/* -*- 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/. */ /** * A HeapSnapshot represents a snapshot of the heap graph */ [ChromeOnly, Exposed=(Window,System,Worker)] interface HeapSnapshot { /** * A time stamp of when the heap snapshot was taken, if available. Units are * microseconds since midnight (00:00:00) 1 January 1970 UTC. */ readonly attribute unsigned long long? creationTime; /** * Take a census of the heap snapshot. * * This is the same as |Debugger.Memory.prototype.takeCensus|, but operates on * the offline heap snapshot's serialized heap graph rather than the live heap * graph. The same optional configuration options that can be passed to that * function can be passed here. * * The returned value is determined by the `"breakdown"` option used, and is * usually a `Map`, `Object`, or `Array`. For example, the following breakdown * * { * by: "coarseType", * objects: { by: "objectClass" }, * other: { by: "internalType" } * } * * produces a result like this: * * { * "objects": { * "Function": { "count": 404, "bytes": 37328 }, * "Object": { "count": 11, "bytes": 1264 }, * "Debugger": { "count": 1, "bytes": 416 }, * "ScriptSource": { "count": 1, "bytes": 64 }, * // ... omitted for brevity... * }, * "scripts": { "count": 1, "bytes": 0 }, * "strings": { "count": 701, "bytes": 49080 }, * "other": { * "js::Shape": { "count": 450, "bytes": 0 }, * "js::BaseShape": { "count": 21, "bytes": 0 }, * "js::ObjectGroup": { "count": 17, "bytes": 0 } * } * } * * See the `takeCensus` section of the `js/src/doc/Debugger/Debugger.Memory.md` * file for detailed documentation. */ [Throws] any takeCensus(object? options); /** * Describe `node` with the specified `breakdown`. See the comment above * `takeCensus` or `js/src/doc/Debugger/Debugger.Memory.md` for detailed * documentation on breakdowns. * * Throws an error when `node` is not the id of a node in the heap snapshot, * or if the breakdown is invalid. */ [Throws] any describeNode(object breakdown, NodeId node); /** * Compute the dominator tree for this heap snapshot. * * @see DominatorTree.webidl */ [Throws] DominatorTree computeDominatorTree(); /** * Find the shortest retaining paths from the node associated with the ID * `start` to each node associated with the IDs in `targets`. Find at most * `maxNumPaths` retaining paths for each target node. * * The return value is a Map object mapping from each target node ID to an * array of retaining paths. The array may be empty if we did not find any * retaining paths. * * A path is an array of objects of the form: * * { * predecessor: <node ID>, * edge: <string or null>, * } * * The first `predecessor` will always be `start`. The last edge in the path * leads to the `target` node that is mapped to the path; the `target` does * not appear as a `predecessor` in the path. * * Throws when `start` or any of the elements of `targets` are not an ID of a * node in the snapshot, or if we encounter an out of memory exception. */ [Throws] object computeShortestPaths(NodeId start, sequence<NodeId> targets, unsigned long long maxNumPaths); };