[FEATURE REQUEST] Optimize the time consumption of scheduled tasks

[ccfish86]

Why this feature?

如图，如果conversation集合中文档比较多的时候， 如果每次只处理100条数据，将会导致mongo查询条件,"skip":放大文档扫描行数

Suggested Solution

1.建议处理时通过查询条件lt/gt加limit进行处理，取代skip、
2.加大limit数，减少skip执行次数。

Additional Information

这是其他耗时比较多的地方（mongo慢日志）

[ccfish86]

谁帮忙看看这样改没问题吧？处理速度是提上来了

 // internal\rpc\conversation\conversation.go
func (c *conversationServer) GetConversationsNeedDestructMsgs(ctx context.Context, _ *pbconversation.GetConversationsNeedDestructMsgsReq) (*pbconversation.GetConversationsNeedDestructMsgsResp, error) {
	num, err := c.conversationDatabase.GetAllConversationIDsNumber(ctx)
	if err != nil {
		log.ZError(ctx, "GetAllConversationIDsNumber failed", err)
		return nil, err
	}
	const batchNum = 200
	maxPage := (num + batchNum - 1) / batchNum

	temp := make([]*model.Conversation, 0, batchNum)
	var curConversationID string

	for pageNumber := 0; pageNumber < int(maxPage); pageNumber++ {
		pagination := &sdkws.RequestPagination{
			PageNumber: 0,
			ShowNumber: batchNum,
		}

		conversationIDs, err := c.conversationDatabase.GetConversationIDsGtID(ctx, curConversationID, pagination)
		if err != nil {
			// log.ZError(ctx, "PageConversationIDs failed", err, "pageNumber", pageNumber)
			continue
		}

		// log.ZDebug(ctx, "PageConversationIDs success", "pageNumber", pageNumber, "conversationIDsNum", len(conversationIDs), "conversationIDs", conversationIDs)
		if len(conversationIDs) == 0 {
			break
		}

		conversations, err := c.conversationDatabase.GetConversationsByConversationID(ctx, conversationIDs)
		if err != nil {
			log.ZError(ctx, "GetConversationsByConversationID failed", err, "conversationIDs", conversationIDs)
			continue
		}

		for _, conversation := range conversations {
			if conversation.IsMsgDestruct && conversation.MsgDestructTime != 0 && ((time.Now().UnixMilli() > (conversation.MsgDestructTime + conversation.LatestMsgDestructTime.UnixMilli() + 8*60*60)) || // 8*60*60 is UTC+8
				conversation.LatestMsgDestructTime.IsZero()) {
				temp = append(temp, conversation)
			}
			curConversationID = conversation.ConversationID
		}
	}

	return &pbconversation.GetConversationsNeedDestructMsgsResp{Conversations: convert.ConversationsDB2Pb(temp)}, nil
}

 // pkg\common\storage\database\mgo\conversation.go

func (c *ConversationMgo) GetConversationIDsGtID(ctx context.Context, fromConversationID string, pagination pagination.Pagination) (conversationIDs []string, err error) {
	var filter bson.M
	if fromConversationID != "" {
		filter = bson.M{"conversation_id": bson.M{"$gt": fromConversationID}}
	}
	return mongoutil.FindPageOnly[string](ctx, c.coll, filter, pagination, options.Find().SetSort("conversation_id").SetProjection(bson.M{"conversation_id": 1}))
}