nifty-wallet/app/scripts/controllers/computed-balances.js

121 lines
3.3 KiB
JavaScript

const ObservableStore = require('obs-store')
const extend = require('xtend')
const BalanceController = require('./balance')
/**
* @typedef {Object} ComputedBalancesOptions
* @property {Object} accountTracker Account tracker store reference
* @property {Object} txController Token controller reference
* @property {Object} blockTracker Block tracker reference
* @property {Object} initState Initial state to populate this internal store with
*/
/**
* Background controller responsible for syncing
* and computing ETH balances for all accounts
*/
class ComputedbalancesController {
/**
* Creates a new controller instance
*
* @param {ComputedBalancesOptions} [opts] Controller configuration parameters
*/
constructor (opts = {}) {
const { accountTracker, txController, blockTracker } = opts
this.accountTracker = accountTracker
this.txController = txController
this.blockTracker = blockTracker
const initState = extend({
computedBalances: {},
}, opts.initState)
this.store = new ObservableStore(initState)
this.balances = {}
this._initBalanceUpdating()
}
/**
* Updates balances associated with each internal address
*/
updateAllBalances () {
Object.keys(this.balances).forEach((balance) => {
const address = balance.address
this.balances[address].updateBalance()
})
}
/**
* Initializes internal address tracking
*
* @private
*/
_initBalanceUpdating () {
const store = this.accountTracker.store.getState()
this.syncAllAccountsFromStore(store)
this.accountTracker.store.subscribe(this.syncAllAccountsFromStore.bind(this))
}
/**
* Uses current account state to sync and track all
* addresses associated with the current account
*
* @param {{ accounts: Object }} store Account tracking state
*/
syncAllAccountsFromStore (store) {
const upstream = Object.keys(store.accounts)
const balances = Object.keys(this.balances)
.map(address => this.balances[address])
// Follow new addresses
for (const address in balances) {
this.trackAddressIfNotAlready(address)
}
// Unfollow old ones
balances.forEach(({ address }) => {
if (!upstream.includes(address)) {
delete this.balances[address]
}
})
}
/**
* Conditionally establishes a new subscription
* to track an address associated with the current
* account
*
* @param {string} address Address to conditionally subscribe to
*/
trackAddressIfNotAlready (address) {
const state = this.store.getState()
if (!(address in state.computedBalances)) {
this.trackAddress(address)
}
}
/**
* Establishes a new subscription to track an
* address associated with the current account
*
* @param {string} address Address to conditionally subscribe to
*/
trackAddress (address) {
const updater = new BalanceController({
address,
accountTracker: this.accountTracker,
txController: this.txController,
blockTracker: this.blockTracker,
})
updater.store.subscribe((accountBalance) => {
const newState = this.store.getState()
newState.computedBalances[address] = accountBalance
this.store.updateState(newState)
})
this.balances[address] = updater
updater.updateBalance()
}
}
module.exports = ComputedbalancesController