X zdata: Deduplicate zfile loading

wcfs/internal/zdata/δftail_test.go

@@ -234,26 +234,15 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 		txn.Abort()
 	}()
 	zconn, err := t.DB.Open(ctx, &zodb.ConnOptions{At: t.Head().At, NoPool: true});  X(err)
-	xzroot, err := zconn.Get(ctx, 0);  X(err)
-	zroot := xzroot.(*zodb.Map)
-	err = zroot.PActivate(ctx);  X(err)
-	zfile := zroot.Data["treegen/file"].(*ZBigFile)
-	zroot.PDeactivate()
+	zfile, blksize := t.XLoadZFile(ctx, zconn)
 	foid := zfile.POid()
-	err = zfile.PActivate(ctx);  X(err)
-	blksize   := zfile.blksize
-	blktabOid := zfile.blktab.POid()
-	if blktabOid != t.Root() {
-		t.Fatalf("BUG: zfile.blktab (%s)  !=  treeroot (%s)", blktabOid, t.Root())
-	}
-	zfile.PDeactivate()
 
 	// update vδf + co for t1
 	vδf = append(vδf, &ΔFile{Rev: t1.At, Epoch: true})
 	vδE = append(vδE, _ΔFileEpoch{
 			Rev:             t1.At,
 			oldRoot:         zodb.InvalidOid,
-			newRoot:         blktabOid,
+			newRoot:         t.Root(),
 			newBlkSize:      blksize,
 			oldTrackSetZBlk: nil,
 	})
@@ -421,13 +410,13 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 		if newEpoch {
 			δE := _ΔFileEpoch{Rev: commit.At}
 			if delfile {
-				δE.oldRoot    = blktabOid
+				δE.oldRoot    = t.Root()
 				δE.newRoot    = zodb.InvalidOid
 				δE.newBlkSize = -1
 				// XXX oldBlkSize ?
 			} else {
 				δE.oldRoot    = zodb.InvalidOid
-				δE.newRoot    = blktabOid
+				δE.newRoot    = t.Root()
 				δE.newBlkSize = blksize
 				// XXX oldBlkSize ?
 			}
@@ -478,8 +467,8 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 		for oid, zt := range δFtail.trackSetZBlk {
 			zblki := commit.ZBlkTab[oid]
 			for root, blocks := range zt.inroot {
-				if root != blktabOid {
-					t.Errorf(".trackSetZBlk: zblk %s points to unexpected blktab %s", zblki.Name, blktabOid)
+				if root != t.Root() {
+					t.Errorf(".trackSetZBlk: zblk %s points to unexpected blktab %s", zblki.Name, t.Root())
 					continue
 				}
 
@@ -515,7 +504,7 @@ func testΔFtail(t_ *testing.T, testq chan ΔFTestEntry) {
 
 		// verify δftail.root
 		δftail := δFtail.byFile[foid]
-		rootOK := blktabOid
+		rootOK := t.Root()
 		if delfile {
 			rootOK = zodb.InvalidOid
 		}
@@ -627,25 +616,12 @@ func TestΔFtailSliceUntrackedUniform(t_ *testing.T) {
 
 
 	// load zfile via root['treegen/file']
-	// XXX dup
 	txn, ctx := transaction.New(context.Background())
 	defer func() {
 		txn.Abort()
 	}()
-	zconn, err := t.DB.Open(ctx, &zodb.ConnOptions{At: t.Head().At, NoPool: true});  X(err)
-	xzroot, err := zconn.Get(ctx, 0);  X(err)
-	zroot := xzroot.(*zodb.Map)
-	err = zroot.PActivate(ctx);  X(err)
-	zfile := zroot.Data["treegen/file"].(*ZBigFile)
-	zroot.PDeactivate()
-//	foid := zfile.POid()
-	err = zfile.PActivate(ctx);  X(err)
-//	blksize   := zfile.blksize
-	blktabOid := zfile.blktab.POid()
-	if blktabOid != t.Root() {
-		t.Fatalf("BUG: zfile.blktab (%s)  !=  treeroot (%s)", blktabOid, t.Root())
-	}
-	zfile.PDeactivate()
+	zconn, err := t.DB.Open(ctx, &zodb.ConnOptions{At: t.Head().At});  X(err)
+	zfile, _ := t.XLoadZFile(ctx, zconn)
 
 	// XXX dup
 	xtrackBlk := func(blk int64) {
@@ -721,6 +697,24 @@ func newT(t *testing.T) *T {
 	return &T{xbtreetest.NewT(t)}
 }
 
+// XLoadZFile loads zfile from root["treegen/file"]@head.
+func (t *T) XLoadZFile(ctx context.Context, zconn *zodb.Connection) (zfile *ZBigFile, blksize int64) {
+	X := exc.Raiseif
+	xzroot, err := zconn.Get(ctx, 0);  X(err)
+	zroot := xzroot.(*zodb.Map)
+	err = zroot.PActivate(ctx);  X(err)
+	zfile = zroot.Data["treegen/file"].(*ZBigFile)
+	zroot.PDeactivate()
+	err = zfile.PActivate(ctx);  X(err)
+	blksize    = zfile.blksize
+	blktabOid := zfile.blktab.POid()
+	if blktabOid != t.Root() {
+		t.Fatalf("BUG: zfile.blktab (%s)  !=  treeroot (%s)", blktabOid, t.Root())
+	}
+	zfile.PDeactivate()
+	return zfile, blksize
+}
+
 // δfstr/vδfstr convert δf/vδf to string taking symbolic at into account.
 func (t *T) δfstr(δf *ΔFile) string {
 	s := fmt.Sprintf("@%s·%s", t.AtSymb(δf.Rev), δf.Blocks)