Struct Rent 

#[repr(C)]
pub struct Rent {
    pub lamports_per_byte_year: u64,
    pub exemption_threshold: f64,
    pub burn_percent: u8,
}

Rent sysvar data.

Fields

lamports_per_byte_year: u64

exemption_threshold: f64

burn_percent: u8

Implementations

impl Rent

pub fn get() -> Result<Self, ProgramError>

Read the Rent sysvar.

Method-style alias for get_rent, matching the Sysvar::get() ergonomics other Solana frameworks expose (Rent::get()).

pub fn minimum_balance(&self, data_len: usize) -> u64

Minimum lamports for rent exemption at data_len, computed from the live sysvar values, the correct source for reaping-relevant decisions after a rent reprice.

This follows Solana’s own solana_rent::Rent::minimum_balance for the two thresholds any cluster has stored, with no floating point at all:

integer_part = (ACCOUNT_STORAGE_OVERHEAD + data_len) * rate
threshold 1.0 => integer_part
threshold 2.0 => integer_part * 2
otherwise     => integer_part * ceil(threshold)   (never below Solana's
                 `(integer_part as f64 * threshold) as u64`)

SIMD-0194 made 1.0 the live wire marker and moved the full price into the rate field; 2.0 is the launch-era value. Both are matched by bit pattern (see scale_by_exemption_threshold), so a program that reads the sysvar links no soft-float code. A threshold no cluster has ever used rounds up to whole years, which can only overfund.

The integer product uses saturating ops purely as an overflow guard; for every loader-permitted data_len (<= 10_485_760) and realistic lamports_per_byte_year it never saturates, so the byte-match with the runtime is exact (proven in the Kani harnesses below).

Trait Implementations

impl Clone for Rent

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Rent

impl Debug for Rent

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Rent

fn default() -> Self

Returns the “default value” for a type.