Struct wasmtime::ModuleLimits

pub struct ModuleLimits {
    pub imported_functions: u32,
    pub imported_tables: u32,
    pub imported_memories: u32,
    pub imported_globals: u32,
    pub types: u32,
    pub functions: u32,
    pub tables: u32,
    pub memories: u32,
    pub globals: u32,
    pub table_elements: u32,
    pub memory_pages: u64,
}

Represents the limits placed on a module for compiling with the pooling instance allocation strategy.

Fields

imported_functions: u32

The maximum number of imported functions for a module (default is 1000).

This value controls the capacity of the VMFunctionImport table and the VMCallerCheckedAnyfunc table in each instance’s VMContext structure.

The allocated size of the VMFunctionImport table will be imported_functions * sizeof(VMFunctionImport) for each instance regardless of how many functions an instance imports.

The allocated size of the VMCallerCheckedAnyfunc table will be imported_functions * functions * sizeof(VMCallerCheckedAnyfunc) for each instance regardless of how many functions are imported and defined by an instance.

imported_tables: u32

The maximum number of imported tables for a module (default is 0).

This value controls the capacity of the VMTableImport table in each instance’s VMContext structure.

The allocated size of the table will be imported_tables * sizeof(VMTableImport) for each instance regardless of how many tables an instance imports.

imported_memories: u32

The maximum number of imported linear memories for a module (default is 0).

This value controls the capacity of the VMMemoryImport table in each instance’s VMContext structure.

The allocated size of the table will be imported_memories * sizeof(VMMemoryImport) for each instance regardless of how many memories an instance imports.

imported_globals: u32

The maximum number of imported globals for a module (default is 0).

This value controls the capacity of the VMGlobalImport table in each instance’s VMContext structure.

The allocated size of the table will be imported_globals * sizeof(VMGlobalImport) for each instance regardless of how many globals an instance imports.

types: u32

The maximum number of defined types for a module (default is 100).

This value controls the capacity of the VMSharedSignatureIndex table in each instance’s VMContext structure.

The allocated size of the table will be types * sizeof(VMSharedSignatureIndex) for each instance regardless of how many types are defined by an instance’s module.

functions: u32

The maximum number of defined functions for a module (default is 10000).

This value controls the capacity of the VMCallerCheckedAnyfunc table in each instance’s VMContext structure.

The allocated size of the VMCallerCheckedAnyfunc table will be imported_functions * functions * sizeof(VMCallerCheckedAnyfunc) for each instance regardless of how many functions are imported and defined by an instance.

tables: u32

The maximum number of defined tables for a module (default is 1).

This value controls the capacity of the VMTableDefinition table in each instance’s VMContext structure.

The allocated size of the table will be tables * sizeof(VMTableDefinition) for each instance regardless of how many tables are defined by an instance’s module.

memories: u32

The maximum number of defined linear memories for a module (default is 1).

This value controls the capacity of the VMMemoryDefinition table in each instance’s VMContext structure.

The allocated size of the table will be memories * sizeof(VMMemoryDefinition) for each instance regardless of how many memories are defined by an instance’s module.

globals: u32

The maximum number of defined globals for a module (default is 10).

This value controls the capacity of the VMGlobalDefinition table in each instance’s VMContext structure.

The allocated size of the table will be globals * sizeof(VMGlobalDefinition) for each instance regardless of how many globals are defined by an instance’s module.

table_elements: u32

The maximum table elements for any table defined in a module (default is 10000).

If a table’s minimum element limit is greater than this value, the module will fail to compile.

If a table’s maximum element limit is unbounded or greater than this value, the maximum will be table_elements for the purpose of any table.grow instruction.

This value is used to reserve the maximum space for each supported table; table elements are pointer-sized in the Wasmtime runtime. Therefore, the space reserved for each instance is tables * table_elements * sizeof::<*const ()>.

memory_pages: u64

The maximum number of pages for any linear memory defined in a module (default is 160).

The default of 160 means at most 10 MiB of host memory may be committed for each instance.

If a memory’s minimum page limit is greater than this value, the module will fail to compile.

If a memory’s maximum page limit is unbounded or greater than this value, the maximum will be memory_pages for the purpose of any memory.grow instruction.

This value is used to control the maximum accessible space for each linear memory of an instance.

The reservation size of each linear memory is controlled by the static_memory_maximum_size setting and this value cannot exceed the configured static memory maximum size.

Trait Implementations

impl Clone for ModuleLimits

fn clone(&self) -> ModuleLimits

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ModuleLimits

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

Formats the value using the given formatter.

impl Default for ModuleLimits

fn default() -> Self

Returns the “default value” for a type.

impl Copy for ModuleLimits