feat: integrated Alipay payment module

api/service/snowflake.go

@@ -0,0 +1,56 @@
+package service
+
+import (
+	"fmt"
+	"sync"
+	"time"
+)
+
+// Snowflake 雪花算法实现
+type Snowflake struct {
+	mu            sync.Mutex
+	lastTimestamp int64
+	workerID      int
+	sequence      int
+}
+
+func NewSnowflake() *Snowflake {
+	return &Snowflake{
+		lastTimestamp: -1,
+		workerID:      0, // TODO: 增加 WorkID 参数
+		sequence:      0,
+	}
+}
+
+// Next 生成一个新的唯一ID
+func (s *Snowflake) Next() (string, error) {
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	timestamp := time.Now().UnixNano() / 1000000 // 转换为毫秒
+	if timestamp < s.lastTimestamp {
+		return "", fmt.Errorf("clock moved backwards. Refusing to generate id for %d milliseconds", s.lastTimestamp-timestamp)
+	}
+
+	if timestamp == s.lastTimestamp {
+		s.sequence = (s.sequence + 1) & 4095
+		if s.sequence == 0 {
+			timestamp = s.waitNextMillis()
+		}
+	} else {
+		s.sequence = 0
+	}
+
+	s.lastTimestamp = timestamp
+	id := (timestamp << 22) | (int64(s.workerID) << 10) | int64(s.sequence)
+	now := time.Now()
+	return fmt.Sprintf("%d%02d%02d%d", now.Year(), now.Month(), now.Day(), id), nil
+}
+
+func (s *Snowflake) waitNextMillis() int64 {
+	timestamp := time.Now().UnixNano() / 1000000
+	for timestamp <= s.lastTimestamp {
+		timestamp = time.Now().UnixNano() / 1000000
+	}
+	return timestamp
+}