init

strategy.go

@@ -0,0 +1,125 @@
+package reconnect
+
+import "time"
+
+// Strategy 重连策略接口
+type Strategy interface {
+	// NextDelay 返回下一次重试的延迟时间
+	// attempt 是当前重试次数（从1开始）
+	NextDelay(attempt int) time.Duration
+
+	// Reset 重置策略状态
+	Reset()
+}
+
+// ExponentialBackoff 指数退避策略
+type ExponentialBackoff struct {
+	initialDelay time.Duration
+	maxDelay     time.Duration
+	multiplier   float64
+}
+
+// NewExponentialBackoff 创建指数退避策略
+func NewExponentialBackoff(initialDelay, maxDelay time.Duration, multiplier float64) *ExponentialBackoff {
+	if multiplier <= 0 {
+		multiplier = 2.0
+	}
+	return &ExponentialBackoff{
+		initialDelay: initialDelay,
+		maxDelay:     maxDelay,
+		multiplier:   multiplier,
+	}
+}
+
+// NextDelay 计算下一次延迟时间
+func (e *ExponentialBackoff) NextDelay(attempt int) time.Duration {
+	if attempt <= 0 {
+		attempt = 1
+	}
+	delay := float64(e.initialDelay)
+	for i := 1; i < attempt; i++ {
+		delay *= e.multiplier
+		if time.Duration(delay) >= e.maxDelay {
+			return e.maxDelay
+		}
+	}
+	if time.Duration(delay) > e.maxDelay {
+		return e.maxDelay
+	}
+	return time.Duration(delay)
+}
+
+// Reset 重置策略
+func (e *ExponentialBackoff) Reset() {
+	// 无状态，无需重置
+}
+
+// FixedInterval 固定间隔策略
+type FixedInterval struct {
+	interval time.Duration
+}
+
+// NewFixedInterval 创建固定间隔策略
+func NewFixedInterval(interval time.Duration) *FixedInterval {
+	return &FixedInterval{
+		interval: interval,
+	}
+}
+
+// NextDelay 返回固定延迟时间
+func (f *FixedInterval) NextDelay(attempt int) time.Duration {
+	return f.interval
+}
+
+// Reset 重置策略
+func (f *FixedInterval) Reset() {
+	// 无状态，无需重置
+}
+
+// LinearBackoff 线性退避策略
+type LinearBackoff struct {
+	initialDelay time.Duration
+	maxDelay     time.Duration
+	increment    time.Duration
+}
+
+// NewLinearBackoff 创建线性退避策略
+func NewLinearBackoff(initialDelay, maxDelay, increment time.Duration) *LinearBackoff {
+	return &LinearBackoff{
+		initialDelay: initialDelay,
+		maxDelay:     maxDelay,
+		increment:    increment,
+	}
+}
+
+// NextDelay 计算下一次延迟时间
+func (l *LinearBackoff) NextDelay(attempt int) time.Duration {
+	if attempt <= 0 {
+		attempt = 1
+	}
+	delay := l.initialDelay + time.Duration(attempt-1)*l.increment
+	if delay > l.maxDelay {
+		return l.maxDelay
+	}
+	return delay
+}
+
+// Reset 重置策略
+func (l *LinearBackoff) Reset() {
+	// 无状态，无需重置
+}
+
+// NewStrategy 根据配置创建策略
+func NewStrategy(cfg Config) Strategy {
+	switch cfg.Strategy {
+	case StrategyFixedInterval:
+		return NewFixedInterval(cfg.InitialDelay)
+	case StrategyLinearBackoff:
+		return NewLinearBackoff(cfg.InitialDelay, cfg.MaxDelay, cfg.LinearIncrement)
+	case StrategyExponentialBackoff:
+		fallthrough
+	default:
+		return NewExponentialBackoff(cfg.InitialDelay, cfg.MaxDelay, cfg.Multiplier)
+	}
+}
+