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Move unwrap_jsmanaged and related machinery to conversions.rs.

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This commit is contained in:
Ms2ger 2014-12-20 14:51:14 +01:00
parent 73c236ce3b
commit 96180ec3ad
5 changed files with 124 additions and 113 deletions
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108
components/script/dom/bindings/utils.rs
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@ -8,10 +8,10 @@
use dom::bindings::codegen::PrototypeList;
use dom::bindings::codegen::PrototypeList::MAX_PROTO_CHAIN_LENGTH;
use dom::bindings::conversions::IDLInterface;
use dom::bindings::conversions::unwrap_jsmanaged;
use dom::bindings::error::throw_type_error;
use dom::bindings::global::GlobalRef;
use dom::bindings::js::{JS, Temporary, Root};
use dom::bindings::js::{Temporary, Root};
use dom::browsercontext;
use dom::window;
@ -20,9 +20,7 @@ use libc::c_uint;
use std::cell::Cell;
use std::mem;
use std::ptr;
use js::glue::{js_IsObjectProxyClass, js_IsFunctionProxyClass, IsProxyHandlerFamily};
use js::glue::{UnwrapObject, GetProxyHandlerExtra};
use js::glue::{IsWrapper, RUST_JSID_IS_INT, RUST_JSID_TO_INT};
use js::glue::{RUST_JSID_IS_INT, RUST_JSID_TO_INT};
use js::jsapi::{JS_AlreadyHasOwnProperty, JS_NewFunction};
use js::jsapi::{JS_DefineProperties, JS_ForwardGetPropertyTo};
use js::jsapi::{JS_GetClass, JS_LinkConstructorAndPrototype, JS_GetStringCharsAndLength};
@ -64,111 +62,11 @@ pub fn GlobalStaticData() -> GlobalStaticData {
}
}
/// Returns whether the given `clasp` is one for a DOM object.
fn is_dom_class(clasp: *const JSClass) -> bool {
unsafe {
((*clasp).flags & js::JSCLASS_IS_DOMJSCLASS) != 0
}
}
/// Returns whether `obj` is a DOM object implemented as a proxy.
pub fn is_dom_proxy(obj: *mut JSObject) -> bool {
unsafe {
(js_IsObjectProxyClass(obj) || js_IsFunctionProxyClass(obj)) &&
IsProxyHandlerFamily(obj)
}
}
/// Returns the index of the slot wherein a pointer to the reflected DOM object
/// is stored.
///
/// Fails if `obj` is not a DOM object.
pub unsafe fn dom_object_slot(obj: *mut JSObject) -> u32 {
let clasp = JS_GetClass(obj);
if is_dom_class(&*clasp) {
DOM_OBJECT_SLOT as u32
} else {
assert!(is_dom_proxy(obj));
DOM_PROXY_OBJECT_SLOT as u32
}
}
/// Get the DOM object from the given reflector.
pub unsafe fn unwrap<T>(obj: *mut JSObject) -> *const T {
let slot = dom_object_slot(obj);
let val = JS_GetReservedSlot(obj, slot);
val.to_private() as *const T
}
/// Get the `DOMClass` from `obj`, or `Err(())` if `obj` is not a DOM object.
pub unsafe fn get_dom_class(obj: *mut JSObject) -> Result<DOMClass, ()> {
let clasp = JS_GetClass(obj);
if is_dom_class(&*clasp) {
debug!("plain old dom object");
let domjsclass: *const DOMJSClass = clasp as *const DOMJSClass;
return Ok((*domjsclass).dom_class);
}
if is_dom_proxy(obj) {
debug!("proxy dom object");
let dom_class: *const DOMClass = GetProxyHandlerExtra(obj) as *const DOMClass;
return Ok(*dom_class);
}
debug!("not a dom object");
return Err(());
}
/// Get a `JS<T>` for the given DOM object, unwrapping any wrapper around it
/// first, and checking if the object is of the correct type.
///
/// Returns Err(()) if `obj` is an opaque security wrapper or if the object is
/// not a reflector for a DOM object of the given type (as defined by the
/// proto_id and proto_depth).
pub fn unwrap_jsmanaged<T>(mut obj: *mut JSObject) -> Result<JS<T>, ()>
where T: Reflectable + IDLInterface
{
unsafe {
let dom_class = try!(get_dom_class(obj).or_else(|_| {
if IsWrapper(obj) == 1 {
debug!("found wrapper");
obj = UnwrapObject(obj, /* stopAtOuter = */ 0, ptr::null_mut());
if obj.is_null() {
debug!("unwrapping security wrapper failed");
Err(())
} else {
assert!(IsWrapper(obj) == 0);
debug!("unwrapped successfully");
get_dom_class(obj)
}
} else {
debug!("not a dom wrapper");
Err(())
}
}));
let proto_id = IDLInterface::get_prototype_id(None::<T>);
let proto_depth = IDLInterface::get_prototype_depth(None::<T>);
if dom_class.interface_chain[proto_depth] == proto_id {
debug!("good prototype");
Ok(JS::from_raw(unwrap(obj)))
} else {
debug!("bad prototype");
Err(())
}
}
}
/// Leak the given pointer.
pub unsafe fn squirrel_away_unique<T>(x: Box<T>) -> *const T {
mem::transmute(x)
}
/// The index of the slot wherein a pointer to the reflected DOM object is
/// stored for non-proxy bindings.
// We use slot 0 for holding the raw object. This is safe for both
// globals and non-globals.
pub const DOM_OBJECT_SLOT: uint = 0;
const DOM_PROXY_OBJECT_SLOT: uint = js::JSSLOT_PROXY_PRIVATE as uint;
// NOTE: This is baked into the Ion JIT as 0 in codegen for LGetDOMProperty and
// LSetDOMProperty. Those constants need to be changed accordingly if this value
// changes.