upgrade github.com/klauspost/compress to v1.15.1 and remove the need for runtime finalizers (#889)

* upgrade github.com/klauspost/compress to v1.15.1 and remove the need for runtime finalizers

* remove lowmem config

Author: Achille

compress/zstd/zstd.go

@@ -3,7 +3,6 @@ package zstd
 
 import (
 	"io"
-	"runtime"
 	"sync"
 
 	"github.com/klauspost/compress/zstd"
@@ -29,19 +28,17 @@ func (c *Codec) Name() string { return "zstd" }
 // NewReader implements the compress.Codec interface.
 func (c *Codec) NewReader(r io.Reader) io.ReadCloser {
 	p := new(reader)
-	if dec, _ := decoderPool.Get().(*decoder); dec == nil {
-		z, err := zstd.NewReader(r)
+	if p.dec, _ = decoderPool.Get().(*zstd.Decoder); p.dec != nil {
+		p.dec.Reset(r)
+	} else {
+		z, err := zstd.NewReader(r,
+			zstd.WithDecoderConcurrency(1),
+		)
 		if err != nil {
 			p.err = err
 		} else {
-			p.dec = &decoder{z}
-			// We need a finalizer because the reader spawns goroutines
-			// that will only be stopped if the Close method is called.
-			runtime.SetFinalizer(p.dec, (*decoder).finalize)
+			p.dec = z
 		}
-	} else {
-		p.dec = dec
-		p.err = dec.Reset(r)
 	}
 	return p
 }
@@ -57,18 +54,10 @@ func (c *Codec) zstdLevel() zstd.EncoderLevel {
 	return zstd.EncoderLevelFromZstd(c.level())
 }
 
-var decoderPool sync.Pool // *decoder
-
-type decoder struct {
-	*zstd.Decoder
-}
-
-func (d *decoder) finalize() {
-	d.Close()
-}
+var decoderPool sync.Pool // *zstd.Decoder
 
 type reader struct {
-	dec *decoder
+	dec *zstd.Decoder
 	err error
 }
 
@@ -88,6 +77,9 @@ func (r *reader) Read(p []byte) (int, error) {
 	if r.err != nil {
 		return 0, r.err
 	}
+	if r.dec == nil {
+		return 0, io.EOF
+	}
 	return r.dec.Read(p)
 }
 
@@ -96,21 +88,25 @@ func (r *reader) WriteTo(w io.Writer) (int64, error) {
 	if r.err != nil {
 		return 0, r.err
 	}
+	if r.dec == nil {
+		return 0, io.ErrClosedPipe
+	}
 	return r.dec.WriteTo(w)
 }
 
 // NewWriter implements the compress.Codec interface.
 func (c *Codec) NewWriter(w io.Writer) io.WriteCloser {
 	p := new(writer)
-	if enc, _ := c.encoderPool.Get().(*encoder); enc == nil {
-		z, err := zstd.NewWriter(w, zstd.WithEncoderLevel(c.zstdLevel()))
+	if enc, _ := c.encoderPool.Get().(*zstd.Encoder); enc == nil {
+		z, err := zstd.NewWriter(w,
+			zstd.WithEncoderLevel(c.zstdLevel()),
+			zstd.WithEncoderConcurrency(1),
+			zstd.WithZeroFrames(true),
+		)
 		if err != nil {
 			p.err = err
 		} else {
-			p.enc = &encoder{z}
-			// We need a finalizer because the writer spawns goroutines
-			// that will only be stopped if the Close method is called.
-			runtime.SetFinalizer(p.enc, (*encoder).finalize)
+			p.enc = z
 		}
 	} else {
 		p.enc = enc
@@ -120,17 +116,9 @@ func (c *Codec) NewWriter(w io.Writer) io.WriteCloser {
 	return p
 }
 
-type encoder struct {
-	*zstd.Encoder
-}
-
-func (e *encoder) finalize() {
-	e.Close()
-}
-
 type writer struct {
 	c   *Codec
-	enc *encoder
+	enc *zstd.Encoder
 	err error
 }
 
@@ -149,7 +137,7 @@ func (w *writer) Close() error {
 		w.enc = nil
 		return err
 	}
-	return nil
+	return w.err
 }
 
 // WriteTo implements the io.WriterTo interface.