.

bigfile/_bigfile.h

@@ -25,8 +25,8 @@
 /* Package _bigfile provides Python bindings to virtmem.
  *
  * - `BigFile` is base class that allows implementing BigFile backends in Python.
- *   Users can inherit from BigFile, implement loadblk/storeblk and this way
- *   provide access to data managed from Python to virtmem subsystem.
+ *   Users can inherit from BigFile, implement loadblk/storeblk/blkmmapper and      XXX review
+ *   this way provide access to data managed from Python to virtmem subsystem.
  * - `BigFileH` represents virtmem file handle for opened BigFile.
  *   It can be mmap'ed and provides writeout control.
  * - `VMA` represents mmap'ed part of a BigFileH.
@@ -101,7 +101,7 @@ typedef struct PyBigFileH PyBigFileH;
 /*
  * BigFile that can be implemented in python
  *
- * Allows subclasses to implement .loadblk() (& friends) in python.
+ * Allows subclasses to implement .loadblk() (& friends) in python.     XXX blkmmapper doc
  * For users .fileh_open() is exposed to get to file handles.
  */
 struct PyBigFile {

bigfile/_file_zodb.pyx

@@ -73,13 +73,14 @@ cdef public class _ZBigFile(BigFile) [object _ZBigFile, type _ZBigFile_Type]:
     def loadblk(self, blk, buf):    return self.zself.loadblk(blk, buf)
     def storeblk(self, blk, buf):   return self.zself.storeblk(blk, buf)
 
-    # blkmmapper returns pycapsule with virtmem mmapper for the file.
-    def blkmmapper(_ZBigFile zf):
-        # it is called from under PyBigFile.fileh_open(mmap_overlay=True) and
-        # .zfile should be already associated with jar and have oid.
-
-        # make sure that WCFS file handle corresponding to ZBigFile is opened.
+    # fileh_open wraps BigFile.fileh_open and makes sure that WCFS file handle
+    # corresponding to ZBigFile is opened if use_wcfs=True.
+    def fileh_open(_ZBigFile zf, bint use_wcfs):
+        mmap_overlay = False
         cdef wcfs.PyFileH pywfileh
+
+        if use_wcfs:
+            mmap_overlay = True
             if zf.wfileh == nil:
                 zconn = zf.zself._p_jar
                 assert zconn is not None
@@ -90,6 +91,27 @@ cdef public class _ZBigFile(BigFile) [object _ZBigFile, type _ZBigFile_Type]:
                 pywfileh  = pywconn.open(zf.zself._p_oid)
                 zf.wfileh = pywfileh.wfileh
 
+        return super(_ZBigFile, zf).fileh_open(mmap_overlay)
+
+    # blkmmapper returns pycapsule with virtmem mmapper for the file.
+    @staticmethod
+    def blkmmapper():
+#    def blkmmapper(_ZBigFile zf):
+#        # it is called from under PyBigFile.fileh_open(mmap_overlay=True) and
+#        # .zfile should be already associated with jar and have oid.
+#
+#        # make sure that WCFS file handle corresponding to ZBigFile is opened.
+#        cdef wcfs.PyFileH pywfileh
+#        if zf.wfileh == nil:
+#            zconn = zf.zself._p_jar
+#            assert zconn is not None
+#            # XXX locking? or rely on that ZODB objects for must be used from under 1 thread only?
+#
+#            # join zconn to wconn; link to wconn from _ZBigFile
+#            pywconn   = pywconnOf(zconn)
+#            pywfileh  = pywconn.open(zf.zself._p_oid)
+#            zf.wfileh = pywfileh.wfileh
+
         # zf is ready to serve mmap requests via .wfileh
         # return pycapsule with corresponding mmap methods.
         #
@@ -99,7 +121,7 @@ cdef public class _ZBigFile(BigFile) [object _ZBigFile, type _ZBigFile_Type]:
 
 
 # _ZBigFile_mmap_pycapsule is pycapsule with functions that we give to
-# PyBigFile for ZBigFile virtmem .mmap* ops.
+# PyBigFile for ZBigFile virtmem .mmap* ops (see _ZBigFile.blkmmapper).
 cdef extern from "<wendelin/bigfile/file.h>" nogil:
     struct bigfile_ops:
         pass

bigfile/file_zodb.py

@@ -624,19 +624,7 @@ class ZBigFile(LivePersistent):
         if _use_wcfs is None:
             _use_wcfs = self._default_use_wcfs()
 
-        wcfileh = None
-        if _use_wcfs:
-            # TODO maintain zconn -> wconn in sync (p_jar -> wconn)
-            # TODO close wconn on zconn del (NOTE not close, as zconn.close() just puts it into DB.poll)
-            # TODO close wcfileh on _ZBigFileH close
-            zconn = self._p_jar
-            zstor = zconn.db().storage
-            zurl = wcfs.zstor_2zurl(zstor)
-            wc = wcfs.join(zurl)
-            wconn = wc.connect(zconn_at(zconn))
-            wcfileh = wconn.open(self._p_oid)
-
-        fileh = _ZBigFileH(self, wcfileh)
+        fileh = _ZBigFileH(self, _use_wcfs)
         self._v_filehset.add(fileh)
         return fileh
 
@@ -722,15 +710,11 @@ Connection.open = Connection_open
 @implementer(ISynchronizer)
 class _ZBigFileH(object):
     # .zfile        ZBigFile we were opened for
-#   # .wcfileh      handle for ZBigFile@zconn.at view in wcfs | None
-    # .zfileh       handle for ZBigFile in virtmem (overlayed over .wcfileh if .wcfileh != ø)
+    # .zfileh       handle for ZBigFile in virtmem
 
-    def __init__(self, zfile, wcfileh):
+    def __init__(self, zfile, use_wcfs):
         self.zfile  = zfile
-        self.wcfileh = wcfileh
-        #self.zfileh = zfile._v_file.fileh_open(wcfileh)    # XXX pass wcfileh in
-        # XXX no - BigFile should fetch wcfileh itself from ZBigFile by calling ZBigFile.blkmmapper()
-        self.zfileh = zfile._v_file.fileh_open()
+        self.zfileh = zfile._v_file.fileh_open(use_wcfs)
 
         # FIXME zfile._p_jar could be None (ex. ZBigFile is newly created
         #       before first commit)