Method replyGetData

server/topic.go:2768–2827

replyGetData is a response to a get.data request - load a list of stored messages, send them to session as {data} response goes to a single session rather than all sessions in a topic

(sess *Session, asUid types.Uid, asChan bool, req *MsgGetOpts, msg *ClientComMessage)

// replyGetData is a response to a get.data request - load a list of stored messages, send them to session as {data}
// response goes to a single session rather than all sessions in a topic
func (t *Topic) replyGetData(sess *Session, asUid types.Uid, asChan bool, req *MsgGetOpts, msg *ClientComMessage) error {
	now := types.TimeNow()
	toriginal := t.original(asUid)

	if req != nil && (req.IfModifiedSince != nil || req.User != "" || req.Topic != "") {
		sess.queueOut(ErrMalformedReply(msg, now))
		return errors.New("invalid MsgGetOpts query")
	}

	// Check if the user has permission to read the topic data
	count := 0
	if userData := t.perUser[asUid]; (userData.modeGiven & userData.modeWant).IsReader() {
		// Read messages from DB
		messages, err := store.Messages.GetAll(t.name, asUid, msgOpts2storeOpts(req))
		if err != nil {
			sess.queueOut(ErrUnknownReply(msg, now))
			return err
		}

		// Push the list of messages to the client as {data}.
		if messages != nil {
			count = len(messages)
			if count > 0 {
				outgoingMessages := make([]*ServerComMessage, count)
				for i := range messages {
					mm := &messages[i]
					from := ""
					if !asChan {
						// Don't show sender for channel readers
						from = types.ParseUid(mm.From).UserId()
					}
					outgoingMessages[i] = &ServerComMessage{
						Data: &MsgServerData{
							Topic:     toriginal,
							Head:      mm.Head,
							SeqId:     mm.SeqId,
							From:      from,
							Timestamp: mm.CreatedAt,
							Content:   mm.Content,
						},
					}
				}
				sess.queueOutBatch(outgoingMessages)
			}
		}
	} else {
		sess.queueOut(ErrPermissionDeniedReply(msg, now))
		return errors.New("attempt to get messages by non-reader")
	}

	// Inform the requester that all the data has been served.
	if count == 0 {
		sess.queueOut(NoContentParamsReply(msg, now, map[string]any{"what": "data"}))
	} else {
		sess.queueOut(NoErrDeliveredParams(msg.Id, msg.Original, now,
			map[string]any{"what": "data", "count": count}))
	}