Improve: refactor ssr and fix #995 (#1189)

Co-authored-by: goomada <madao@DESKTOP-IOEBS0C.localdomain>

component/ssr/tools/bufPool.go

@@ -0,0 +1,18 @@
+package tools
+
+import (
+	"bytes"
+	"math/rand"
+	"sync"
+
+	"github.com/Dreamacro/clash/common/pool"
+)
+
+var BufPool = sync.Pool{New: func() interface{} { return &bytes.Buffer{} }}
+
+func AppendRandBytes(b *bytes.Buffer, length int) {
+	randBytes := pool.Get(length)
+	defer pool.Put(randBytes)
+	rand.Read(randBytes)
+	b.Write(randBytes)
+}