How can I instances of an account when more than one ref is used for seeds?

Question

In order to create history and statistics, I'm struggling to figure out the best way to implement a lookup system. I'm building a game, and right now, my init for the entrant account looks like this:

    #[account(
        init, 
        payer = player,
        seeds = [b"entrant", player.key().as_ref(), round.key().as_ref()],
        bump,
        space = 8 + Entrant::MAXIMUM_SIZE)
    ]
    pub entrant: Account<'info, Entrant>,

Since a player can enter more than one round, I'm using both the player key and the round key as the seeds.

However, given the player, I want to be able to somehow lookup all the rounds the player has ever played. I don't want to keep in in one account, as this game can have a lot of rounds and I don't want to run out space.

What would be the best practice in dealing with a situation like this?

Answer 1

I think you should use:

seeds = [b"entrant", game.key().as_ref(), player.key().as_ref(), round.key().as_ref()]

And pass the relevant round to the program.

The client can search via getProgramAccounts for the player/game combo.

Answer 2

You have two main options:

• iterate through all the possible combinations of seeds for a user. If you know that the current max round is 2000, you can try all possible 2000 entrant addresses and fetch the account there. For huge numbers, this will be tricky.
• store the player address in the entrant account, and then do a get_program_accounts with the correct offsets for the entrant account type and the user's address