlk moved  from blk1 -> blk2 ; for the same file and for file1 -> file2
 
     # XXX read file[blk]=hole; then file[blk]=zblk - must be invalidated and
     # setupWatch must send pins.
 
-    # XXX watch @at when file did not existed
-
 
 def test_wcfs_invproto():
     # XXX