.

go/zodb/storage/fs1/index.go

@@ -80,9 +80,9 @@ 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
-	posValidMask   uint64   = 1<<48 - 1			// 0x0000ffffffffffff
+	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
 )
 
 // IndexSaveError is the error type returned by index save routines
@@ -95,80 +95,77 @@ func (e *IndexSaveError) Error() string {
 }
 
 // Save saves index to a writer
-func (fsi *Index) Save(w io.Writer) error {
-	var err error
-
-	{
-		p := pickle.NewEncoder(w)
+func (fsi *Index) Save(w io.Writer) (err error) {
+	defer func() {
+		if err == nil {
+			return
+		}
 
-		err = p.Encode(fsi.TopPos)
-		if err != nil {
-			goto out
+		if _, ok := err.(*pickle.TypeError); ok {
+			panic(err) // all our types are expected to be supported by pickle
 		}
 
-		var oidb [8]byte
-		var posb [8]byte
-		var oidPrefixCur zodb.Oid	// current oid[0:6] with [6:8] = 00
-		oidBuf := []byte{}		// current oid[6:8]oid[6:8]...
-		posBuf := []byte{}		// current pos[2:8]pos[2:8]...
-		var t [2]interface{}		// tuple for (oid, fsBucket.toString())
-
-		e, _ := fsi.SeekFirst()
-		if e != nil {
-			defer e.Close()
-
-			for  {
-				oid, pos, errStop := e.Next()
-				oidPrefix := oid & oidPrefixMask
-
-				if oidPrefix != oidPrefixCur || errStop != nil {
-					// emit (oid[0:6], oid[6:8]oid[6:8]...pos[2:8]pos[2:8]...)
-					binary.BigEndian.PutUint64(oidb[:], uint64(oidPrefixCur))
-					t[0] = oidb[0:6]
-					t[1] = bytes.Join([][]byte{oidBuf, posBuf}, nil)
-					err = p.Encode(pickle.Tuple(t[:]))
-					if err != nil {
-						goto out
-					}
-
-					oidPrefixCur = oidPrefix
-					oidBuf = oidBuf[:0]
-					posBuf = posBuf[:0]
-				}
+		// otherwise it is an error returned by writer, which should already
+		// have filename & op as context.
+		err = &IndexSaveError{err}
+	}()
 
-				if errStop != nil {
-					break
-				}
+	p := pickle.NewEncoder(w)
 
-				// check pos does not overflow 6 bytes
-				if uint64(pos) & posInvalidMask != 0 {
-					err = fmt.Errorf("entry position too large: 0x%x", pos)
-					goto out
+	err = p.Encode(fsi.TopPos)
+	if err != nil {
+		return err
+	}
+
+	var oidb [8]byte
+	var posb [8]byte
+	var oidPrefixCur zodb.Oid // current oid[0:6] with [6:8] = 00
+	oidBuf := []byte{}        // current oid[6:8]oid[6:8]...
+	posBuf := []byte{}        // current pos[2:8]pos[2:8]...
+	var t [2]interface{}      // tuple for (oid, fsBucket.toString())
+
+	e, _ := fsi.SeekFirst()
+	if e != nil {
+		defer e.Close()
+
+		for {
+			oid, pos, errStop := e.Next()
+			oidPrefix := oid & oidPrefixMask
+
+			if oidPrefix != oidPrefixCur || errStop != nil {
+				// emit (oid[0:6], oid[6:8]oid[6:8]...pos[2:8]pos[2:8]...)
+				binary.BigEndian.PutUint64(oidb[:], uint64(oidPrefixCur))
+				t[0] = oidb[0:6]
+				t[1] = bytes.Join([][]byte{oidBuf, posBuf}, nil)
+				err = p.Encode(pickle.Tuple(t[:]))
+				if err != nil {
+					return err
 				}
 
-				binary.BigEndian.PutUint64(oidb[:], uint64(oid))
-				binary.BigEndian.PutUint64(posb[:], uint64(pos))
+				oidPrefixCur = oidPrefix
+				oidBuf = oidBuf[:0]
+				posBuf = posBuf[:0]
+			}
 
-				oidBuf = append(oidBuf, oidb[6:8]...)
-				posBuf = append(posBuf, posb[2:8]...)
+			if errStop != nil {
+				break
 			}
-		}
 
-		err = p.Encode(pickle.None{})
-	}
+			// check pos does not overflow 6 bytes
+			if uint64(pos)&posInvalidMask != 0 {
+				return fmt.Errorf("entry position too large: 0x%x", pos)
+			}
 
-out:
-	if err == nil {
-		return err
-	}
+			binary.BigEndian.PutUint64(oidb[:], uint64(oid))
+			binary.BigEndian.PutUint64(posb[:], uint64(pos))
 
-	if _, ok := err.(*pickle.TypeError); ok {
-		panic(err)	// all our types are expected to be supported by pickle
+			oidBuf = append(oidBuf, oidb[6:8]...)
+			posBuf = append(posBuf, posb[2:8]...)
+		}
 	}
 
-	// otherwise it is an error returned by writer, which should already
-	// have filename & op as context.
-	return &IndexSaveError{err}
+	err = p.Encode(pickle.None{})
+	return 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
@@ -210,7 +207,7 @@ func (fsi *Index) SaveFile(path string) error {
 type IndexLoadError struct {
 	Filename string
 	Pos      int64
-	Err	 error
+	Err      error
 }
 
 func (e *IndexLoadError) Error() string {
@@ -242,111 +239,101 @@ 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{}
+	var ok bool
+	var xtopPos, xv interface{}
 
-		xr := xbufio.NewReader(r)
-		// by passing bufio.Reader directly we make sure it won't create one internally
-		p := pickle.NewDecoder(xr.Reader)
+	xr := xbufio.NewReader(r)
+	// by passing bufio.Reader directly we make sure it won't create one internally
+	p := pickle.NewDecoder(xr.Reader)
 
+	picklePos = xr.InputOffset()
+	xtopPos, err = p.Decode()
+	if err != nil {
+		return nil, err
+	}
+	topPos, ok := xint64(xtopPos)
+	if !ok {
+		return nil, fmt.Errorf("topPos is %T:%v  (expected int64)", xtopPos, xtopPos)
+	}
+
+	fsi = IndexNew()
+	fsi.TopPos = topPos
+	var oidb [8]byte
+
+loop:
+	for {
+		// load/decode next entry
+		var v pickle.Tuple
 		picklePos = xr.InputOffset()
-		xtopPos, err = p.Decode()
+		xv, err = p.Decode()
 		if err != nil {
-			goto out
-		}
-		topPos, ok := xint64(xtopPos)
-		if !ok {
-			err = fmt.Errorf("topPos is %T:%v  (expected int64)", xtopPos, xtopPos)
-			goto out
+			return nil, err
 		}
 
-		fsi = IndexNew()
-		fsi.TopPos = topPos
-		var oidb [8]byte
-
-	loop:
-		for {
-			// load/decode next entry
-			var v pickle.Tuple
-			picklePos = xr.InputOffset()
-			xv, err = p.Decode()
-			if err != nil {
-				goto out
-			}
-
-			switch xv := xv.(type) {
-			default:
-				err = fmt.Errorf("invalid entry: type %T", xv)
-				goto out
+		switch xv := xv.(type) {
+		default:
+			return nil, fmt.Errorf("invalid entry: type %T", xv)
 
-			case pickle.None:
-				break loop
+		case pickle.None:
+			break loop
 
-			// we accept tuple or list
-			// XXX accept only tuple ?
-			case pickle.Tuple:
-				v = xv
-			case []interface{}:
-				v = pickle.Tuple(xv)
-			}
+		// we accept tuple or list
+		case pickle.Tuple:
+			v = xv
+		case []interface{}:
+			v = pickle.Tuple(xv)
+		}
 
-			// unpack entry tuple -> oidPrefix, fsBucket
-			if len(v) != 2 {
-				err = fmt.Errorf("invalid entry: len = %i", len(v))
-				goto out
-			}
+		// unpack entry tuple -> oidPrefix, fsBucket
+		if len(v) != 2 {
+			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
-			}
-			if l := len(oidPrefixStr); l != 6 {
-				err = fmt.Errorf("invalid oidPrefix: len = %i", l)
-				goto out
-			}
-			copy(oidb[:], oidPrefixStr)
-			oidPrefix := zodb.Oid(binary.BigEndian.Uint64(oidb[:]))
+		// decode oidPrefix
+		xoidPrefixStr := v[0]
+		oidPrefixStr, ok := xoidPrefixStr.(string)
+		if !ok {
+			return nil, fmt.Errorf("invalid oidPrefix: type %T", xoidPrefixStr)
+		}
+		if l := len(oidPrefixStr); l != 6 {
+			return nil, fmt.Errorf("invalid oidPrefix: len = %i", l)
+		}
+		copy(oidb[:], oidPrefixStr)
+		oidPrefix := zodb.Oid(binary.BigEndian.Uint64(oidb[:]))
 
-			// check fsBucket
-			xkvStr := v[1]
-			kvStr, ok := xkvStr.(string)
-			if !ok {
-				err = fmt.Errorf("invalid fsBucket: type %T", xkvStr)
-				goto out
-			}
-			if l := len(kvStr); l % 8 != 0 {
-				err = fmt.Errorf("invalid fsBucket: len = %i", l)
-				goto out
-			}
+		// check fsBucket
+		xkvStr := v[1]
+		kvStr, ok := xkvStr.(string)
+		if !ok {
+			return nil, fmt.Errorf("invalid fsBucket: type %T", xkvStr)
+		}
+		if l := len(kvStr); l%8 != 0 {
+			return nil, fmt.Errorf("invalid fsBucket: len = %i", l)
+		}
 
-			// load btree from fsBucket entries
-			kvBuf := mem.Bytes(kvStr)
+		// load btree from fsBucket entries
+		kvBuf := mem.Bytes(kvStr)
 
-			n := len(kvBuf) / 8
-			oidBuf := kvBuf[:n*2]
-			posBuf := kvBuf[n*2-2:] // NOTE starting 2 bytes behind
+		n := len(kvBuf) / 8
+		oidBuf := kvBuf[:n*2]
+		posBuf := kvBuf[n*2-2:] // NOTE starting 2 bytes behind
 
-			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)
+		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)
 
-				fsi.Set(oid, pos)
-			}
+			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.
@@ -419,10 +406,10 @@ func treeEqual(a, b *fsb.Tree) bool {
 
 // IndexUpdateProgress is data sent by Index.Update to notify about progress
 type IndexUpdateProgress struct {
-	TopPos     int64	// data range to update to; if = -1 -- till EOF
-	TxnIndexed int		// # transactions read/indexed so far
-	Index      *Index	// index built so far
-	Iter       *Iter	// iterator through data	XXX needed?
+	TopPos     int64  // data range to update to; if = -1 -- till EOF
+	TxnIndexed int    // # transactions read/indexed so far
+	Index      *Index // index built so far
+	Iter       *Iter  // iterator through data	XXX needed?
 }
 
 // Update updates in-memory index from r's FileStorage data in byte-range index.TopPos..topPos
@@ -441,11 +428,11 @@ 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 {
-	     return fmt.Errorf("backward update requested")
+		return fmt.Errorf("backward update requested")
 	}
 
 	// XXX another way to compute index: iterate backwards - then
@@ -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)
 		}
@@ -497,7 +484,7 @@ func (index *Index) Update(ctx context.Context, r io.ReaderAt, topPos int64, pro
 		// do not update the index immediately so that in case of error
 		// in the middle of txn's data, index stays consistent and
 		// correct for topPos pointing to previous transaction.
-		update := map[zodb.Oid]int64{}	// XXX malloc every time -> better reuse
+		update := map[zodb.Oid]int64{} // XXX malloc every time -> better reuse
 		for {
 			err = it.NextData()
 			if err != nil {
@@ -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() {
@@ -580,10 +567,10 @@ func indexCorrupt(r io.ReaderAt, format string, argv ...interface{}) *IndexCorru
 
 // IndexVerifyProgress is data sent by Index.Verify to notify about progress
 type IndexVerifyProgress struct {
-	TxnTotal   int			 // total # of transactions to verify; if = -1 -- whole data
+	TxnTotal   int                   // total # of transactions to verify; if = -1 -- whole data
 	TxnChecked int
-	Index      *Index		 // index verification runs for
-	Iter       *Iter		 // iterator through data
+	Index      *Index                // index verification runs for
+	Iter       *Iter                 // iterator through data
 	OidChecked map[zodb.Oid]struct{} // oid checked so far
 }
 
@@ -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
@@ -716,7 +703,7 @@ func (index *Index) VerifyForFile(ctx context.Context, path string, ntxn int, pr
 		return nil, err
 	}
 
-	topPos := fi.Size()	// XXX there might be last TxnInprogress transaction
+	topPos := fi.Size() // XXX there might be last TxnInprogress transaction
 	if index.TopPos != topPos {
 		return nil, indexCorrupt(f, "topPos mismatch: data=%v  index=%v", topPos, index.TopPos)
 	}