package global import ( "crypto/md5" "encoding/hex" "regexp" "sync" "time" ) // HashEntry represents a stored hash entry with its value and timestamp. type HashEntry struct { Hash string // MD5 hash string Value string // Original value Timestamp time.Time // Time when the hash was created } // HashStorage provides thread-safe storage for hash-value pairs with expiration. type HashStorage struct { sync.RWMutex Data map[string]HashEntry // Map of hash to entry Expiration time.Duration // Expiration duration for entries } // NewHashStorage creates a new HashStorage instance with the specified expiration duration. func NewHashStorage(expiration time.Duration) *HashStorage { return &HashStorage{ Data: make(map[string]HashEntry), Expiration: expiration, } } // SaveHash generates an MD5 hash for the given query string and stores it with a timestamp. func (h *HashStorage) SaveHash(query string) string { h.Lock() defer h.Unlock() md5Hash := md5.Sum([]byte(query)) md5HashString := hex.EncodeToString(md5Hash[:]) entry := HashEntry{ Hash: md5HashString, Value: query, Timestamp: time.Now(), } h.Data[md5HashString] = entry return md5HashString } // GetValue retrieves the original value for the given hash, returning true if found. func (h *HashStorage) GetValue(hash string) (string, bool) { h.RLock() defer h.RUnlock() entry, exists := h.Data[hash] return entry.Value, exists } // IsMD5 checks if the given string is a valid 32-character MD5 hash. func (h *HashStorage) IsMD5(hash string) bool { match, _ := regexp.MatchString("^[a-f0-9]{32}$", hash) return match } // RemoveExpiredHashes removes all hash entries that have exceeded the expiration duration. func (h *HashStorage) RemoveExpiredHashes() { h.Lock() defer h.Unlock() now := time.Now() for hash, entry := range h.Data { if now.Sub(entry.Timestamp) > h.Expiration { delete(h.Data, hash) } } } // Reset clears all stored hash entries. func (h *HashStorage) Reset() { h.Lock() defer h.Unlock() h.Data = make(map[string]HashEntry) }