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@@ -0,0 +1,81 @@
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+package order
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+
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+import (
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+ "fmt"
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+ "sync"
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+ "time"
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+)
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+
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+// 更安全的版本：带毫秒时间戳
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+type Generator struct {
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+ machineID int
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+ lastTime int64 // 上次时间（毫秒）
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+ sequence int64
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+ mu sync.Mutex
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+}
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+
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+func NewOrderGenerator(machineID int) *Generator {
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+ return &Generator{
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+ machineID: machineID,
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+ lastTime: time.Now().UnixMilli(),
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+ sequence: 0,
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+ }
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+}
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+
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+func (g *Generator) Generate() string {
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+ g.mu.Lock()
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+ defer g.mu.Unlock()
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+
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+ // 获取当前毫秒时间戳
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+ currentTime := time.Now().UnixMilli()
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+
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+ if currentTime == g.lastTime {
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+ g.sequence++
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+ } else {
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+ g.sequence = 0
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+ g.lastTime = currentTime
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+ }
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+
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+ // 获取当前日期（年月日）
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+ dateStr := time.Now().Format("20060102")
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+
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+ return fmt.Sprintf("%s%02d%04d", dateStr, g.machineID, g.sequence)
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+}
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+
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+// 并发测试函数
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+func testConcurrentGeneration() {
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+ fmt.Println("=== 并发测试 ===")
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+ generator := NewOrderGenerator(1)
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+
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+ // 使用map检查重复
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+ results := sync.Map{}
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+ var wg sync.WaitGroup
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+ start := time.Now()
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+
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+ // 启动1000个协程同时生成订单号
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+ for i := 0; i < 1000; i++ {
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+ wg.Add(1)
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+ go func(id int) {
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+ defer wg.Done()
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+ orderNo := generator.Generate()
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+
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+ // 检查是否重复
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+ if _, loaded := results.LoadOrStore(orderNo, true); loaded {
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+ fmt.Printf("⚠️ 发现重复订单号: %s\n", orderNo)
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+ }
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+ }(i)
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+ }
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+
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+ wg.Wait()
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+ elapsed := time.Since(start)
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+
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+ // 统计结果
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+ count := 0
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+ results.Range(func(key, value interface{}) bool {
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+ count++
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+ return true
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+ })
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+
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+ fmt.Printf("生成 %d 个订单号，耗时 %v\n", count, elapsed)
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+ fmt.Printf("平均每秒生成: %.0f 个\n", float64(count)/elapsed.Seconds())
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+}
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