1 files changed, 61 insertions, 54 deletions

diff --git a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/journal/journal.go b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/journal/journal.go
index b522c76e6..6519ec660 100644
--- a/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/journal/journal.go
+++ b/Godeps/_workspace/src/github.com/syndtr/goleveldb/leveldb/journal/journal.go
@@ -79,10 +79,10 @@ package journal
 
 import (
 	"encoding/binary"
-	"errors"
 	"fmt"
 	"io"
 
+	"github.com/syndtr/goleveldb/leveldb/errors"
 	"github.com/syndtr/goleveldb/leveldb/util"
 )
 
@@ -103,18 +103,18 @@ type flusher interface {
 	Flush() error
 }
 
-// DroppedError is the error type that passed to Dropper.Drop method.
-type DroppedError struct {
+// ErrCorrupted is the error type that generated by corrupted block or chunk.
+type ErrCorrupted struct {
 	Size   int
 	Reason string
 }
 
-func (e DroppedError) Error() string {
-	return fmt.Sprintf("leveldb/journal: dropped %d bytes: %s", e.Size, e.Reason)
+func (e *ErrCorrupted) Error() string {
+	return fmt.Sprintf("leveldb/journal: block/chunk corrupted: %s (%d bytes)", e.Reason, e.Size)
 }
 
 // Dropper is the interface that wrap simple Drop method. The Drop
-// method will be called when the journal reader dropping a chunk.
+// method will be called when the journal reader dropping a block or chunk.
 type Dropper interface {
 	Drop(err error)
 }
@@ -158,76 +158,78 @@ func NewReader(r io.Reader, dropper Dropper, strict, checksum bool) *Reader {
 	}
 }
 
+var errSkip = errors.New("leveldb/journal: skipped")
+
+func (r *Reader) corrupt(n int, reason string, skip bool) error {
+	if r.dropper != nil {
+		r.dropper.Drop(&ErrCorrupted{n, reason})
+	}
+	if r.strict && !skip {
+		r.err = errors.NewErrCorrupted(nil, &ErrCorrupted{n, reason})
+		return r.err
+	}
+	return errSkip
+}
+
 // nextChunk sets r.buf[r.i:r.j] to hold the next chunk's payload, reading the
 // next block into the buffer if necessary.
-func (r *Reader) nextChunk(wantFirst, skip bool) error {
+func (r *Reader) nextChunk(first bool) error {
 	for {
 		if r.j+headerSize <= r.n {
 			checksum := binary.LittleEndian.Uint32(r.buf[r.j+0 : r.j+4])
 			length := binary.LittleEndian.Uint16(r.buf[r.j+4 : r.j+6])
 			chunkType := r.buf[r.j+6]
 
-			var err error
 			if checksum == 0 && length == 0 && chunkType == 0 {
 				// Drop entire block.
-				err = DroppedError{r.n - r.j, "zero header"}
+				m := r.n - r.j
 				r.i = r.n
 				r.j = r.n
+				return r.corrupt(m, "zero header", false)
 			} else {
 				m := r.n - r.j
 				r.i = r.j + headerSize
 				r.j = r.j + headerSize + int(length)
 				if r.j > r.n {
 					// Drop entire block.
-					err = DroppedError{m, "chunk length overflows block"}
 					r.i = r.n
 					r.j = r.n
+					return r.corrupt(m, "chunk length overflows block", false)
 				} else if r.checksum && checksum != util.NewCRC(r.buf[r.i-1:r.j]).Value() {
 					// Drop entire block.
-					err = DroppedError{m, "checksum mismatch"}
 					r.i = r.n
 					r.j = r.n
+					return r.corrupt(m, "checksum mismatch", false)
 				}
 			}
-			if wantFirst && err == nil && chunkType != fullChunkType && chunkType != firstChunkType {
-				if skip {
-					// The chunk are intentionally skipped.
-					if chunkType == lastChunkType {
-						skip = false
-					}
-					continue
-				} else {
-					// Drop the chunk.
-					err = DroppedError{r.j - r.i + headerSize, "orphan chunk"}
-				}
-			}
-			if err == nil {
-				r.last = chunkType == fullChunkType || chunkType == lastChunkType
-			} else {
-				if r.dropper != nil {
-					r.dropper.Drop(err)
-				}
-				if r.strict {
-					r.err = err
-				}
+			if first && chunkType != fullChunkType && chunkType != firstChunkType {
+				m := r.j - r.i
+				r.i = r.j
+				// Report the error, but skip it.
+				return r.corrupt(m+headerSize, "orphan chunk", true)
 			}
-			return err
+			r.last = chunkType == fullChunkType || chunkType == lastChunkType
+			return nil
 		}
+
+		// The last block.
 		if r.n < blockSize && r.n > 0 {
-			// This is the last block.
-			if r.j != r.n {
-				r.err = io.ErrUnexpectedEOF
-			} else {
-				r.err = io.EOF
+			if !first {
+				return r.corrupt(0, "missing chunk part", false)
 			}
+			r.err = io.EOF
 			return r.err
 		}
+
+		// Read block.
 		n, err := io.ReadFull(r.r, r.buf[:])
-		if err != nil && err != io.ErrUnexpectedEOF {
-			r.err = err
-			return r.err
+		if err != nil && err != io.EOF && err != io.ErrUnexpectedEOF {
+			return err
 		}
 		if n == 0 {
+			if !first {
+				return r.corrupt(0, "missing chunk part", false)
+			}
 			r.err = io.EOF
 			return r.err
 		}
@@ -237,29 +239,26 @@ func (r *Reader) nextChunk(wantFirst, skip bool) error {
 
 // Next returns a reader for the next journal. It returns io.EOF if there are no
 // more journals. The reader returned becomes stale after the next Next call,
-// and should no longer be used.
+// and should no longer be used. If strict is false, the reader will returns
+// io.ErrUnexpectedEOF error when found corrupted journal.
 func (r *Reader) Next() (io.Reader, error) {
 	r.seq++
 	if r.err != nil {
 		return nil, r.err
 	}
-	skip := !r.last
+	r.i = r.j
 	for {
-		r.i = r.j
-		if r.nextChunk(true, skip) != nil {
-			// So that 'orphan chunk' drop will be reported.
-			skip = false
-		} else {
+		if err := r.nextChunk(true); err == nil {
 			break
-		}
-		if r.err != nil {
-			return nil, r.err
+		} else if err != errSkip {
+			return nil, err
 		}
 	}
 	return &singleReader{r, r.seq, nil}, nil
 }
 
-// Reset resets the journal reader, allows reuse of the journal reader.
+// Reset resets the journal reader, allows reuse of the journal reader. Reset returns
+// last accumulated error.
 func (r *Reader) Reset(reader io.Reader, dropper Dropper, strict, checksum bool) error {
 	r.seq++
 	err := r.err
@@ -296,7 +295,11 @@ func (x *singleReader) Read(p []byte) (int, error) {
 		if r.last {
 			return 0, io.EOF
 		}
-		if x.err = r.nextChunk(false, false); x.err != nil {
+		x.err = r.nextChunk(false)
+		if x.err != nil {
+			if x.err == errSkip {
+				x.err = io.ErrUnexpectedEOF
+			}
 			return 0, x.err
 		}
 	}
@@ -320,7 +323,11 @@ func (x *singleReader) ReadByte() (byte, error) {
 		if r.last {
 			return 0, io.EOF
 		}
-		if x.err = r.nextChunk(false, false); x.err != nil {
+		x.err = r.nextChunk(false)
+		if x.err != nil {
+			if x.err == errSkip {
+				x.err = io.ErrUnexpectedEOF
+			}
 			return 0, x.err
 		}
 	}