Re-use zstd and zlib readers

internal/decompress/zlib.go

@@ -2,17 +2,31 @@ package decompress
 
 import (
 	"bytes"
-	"compress/zlib"
 	"io"
+	"sync"
+
+	"github.com/klauspost/compress/zlib"
 )
 
-type Zlib struct{}
+type Zlib struct {
+	pool sync.Pool
+}
 
-func (z Zlib) Decompress(data []byte) ([]byte, error) {
-	rdr, err := zlib.NewReader(bytes.NewReader(data))
+func NewZlib() *Zlib {
+	return &Zlib{}
+}
+
+func (z *Zlib) Decompress(data []byte) ([]byte, error) {
+	rdr := z.pool.Get()
+	defer z.pool.Put(rdr)
+	var err error
+	if rdr == nil {
+		rdr, err = zlib.NewReader(bytes.NewReader(data))
+	} else {
+		err = rdr.(zlib.Resetter).Reset(bytes.NewReader(data), nil)
+	}
 	if err != nil {
 		return nil, err
 	}
-	defer rdr.Close()
-	return io.ReadAll(rdr)
+	return io.ReadAll(rdr.(io.ReadCloser))
 }