add cache for groups and clients, http sending message remains to be add

cache.go

@@ -0,0 +1,57 @@
+package main
+
+import (
+	"context"
+	"errors"
+	"sync"
+)
+
+var Groups map[uint32]ChatGroup
+var ConnectedClients map[uint32]map[*Client]struct{}
+
+func InitCache() {
+	groups, err := GetAllChatGroups(context.Background())
+	if err != nil {
+		panic(err)
+	}
+
+	for _, group := range groups {
+		Groups[group.Id] = group
+	}
+}
+
+func GetGroupById(groupId uint32) (*ChatGroup, error) {
+	group, ok := Groups[groupId]
+	if !ok {
+		return nil, errors.New("group not found")
+	}
+	return &group, nil
+}
+
+func AddOrUpdateGroupToCache(mu *sync.Mutex, group ChatGroup) {
+	mu.Lock()
+	defer mu.Unlock()
+	Groups[group.Id] = group
+}
+
+func RemoveGroupFromCache(mu *sync.Mutex, groupId uint32) {
+	mu.Lock()
+	defer mu.Unlock()
+	delete(Groups, groupId)
+}
+
+func AddOrUpdateConnectedClientToCache(mu *sync.Mutex, client *Client) {
+	mu.Lock()
+	defer mu.Unlock()
+	for _, groupId := range client.User.MemberGroupsId {
+		ConnectedClients[groupId][client] = struct{}{}
+	}
+}
+
+func RemoveConnectedClientFromCache(mu *sync.Mutex, client *Client) {
+	mu.Lock()
+	defer mu.Unlock()
+	for _, groupId := range client.User.MemberGroupsId {
+		delete(ConnectedClients[groupId], client)
+	}
+}