chrly/mojangtextures/in_memory_textures_storage.go

116 lines
2.3 KiB
Go

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.RWMutex
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.RLock()
defer s.lock.RUnlock()
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
}