metamask源码学习-background.js
这个就是浏览器后台所进⾏操作的地⽅了，它就是页⾯也区块链进⾏交互的中间部分。 metamask-background描述了为web扩展单例的⽂件app/scripts/background.js。该上下⽂实例化了⼀个MetaMask控制器的实例，该实例表⽰⽤户的帐户、到区块链的连接以及与新Dapps的交互。 Since background.js is essentially the Extension setup file, we can see it doing all the things specific to the extension platform:
因为background.js本质上是扩展设置⽂件，我们可以看到它做所有特定于扩展平台的事情 Defining how to open the UI for new messages, transactions, and even requests to unlock (reveal to the site) their account.定义如何为新消息、事务、甚⾄为解锁(向站点显⽰)其帐户的请求打开UI Provide the instance's initial state, leaving MetaMask persistence to the platform.提供实例的初始状态，将MetaMask持久化保留到平台
Providing a platform object. This is becoming our catch-all adapter for platforms to define a few other platform-variant features we require, like opening a web link. (Soon we will be moving encryption out here too, since our browser-encryption isn't portable enough!)提供平台对象。这将成为平台的通⽤适配器，⽤于定义我们需要的其他⼀些平台变体特性，⽐如打开web链接。(不久我们也将把加密技术移
到这⾥，因为我们的浏览器加密还不够便携!)
/**
* @file The entry point for the web extension singleton process.车辆排队长度
*/
const urlUtil = require('url')
const endOfStream = require('end-of-stream')
const endOfStream = require('end-of-stream')
const pump = require('pump')
const debounce = require('debounce-stream')
const log = require('loglevel')
const extension = require('extensionizer')
const LocalStorageStore = require('obs-store/lib/localStorage')
const LocalStore = require('./lib/local-store')
const storeTransform = require('obs-store/lib/transform')
const asStream = require('obs-store/lib/asStream')
const ExtensionPlatform = require('./platforms/extension')
const Migrator = require('./lib/migrator/') //初始化就是设置migrations有默认设置的就⽤默认的，否则就⽤最新版本的，不然就⽤0版本
const migrations = require('./migrations/') //Data (user data, config files etc.) is migrated from one version to another.从版本2⼀直到28，0为初始版本const PortStream = require('./lib/port-stream.js')
const createStreamSink = require('./lib/createStreamSink')
const NotificationManager = require('./lib/notification-manager.js')
const MetamaskController = require('./metamask-controller')
const firstTimeState = require('./first-time-state')
const setupRaven = require('./lib/setupRaven')
const reportFailedTxToSentry = require('./lib/reportFailedTxToSentry')
const setupMetamaskMeshMetrics = require('./lib/setupMetamaskMeshMetrics')
const EdgeEncryptor = require('./edge-encryptor')
const getFirstPreferredLangCode = require('./lib/get-first-preferred-lang-code')
const getObjStructure = require('./lib/getObjStructure')
const ipfsContent = require('./lib/ipfsContent.js')
const {
ENVIRONMENT_TYPE_POPUP,
ENVIRONMENT_TYPE_NOTIFICATION,
ENVIRONMENT_TYPE_FULLSCREEN,
} = require('./lib/enums')
const STORAGE_KEY = 'metamask-config'
const METAMASK_DEBUG = v.METAMASK_DEBUG
log.v.METAMASK_DEBUG ? 'debug' : 'warn')
const platform = new ExtensionPlatform()
const notificationManager = new NotificationManager()
global.METAMASK_NOTIFIER = notificationManager
// setup sentry error reporting
const release = Version()
const raven = setupRaven({ release })
/
/ browser check if it is Edge - stackoverflow/questions/9847580/how-to-detect-safari-chrome-ie-firefox-and-opera-browser
// Internet Explorer 6-11，即
const isIE = !!document.documentMode //查看所使⽤的浏览器类型
// Edge 20+
const isEdge = !isIE && !!window.StyleMedia
let ipfsHandle
let popupIsOpen = false //弹出窗⼝是否打开
let notificationIsOpen = false //通知是否打开
const openMetamaskTabsIDs = {}
// state persistence
const diskStore = new LocalStorageStore({ storageKey: STORAGE_KEY }) //硬盘的存储
const localStore = new LocalStore() //本地的存储
let versionedData
// initialization flow
initialize().)
// setup metamask mesh testing container
setupMetamaskMeshMetrics()
/**
* An object representing a transaction, in whatever state it is in.
* @typedef TransactionMeta 交易中信息的意义
*
人名翻译* @property {number} id - An internally unique tx identifier.
* @property {number} time - Time the tx was first suggested, in unix epoch time (ms).
* @property {string} status - The current transaction status (unapproved, signed, submitted, dropped, failed, rejected), as defined in `tx-state-manager.js`.
* @property {string} metamaskNetworkId - The transaction's network ID, used for EIP-155 compliance.
* @property {boolean} loadingDefaults - TODO: Document
* @property {Object} txParams - The tx params as passed to the network provider.
* @property {Object[]} history - A history of mutations to this TransactionMeta object.
* @property {boolean} gasPriceSpecified - True if the suggesting dapp specified a gas price, prevents auto-estimation.
* @property {boolean} gasLimitSpecified - True if the suggesting dapp specified a gas limit, prevents auto-estimation.
* @property {string} estimatedGas - A hex string represented the estimated gas limit required to complete the transaction.
* @property {string} origin - A string representing the interface that suggested the transaction.
* @property {Object} nonceDetails - A metadata object containing information used to derive the suggested nonce, useful for debugging nonce issues. * @property {string} rawTx - A hex string of the final signed transaction, ready to submit to the network.
* @property {string} hash - A hex string of the transaction hash, used to identify the transaction on the network.
* @property {number} submittedTime - The time the transaction was submitted to the network, in Unix epoch time (ms).
*/
/**
* The data emitted from the MetaMaskController.store EventEmitter, also used to initialize the MetaMaskController. Available in UI on React state amask.
* @typedef MetaMaskState 存储信息
* @property {boolean} isInitialized - Whether the first vault has been created. metamask是否初始化
* @property {boolean} isUnlocked - Whether the vault is currently decrypted and accounts are available for selection. metamask是否没上锁
* @property {boolean} isAccountMenuOpen - Represents whether the main account selection UI is currently displayed.
* @property {boolean} isMascara - True if the current context is the extensionless MetaMascara project.
* @property {boolean} isPopup - Returns true if the current view is an externally-triggered notification.
* @property {string} rpcTarget - DEPRECATED - The URL of the current RPC provider.
* @property {Object} identities - An object matching lower-case hex addresses to Identity objects with "address" and "name" (nickname) keys.
* @property {Object} unapprovedTxs - An object mapping transaction hashes to unapproved transactions.
* @property {boolean} noActiveNotices - False if there are notices the user should confirm before using the application.
* @property {Array} frequentRpcList - A list of frequently used RPCs, including custom user-provided ones.
* @property {Array} addressBook - A list of previously sent to addresses.
* @property {address} selectedTokenAddress - Used to indicate if a token is globally selected. Should be deprecated in favor of UI-centric token selection.
* @property {Object} tokenExchangeRates - Info about current token prices.
* @property {Array} tokens - Tokens held by the current user, including their balances.
* @property {Object} send - TODO: Document
* @property {Object} coinOptions - TODO: Document
* @property {boolean} useBlockie - Indicates preferred user identicon format. True for blockie, false for Jazzicon.
* @property {Object} featureFlags - An object for optional feature flags.
* @property {string} networkEndpointType - TODO: Document
* @property {boolean} isRevealingSeedWords - True if seed words are currently being recovered, and should be shown to user.
* @property {boolean} welcomeScreen - True if welcome screen should be shown.
* @property {string} currentLocale - A locale string matching the user's preferred display language.这个语⾔的选择
* @property {Object} provider - The current selected network provider.
* @property {string} provider.rpcTarget - The address for the RPC API, if using an RPC API.
* @property {string} pe - An identifier for the type of network selected, allows MetaMask to use custom provider strategies for known networks.
* @property {string} network - A stringified number of the current network ID.
* @property {Object} accounts - An object mapping lower-case hex addresses to objects with "balance" and "address" keys, both storing hex string values.
* @property {hex} currentBlockGasLimit - The most recently seen block gas limit, in a lower case hex prefixed string.
* @property {TransactionMeta[]} selectedAddressTxList - An array of transactions associated with the currently selected account.
* @property {Object} unapprovedMsgs - An object of messages associated with the currently selected account, mapping a unique ID to the options. * @property {number} unapprovedMsgCount - The number of messages in unapprovedMsgs.
* @property {Object} unapprovedPersonalMsgs - An object of messages associated with the currently selected account, mapping a unique ID to the options.
* @property {number} unapprovedPersonalMsgCount - The number of messages in unapprovedPersonalMsgs.
* @property {Object} unapprovedTypedMsgs - An object of messages associated with the currently selected account, mapping a unique ID to the
* @property {Object} unapprovedTypedMsgs - An object of messages associated with the currently selected account, mapping a unique ID to the options.
* @property {number} unapprovedTypedMsgCount - The number of messages in unapprovedTypedMsgs.
* @property {string[]} keyringTypes - An array of unique keyring identifying strings, representing available strategies for creating accounts.
* @property {Keyring[]} keyrings - An array of keyring descriptions, summarizing the accounts that are available for use, and what keyrings they belong to.
* @property {Object} computedBalances - Maps accounts to their balances, accounting for balance changes from pending transactions.
* @property {string} currentAccountTab - A view identifying string for displaying the current displayed view, allows user to have a preferred tab in the old UI (between tokens and history).
* @property {string} selectedAddress - A lower case hex string of the currently selected address.
* @property {string} currentCurrency - A string identifying the user's preferred display currency, for use in showing conversion rates.
* @property {number} conversionRate - A number representing the current exchange rate from the user's preferred currency to Ether.
* @property {number} conversionDate - A unix epoch date (ms) for the time the current conversion rate was last retrieved.
* @property {Object} infuraNetworkStatus - An object of infura network status checks.
* @property {Block[]} recentBlocks - An array of recent blocks, used to calculate an effective but cheap gas price.
* @property {Array} shapeShiftTxList - An array of objects describing shapeshift exchange attempts.
* @property {Array} lostAccounts - TODO: Remove this feature. A leftover from the version-3 migration where our seed-phrase library changed to fix a bug where some accounts were mis-generated, but we recovered the old accounts as "lost" instead of losing them.
* @property {boolean} forgottenPassword - Returns true if the user has initiated the password recovery screen, is recovering from seed phrase.
*/
甲基丙烯酸三氟乙酯/**
* @typedef VersionedData
* @property {MetaMaskState} data - The data emitted from MetaMask controller, or used to initialize it.
* @property {Number} version - The latest migration version that has been run.
*/
/**
* Initializes the MetaMask controller, and sets up all platform configuration.
* @returns {Promise} Setup complete.
*/
async function initialize () {
const initState = await loadStateFromPersistence() //得到state信息
const initLangCode = await getFirstPreferredLangCode() //设置使⽤的语⾔
await setupController(initState, initLangCode)//metamask控制器的创建
log.debug('MetaMask initialization complete.')
ipfsHandle = ipfsContent(initState.NetworkController.provider)
}
//
// State and Persistence
//
/
**
* Loads any stored data, prioritizing the latest storage strategy.加载所有存储数据，优先考虑最新的存储策略 * Migrates that data schema in case it was last loaded on an older version.迁移该数据模式，以防最后⼀次加载到旧版本
* @returns {Promise<MetaMaskState>} Last data emitted from previous instance of MetaMask.返回上次MetaMask实例发出的数据
*/
async function loadStateFromPersistence () {
// migrations
const migrator = new Migrator({ migrations })
// read from disk
/
/ first from preferred, async API: 先从本地读取，没有则从硬盘读取，最后则是初始化⽣成
versionedData = (()) ||
// check if somehow state is empty 就是如果不知道为何state为空
// this should never happen but new error reporting suggests that it has
// for a small number of users
//github/metamask/metamask-extension/issues/3919
if (versionedData && !versionedData.data) {
// try to recover from diskStore incase only localStore is bad
const diskStoreState = State() //⾸先是试着从硬盘中的数据进⾏恢复，以免只是本地数据出现了问题
if (diskStoreState && diskStoreState.data) {
if (diskStoreState && diskStoreState.data) {
// we were able to recover (though it might be old)
versionedData = diskStoreState
const vaultStructure = getObjStructure(versionedData)
raven.captureMessage('MetaMask - Empty vault found - recovered from diskStore', {
// "extra" key is required by Sentry
extra: { vaultStructure },
})
} else {//发现连硬盘中的数据也损坏了，那就没有办法恢复了
// unable to recover, clear state
鸭子捉兔versionedData = ateInitialState(firstTimeState)
raven.captureMessage('MetaMask - Empty vault found - unable to recover')
}
}
// report migration errors to sentry
<('error', (err) => {
// get vault structure without secrets
const vaultStructure = getObjStructure(versionedData)
raven.captureException(err, {
// "extra" key is required by Sentry
extra: { vaultStructure },斯皮尔博格
})
})
// migrate data
versionedData = await migrator.migrateData(versionedData)
if (!versionedData) {
throw new Error('MetaMask - migrator returned undefined')
}
// write to disk
if (localStore.isSupported) {
localStore.set(versionedData)
} else {
/
/ throw in setTimeout so as to not block boot
setTimeout(() => {
throw new Error('MetaMask - Localstore not supported')
})
}
// return just the data
return versionedData.data
}
/**
* Initializes the MetaMask Controller with any initial state and default language. 使⽤初始状态和默认语⾔来初始化metamask控制器
* Configures platform-specific error reporting strategy. 配置特定于平台的错误报告策略
* Streams emitted state updates to platform-specific storage strategy.流向特定于平台的存储策略发出状态更新
* Creates platform listeners for new Dapps/Contexts, and sets up their data connections to the controller.为新的Dapps/上下⽂创建平台侦听器，并设置它们与控制器的数据连接
*
* @param {Object} initState - The initial state to start the controller with, matches the state that is emitted from the controller.
* @param {String} initLangCode - The region code for the language preferred by the current user.
* @returns {Promise} After setup is complete. 当设置完成后返回
*/
function setupController (initState, initLangCode) {
//
/
/ MetaMask Controller
//
const controller = new MetamaskController({//metamask控制器的创建
// User confirmation callbacks:
showUnconfirmedMessage: triggerUi,
unlockAccountMessage: triggerUi,
showUnapprovedTx: triggerUi,
