fix: streamutils error for zero sized input

util/fileutils/filesize.go

@@ -63,3 +63,7 @@ func GetSizeKb(sizeStr string, defaultSize byte, base int) (int, error) {
 	size, err := parseSizeStr(sizeStr, defaultSize, base)
 	return size / base, err
 }
+
+func GetSizeBytes(sizeStr string, base int) (int, error) {
+	return parseSizeStr(sizeStr, 'B', base)
+}

util/streamutils/streamutils.go

@@ -33,21 +33,30 @@ type SStreamProperty struct {
 type sXZReadAheadReader struct {
 	offset   int64
 	header   []byte
+	hdrEof   bool
 	upstream io.Reader
 }
 
 func newXZReadAheadReader(stream io.Reader) (*sXZReadAheadReader, error) {
 	xzHdr := make([]byte, xz.HeaderLen)
 	n, err := stream.Read(xzHdr)
+	hdrEof := false
 	if err != nil {
-		return nil, errors.Wrap(err, "Read XZ hader")
-	}
-	if n != len(xzHdr) {
-		return nil, errors.Wrap(errors.ErrEOF, "too few header bytes")
+		if errors.Cause(err) == io.EOF {
+			// delay the EOF
+			hdrEof = true
+			xzHdr = xzHdr[:n]
+		} else {
+			return nil, errors.Wrap(err, "Read XZ header")
+		}
+	} else if n != len(xzHdr) {
+		hdrEof = true
+		xzHdr = xzHdr[:n]
 	}
 	return &sXZReadAheadReader{
 		offset:   0,
 		header:   xzHdr,
+		hdrEof:   hdrEof,
 		upstream: stream,
 	}, nil
 }
@@ -57,6 +66,7 @@ func (s *sXZReadAheadReader) IsXz() bool {
 }
 
 func (s *sXZReadAheadReader) Read(buf []byte) (int, error) {
+	bufOffset := 0
 	if s.offset < int64(len(s.header)) {
 		// read from header
 		rdSize := len(s.header) - int(s.offset)
@@ -65,12 +75,19 @@ func (s *sXZReadAheadReader) Read(buf []byte) (int, error) {
 		}
 		n := copy(buf, s.header[s.offset:s.offset+int64(rdSize)])
 		s.offset += int64(n)
-		return n, nil
-	} else {
-		n, err := s.upstream.Read(buf)
-		s.offset += int64(n)
-		return n, err
+		bufOffset = n
 	}
+	// read buffer is full
+	if bufOffset >= len(buf) {
+		return bufOffset, nil
+	}
+	if s.offset >= int64(len(s.header)) && s.hdrEof {
+		return bufOffset, io.EOF
+	}
+
+	n, err := s.upstream.Read(buf[bufOffset:])
+	s.offset += int64(n)
+	return n + bufOffset, err
 }
 
 func StreamPipe(upstream io.Reader, writer io.Writer, CalChecksum bool, callback func(savedTotal int64)) (*SStreamProperty, error) {

util/streamutils/streamutils_test.go

@@ -28,6 +28,8 @@ func TestStreamPipe(t *testing.T) {
 	for _, bufSize := range []int{
 		324553,
 		2312,
+		5,
+		0,
 	} {
 		seed := rand.New(rand.NewSource(int64(bufSize)))
 		buf := make([]byte, bufSize)
@@ -45,7 +47,9 @@ func TestStreamPipe(t *testing.T) {
 			t.Errorf("Steampipe fail %s", err)
 		} else {
 			t.Logf("stat %#v", stat)
-			if !reflect.DeepEqual(buf, outBuf.Bytes()) {
+			if len(buf) != len(outBuf.Bytes()) {
+				t.Errorf("input len %d != output len %d", len(buf), len(outBuf.Bytes()) )
+			} else if len(buf) > 0 && !reflect.DeepEqual(buf, outBuf.Bytes()) {
 				t.Errorf("input != output")
 			}
 		}
@@ -56,6 +60,8 @@ func TestStreamPipeXZ(t *testing.T) {
 	for _, bufSize := range []int{
 		324553,
 		2312,
+		5,
+		0,
 	} {
 		seed := rand.New(rand.NewSource(int64(bufSize)))
 		buf := make([]byte, bufSize)
@@ -97,7 +103,9 @@ func TestStreamPipeXZ(t *testing.T) {
 			t.Errorf("Steampipe fail %s", err)
 		} else {
 			t.Logf("stat %#v", stat)
-			if !reflect.DeepEqual(buf, outBuf.Bytes()) {
+			if len(buf) != len(outBuf.Bytes()) {
+				t.Errorf("input len %d != output len %d", len(buf), len(outBuf.Bytes()) )
+			} else if len(buf) > 0 && !reflect.DeepEqual(buf, outBuf.Bytes()) {
 				t.Errorf("input != output")
 			}
 		}