04b7c77951
After after using `processId-contextCounter` as contextId, it may happen that contexts in different WebContents sharing the same renderer process get the same contextId. Using webContentsId as part of key in ObjectsRegistry can fix this.
110 lines
3.1 KiB
JavaScript
110 lines
3.1 KiB
JavaScript
'use strict'
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const v8Util = process.atomBinding('v8_util')
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class ObjectsRegistry {
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constructor () {
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this.nextId = 0
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// Stores all objects by ref-counting.
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// (id) => {object, count}
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this.storage = {}
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// Stores the IDs of objects referenced by WebContents.
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// (webContentsContextId) => [id]
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this.owners = {}
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}
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// Register a new object and return its assigned ID. If the object is already
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// registered then the already assigned ID would be returned.
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add (webContents, contextId, obj) {
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// Get or assign an ID to the object.
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const id = this.saveToStorage(obj)
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// Add object to the set of referenced objects.
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const webContentsContextId = `${webContents.id}-${contextId}`
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let owner = this.owners[webContentsContextId]
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if (!owner) {
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owner = this.owners[webContentsContextId] = new Set()
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this.registerDeleteListener(webContents, contextId)
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}
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if (!owner.has(id)) {
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owner.add(id)
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// Increase reference count if not referenced before.
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this.storage[id].count++
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}
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return id
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}
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// Get an object according to its ID.
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get (id) {
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const pointer = this.storage[id]
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if (pointer != null) return pointer.object
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}
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// Dereference an object according to its ID.
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// Note that an object may be double-freed (cleared when page is reloaded, and
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// then garbage collected in old page).
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remove (webContents, contextId, id) {
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const webContentsContextId = `${webContents.id}-${contextId}`
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let owner = this.owners[webContentsContextId]
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if (owner) {
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// Remove the reference in owner.
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owner.delete(id)
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// Dereference from the storage.
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this.dereference(id)
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}
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}
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// Clear all references to objects refrenced by the WebContents.
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clear (webContents, contextId) {
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const webContentsContextId = `${webContents.id}-${contextId}`
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let owner = this.owners[webContentsContextId]
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if (!owner) return
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for (let id of owner) this.dereference(id)
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delete this.owners[webContentsContextId]
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}
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// Private: Saves the object into storage and assigns an ID for it.
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saveToStorage (object) {
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let id = v8Util.getHiddenValue(object, 'atomId')
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if (!id) {
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id = ++this.nextId
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this.storage[id] = {
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count: 0,
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object: object
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}
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v8Util.setHiddenValue(object, 'atomId', id)
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}
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return id
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}
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// Private: Dereference the object from store.
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dereference (id) {
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let pointer = this.storage[id]
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if (pointer == null) {
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return
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}
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pointer.count -= 1
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if (pointer.count === 0) {
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v8Util.deleteHiddenValue(pointer.object, 'atomId')
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delete this.storage[id]
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}
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}
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// Private: Clear the storage when renderer process is destoryed.
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registerDeleteListener (webContents, contextId) {
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const processId = webContents.getProcessId()
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const listener = (event, deletedProcessId) => {
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if (deletedProcessId === processId) {
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webContents.removeListener('render-view-deleted', listener)
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this.clear(webContents, contextId)
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}
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}
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webContents.on('render-view-deleted', listener)
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}
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}
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module.exports = new ObjectsRegistry()
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