package mojangtextures import ( "sync" "time" "github.com/elyby/chrly/api/mojang" "github.com/tevino/abool" ) var now = time.Now type inMemoryItem struct { textures *mojang.SignedTexturesResponse timestamp int64 } type InMemoryTexturesStorage struct { GCPeriod time.Duration Duration time.Duration lock sync.Mutex data map[string]*inMemoryItem working *abool.AtomicBool } func NewInMemoryTexturesStorage() *InMemoryTexturesStorage { storage := &InMemoryTexturesStorage{ GCPeriod: 10 * time.Second, Duration: time.Minute + 10*time.Second, data: make(map[string]*inMemoryItem), } return storage } func (s *InMemoryTexturesStorage) Start() { if s.working == nil { s.working = abool.New() } if !s.working.IsSet() { go func() { time.Sleep(s.GCPeriod) // TODO: this can be reimplemented in future with channels, but right now I have no idea how to make it right for s.working.IsSet() { start := time.Now() s.gc() time.Sleep(s.GCPeriod - time.Since(start)) } }() } s.working.Set() } func (s *InMemoryTexturesStorage) Stop() { s.working.UnSet() } func (s *InMemoryTexturesStorage) GetTextures(uuid string) (*mojang.SignedTexturesResponse, error) { s.lock.Lock() defer s.lock.Unlock() item, exists := s.data[uuid] validRange := s.getMinimalNotExpiredTimestamp() if !exists || validRange > item.timestamp { return nil, &ValueNotFound{} } return item.textures, nil } func (s *InMemoryTexturesStorage) StoreTextures(uuid string, textures *mojang.SignedTexturesResponse) { var timestamp int64 if textures != nil { decoded := textures.DecodeTextures() if decoded == nil { panic("unable to decode textures") } timestamp = decoded.Timestamp } else { timestamp = unixNanoToUnixMicro(now().UnixNano()) } s.lock.Lock() defer s.lock.Unlock() s.data[uuid] = &inMemoryItem{ textures: textures, timestamp: timestamp, } } func (s *InMemoryTexturesStorage) gc() { s.lock.Lock() defer s.lock.Unlock() maxTime := s.getMinimalNotExpiredTimestamp() for uuid, value := range s.data { if maxTime > value.timestamp { delete(s.data, uuid) } } } func (s *InMemoryTexturesStorage) getMinimalNotExpiredTimestamp() int64 { return unixNanoToUnixMicro(now().Add(s.Duration * time.Duration(-1)).UnixNano()) } func unixNanoToUnixMicro(unixNano int64) int64 { return unixNano / 10e5 }