Struct ReallocGuard 

pub struct ReallocGuard<const N: usize> { /* private fields */ }

Per-instruction realloc budget guard.

N is the maximum number of accounts to track (const generic, stack-allocated). Typical values: 4, 8, or 16.

Implementations

impl<const N: usize> ReallocGuard<N>

pub const fn new(budget: u32) -> Self

Create a new guard with the given growth budget (bytes).

pub fn register(&mut self, slot: usize, size: usize) -> Result<(), ProgramError>

Register an account’s original size for tracking.

slot is the local tracking index (0..N-1), not the account index. size is the current data length. Returns Err if slot >= N.

pub fn check_growth( &self, slot: usize, new_size: usize, ) -> Result<(), ProgramError>

Check if growing account slot to new_size is within budget.

Does NOT commit the growth – call commit_growth after the actual realloc succeeds.

pub fn commit_growth( &mut self, slot: usize, new_size: usize, ) -> Result<(), ProgramError>

Commit a growth after successful realloc.

Must be called after the actual safe_realloc succeeds. Returns Err if slot is not registered.

pub const fn remaining(&self) -> u32

Remaining budget (bytes).

pub const fn consumed(&self) -> u32

Total consumed growth (bytes).

pub const fn budget(&self) -> u32

Budget cap (bytes).

pub fn slot_growth(&self, slot: usize) -> i32

Growth of a specific slot from its original size (bytes).