Intention preservation is an obvious goal in a chat app because the point of the chat app is to facilitate a conversation between two people where messages are created in response to other messages.
Alice asks Bob a question and sees that the question is optimistically added to her replica of the chat history. In the meantime, Bob is typing up a response to another question Alice asked a day before. If Alice is on a really slow network, Bob will not see her new question come into his chat history until some time after he sends his reply to her old question. Bob’s intent is for Alice (the remote site) to see the new message as a response to her old question but because of network latency, Bob’s message will be misunderstood by Alice as a response to her new question. Bob’s intention is not preserved.
How do we prevent this misunderstanding? When Alice gets the event announcing that a message has been added to the conversation by Bob, rather than simply adding the message to the end of her chat history replica, she can perform some comparisons based on the message timestamps to insert Bob’s message in the right place in her chat history. This is possible because the real order of the messages is determined by the timestamp, which is created by the sender client at the time of creation shaadi dating site arvostelu (when the message is sent).
Solution Design
There are many optimistic replication and multiplayer functionalities implementations out there in collaborative editing tools such as Google Docs, Notion, Figma, and Peritext. Continue reading
