solana-program-library/token-lending/program/src/state/mod.rs

94 lines
2.5 KiB
Rust

//! State types
mod lending_market;
mod obligation;
mod reserve;
pub use lending_market::*;
pub use obligation::*;
pub use reserve::*;
use crate::math::{Decimal, WAD};
use arrayref::{array_refs, mut_array_refs};
use solana_program::{
clock::{DEFAULT_TICKS_PER_SECOND, DEFAULT_TICKS_PER_SLOT, SECONDS_PER_DAY},
program_error::ProgramError,
program_option::COption,
pubkey::Pubkey,
};
/// Collateral tokens are initially valued at a ratio of 5:1 (collateral:liquidity)
pub const INITIAL_COLLATERAL_RATIO: u64 = 5;
const INITIAL_COLLATERAL_RATE: u64 = INITIAL_COLLATERAL_RATIO * WAD;
/// Current version of the program and all new accounts created
pub const PROGRAM_VERSION: u8 = 1;
/// Accounts are created with data zeroed out, so uninitialized state instances
/// will have the version set to 0.
pub const UNINITIALIZED_VERSION: u8 = 0;
/// Number of slots per year
pub const SLOTS_PER_YEAR: u64 =
DEFAULT_TICKS_PER_SECOND / DEFAULT_TICKS_PER_SLOT * SECONDS_PER_DAY * 365;
/// Token converter
pub trait TokenConverter {
/// Return best price for specified token
fn best_price(&mut self, token_mint: &Pubkey) -> Result<Decimal, ProgramError>;
/// Convert between two different tokens
fn convert(
self,
from_amount: Decimal,
from_token_mint: &Pubkey,
) -> Result<Decimal, ProgramError>;
}
// Helpers
fn pack_coption_key(src: &COption<Pubkey>, dst: &mut [u8; 36]) {
let (tag, body) = mut_array_refs![dst, 4, 32];
match src {
COption::Some(key) => {
*tag = [1, 0, 0, 0];
body.copy_from_slice(key.as_ref());
}
COption::None => {
*tag = [0; 4];
}
}
}
fn unpack_coption_key(src: &[u8; 36]) -> Result<COption<Pubkey>, ProgramError> {
let (tag, body) = array_refs![src, 4, 32];
match *tag {
[0, 0, 0, 0] => Ok(COption::None),
[1, 0, 0, 0] => Ok(COption::Some(Pubkey::new_from_array(*body))),
_ => Err(ProgramError::InvalidAccountData),
}
}
fn pack_decimal(decimal: Decimal, dst: &mut [u8; 16]) {
*dst = decimal
.to_scaled_val()
.expect("could not pack decimal")
.to_le_bytes();
}
fn unpack_decimal(src: &[u8; 16]) -> Decimal {
Decimal::from_scaled_val(u128::from_le_bytes(*src))
}
#[cfg(test)]
mod test {
use super::*;
#[test]
fn initial_collateral_rate_sanity() {
assert_eq!(
INITIAL_COLLATERAL_RATIO.checked_mul(WAD).unwrap(),
INITIAL_COLLATERAL_RATE
);
}
}