From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- dom/chrome-webidl/DominatorTree.webidl | 70 ++++++++++++++++++++++++++++++++++ 1 file changed, 70 insertions(+) create mode 100644 dom/chrome-webidl/DominatorTree.webidl (limited to 'dom/chrome-webidl/DominatorTree.webidl') diff --git a/dom/chrome-webidl/DominatorTree.webidl b/dom/chrome-webidl/DominatorTree.webidl new file mode 100644 index 0000000000..518f0e9802 --- /dev/null +++ b/dom/chrome-webidl/DominatorTree.webidl @@ -0,0 +1,70 @@ +/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* 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/. + */ + +typedef unsigned long long NodeId; +typedef unsigned long long NodeSize; + +/** + * In a directed graph with a root node `R`, a node `A` is said to "dominate" a + * node `B` iff every path from `R` to `B` contains `A`. A node `A` is said to + * be the "immediate dominator" of a node `B` iff it dominates `B`, is not `B` + * itself, and does not dominate any other nodes which also dominate `B` in + * turn. + * + * If we take every node from a graph `G` and create a new graph `T` with edges + * to each node from its immediate dominator, then `T` is a tree (each node has + * only one immediate dominator, or none if it is the root). This tree is called + * a "dominator tree". + * + * This interface represents a dominator tree constructed from a HeapSnapshot's + * heap graph. The domination relationship and dominator trees are useful tools + * for analyzing heap graphs because they tell you: + * + * - Exactly what could be reclaimed by the GC if some node `A` became + * unreachable: those nodes which are dominated by `A`, + * + * - The "retained size" of a node in the heap graph, in contrast to its + * "shallow size". The "shallow size" is the space taken by a node itself, + * not counting anything it references. The "retained size" of a node is its + * shallow size plus the size of all the things that would be collected if + * the original node wasn't (directly or indirectly) referencing them. In + * other words, the retained size is the shallow size of a node plus the + * shallow sizes of every other node it dominates. For example, the root + * node in a binary tree might have a small shallow size that does not take + * up much space itself, but it dominates the rest of the binary tree and + * its retained size is therefore significant (assuming no external + * references into the tree). + */ +[ChromeOnly, Exposed=(Window,Worker)] +interface DominatorTree { + /** + * The `NodeId` for the root of the dominator tree. This is a "meta-root" in + * that it has an edge to each GC root in the heap snapshot this dominator + * tree was created from. + */ + readonly attribute NodeId root; + + /** + * Get the retained size of the node with the given id. If given an invalid + * id, null is returned. Throws an error on OOM. + */ + [Throws] + NodeSize? getRetainedSize(NodeId node); + + /** + * Get the set of ids of nodes immediately dominated by the node with the + * given id. The resulting array is sorted by greatest to least retained + * size. If given an invalid id, null is returned. Throws an error on OOM. + */ + [Throws] + sequence? getImmediatelyDominated(NodeId node); + + /** + * Get the immediate dominator of the node with the given id. Returns null if + * given an invalid id, or the id of the root node. + */ + NodeId? getImmediateDominator(NodeId node); +}; -- cgit v1.2.3