Struct v8::fast_api::FastApiCallbackOptions

#[repr(C)]
pub struct FastApiCallbackOptions<'a> {
    pub fallback: bool,
    pub data: FastApiCallbackData<'a>,
    pub wasm_memory: *const FastApiTypedArray<u8>,
}

A struct which may be passed to a fast call callback, like so

void FastMethodWithOptions(int param, FastApiCallbackOptions& options);

Fields

fallback: bool

If the callback wants to signal an error condition or to perform an allocation, it must set options.fallback to true and do an early return from the fast method. Then V8 checks the value of options.fallback and if it’s true, falls back to executing the SlowCallback, which is capable of reporting the error (either by throwing a JS exception or logging to the console) or doing the allocation. It’s the embedder’s responsibility to ensure that the fast callback is idempotent up to the point where error and fallback conditions are checked, because otherwise executing the slow callback might produce visible side-effects twice.

data: FastApiCallbackData<'a>

wasm_memory: *const FastApiTypedArray<u8>

When called from WebAssembly, a view of the calling module’s memory.