.

wcfs/__init__.py

@@ -94,16 +94,19 @@ class Conn(object):
 
 # _File represent isolated file view under Conn.
 class _File(object):
+    # .wconn    Conn
+    # .foid     hex of ZBigFile root object ID
     # .headf    file object of head/file
-    # .pin      {} blk -> rev   that wcfs already sent us for this file
+    # .pinned   {} blk -> rev   that wcfs already sent us for this file
     # .mmaps    []_Mapping ↑blk_start    mappings of this file
     pass
 
 
 # _Mapping represents one mapping of _File.
 class _Mapping(object):
-    # .mem          mmaped memory
+    # .file         _File
     # .blk_start    offset of this mapping in file
+    # .mem          mmaped memory
     pass
 
     # XXX property .blk_stop = blk_start + len(mem) // blksize      & assert len(mem) % blksize == 0
@@ -130,31 +133,52 @@ def _pinner(wconn, ctx):
                 if not (mmap.blk_start <= req.blk && req.blk < mmap.blk_stop):
                     continue
 
-                # this mmap covers f[blk] - let's remmap it to @rev/f or head/f
-                if req.at is None:
-                    fsfile = f.headf
-                else:
-                    # TODO share @rev fd until Conn is recynced?
-                    fsfile = wconn._wc._open("@%s/%s" % (ashex(req.at), ashex(req.foid))):
-
                 # FIXME check if virtmem did not mapped RW page into this block already
-                mm.mmap_into_ro(mmap.mem[(req.blk-mmap.blk_start)*blksize:][:blksize], fsfile.fileno(), req.blk*blksize)
-
-                if req.at is not None:
-                    fsfile.close()
+                mmap.pin(req.blk, req.at)
 
-            # update .pin
+            # update .pinned
             if req.at is None:
-                f.pin.pop(req.blk, None)    # = delete(f.pin, req.blk)  -- unpin to @head
+                f.pinned.pop(req.blk, None)     # = delete(f.pinned, req.blk)  -- unpin to @head
             else:
-                f.pin[req.blk] = req.at
+                f.pinned[req.blk] = req.at
+
+
+# pin remmaps mapping memory for [blk] to be viewing database as of @at state.
+#
+# at=None means unpin to head/ .
+# NOTE this does not check wrt virtmem already mapped blk as RW     XXX ok?
+@func(_Mapping)
+def pin(mmap, blk, at):
+    f = mmap.file
+    if at is None:
+        fsfile = f.headf
+    else:
+        # TODO share @rev fd until wconn is recynced?
+        fsfile = f.wconn._wc._open("@%s/%s" % (ashex(at), ashex(f.foid)), "rb")
+        defer(fsfile.close)
 
+    mm.mmap_into_ro(mmap.mem[(blk-mmap.blk_start)*blksize:][:blksize], fsfile.fileno(), blk*blksize)
 
 
 # mmap creats file mapping representing file data as of wconn.at database state.
 @func(Conn)
 def mmap(wconn, foid, offset, size): # -> Mapping       XXX offset, size -> blkoff, blksize ?
-    # XXX
+    with wconn._filemu:
+        f = wconn._filetab.get(foid)
+        if f is None:
+            headf = wconn._wc._open("head/%s" % (ashex(foid),), "rb")
+            f = File(headf)
+            wconn._filetab[foid] = f
+
+        # XXX relock wconn -> f ?
+
+        # create memory with head/f mapping and applied pins
+        mem = mm.mmap_ro(f.headf.fileno(), offset, size)
+        for blk, rev in f.pin.items():  # XXX keep f.pin ↑blk and use binary search?
+            if not (blk_start <= blk && blk < blk_stop):
+                continue    # blk out of this mapping
+
+            mm.mmap_into_ro(mem[(blk - blk_start)*blksize:][:blksize],
 
 
 # XXX Watch