dom.rs (1191B)
1 /* This Source Code Form is subject to the terms of the Mozilla Public 2 * License, v. 2.0. If a copy of the MPL was not distributed with this 3 * file, You can obtain one at https://mozilla.org/MPL/2.0/. */ 4 5 //! Types used to access the DOM from style calculation. 6 7 /// An opaque handle to a node, which, unlike UnsafeNode, cannot be transformed 8 /// back into a non-opaque representation. The only safe operation that can be 9 /// performed on this node is to compare it to another opaque handle or to another 10 /// OpaqueNode. 11 /// 12 /// Layout and Graphics use this to safely represent nodes for comparison purposes. 13 /// Because the script task's GC does not trace layout, node data cannot be safely stored in layout 14 /// data structures. Also, layout code tends to be faster when the DOM is not being accessed, for 15 /// locality reasons. Using `OpaqueNode` enforces this invariant. 16 #[derive(Clone, Copy, Debug, Eq, Hash, MallocSizeOf, PartialEq)] 17 #[cfg_attr(feature = "servo", derive(Deserialize, Serialize))] 18 pub struct OpaqueNode(pub usize); 19 20 impl OpaqueNode { 21 /// Returns the address of this node, for debugging purposes. 22 #[inline] 23 pub fn id(&self) -> usize { 24 self.0 25 } 26 }