public Map<String, ConcurrentHashMap<Integer, MessageStore>> getMessageStores() {
        return Collections.unmodifiableMap(this.dataStores);
    }
Get message from store.

@param msgStore        the message-store
@param topic           the topic name
@param partitionId     the partition id
@param msgCount        the message count to read
@param filterCondSet   the filter condition set
@return                the query result
@throws IOException    the exception during processing
inlong-tubemq/tubemq-server/src/main/java/org/apache/inlong/tubemq/server/broker/msgstore/MessageStoreManager.java