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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
use dom::bindings::callback::CallbackContainer;
use dom::bindings::codegen::Bindings::PromiseBinding::AnyCallback;
use dom::bindings::conversions::root_from_object;
use dom::bindings::error::Fallible;
use dom::bindings::global::GlobalRef;
use dom::bindings::reflector::{Reflectable, MutReflectable, Reflector};
use dom::promisenativehandler::PromiseNativeHandler;
use js::conversions::ToJSValConvertible;
use js::jsapi::{CallOriginalPromiseResolve, CallOriginalPromiseReject, CallOriginalPromiseThen};
use js::jsapi::{JSAutoCompartment, CallArgs, JS_GetFunctionObject, JS_NewFunction};
use js::jsapi::{JSContext, HandleValue, HandleObject, IsPromiseObject, GetFunctionNativeReserved};
use js::jsapi::{JS_ClearPendingException, JSObject};
use js::jsapi::{MutableHandleObject, NewPromiseObject, ResolvePromise, RejectPromise};
use js::jsapi::{SetFunctionNativeReserved, NewFunctionWithReserved, AddPromiseReactions};
use js::jsval::{JSVal, UndefinedValue, ObjectValue, Int32Value};
use std::ptr;
use std::rc::Rc;
#[dom_struct]
pub struct Promise {
reflector: Reflector,
}
impl Promise {
#[allow(unsafe_code)]
pub fn new(global: GlobalRef) -> Rc<Promise> {
let cx = global.get_cx();
rooted!(in(cx) let mut obj = ptr::null_mut());
unsafe {
Promise::create_js_promise(cx, HandleObject::null(), obj.handle_mut());
}
Promise::new_with_js_promise(obj.handle())
}
#[allow(unsafe_code, unrooted_must_root)]
fn new_with_js_promise(obj: HandleObject) -> Rc<Promise> {
unsafe {
assert!(IsPromiseObject(obj));
}
let mut promise = Promise {
reflector: Reflector::new(),
};
promise.init_reflector(obj.get());
Rc::new(promise)
}
#[allow(unsafe_code)]
unsafe fn create_js_promise(cx: *mut JSContext, proto: HandleObject, obj: MutableHandleObject) {
let do_nothing_func = JS_NewFunction(cx, Some(do_nothing_promise_executor), /* nargs = */ 2,
/* flags = */ 0, ptr::null());
assert!(!do_nothing_func.is_null());
rooted!(in(cx) let do_nothing_obj = JS_GetFunctionObject(do_nothing_func));
assert!(!do_nothing_obj.is_null());
obj.set(NewPromiseObject(cx, do_nothing_obj.handle(), proto));
assert!(!obj.is_null());
}
#[allow(unrooted_must_root, unsafe_code)]
pub fn Resolve(global: GlobalRef,
cx: *mut JSContext,
value: HandleValue) -> Fallible<Rc<Promise>> {
let _ac = JSAutoCompartment::new(cx, global.reflector().get_jsobject().get());
rooted!(in(cx) let p = unsafe { CallOriginalPromiseResolve(cx, value) });
assert!(!p.handle().is_null());
Ok(Promise::new_with_js_promise(p.handle()))
}
#[allow(unrooted_must_root, unsafe_code)]
pub fn Reject(global: GlobalRef,
cx: *mut JSContext,
value: HandleValue) -> Fallible<Rc<Promise>> {
let _ac = JSAutoCompartment::new(cx, global.reflector().get_jsobject().get());
rooted!(in(cx) let p = unsafe { CallOriginalPromiseReject(cx, value) });
assert!(!p.handle().is_null());
Ok(Promise::new_with_js_promise(p.handle()))
}
#[allow(unsafe_code)]
pub fn maybe_resolve_native<T>(&self, cx: *mut JSContext, val: &T) where T: ToJSValConvertible {
rooted!(in(cx) let mut v = UndefinedValue());
unsafe {
val.to_jsval(cx, v.handle_mut());
}
self.maybe_resolve(cx, v.handle());
}
#[allow(unrooted_must_root, unsafe_code)]
pub fn maybe_resolve(&self,
cx: *mut JSContext,
value: HandleValue) {
unsafe {
if !ResolvePromise(cx, self.promise_obj(), value) {
JS_ClearPendingException(cx);
}
}
}
#[allow(unsafe_code)]
pub fn maybe_reject_native<T>(&self, cx: *mut JSContext, val: &T) where T: ToJSValConvertible {
rooted!(in(cx) let mut v = UndefinedValue());
unsafe {
val.to_jsval(cx, v.handle_mut());
}
self.maybe_reject(cx, v.handle());
}
#[allow(unrooted_must_root, unsafe_code)]
pub fn maybe_reject(&self,
cx: *mut JSContext,
value: HandleValue) {
unsafe {
if !RejectPromise(cx, self.promise_obj(), value) {
JS_ClearPendingException(cx);
}
}
}
#[allow(unrooted_must_root, unsafe_code)]
pub fn then(&self,
cx: *mut JSContext,
_callee: HandleObject,
cb_resolve: AnyCallback,
cb_reject: AnyCallback,
result: MutableHandleObject) {
let promise = self.promise_obj();
rooted!(in(cx) let resolve = cb_resolve.callback());
rooted!(in(cx) let reject = cb_reject.callback());
unsafe {
rooted!(in(cx) let res =
CallOriginalPromiseThen(cx, promise, resolve.handle(), reject.handle()));
result.set(*res);
}
}
#[allow(unsafe_code)]
fn promise_obj(&self) -> HandleObject {
let obj = self.reflector().get_jsobject();
unsafe {
assert!(IsPromiseObject(obj));
}
obj
}
#[allow(unsafe_code)]
pub fn append_native_handler(&self, handler: &PromiseNativeHandler) {
let global = self.global();
let cx = global.r().get_cx();
rooted!(in(cx) let resolve_func =
create_native_handler_function(cx,
handler.reflector().get_jsobject(),
NativeHandlerTask::Resolve));
rooted!(in(cx) let reject_func =
create_native_handler_function(cx,
handler.reflector().get_jsobject(),
NativeHandlerTask::Reject));
unsafe {
let ok = AddPromiseReactions(cx,
self.promise_obj(),
resolve_func.handle(),
reject_func.handle());
assert!(ok);
}
}
}
#[allow(unsafe_code)]
unsafe extern fn do_nothing_promise_executor(_cx: *mut JSContext, argc: u32, vp: *mut JSVal) -> bool {
let args = CallArgs::from_vp(vp, argc);
*args.rval() = UndefinedValue();
true
}
const SLOT_NATIVEHANDLER: usize = 0;
const SLOT_NATIVEHANDLER_TASK: usize = 1;
#[derive(PartialEq)]
enum NativeHandlerTask {
Resolve = 0,
Reject = 1,
}
#[allow(unsafe_code)]
unsafe extern fn native_handler_callback(cx: *mut JSContext, argc: u32, vp: *mut JSVal) -> bool {
let args = CallArgs::from_vp(vp, argc);
rooted!(in(cx) let v = *GetFunctionNativeReserved(args.callee(), SLOT_NATIVEHANDLER));
assert!(v.get().is_object());
let handler = root_from_object::<PromiseNativeHandler>(v.to_object())
.ok().expect("unexpected value for native handler in promise native handler callback");
rooted!(in(cx) let v = *GetFunctionNativeReserved(args.callee(), SLOT_NATIVEHANDLER_TASK));
match v.to_int32() {
v if v == NativeHandlerTask::Resolve as i32 => handler.resolved_callback(cx, args.get(0)),
v if v == NativeHandlerTask::Reject as i32 => handler.rejected_callback(cx, args.get(0)),
_ => panic!("unexpected native handler task value"),
};
true
}
#[allow(unsafe_code)]
fn create_native_handler_function(cx: *mut JSContext,
holder: HandleObject,
task: NativeHandlerTask) -> *mut JSObject {
unsafe {
let func = NewFunctionWithReserved(cx, Some(native_handler_callback), 1, 0, ptr::null());
assert!(!func.is_null());
rooted!(in(cx) let obj = JS_GetFunctionObject(func));
assert!(!obj.is_null());
SetFunctionNativeReserved(obj.get(),
SLOT_NATIVEHANDLER,
&ObjectValue(&**holder));
SetFunctionNativeReserved(obj.get(),
SLOT_NATIVEHANDLER_TASK,
&Int32Value(task as i32));
obj.get()
}
}
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