EvoBGP/internal/httpclient/circuit.go

package httpclient

import (
	"sync"
	"time"
)

const (
	defaultBreakerThreshold = 5
	defaultBreakerCooldown  = 30 * time.Second
)

type hostBreaker struct {
	mu        sync.Mutex
	failures  int
	openUntil time.Time
}

var hostBreakers sync.Map // string -> *hostBreaker

func breakerForHost(host string) *hostBreaker {
	if host == "" {
		host = "_"
	}
	v, _ := hostBreakers.LoadOrStore(host, &hostBreaker{})
	return v.(*hostBreaker)
}

func (b *hostBreaker) allow() bool {
	b.mu.Lock()
	defer b.mu.Unlock()
	return time.Now().After(b.openUntil)
}

func (b *hostBreaker) recordSuccess() {
	b.mu.Lock()
	defer b.mu.Unlock()
	b.failures = 0
	b.openUntil = time.Time{}
}

func (b *hostBreaker) recordFailure() {
	b.mu.Lock()
	defer b.mu.Unlock()
	b.failures++
	if b.failures >= defaultBreakerThreshold {
		b.openUntil = time.Now().Add(defaultBreakerCooldown)
		b.failures = 0
	}
}

// SnapshotBreakers returns whether each known host breaker is currently open.
func SnapshotBreakers() map[string]bool {
	out := map[string]bool{}
	hostBreakers.Range(func(key, value any) bool {
		host, _ := key.(string)
		b, _ := value.(*hostBreaker)
		if b == nil {
			return true
		}
		b.mu.Lock()
		open := time.Now().Before(b.openUntil)
		b.mu.Unlock()
		out[host] = open
		return true
	})
	return out
}

// ResetHostBreakers clears all circuit breakers (tests only).
func ResetHostBreakers() {
	hostBreakers = sync.Map{}
}