From 0f1142d434395eb9d36d668bfa307343292c3cd2 Mon Sep 17 00:00:00 2001
From: bandl <1658002533@qq.com>
Date: Thu, 4 Nov 2021 16:31:55 +0800
Subject: [PATCH] perf(structure-value): perf set bit

---
 pkg/structure/value.go | 28 +++++++++++++++-------------
 1 file changed, 15 insertions(+), 13 deletions(-)

diff --git a/pkg/structure/value.go b/pkg/structure/value.go
index ea779fd..36a5a26 100644
--- a/pkg/structure/value.go
+++ b/pkg/structure/value.go
@@ -147,26 +147,28 @@ func (v *Value) ChangeValueLength(f func()) UpdateLength {
 
 func (v *Value) SetByte(offset int, val bool) {
 	v.onType = DynamicNull // 位图使用无类型
-	b := byte(0)
-	if val {
-		b = byte(1)
-	}
 
-	if v.length >= offset {
-		v.val[offset] = b
+	// 扩容
+	if len(v.val) <= offset/8 {
+		newByte := make([]byte, (offset/8)+1)
+		copy(newByte, v.val[:len(v.val)])
+		v.val = newByte
+		v.length = len(v.val)
+	}
+	if val {
+		// true 位
+		v.val[offset/8] |= (0b1 << (offset % 8))
 		return
 	}
 
-	newByte := make([]byte, offset+1)
-	newByte[offset] = b
-	copy(newByte, v.val[:v.length])
-	v.val = newByte
-	v.length = len(newByte)
+	// false 位
+	v.val[offset/8] ^= (0b1 << (offset % 8))
 }
 
 func (v *Value) GetByte(offset int) (bool, error) {
-	if v.length >= offset {
-		return v.val[offset] == byte(1), nil
+	if len(v.val) >= offset/8 {
+		// 采用 & 来运算 是否为 true
+		return v.val[offset/8]&(0b1<<(offset%8)) != 0, nil
 	}
 
 	return false, errorx.New("the maximum length is exceeded")