.

wcfs/wcfs.go

@@ -1012,11 +1012,13 @@ func (f *BigFile) readBlk(ctx context.Context, blk int64, dest []byte) error {
 }
 
 
-// /bigfile/<bigfileX>/head/at -> readAt serves read.
-func (bf *BigFile) readAt() []byte {
-	// XXX locking
-	// XXX zbf.PJar() not good if we want to share objects between connections?
-	return []byte(bf.zbf.PJar().At().String())
+// /(head|<rev>)/at -> readAt serves read.
+func (h *Head) readAt() []byte {
+	// XXX implemented only for Head, not Rev
+	root := groot
+	root.zheadMu.Lock()
+	defer root.zheadMu.Unlock()
+	return []byte(root.zhead.At().String())
 }
 
 
@@ -1108,6 +1110,7 @@ func main() {
 		Node:  nodefs.NewDefaultNode(),
 		tab:   make(map[zodb.Oid]*BigFile),
 	})
+	mkfile(head, "at", NewSmallFile(head.readAt))   // TODO mtime(at) = tidtime(at)
 
 	// TODO handle autoexit
 	_ = autoexit

wcfs/wcfs_test.py

@@ -165,8 +165,9 @@ def test_bigfile_empty():
     wc = wcfs.join(testzurl, autostart=True)
     defer(wc.close)
 
-    # path to head/bigfile/ under wcfs
-    bigpath = wc.mountpoint + "/head/bigfile"
+    # path to head/ and head/bigfile/ under wcfs
+    head = wc.mountpoint + "/head"
+    bigpath = head + "/bigfile"
 
     # lookup to non-BigFile - must be rejected
     with raises(OSError) as exc:
@@ -182,7 +183,7 @@ def test_bigfile_empty():
     assert st.st_mtime == tidtime(tid1)
 
     # head/at = last txn of whole db
-    assert readfile(fpath + "/head/at") == tid2.encode('hex')
+    assert readfile(head + "/at") == tid2.encode('hex')
 
     # TODO check head/at syncs to later non-bigfile commits