Vault: to store native token. Vault always has a buffer, that user can withdraw at anytime
Strategy Handler: submit liquidity in various lending protocols.
Treasury: hold rewards and operation (performance) fee
How vault sync balances from various strategies:
Vault state:
pub struct Vault {
/// The flag, if admin set enable = false, then the user can only withdraw and cannot deposit in the vault.
pub enabled: u8,
/// Vault nonce, to create vault seeds
pub bumps: VaultBumps,
/// The total liquidity of the vault, including remaining tokens in token_vault and the liquidity in all strategies.
pub total_amount: u64,
/// Token account, hold liquidity in vault reserve
pub token_vault: Pubkey,
/// Hold lp token of vault, each time rebalance crank is called, vault calculate performance fee and mint corresponding lp token amount to fee_vault. fee_vault is owned by treasury address
pub fee_vault: Pubkey,
/// Token mint that vault supports
pub token_mint: Pubkey,
/// Lp mint of vault
pub lp_mint: Pubkey,
/// The list of strategy addresses that vault supports, vault can support up to MAX_STRATEGY strategies at the same time.
pub strategies: [Pubkey; MAX_STRATEGY],
/// The base address to create vault seeds
pub base: Pubkey,
/// Admin of vault
pub admin: Pubkey,
/// Person who can send the crank. Operator can only send liquidity to strategies that admin defined, and claim reward to account of treasury address
pub operator: Pubkey,
/// Stores information for locked profit.
pub locked_profit_tracker: LockedProfitTracker,
}
Strategy state:
pub struct Strategy {
/// Lending pool address, that the strategy will deposit/withdraw balance
pub reserve: Pubkey,
/// The token account, that holds the collateral token
pub collateral_vault: Pubkey,
/// Specify type of strategy
pub strategy_type: StrategyType,
/// The liquidity in strategy at the time vault deposit/withdraw from a lending protocol
pub current_liquidity: u64,
/// Hold some bumps, in case the strategy needs to use other seeds to sign a CPI call.
pub bumps: [u8; MAX_BUMPS],
/// Vault address, that the strategy belongs
pub vault: Pubkey,
}
In which total_amount denotes to vault liquidity. Buffer liquidity is stored in token_vault account. strategies stores all strategy pubkey, that vault integrate.
At any point of time, the following assertion must be satisfied:
Which means total vault liquidity must be equal to buffer liquidity in vault and total liquidity in all strategies.
When keeper send rebalance crank in a strategy, program will update vault.total_amount and strategy.current_liquidity
// reload the new liquidity in this strategy
let new_liquidity = get_new_liquidity_in_this_strategy()
// sync balance in vault and this strategy
vault.total_amount = vault.total_amount + new_liqudity - strategy.current_liquidity;
strategy.current_liquidity = new_liquidity;