asarfuckery/electronasar/stable/renderer/api/remote.js

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2019-01-17 18:22:05 +00:00
'use strict'
const v8Util = process.atomBinding('v8_util')
const { isPromise } = require('electron')
const resolvePromise = Promise.resolve.bind(Promise)
const CallbacksRegistry = require('@electron/internal/renderer/callbacks-registry')
const bufferUtils = require('@electron/internal/common/buffer-utils')
const errorUtils = require('@electron/internal/common/error-utils')
const ipcRenderer = require('@electron/internal/renderer/ipc-renderer-internal')
const callbacksRegistry = new CallbacksRegistry()
const remoteObjectCache = v8Util.createIDWeakMap()
// An unique ID that can represent current context.
const contextId = v8Util.getHiddenValue(global, 'contextId')
// Notify the main process when current context is going to be released.
// Note that when the renderer process is destroyed, the message may not be
// sent, we also listen to the "render-view-deleted" event in the main process
// to guard that situation.
process.on('exit', () => {
const command = 'ELECTRON_BROWSER_CONTEXT_RELEASE'
ipcRenderer.sendSync(command, contextId)
})
// Convert the arguments object into an array of meta data.
function wrapArgs (args, visited = new Set()) {
const valueToMeta = (value) => {
// Check for circular reference.
if (visited.has(value)) {
return {
type: 'value',
value: null
}
}
if (Array.isArray(value)) {
visited.add(value)
const meta = {
type: 'array',
value: wrapArgs(value, visited)
}
visited.delete(value)
return meta
} else if (bufferUtils.isBuffer(value)) {
return {
type: 'buffer',
value: bufferUtils.bufferToMeta(value)
}
} else if (value instanceof Date) {
return {
type: 'date',
value: value.getTime()
}
} else if ((value != null) && typeof value === 'object') {
if (isPromise(value)) {
return {
type: 'promise',
then: valueToMeta(function (onFulfilled, onRejected) {
value.then(onFulfilled, onRejected)
})
}
} else if (v8Util.getHiddenValue(value, 'atomId')) {
return {
type: 'remote-object',
id: v8Util.getHiddenValue(value, 'atomId')
}
}
const meta = {
type: 'object',
name: value.constructor ? value.constructor.name : '',
members: []
}
visited.add(value)
for (const prop in value) {
meta.members.push({
name: prop,
value: valueToMeta(value[prop])
})
}
visited.delete(value)
return meta
} else if (typeof value === 'function' && v8Util.getHiddenValue(value, 'returnValue')) {
return {
type: 'function-with-return-value',
value: valueToMeta(value())
}
} else if (typeof value === 'function') {
return {
type: 'function',
id: callbacksRegistry.add(value),
location: v8Util.getHiddenValue(value, 'location'),
length: value.length
}
} else {
return {
type: 'value',
value: value
}
}
}
return args.map(valueToMeta)
}
// Populate object's members from descriptors.
// The |ref| will be kept referenced by |members|.
// This matches |getObjectMemebers| in rpc-server.
function setObjectMembers (ref, object, metaId, members) {
if (!Array.isArray(members)) return
for (const member of members) {
if (object.hasOwnProperty(member.name)) continue
const descriptor = { enumerable: member.enumerable }
if (member.type === 'method') {
const remoteMemberFunction = function (...args) {
let command
if (this && this.constructor === remoteMemberFunction) {
command = 'ELECTRON_BROWSER_MEMBER_CONSTRUCTOR'
} else {
command = 'ELECTRON_BROWSER_MEMBER_CALL'
}
const ret = ipcRenderer.sendSync(command, contextId, metaId, member.name, wrapArgs(args))
return metaToValue(ret)
}
let descriptorFunction = proxyFunctionProperties(remoteMemberFunction, metaId, member.name)
descriptor.get = () => {
descriptorFunction.ref = ref // The member should reference its object.
return descriptorFunction
}
// Enable monkey-patch the method
descriptor.set = (value) => {
descriptorFunction = value
return value
}
descriptor.configurable = true
} else if (member.type === 'get') {
descriptor.get = () => {
const command = 'ELECTRON_BROWSER_MEMBER_GET'
const meta = ipcRenderer.sendSync(command, contextId, metaId, member.name)
return metaToValue(meta)
}
if (member.writable) {
descriptor.set = (value) => {
const args = wrapArgs([value])
const command = 'ELECTRON_BROWSER_MEMBER_SET'
const meta = ipcRenderer.sendSync(command, contextId, metaId, member.name, args)
if (meta != null) metaToValue(meta)
return value
}
}
}
Object.defineProperty(object, member.name, descriptor)
}
}
// Populate object's prototype from descriptor.
// This matches |getObjectPrototype| in rpc-server.
function setObjectPrototype (ref, object, metaId, descriptor) {
if (descriptor === null) return
const proto = {}
setObjectMembers(ref, proto, metaId, descriptor.members)
setObjectPrototype(ref, proto, metaId, descriptor.proto)
Object.setPrototypeOf(object, proto)
}
// Wrap function in Proxy for accessing remote properties
function proxyFunctionProperties (remoteMemberFunction, metaId, name) {
let loaded = false
// Lazily load function properties
const loadRemoteProperties = () => {
if (loaded) return
loaded = true
const command = 'ELECTRON_BROWSER_MEMBER_GET'
const meta = ipcRenderer.sendSync(command, contextId, metaId, name)
setObjectMembers(remoteMemberFunction, remoteMemberFunction, meta.id, meta.members)
}
return new Proxy(remoteMemberFunction, {
set: (target, property, value, receiver) => {
if (property !== 'ref') loadRemoteProperties()
target[property] = value
return true
},
get: (target, property, receiver) => {
if (!target.hasOwnProperty(property)) loadRemoteProperties()
const value = target[property]
if (property === 'toString' && typeof value === 'function') {
return value.bind(target)
}
return value
},
ownKeys: (target) => {
loadRemoteProperties()
return Object.getOwnPropertyNames(target)
},
getOwnPropertyDescriptor: (target, property) => {
const descriptor = Object.getOwnPropertyDescriptor(target, property)
if (descriptor) return descriptor
loadRemoteProperties()
return Object.getOwnPropertyDescriptor(target, property)
}
})
}
// Convert meta data from browser into real value.
function metaToValue (meta) {
const types = {
value: () => meta.value,
array: () => meta.members.map((member) => metaToValue(member)),
buffer: () => bufferUtils.metaToBuffer(meta.value),
promise: () => resolvePromise({ then: metaToValue(meta.then) }),
error: () => metaToPlainObject(meta),
date: () => new Date(meta.value),
exception: () => { throw errorUtils.deserialize(meta.value) }
}
if (meta.type in types) {
return types[meta.type]()
} else {
let ret
if (remoteObjectCache.has(meta.id)) {
return remoteObjectCache.get(meta.id)
}
// A shadow class to represent the remote function object.
if (meta.type === 'function') {
const remoteFunction = function (...args) {
let command
if (this && this.constructor === remoteFunction) {
command = 'ELECTRON_BROWSER_CONSTRUCTOR'
} else {
command = 'ELECTRON_BROWSER_FUNCTION_CALL'
}
const obj = ipcRenderer.sendSync(command, contextId, meta.id, wrapArgs(args))
return metaToValue(obj)
}
ret = remoteFunction
} else {
ret = {}
}
setObjectMembers(ret, ret, meta.id, meta.members)
setObjectPrototype(ret, ret, meta.id, meta.proto)
Object.defineProperty(ret.constructor, 'name', { value: meta.name })
// Track delegate obj's lifetime & tell browser to clean up when object is GCed.
v8Util.setRemoteObjectFreer(ret, contextId, meta.id)
v8Util.setHiddenValue(ret, 'atomId', meta.id)
remoteObjectCache.set(meta.id, ret)
return ret
}
}
// Construct a plain object from the meta.
function metaToPlainObject (meta) {
const obj = (() => meta.type === 'error' ? new Error() : {})()
for (let i = 0; i < meta.members.length; i++) {
const { name, value } = meta.members[i]
obj[name] = value
}
return obj
}
function handleMessage (channel, handler) {
ipcRenderer.on(channel, (event, passedContextId, id, ...args) => {
if (passedContextId === contextId) {
handler(id, ...args)
} else {
// Message sent to an un-exist context, notify the error to main process.
ipcRenderer.send('ELECTRON_BROWSER_WRONG_CONTEXT_ERROR', contextId, passedContextId, id)
}
})
}
// Browser calls a callback in renderer.
handleMessage('ELECTRON_RENDERER_CALLBACK', (id, args) => {
callbacksRegistry.apply(id, metaToValue(args))
})
// A callback in browser is released.
handleMessage('ELECTRON_RENDERER_RELEASE_CALLBACK', (id) => {
callbacksRegistry.remove(id)
})
exports.require = (module) => {
const command = 'ELECTRON_BROWSER_REQUIRE'
const meta = ipcRenderer.sendSync(command, contextId, module)
return metaToValue(meta)
}
// Alias to remote.require('electron').xxx.
exports.getBuiltin = (module) => {
const command = 'ELECTRON_BROWSER_GET_BUILTIN'
const meta = ipcRenderer.sendSync(command, contextId, module)
return metaToValue(meta)
}
exports.getCurrentWindow = () => {
const command = 'ELECTRON_BROWSER_CURRENT_WINDOW'
const meta = ipcRenderer.sendSync(command, contextId)
return metaToValue(meta)
}
// Get current WebContents object.
exports.getCurrentWebContents = () => {
return metaToValue(ipcRenderer.sendSync('ELECTRON_BROWSER_CURRENT_WEB_CONTENTS', contextId))
}
// Get a global object in browser.
exports.getGlobal = (name) => {
const command = 'ELECTRON_BROWSER_GLOBAL'
const meta = ipcRenderer.sendSync(command, contextId, name)
return metaToValue(meta)
}
// Get the process object in browser.
exports.__defineGetter__('process', () => exports.getGlobal('process'))
// Create a function that will return the specified value when called in browser.
exports.createFunctionWithReturnValue = (returnValue) => {
const func = () => returnValue
v8Util.setHiddenValue(func, 'returnValue', true)
return func
}
// Get the guest WebContents from guestInstanceId.
exports.getGuestWebContents = (guestInstanceId) => {
const command = 'ELECTRON_BROWSER_GUEST_WEB_CONTENTS'
const meta = ipcRenderer.sendSync(command, contextId, guestInstanceId)
return metaToValue(meta)
}
const addBuiltinProperty = (name) => {
Object.defineProperty(exports, name, {
get: () => exports.getBuiltin(name)
})
}
const browserModules =
require('@electron/internal/common/api/module-list').concat(
require('@electron/internal/browser/api/module-list'))
// And add a helper receiver for each one.
browserModules
.filter((m) => !m.private)
.map((m) => m.name)
.forEach(addBuiltinProperty)