Creating singleton / global state for Solana program

lib.rs

use anchor_lang::prelude::*;

declare_id!("Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS");

#[program]
pub mod auction {
    use super::*;
    pub fn create_game_state(ctx: Context<CreateGameState>) -> ProgramResult {
        Ok(())
    }
}


#[derive(Accounts)]
#[instruction(bump: u8)]
pub struct CreateGameState<'info> {
    #[account(init, payer=user,
      space=GameState::space(),
      seeds=[
        b"Fg6PaFpoGXkYsidMpWTK6W2BeZ7FEfcYkg476zPFsLnS",
      ],
      bump=bump)]
    pub data: Account<'info, GameState>,
    pub user: Signer<'info>,
    pub system_program: Program<'info, System>,
}

#[account]
pub struct GameState {
    pub bump: u8,
}

impl GameState {
    fn space() -> usize {
        // discriminator + bump
        8 + 1
    }
}