Module sysvar 

Sysvar access via direct syscalls.

Provides zero-alloc, zero-deserialization access to Solana sysvars by reading them directly into stack buffers via syscalls, including the epoch schedule sysvar.

Structs

Clock

Clock sysvar data, read directly from the runtime.

EpochRewards

EpochRewards sysvar data (SIMD-0118).

EpochSchedule

Epoch schedule sysvar data.

Rent

Rent sysvar data.

SlotHash

One (slot, hash) entry from the SlotHashes sysvar.

StakeHistoryEntry

One epoch’s stake-history entry.

Constants

ACCOUNT_STORAGE_OVERHEAD

Fixed per-account storage overhead charged by the cluster.

CLOCK_ID

Clock sysvar address.

EPOCH_REWARDS_ID

EpochRewards sysvar address (SIMD-0118).

EPOCH_SCHEDULE_ID

Epoch schedule sysvar address.

EXEMPTION_THRESHOLD_YEARS

Years of rent an account must prepay to be rent-exempt.

INSTRUCTIONS_ID

Instructions sysvar address (for instruction introspection).

LAMPORTS_PER_BYTE_YEAR

Lamports charged per byte of account storage per year.

LAST_RESTART_SLOT_ID

LastRestartSlot sysvar address.

RENT_ID

Rent sysvar address.

SLOT_HASHES_ID

SlotHashes sysvar address.

STAKE_HISTORY_ID

StakeHistory sysvar address.

Functions

get_clock

Read the Clock sysvar.

get_epoch_rewards

Read the EpochRewards sysvar (SIMD-0118).

get_epoch_schedule

Read the EpochSchedule sysvar.

get_epoch_stake

Get the current-epoch activated stake of the vote account at vote.

get_last_restart_slot

Read the slot of the last cluster restart (hard fork), or 0 if the cluster has never been restarted.

get_rent

Read the Rent sysvar.

get_sysvar_into

Copy dst.len() bytes starting at offset from the sysvar identified by sysvar_id into dst.

get_total_epoch_stake

Get the cluster-wide total activated stake for the current epoch.

rent_exempt_minimum

Minimum balance for rent exemption assuming the launch-era rent constants (LAMPORTS_PER_BYTE_YEAR, EXEMPTION_THRESHOLD_YEARS, ACCOUNT_STORAGE_OVERHEAD).

saturating_mul_u64

a * b, saturating at u64::MAX, without the 128-bit multiply helper.

scale_by_exemption_threshold

Apply the rent exemption_threshold (given as its IEEE-754 bit pattern) to an integer lamport amount without any floating-point instruction.

slot_hashes_latest

Read the most recent (slot, hash) from the SlotHashes sysvar.

stake_history_latest

Read the most recent stake-history entry.