refactor(backend): rename OpenFlare directory to lowercase openflare

backend/openflare/plugins/server/domain/observability/chwriter/dedup.go

@@ -0,0 +1,65 @@
+// Copyright 2026 Arctel.net
+// SPDX-License-Identifier: Apache-2.0
+
+package chwriter
+
+import (
+	"sync"
+	"time"
+)
+
+const dedupTTL = 2 * time.Minute
+
+type dedupSet struct {
+	mu          sync.Mutex
+	keys        map[string]time.Time
+	lastCleanup time.Time
+}
+
+func newDedupSet() *dedupSet {
+	return &dedupSet{
+		keys:        make(map[string]time.Time),
+		lastCleanup: time.Now(),
+	}
+}
+
+// markIfNew records key when it has not been seen within dedupTTL.
+func (s *dedupSet) markIfNew(key string) bool {
+	if s == nil || key == "" {
+		return false
+	}
+
+	now := time.Now()
+	s.mu.Lock()
+	defer s.mu.Unlock()
+
+	s.cleanupExpiredLocked(now)
+
+	if expiresAt, exists := s.keys[key]; exists && now.Before(expiresAt) {
+		return false
+	}
+	s.keys[key] = now.Add(dedupTTL)
+	return true
+}
+
+// unmark removes a key so a later enqueue or flush retry may accept it again.
+func (s *dedupSet) unmark(key string) {
+	if s == nil || key == "" {
+		return
+	}
+	s.mu.Lock()
+	defer s.mu.Unlock()
+	delete(s.keys, key)
+}
+
+func (s *dedupSet) cleanupExpiredLocked(now time.Time) {
+	if now.Sub(s.lastCleanup) < 30*time.Second {
+		return
+	}
+	for existing, expiresAt := range s.keys {
+		if now.After(expiresAt) {
+			delete(s.keys, existing)
+		}
+	}
+	s.lastCleanup = now
+}