Make the chats/users cache thread-safe

1 files changed, 84 insertions, 0 deletions

diff --git a/telegram/cache/cache.go b/telegram/cache/cache.go
new file mode 100644
index 0000000..d1d16f9
--- /dev/null
+++ b/telegram/cache/cache.go
@@ -0,0 +1,84 @@
+package cache
+
+import (
+	"sync"
+
+	"github.com/zelenin/go-tdlib/client"
+)
+
+// Cache allows operating the chats and users cache in
+// a thread-safe manner
+type Cache struct {
+	chats     map[int64]*client.Chat
+	users     map[int32]*client.User
+	chatsLock sync.Mutex
+	usersLock sync.Mutex
+}
+
+// NewCache initializes a cache
+func NewCache() *Cache {
+	return &Cache{
+		chats: map[int64]*client.Chat{},
+		users: map[int32]*client.User{},
+	}
+}
+
+// ChatsKeys grabs chat ids synchronously to avoid lockups
+// while they are used
+func (cache *Cache) ChatsKeys() []int64 {
+	cache.chatsLock.Lock()
+	defer cache.chatsLock.Unlock()
+
+	var keys []int64
+	for id := range cache.chats {
+		keys = append(keys, id)
+	}
+	return keys
+}
+
+// UsersKeys grabs user ids synchronously to avoid lockups
+// while they are used
+func (cache *Cache) UsersKeys() []int32 {
+	cache.usersLock.Lock()
+	defer cache.usersLock.Unlock()
+
+	var keys []int32
+	for id := range cache.users {
+		keys = append(keys, id)
+	}
+	return keys
+}
+
+// GetChat retrieves chat by id if it's present in the cache
+func (cache *Cache) GetChat(id int64) (*client.Chat, bool) {
+	cache.chatsLock.Lock()
+	defer cache.chatsLock.Unlock()
+
+	chat, ok := cache.chats[id]
+	return chat, ok
+}
+
+// GetUser retrieves user by id if it's present in the cache
+func (cache *Cache) GetUser(id int32) (*client.User, bool) {
+	cache.usersLock.Lock()
+	defer cache.usersLock.Unlock()
+
+	user, ok := cache.users[id]
+	return user, ok
+}
+
+// SetChat stores a chat in the cache
+func (cache *Cache) SetChat(id int64, chat *client.Chat) {
+	cache.chatsLock.Lock()
+	defer cache.chatsLock.Unlock()
+
+	cache.chats[id] = chat
+}
+
+// SetUser stores a user in the cache
+func (cache *Cache) SetUser(id int32, user *client.User) {
+	cache.usersLock.Lock()
+	defer cache.usersLock.Unlock()
+
+	cache.users[id] = user
+}