added preload and streaming buffer pool

pkg/fs/discard.go

@@ -4,7 +4,6 @@ package fs
 
 import (
 	"io"
-	"sync"
 )
 
 var Discard io.Writer = discard{}
@@ -21,30 +20,33 @@ func (discard) WriteString(s string) (int, error) {
 	return len(s), nil
 }
 
-const DefaultBufferSize = 8192
+const (
+	StreamingBufferSize = 32768
+	DefaultBufferSize   = 8192
+)
 
-var blackHolePool = sync.Pool{
-	New: func() any {
-		b := make([]byte, DefaultBufferSize)
+func poolNewFunc(size int) func() *[]byte {
+	return func() *[]byte {
+		b := make([]byte, size)
 		return &b
-	},
+	}
 }
 
+var (
+	streamingPool = newPool(poolNewFunc(StreamingBufferSize))
+	blackHolePool = newPool(poolNewFunc(DefaultBufferSize))
+)
+
 func SetBufferSize(size int) bool {
 	if size < 0 || size == DefaultBufferSize {
 		return false
 	}
-	blackHolePool = sync.Pool{
-		New: func() any {
-			b := make([]byte, size)
-			return &b
-		},
-	}
+	blackHolePool = newPool(poolNewFunc(size))
 	return true
 }
 
 func (discard) ReadFrom(r io.Reader) (n int64, err error) {
-	bufp := blackHolePool.Get().(*[]byte)
+	bufp := blackHolePool.Get()
 	readSize := 0
 	for {
 		readSize, err = r.Read(*bufp)