增加内存池机制，尝试优化性能

utils.go

@@ -91,27 +91,58 @@ func textSliceToString(text []Text) string {
 	return Join(text)
 }
 
+var globalMemPool *MemPool
+
+type memPoolOption struct {
+	bufLen int
+}
+
+type MemPool struct {
+	buffer    []byte
+	bufCurent int
+	option    *memPoolOption
+}
+
+func (p *MemPool) GetBytes(n int) []byte {
+	if n > p.option.bufLen {
+		bigbyte := make([]byte, n)
+		return bigbyte
+	}
+	if p.bufCurent+n >= p.option.bufLen {
+		p.buffer = make([]byte, p.option.bufLen)
+		p.bufCurent = 0
+	}
+	startOps := p.bufCurent
+	p.bufCurent += n
+	return p.buffer[startOps:p.bufCurent]
+}
+
+func WithMemPool(bufLen int) {
+	option := &memPoolOption{bufLen: bufLen}
+	globalMemPool = &MemPool{
+		buffer: make([]byte, option.bufLen),
+		option: option,
+	}
+}
+
 func Join(a []Text) string {
 	switch len(a) {
 	case 0:
 		return ""
 	case 1:
 		return string(a[0])
-	case 2:
-		// Special case for common small values.
-		// Remove if golang.org/issue/6714 is fixed
-		return string(a[0]) + string(a[1])
-	case 3:
-		// Special case for common small values.
-		// Remove if golang.org/issue/6714 is fixed
-		return string(a[0]) + string(a[1]) + string(a[2])
 	}
 	n := 0
 	for i := 0; i < len(a); i++ {
 		n += len(a[i])
 	}
 
-	b := make([]byte, n)
+	var b []byte
+	if globalMemPool != nil {
+		b = globalMemPool.GetBytes(n)
+	} else {
+		b = make([]byte, n)
+	}
 	bp := copy(b, a[0])
 	for _, s := range a[1:] {
 		bp += copy(b[bp:], s)