Database schema

We use DynamoDB, which is "schemaless" meaning the fields are not formally defined within the database itself. Nevertheless we obviously have a consistent format for our data, which is described below.

PK	SK	fields
ROOM:[roomId]	ROOM	hostKey, validSizes, isRevealed, createdOn, updatedOn
ROOM:[roomId]	USER:[userKey]	userId, username, vote, createdOn, updatedOn

Fields

Name	Description
roomId	Randomly generated ID (public)
hostKey	Randomly generated key (private, known only to the host)
validSizes	Space-delimited list of valid sizes e.g. 1 2 3
isRevealed	true if users are allowed to see all votes
createdOn	The timestamp the item was created
updatedOn	The timestamp the item was last updated
userKey	Randomly generated key (known only to the given user)
userId	An identifier for the user -- to disambiguate two users with the same username
username	A display name to use.
vote	The current vote for the user. One of validSizes

Operations

• Create room generates ID/hostKey and inserts ROOM:[roomId] with default sizes (1 2 3 5 8 13 20 ? ∞) and isVoteRevealed=false.
• Subscribe Creates a USER:[userKey] item by generating a userKey and userId for the user and stores them with the connectionId from the caller.
• Join room Sets the username on the user with the given userKey.
• Leave room Clears the username on the user with the given userKey.
• Set valid sizes updates the value of validSizes for the given room key
• Reconnect Resets the connectionId for the user with the given userKey. Also clears the username and vote.
• Kick user Clears the username, vote, and connectionId for the user with the given userKey.
• Set cards revealed Sets isVoteRevealed to a given (boolean) value which shows or hides the value of vote for all users.
• Vote Sets the vote for the user with the given userKey
• Reset Sets isVoteRevealed to false and deletes all VOTES rows
• Delete user Deletes the USER item for the given userKey
• Delete room Deletes all rows with the ROOM[roomId] prefix