Function HandleBoost

controller/boost.go:105–207

HandleBoost 同时发起多路拨号，挑选最先成功的连接并套上单边加速。

(conn net.Conn, rule *config.Rule)

	return defaultRoutingRuntime.loadBoostWinner(key)
}

func (runtime *routingRuntime) loadBoostWinner(key string) (string, bool, time.Time) {
	now := time.Now()
	runtime.boost.cache.Lock()
	defer runtime.boost.cache.Unlock()
	entry, ok := runtime.boost.cache.entries[key]
	if !ok {
		return "", false, time.Time{}
	}
	if !now.Before(entry.expires) {
		delete(runtime.boost.cache.entries, key)
		return "", false, time.Time{}
	}
	return entry.addr, true, entry.expires
}

func (runtime *routingRuntime) loadBoostWinnerToken(key string) (boostWinnerEntry, bool) {
	now := time.Now()
	runtime.boost.cache.Lock()
	defer runtime.boost.cache.Unlock()
	entry, ok := runtime.boost.cache.entries[key]
	if !ok {
		return boostWinnerEntry{}, false
	}
	if !now.Before(entry.expires) {
		delete(runtime.boost.cache.entries, key)
		return boostWinnerEntry{}, false
	}
	return entry, true
}

// loadUsableBoostWinnerToken rejects a cached winner whose currently selected
// protocol is degraded. Eviction uses the generation token loaded with the
// entry, so a concurrent refresh cannot be deleted by this stale observation.
func (runtime *routingRuntime) loadUsableBoostWinnerToken(key string, rule *config.Rule, now time.Time) (boostWinnerEntry, bool) {
	if runtime == nil {
		return boostWinnerEntry{}, false
	}
	entry, ok := runtime.loadBoostWinnerToken(key)
	if !ok || runtime.routes == nil {
		return entry, ok
	}
	var target *config.Target
	if rule != nil {
		for _, candidate := range rule.Targets {
			if candidate != nil && candidate.Address == entry.addr {
				target = candidate
				break
			}
		}
	}
	if target == nil || runtime.routes.protocolPenalty(rule, target, now) == 0 {
		return entry, true
	}
	runtime.deleteBoostWinnerIfCurrent(boostWinnerToken{
		key:        key,
		addr:       entry.addr,
		generation: entry.generation,