.

wcfs/internal/zdata/δftail.go

@@ -330,9 +330,10 @@ func (δFtail *ΔFtail) Update(δZ *zodb.EventCommit) (_ ΔF, err error) {
 		δfile.Blocks = nil
 		δfile.Size = false
 
+		// XXX + rebuild	XXX not here - in track(new file)
+
 		_ = δ
 		//fmt.Printf("δZBigFile: %v\n", δ)
-		//return ΔF{}, fmt.Errorf("ZBigFile<%s> changed @%s", oid, δZ.Tid)
 	}
 
 //	fmt.Printf("-> δF: %v\n", δF)
@@ -538,7 +539,7 @@ func (δFtail *ΔFtail) LastBlkRev(ctx context.Context, zf *ZBigFile, blk int64,
 // ----------------------------------------
 
 
-// zfilediff ... XXX
+// zfilediff returns direct difference for ZBigFile<foid> old..new .
 type _ΔZBigFile struct {
 	blksizeOld, blksizeNew int64
 	blktabOld,  blktabNew  zodb.Oid
@@ -565,7 +566,7 @@ func zfilediff(db *zodb.DB, foid zodb.Oid, old, new zodb.Tid) (δ *_ΔZBigFile,
 	return diffF(ctx, a, b)
 }
 
-// diffF computes direct difference in between two ZBigFile objects.
+// diffF returns direct difference in between two ZBigFile objects.
 func diffF(ctx context.Context, a, b *ZBigFile) (δ *_ΔZBigFile, err error) {
 	defer xerr.Contextf(&err, "diffF %s %s", xzodb.XidOf(a), xzodb.XidOf(b))
 

wcfs/internal/zdata/δftail_test.go

@@ -256,9 +256,8 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 		if epoch {
 			blkTab = map[int64]string{}
 			Zinblk = map[string]setI64{}
-		}
-
-		// XXX else?
+			δblk   = nil
+		} else {
 			// rebuild blkTab/Zinblk
 			for blk, zblk := range test.δblkTab {
 				zprev, ok := blkTab[blk]
@@ -301,6 +300,7 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 					δblk.Add(blk)
 				}
 			}
+		}
 
 		// commit updated zfile / blkTab + dataTab
 		var req string
@@ -337,10 +337,10 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 		err = zconn.Resync(ctx, commit.At);  X(err)
 
 		var δfok *ΔFile
-		if len(δblk) != 0 {
+		if epoch || len(δblk) != 0 {
 			δfok = &ΔFile{
 				Rev:    commit.At,
-				Epoch:  epoch, // XXX epoch -> blocks/size = nil ?
+				Epoch:  epoch,
 				Blocks: δblk,
 				Size:   δtree, // not strictly ok, but matches current ΔFtail code
 			}