.

t/neo/storage/fs1/index.go

@@ -16,9 +16,14 @@
 package fs1
 
 import (
+	"bufio"
 	"bytes"
 	"encoding/binary"
+	"fmt"
 	"io"
+	"net"
+	"os"
+	"strconv"
 
 	"../../zodb"
 	"./fsb"
@@ -73,6 +78,8 @@ func (fsi *fsIndex) Save(topPos int64, w io.Writer) error {
 	p := pickle.NewEncoder(w)
 
 	err := p.Encode(topPos)
+
+	{
 		if err != nil {
 			goto out
 		}
@@ -84,7 +91,6 @@ func (fsi *fsIndex) Save(topPos int64, w io.Writer) error {
 		posBuf := []byte{}		// current pos[0:6]pos[0:6]...
 		var t [2]interface{}		// tuple for (oid, fsBucket.toString())
 
-
 		e, err := fsi.SeekFirst()
 		if err == io.EOF {	// always only io.EOF indicating an empty btree
 			goto skip
@@ -123,15 +129,16 @@ func (fsi *fsIndex) Save(topPos int64, w io.Writer) error {
 
 		e.Close()
 
-skip:
+	skip:
 		err = p.Encode(pickle.None{})
+	}
 
 out:
 	if err == nil {
 		return err
 	}
 
-	if _, ok := err.(pikle.TypeError); ok {
+	if _, ok := err.(*pickle.TypeError); ok {
 		panic(err)	// all our types are expected to be supported by pickle
 	}
 
@@ -140,26 +147,42 @@ out:
 	return &IndexIOError{"save", err}
 }
 
+
+// IndexLoadError is the errortype returned by index load routines
+type IndexLoadError struct {
+	Filename string
+	Pos      int64
+	Err	 error
+}
+
+func (e *IndexLoadError) Error() string {
+	s := e.Filename
+	if s != "" {
+		s += ": "
+	}
+	s += "pickle @" + strconv.FormatInt(e.Pos, 10) + ": "
+	s += e.Err.Error()
+	return s
+}
+
 // LoadIndex loads index from a reader
 func LoadIndex(r io.Reader) (topPos int64, fsi *fsIndex, err error) {
-	p := pickle.NewDecoder(r)
-
-	// if we can know file position we can show it in error context
-	rseek, _ := r.(io.Seeker)
-	var rpos int64
-	decode := func() (interface{}, error) {
-		if rseek != nil {
-			rpos = rseek.Seek(...)	// XXX not ok as p buffers r internally
-		}
-	}
+	xr := NewBufReader(r)
+	// by passing bufio.Reader directly we make sure it won't create one internally
+	p := pickle.NewDecoder(xr.Reader)
+	var picklePos int64
 
+	{
+		picklePos = xr.InputOffset()
 		xtopPos, err := p.Decode()
 		if err != nil {
-		// TODO err
+			goto out
 		}
-	topPos, ok := xtopPos.(int64)
+		var ok bool
+		topPos, ok = xtopPos.(int64)
 		if !ok {
-		// TODO err
+			err = fmt.Errorf("topPos is %T  (expected int64)", xtopPos)
+			goto out
 		}
 
 		fsi = &fsIndex{}	// TODO cmpFunc ...
@@ -168,14 +191,17 @@ func LoadIndex(r io.Reader) (topPos int64, fsi *fsIndex, err error) {
 
 loop:
 		for {
+			// load/decode next entry
+			picklePos = xr.InputOffset()
 			xv, err := p.Decode()
 			if err != nil {
-			// TODO err
+				goto out
 			}
+
 			switch xv.(type) {
 			default:
-			// TODO err
-			break
+				err = fmt.Errorf("invalid entry: type %T", xv)
+				goto out
 
 			case pickle.None:
 				break loop
@@ -184,25 +210,40 @@ loop:
 				// so far ok
 			}
 
+			// unpack entry tuple -> oidPrefix, fsBucket
 			v := xv.([]interface{})
 			if len(v) != 2 {
-			// TODO err
+				err = fmt.Errorf("invalid entry: len = %i", len(v))
+				goto out
 			}
 
+			// decode oidPrefix
 			xoidPrefixStr := v[0]
 			oidPrefixStr, ok := xoidPrefixStr.(string)
-		if !ok || len(oidPrefixStr) != 6 {
-			// TODO
+			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[:]))
 
+			// check fsBucket
 			xkvStr := v[1]
 			kvStr, ok := xkvStr.(string)
-		if !ok || len(kvStr) % 8 != 0 {
-			// TODO
+			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
 			}
 
+			// load btree from fsBucket entries
 			kvBuf := mem.Bytes(kvStr)
 
 			n := len(kvBuf) / 8
@@ -213,26 +254,66 @@ loop:
 				oid := zodb.Oid(binary.BigEndian.Uint16(oidBuf[i*2:]))
 				oid |= oidPrefix
 				copy(posb[2:], posBuf[i*6:])
-			tid := zodb.Tid(binary.BigEndian.Uint64(posb[:]))
+				pos := int64(binary.BigEndian.Uint64(posb[:]))
 
-			fsi.Set(oid, tid)
+				fsi.Set(oid, pos)
+			}
 		}
 	}
-
-	return topPos, fsi, nil
 
 out:
 	if err == nil {
 		return topPos, fsi, err
 	}
 
-	rname := IOName(r)
+	return 0, nil, &IndexLoadError{IOName(r), picklePos, err}
+}
+
+
+
+// CountReader is an io.Reader that count total bytes read.
+type CountReader struct {
+	io.Reader
+	nread int64
+}
 
-	// same for file name
-	rname, _ := r.(interface{ Name() string })
+func (r *CountReader) Read(p []byte) (int, error) {
+	n, err := r.Reader.Read(p)
+	r.nread += int64(n)
+	return n, err
+}
 
+// InputOffset returns current position in input stream
+func (r *CountReader) InputOffset() int64 {
+	return r.nread
 }
 
+// BufReader is a bufio.Reader + bell & whistles
+type BufReader struct {
+	*bufio.Reader
+	cr *CountReader
+}
+
+func NewBufReader(r io.Reader) *BufReader {
+	// idempotent(BufReader)
+	if r, ok := r.(*BufReader); ok {
+		return r
+	}
+
+	// idempotent(CountReader)
+	cr, ok := r.(*CountReader)
+	if !ok {
+		cr = &CountReader{r, 0}
+	}
+
+
+	return &BufReader{bufio.NewReader(cr), cr}
+}
+
+// InputOffset returns current position in input stream
+func (r *BufReader) InputOffset() int64 {
+	return r.cr.InputOffset() - int64(r.Reader.Buffered())
+}
 
 // IOName returns a "filename" associated with io.Reader, io.Writer, net.Conn, ...
 // if name cannot be deterined - "" is returned.
@@ -245,14 +326,14 @@ func IOName(f interface {}) string {
 
 	case net.Conn:
 		// XXX not including LocalAddr is ok?
-		return f.RemoteAddr.String()
+		return f.RemoteAddr().String()
 
 	case *io.LimitedReader:
 		return IOName(f.R)
 
 
 	case *io.PipeReader:
-		fallthrough
+		return "pipe"
 	case *io.PipeWriter:
 		return "pipe"