.

go/zodb/storage/fs1/index.go

@@ -80,8 +80,8 @@ func IndexNew() *Index {
 // oid[6:8]oid[6:8]oid[6:8]...pos[2:8]pos[2:8]pos[2:8]...
 
 const (
-	oidPrefixMask  zodb.Oid = (1<<64-1) ^ (1<<16 - 1)	// 0xffffffffffff0000
-	posInvalidMask uint64   = (1<<64-1) ^ (1<<48 - 1)	// 0xffff000000000000
+	oidPrefixMask  zodb.Oid = (1<<64 - 1) ^ (1<<16 - 1) // 0xffffffffffff0000
+	posInvalidMask uint64   = (1<<64 - 1) ^ (1<<48 - 1) // 0xffff000000000000
 	posValidMask   uint64   = 1<<48 - 1                 // 0x0000ffffffffffff
 )
 
@@ -95,15 +95,26 @@ func (e *IndexSaveError) Error() string {
 }
 
 // Save saves index to a writer
-func (fsi *Index) Save(w io.Writer) error {
-	var err error
+func (fsi *Index) Save(w io.Writer) (err error) {
+	defer func() {
+		if err == nil {
+			return
+		}
+
+		if _, ok := err.(*pickle.TypeError); ok {
+			panic(err) // all our types are expected to be supported by pickle
+		}
+
+		// otherwise it is an error returned by writer, which should already
+		// have filename & op as context.
+		err = &IndexSaveError{err}
+	}()
 
-	{
 	p := pickle.NewEncoder(w)
 
 	err = p.Encode(fsi.TopPos)
 	if err != nil {
-			goto out
+		return err
 	}
 
 	var oidb [8]byte
@@ -128,7 +139,7 @@ func (fsi *Index) Save(w io.Writer) error {
 				t[1] = bytes.Join([][]byte{oidBuf, posBuf}, nil)
 				err = p.Encode(pickle.Tuple(t[:]))
 				if err != nil {
-						goto out
+					return err
 				}
 
 				oidPrefixCur = oidPrefix
@@ -141,9 +152,8 @@ func (fsi *Index) Save(w io.Writer) error {
 			}
 
 			// check pos does not overflow 6 bytes
-				if uint64(pos) & posInvalidMask != 0 {
-					err = fmt.Errorf("entry position too large: 0x%x", pos)
-					goto out
+			if uint64(pos)&posInvalidMask != 0 {
+				return fmt.Errorf("entry position too large: 0x%x", pos)
 			}
 
 			binary.BigEndian.PutUint64(oidb[:], uint64(oid))
@@ -155,20 +165,7 @@ func (fsi *Index) Save(w io.Writer) error {
 	}
 
 	err = p.Encode(pickle.None{})
-	}
-
-out:
-	if err == nil {
 	return err
-	}
-
-	if _, ok := err.(*pickle.TypeError); ok {
-		panic(err)	// all our types are expected to be supported by pickle
-	}
-
-	// otherwise it is an error returned by writer, which should already
-	// have filename & op as context.
-	return &IndexSaveError{err}
 }
 
 // SaveFile saves index to a file @ path.
@@ -178,9 +175,9 @@ out:
 // updated only with complete index data.
 func (fsi *Index) SaveFile(path string) error {
 	dir, name := filepath.Dir(path), filepath.Base(path)
-	f, err := ioutil.TempFile(dir, name + ".tmp")
+	f, err := ioutil.TempFile(dir, name+".tmp")
 	if err != nil {
-		return &IndexSaveError{err}	// XXX needed?
+		return &IndexSaveError{err}
 	}
 
 	// use buffering for f (ogórek does not buffer itself on encoding)
@@ -193,14 +190,14 @@ func (fsi *Index) SaveFile(path string) error {
 		os.Remove(f.Name())
 		err = err1
 		if err == nil {
-			err = &IndexSaveError{xerr.First(err2, err3)}	// XXX needed?
+			err = &IndexSaveError{xerr.First(err2, err3)}
 		}
 		return err
 	}
 
 	err = os.Rename(f.Name(), path)
 	if err != nil {
-		return &IndexSaveError{err}	// XXX needed?
+		return &IndexSaveError{err}
 	}
 
 	return nil
@@ -242,8 +239,12 @@ func xint64(xv interface{}) (v int64, ok bool) {
 // LoadIndex loads index from a reader
 func LoadIndex(r io.Reader) (fsi *Index, err error) {
 	var picklePos int64
+	defer func() {
+		if err != nil {
+			err = &IndexLoadError{xio.Name(r), picklePos, err}
+		}
+	}()
 
-	{
 	var ok bool
 	var xtopPos, xv interface{}
 
@@ -254,38 +255,35 @@ func LoadIndex(r io.Reader) (fsi *Index, err error) {
 	picklePos = xr.InputOffset()
 	xtopPos, err = p.Decode()
 	if err != nil {
-			goto out
+		return nil, err
 	}
 	topPos, ok := xint64(xtopPos)
 	if !ok {
-			err = fmt.Errorf("topPos is %T:%v  (expected int64)", xtopPos, xtopPos)
-			goto out
+		return nil, fmt.Errorf("topPos is %T:%v  (expected int64)", xtopPos, xtopPos)
 	}
 
 	fsi = IndexNew()
 	fsi.TopPos = topPos
 	var oidb [8]byte
 
-	loop:
+loop:
 	for {
 		// load/decode next entry
 		var v pickle.Tuple
 		picklePos = xr.InputOffset()
 		xv, err = p.Decode()
 		if err != nil {
-				goto out
+			return nil, err
 		}
 
 		switch xv := xv.(type) {
 		default:
-				err = fmt.Errorf("invalid entry: type %T", xv)
-				goto out
+			return nil, fmt.Errorf("invalid entry: type %T", xv)
 
 		case pickle.None:
 			break loop
 
 		// we accept tuple or list
-			// XXX accept only tuple ?
 		case pickle.Tuple:
 			v = xv
 		case []interface{}:
@@ -294,20 +292,17 @@ func LoadIndex(r io.Reader) (fsi *Index, err error) {
 
 		// unpack entry tuple -> oidPrefix, fsBucket
 		if len(v) != 2 {
-				err = fmt.Errorf("invalid entry: len = %i", len(v))
-				goto out
+			return nil, fmt.Errorf("invalid entry: len = %i", len(v))
 		}
 
 		// decode oidPrefix
 		xoidPrefixStr := v[0]
 		oidPrefixStr, ok := xoidPrefixStr.(string)
 		if !ok {
-				err = fmt.Errorf("invalid oidPrefix: type %T", xoidPrefixStr)
-				goto out
+			return nil, fmt.Errorf("invalid oidPrefix: type %T", xoidPrefixStr)
 		}
 		if l := len(oidPrefixStr); l != 6 {
-				err = fmt.Errorf("invalid oidPrefix: len = %i", l)
-				goto out
+			return nil, fmt.Errorf("invalid oidPrefix: len = %i", l)
 		}
 		copy(oidb[:], oidPrefixStr)
 		oidPrefix := zodb.Oid(binary.BigEndian.Uint64(oidb[:]))
@@ -316,12 +311,10 @@ func LoadIndex(r io.Reader) (fsi *Index, err error) {
 		xkvStr := v[1]
 		kvStr, ok := xkvStr.(string)
 		if !ok {
-				err = fmt.Errorf("invalid fsBucket: type %T", xkvStr)
-				goto out
+			return nil, fmt.Errorf("invalid fsBucket: type %T", xkvStr)
 		}
-			if l := len(kvStr); l % 8 != 0 {
-				err = fmt.Errorf("invalid fsBucket: len = %i", l)
-				goto out
+		if l := len(kvStr); l%8 != 0 {
+			return nil, fmt.Errorf("invalid fsBucket: len = %i", l)
 		}
 
 		// load btree from fsBucket entries
@@ -331,7 +324,7 @@ func LoadIndex(r io.Reader) (fsi *Index, err error) {
 		oidBuf := kvBuf[:n*2]
 		posBuf := kvBuf[n*2-2:] // NOTE starting 2 bytes behind
 
-			for i:=0; i<n; i++ {
+		for i := 0; i < n; i++ {
 			oid := zodb.Oid(binary.BigEndian.Uint16(oidBuf[i*2:]))
 			oid |= oidPrefix
 			pos := int64(binary.BigEndian.Uint64(posBuf[i*6:]) & posValidMask)
@@ -339,14 +332,8 @@ func LoadIndex(r io.Reader) (fsi *Index, err error) {
 			fsi.Set(oid, pos)
 		}
 	}
-	}
-
-out:
-	if err == nil {
-		return fsi, err
-	}
 
-	return nil, &IndexLoadError{xio.Name(r), picklePos, err}
+	return fsi, nil
 }
 
 // LoadIndexFile loads index from a file @ path.
@@ -441,7 +428,7 @@ type IndexUpdateProgress struct {
 // On success returned error is nil and index.TopPos is set to either:
 // - topPos (if it is != -1), or
 // - r's position at which read got EOF (if topPos=-1).
-func (index *Index) Update(ctx context.Context, r io.ReaderAt, topPos int64, progress func (*IndexUpdateProgress)) (err error) {
+func (index *Index) Update(ctx context.Context, r io.ReaderAt, topPos int64, progress func(*IndexUpdateProgress)) (err error) {
 	defer xerr.Contextf(&err, "%s: reindex %v..%v", xio.Name(r), index.TopPos, topPos)
 
 	if topPos >= 0 && index.TopPos > topPos {
@@ -485,7 +472,7 @@ func (index *Index) Update(ctx context.Context, r io.ReaderAt, topPos int64, pro
 
 		// check for topPos overlapping txn & whether we are done.
 		// topPos=-1 will never match here
-		if it.Txnh.Pos < topPos && (it.Txnh.Pos + it.Txnh.Len) > topPos {
+		if it.Txnh.Pos < topPos && (it.Txnh.Pos+it.Txnh.Len) > topPos {
 			return fmt.Errorf("transaction %v @%v overlaps topPos boundary",
 				it.Txnh.Tid, it.Txnh.Pos)
 		}
@@ -547,7 +534,7 @@ func BuildIndex(ctx context.Context, r io.ReaderAt, progress func(*IndexUpdatePr
 func BuildIndexForFile(ctx context.Context, path string, progress func(*IndexUpdateProgress)) (index *Index, err error) {
 	f, err := os.Open(path)
 	if err != nil {
-		return IndexNew(), err // XXX add err ctx?
+		return IndexNew(), err
 	}
 
 	defer func() {
@@ -637,7 +624,7 @@ func (index *Index) Verify(ctx context.Context, r io.ReaderAt, ntxn int, progres
 				wholeData = true
 				break
 			}
-			return oidChecked, err		// XXX err ctx
+			return oidChecked, err
 		}
 
 		for {
@@ -646,7 +633,7 @@ func (index *Index) Verify(ctx context.Context, r io.ReaderAt, ntxn int, progres
 				if err == io.EOF {
 					break
 				}
-				return oidChecked, err	// XXX err ctx
+				return oidChecked, err
 			}
 
 			// if oid was already checked - do not check index anymore
@@ -700,7 +687,7 @@ func (index *Index) Verify(ctx context.Context, r io.ReaderAt, ntxn int, progres
 // VerifyForFile checks index correctness against FileStorage data in file @ path
 //
 // See Verify for semantic description.
-func (index *Index) VerifyForFile(ctx context.Context, path string, ntxn int, progress func (*IndexVerifyProgress)) (oidChecked map[zodb.Oid]struct{}, err error) {
+func (index *Index) VerifyForFile(ctx context.Context, path string, ntxn int, progress func(*IndexVerifyProgress)) (oidChecked map[zodb.Oid]struct{}, err error) {
 	f, err := os.Open(path)
 	if err != nil {
 		return nil, err