Fix excess checksum bytes bug.

xichen2020 · Feb 28, 2019 · 21bcf6e · 21bcf6e
1 parent 53cb7e6
commit 21bcf6e
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Showing 2 changed files with 7 additions and 6 deletions.
diff --git a/digest/digest.go b/digest/digest.go
@@ -27,14 +27,14 @@ func Checksum(buf []byte) uint32 {
 
 // Validate validates the data in the buffer against its checksum.
 // The checksum is at the end of the buffer occupying `numChecksumBytes` bytes.
-func Validate(b []byte) error {
+func Validate(b []byte) ([]byte, error) {
 	if len(b) < numChecksumBytes {
-		return errChecksumMismatch
+		return nil, errChecksumMismatch
 	}
 	checksumStart := len(b) - numChecksumBytes
 	expectedChecksum := ToBuffer(b[checksumStart:]).ReadDigest()
 	if Checksum(b[:checksumStart]) != expectedChecksum {
-		return errChecksumMismatch
+		return nil, errChecksumMismatch
 	}
-	return nil
+	return b[:checksumStart], nil
 }
diff --git a/persist/fs/reader.go b/persist/fs/reader.go
@@ -390,11 +390,12 @@ func (r *reader) mmapReadAllAndValidateChecksum(fd *os.File) ([]byte, error) {
 	if res.Warning != nil {
 		r.logger.Warnf("warning during memory mapping info file %s: %s", fd.Name(), res.Warning)
 	}
-	if err := digest.Validate(res.Result); err != nil {
+	validatedBytes, err := digest.Validate(res.Result)
+	if err != nil {
 		mmap.Munmap(res.Result)
 		return nil, err
 	}
-	return res.Result, nil
+	return validatedBytes, nil
 }
 
 func (r *reader) readDocIDSet(data []byte) (index.DocIDSet, []byte, error) {