Struct mozjs::jsapi::js::ClassExtension

#[repr(C)]
pub struct ClassExtension {
    pub objectMovedOp: Option<unsafe extern "C" fn(_: *mut JSObject, _: *mut JSObject) -> usize>,
}

Fields

objectMovedOp: Option<unsafe extern "C" fn(_: *mut JSObject, _: *mut JSObject) -> usize>

Optional hook called when an object is moved by generational or compacting GC.

There may exist weak pointers to an object that are not traced through when the normal trace APIs are used, for example objects in the wrapper cache. This hook allows these pointers to be updated.

Note that this hook can be called before JS_NewObject() returns if a GC is triggered during construction of the object. This can happen for global objects for example.

The function should return the difference between nursery bytes used and tenured bytes used, which may be nonzero e.g. if some nursery-allocated data beyond the actual GC thing is moved into malloced memory.

This is used to compute the nursery promotion rate.

Trait Implementations

impl Clone for ClassExtension

fn clone(&self) -> ClassExtension

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for ClassExtension

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

Formats the value using the given formatter.

impl PartialEq for ClassExtension

fn eq(&self, other: &ClassExtension) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Copy for ClassExtension

impl StructuralPartialEq for ClassExtension