Struct Tunables 

pub struct Tunables {

    pub collector: Option<Collector>,
    pub memory_reservation: u64,
    pub memory_guard_size: u64,
    pub memory_reservation_for_growth: u64,
    pub generate_native_debuginfo: bool,
    pub parse_wasm_debuginfo: bool,
    pub consume_fuel: bool,
    pub epoch_interruption: bool,
    pub memory_may_move: bool,
    pub guard_before_linear_memory: bool,
    pub table_lazy_init: bool,
    pub generate_address_map: bool,
    pub debug_adapter_modules: bool,
    pub relaxed_simd_deterministic: bool,
    pub winch_callable: bool,
    pub signals_based_traps: bool,
    pub memory_init_cow: bool,
    pub inlining: bool,
    pub inlining_intra_module: IntraModuleInlining,
    pub inlining_small_callee_size: u32,
    pub inlining_sum_size_threshold: u32,
}

Tunable parameters for WebAssembly compilation.

Fields

collector: Option<Collector>

The garbage collector implementation to use, which implies the layout of GC objects and barriers that must be emitted in Wasm code.

memory_reservation: u64

Initial size, in bytes, to be allocated for linear memories.

memory_guard_size: u64

The size, in bytes, of the guard page region for linear memories.

memory_reservation_for_growth: u64

The size, in bytes, to allocate at the end of a relocated linear memory for growth.

generate_native_debuginfo: bool

Whether or not to generate native DWARF debug information.

parse_wasm_debuginfo: bool

Whether or not to retain DWARF sections in compiled modules.

consume_fuel: bool

Whether or not fuel is enabled for generated code, meaning that fuel will be consumed every time a wasm instruction is executed.

epoch_interruption: bool

Whether or not we use epoch-based interruption.

memory_may_move: bool

Whether or not linear memories are allowed to be reallocated after initial allocation at runtime.

guard_before_linear_memory: bool

Whether or not linear memory allocations will have a guard region at the beginning of the allocation in addition to the end.

table_lazy_init: bool

Whether to initialize tables lazily, so that instantiation is fast but indirect calls are a little slower. If false, tables are initialized eagerly from any active element segments that apply to them during instantiation.

generate_address_map: bool

Indicates whether an address map from compiled native code back to wasm offsets in the original file is generated.

debug_adapter_modules: bool

Flag for the component module whether adapter modules have debug assertions baked into them.

relaxed_simd_deterministic: bool

Whether or not lowerings for relaxed simd instructions are forced to be deterministic.

winch_callable: bool

Whether or not Wasm functions target the winch abi.

signals_based_traps: bool

Whether or not the host will be using native signals (e.g. SIGILL, SIGSEGV, etc) to implement traps.

memory_init_cow: bool

Whether CoW images might be used to initialize linear memories.

inlining: bool

Whether to enable inlining in Wasmtime’s compilation orchestration or not.

inlining_intra_module: IntraModuleInlining

Whether to inline calls within the same core Wasm module or not.

inlining_small_callee_size: u32

The size of “small callees” that can be inlined regardless of the caller’s size.

inlining_sum_size_threshold: u32

The general size threshold for the sum of the caller’s and callee’s sizes, past which we will generally not inline calls anymore.

Implementations

impl Tunables

pub fn default_host() -> Self

Returns a Tunables configuration assumed for running code on the host.

pub fn default_for_target(target: &Triple) -> Result<Self>

Returns the default set of tunables for the given target triple.

pub const fn default_miri() -> Tunables

Returns the default set of tunables for running under MIRI.

pub const fn default_u32() -> Tunables

Returns the default set of tunables for running under a 32-bit host.

pub const fn default_u64() -> Tunables

Returns the default set of tunables for running under a 64-bit host.

pub fn gc_heap_memory_type(&self) -> Memory

Get the GC heap’s memory type, given our configured tunables.

Trait Implementations

impl Clone for Tunables

fn clone(&self) -> Tunables

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Tunables

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

Formats the value using the given formatter.

impl<'de> Deserialize<'de> for Tunables

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl Hash for Tunables

fn hash<__H: Hasher>(&self, state: &mut __H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)

where H: Hasher, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl Serialize for Tunables

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.