1 files changed, 16 insertions, 23 deletions

diff --git a/vendor/github.com/klauspost/compress/flate/deflate.go b/vendor/github.com/klauspost/compress/flate/deflate.go
index d9948ab40..2b101d26b 100644
--- a/vendor/github.com/klauspost/compress/flate/deflate.go
+++ b/vendor/github.com/klauspost/compress/flate/deflate.go
@@ -48,6 +48,8 @@ const (
 	maxHashOffset       = 1 << 24
 
 	skipNever = math.MaxInt32
+
+	debugDeflate = false
 )
 
 type compressionLevel struct {
@@ -59,15 +61,13 @@ type compressionLevel struct {
 // See https://blog.klauspost.com/rebalancing-deflate-compression-levels/
 var levels = []compressionLevel{
 	{}, // 0
-	// Level 1-4 uses specialized algorithm - values not used
+	// Level 1-6 uses specialized algorithm - values not used
 	{0, 0, 0, 0, 0, 1},
 	{0, 0, 0, 0, 0, 2},
 	{0, 0, 0, 0, 0, 3},
 	{0, 0, 0, 0, 0, 4},
-	// For levels 5-6 we don't bother trying with lazy matches.
-	// Lazy matching is at least 30% slower, with 1.5% increase.
-	{6, 0, 12, 8, 12, 5},
-	{8, 0, 24, 16, 16, 6},
+	{0, 0, 0, 0, 0, 5},
+	{0, 0, 0, 0, 0, 6},
 	// Levels 7-9 use increasingly more lazy matching
 	// and increasingly stringent conditions for "good enough".
 	{8, 8, 24, 16, skipNever, 7},
@@ -203,9 +203,8 @@ func (d *compressor) writeBlockSkip(tok *tokens, index int, eof bool) error {
 // This is much faster than doing a full encode.
 // Should only be used after a start/reset.
 func (d *compressor) fillWindow(b []byte) {
-	// Do not fill window if we are in store-only mode,
-	// use constant or Snappy compression.
-	if d.level == 0 {
+	// Do not fill window if we are in store-only or huffman mode.
+	if d.level <= 0 {
 		return
 	}
 	if d.fast != nil {
@@ -368,7 +367,7 @@ func (d *compressor) deflateLazy() {
 	// Sanity enables additional runtime tests.
 	// It's intended to be used during development
 	// to supplement the currently ad-hoc unit tests.
-	const sanity = false
+	const sanity = debugDeflate
 
 	if d.windowEnd-s.index < minMatchLength+maxMatchLength && !d.sync {
 		return
@@ -667,6 +666,7 @@ func (d *compressor) init(w io.Writer, level int) (err error) {
 	default:
 		return fmt.Errorf("flate: invalid compression level %d: want value in range [-2, 9]", level)
 	}
+	d.level = level
 	return nil
 }
 
@@ -720,6 +720,7 @@ func (d *compressor) close() error {
 		return d.w.err
 	}
 	d.w.flush()
+	d.w.reset(nil)
 	return d.w.err
 }
 
@@ -750,8 +751,7 @@ func NewWriter(w io.Writer, level int) (*Writer, error) {
 // can only be decompressed by a Reader initialized with the
 // same dictionary.
 func NewWriterDict(w io.Writer, level int, dict []byte) (*Writer, error) {
-	dw := &dictWriter{w}
-	zw, err := NewWriter(dw, level)
+	zw, err := NewWriter(w, level)
 	if err != nil {
 		return nil, err
 	}
@@ -760,14 +760,6 @@ func NewWriterDict(w io.Writer, level int, dict []byte) (*Writer, error) {
 	return zw, err
 }
 
-type dictWriter struct {
-	w io.Writer
-}
-
-func (w *dictWriter) Write(b []byte) (n int, err error) {
-	return w.w.Write(b)
-}
-
 // A Writer takes data written to it and writes the compressed
 // form of that data to an underlying writer (see NewWriter).
 type Writer struct {
@@ -805,11 +797,12 @@ func (w *Writer) Close() error {
 // the result of NewWriter or NewWriterDict called with dst
 // and w's level and dictionary.
 func (w *Writer) Reset(dst io.Writer) {
-	if dw, ok := w.d.w.writer.(*dictWriter); ok {
+	if len(w.dict) > 0 {
 		// w was created with NewWriterDict
-		dw.w = dst
-		w.d.reset(dw)
-		w.d.fillWindow(w.dict)
+		w.d.reset(dst)
+		if dst != nil {
+			w.d.fillWindow(w.dict)
+		}
 	} else {
 		// w was created with NewWriter
 		w.d.reset(dst)