Struct MemoryTracker 

pub struct MemoryTracker { /* private fields */ }

Memory tracker for a single Wasmtime Store.

One tracker per store. The Store::limiter closure should hand back &mut self so Wasmtime can call memory_growing / table_growing for resource accounting.

Implementations

impl MemoryTracker

pub fn new(max_memory_mb: usize) -> Self

Create a tracker with a megabyte-precision cap.

pub fn with_byte_limit(max_memory_bytes: usize) -> Self

Create a tracker with a byte-precision cap. Use this when the caller already has a value in bytes (e.g. from ExecutionLimits::max_memory_bytes) so the conversion can be exact.

pub fn current_memory(&self) -> usize

Current linear-memory size in bytes.

pub fn peak_memory(&self) -> usize

Highest linear-memory size observed in this store’s lifetime.

pub fn max_memory(&self) -> usize

Configured upper bound in bytes.

pub fn memory_usage_percent(&self) -> f64

Memory usage as a percentage of the configured limit.

pub fn is_memory_exceeded(&self) -> bool

Whether the most recent observation exceeded the cap.

Trait Implementations

impl ResourceLimiter for MemoryTracker

fn memory_growing( &mut self, current: usize, desired: usize, _maximum: Option<usize>, ) -> Result<bool>

Notifies the resource limiter that an instance’s linear memory has been requested to grow.

fn table_growing( &mut self, _current: usize, _desired: usize, _maximum: Option<usize>, ) -> Result<bool>

Notifies the resource limiter that an instance’s table has been requested to grow.

fn tables(&self) -> usize

The maximum number of tables that can be created for a Store.

fn memories(&self) -> usize

The maximum number of linear memories that can be created for a Store

fn memory_grow_failed(&mut self, error: Error) -> Result<(), Error>

Notifies the resource limiter that growing a linear memory, permitted by the memory_growing method, has failed.

fn table_grow_failed(&mut self, error: Error) -> Result<(), Error>

Notifies the resource limiter that growing a linear memory, permitted by the table_growing method, has failed.

fn instances(&self) -> usize

The maximum number of instances that can be created for a Store.