accounts包实现了以太坊客户端的钱包和账户管理。以太坊的钱包提供了keyStore模式和usb两种钱包。同时以太坊的 合约的ABI的代码也放在了account/abi目录。 abi项目好像跟账户管理没有什么关系。 这里暂时只分析了账号管理的接口。 具体的keystore和usb的实现代码暂时不会给出。
账号是通过数据结构和接口来定义了
账号
// Account represents an Ethereum account located at a specific location defined
// by the optional URL field.
// 一个账号是20个字节的数据。 URL是可选的字段。
type Account struct {
Address common.Address `json:"address"` // Ethereum account address derived from the key
URL URL `json:"url"` // Optional resource locator within a backend
}
const (
HashLength = 32
AddressLength = 20
)
// Address represents the 20 byte address of an Ethereum account.
type Address [AddressLength]byte
钱包。钱包应该是这里面最重要的一个接口了。 具体的钱包也是实现了这个接口。 钱包又有所谓的分层确定性钱包和普通钱包。
// Wallet represents a software or hardware wallet that might contain one or more
// accounts (derived from the same seed).
// Wallet 是指包含了一个或多个账户的软件钱包或者硬件钱包
type Wallet interface {
// URL retrieves the canonical path under which this wallet is reachable. It is
// user by upper layers to define a sorting order over all wallets from multiple
// backends.
// URL 用来获取这个钱包可以访问的规范路径。 它会被上层使用用来从所有的后端的钱包来排序。
URL() URL
// Status returns a textual status to aid the user in the current state of the
// wallet. It also returns an error indicating any failure the wallet might have
// encountered.
// 用来返回一个文本值用来标识当前钱包的状态。 同时也会返回一个error用来标识钱包遇到的任何错误。
Status() (string, error)
// Open initializes access to a wallet instance. It is not meant to unlock or
// decrypt account keys, rather simply to establish a connection to hardware
// wallets and/or to access derivation seeds.
// Open 初始化对钱包实例的访问。这个方法并不意味着解锁或者解密账户，而是简单地建立与硬件钱包的连接和/或访问衍生种子。
// The passphrase parameter may or may not be used by the implementation of a
// particular wallet instance. The reason there is no passwordless open method
// is to strive towards a uniform wallet handling, oblivious to the different
// backend providers.
// passphrase参数可能在某些实现中并不需要。 没有提供一个无passphrase参数的Open方法的原因是为了提供一个统一的接口。
// Please note, if you open a wallet, you must close it to release any allocated
// resources (especially important when working with hardware wallets).
// 请注意，如果你open了一个钱包，你必须close它。不然有些资源可能没有释放。 特别是使用硬件钱包的时候需要特别注意。
Open(passphrase string) error
// Close releases any resources held by an open wallet instance.
// Close 释放由Open方法占用的任何资源。
Close() error
// Accounts retrieves the list of signing accounts the wallet is currently aware
// of. For hierarchical deterministic wallets, the list will not be exhaustive,
// rather only contain the accounts explicitly pinned during account derivation.
// Accounts用来获取钱包发现了账户列表。 对于分层次的钱包， 这个列表不会详尽的列出所有的账号， 而是只包含在帐户派生期间明确固定的帐户。
Accounts() []Account
// Contains returns whether an account is part of this particular wallet or not.
// Contains 返回一个账号是否属于本钱包。
Contains(account Account) bool
// Derive attempts to explicitly derive a hierarchical deterministic account at
// the specified derivation path. If requested, the derived account will be added
// to the wallet's tracked account list.
// Derive尝试在指定的派生路径上显式派生出分层确定性帐户。 如果pin为true，派生帐户将被添加到钱包的跟踪帐户列表中。
Derive(path DerivationPath, pin bool) (Account, error)
// SelfDerive sets a base account derivation path from which the wallet attempts
// to discover non zero accounts and automatically add them to list of tracked
// accounts.
// SelfDerive设置一个基本帐户导出路径，从中钱包尝试发现非零帐户，并自动将其添加到跟踪帐户列表中。
// Note, self derivaton will increment the last component of the specified path
// opposed to decending into a child path to allow discovering accounts starting
// from non zero components.
// 注意，SelfDerive将递增指定路径的最后一个组件，而不是下降到子路径，以允许从非零组件开始发现帐户。
// You can disable automatic account discovery by calling SelfDerive with a nil
// chain state reader.
// 你可以通过传递一个nil的ChainStateReader来禁用自动账号发现。
SelfDerive(base DerivationPath, chain ethereum.ChainStateReader)
// SignHash requests the wallet to sign the given hash.
// SignHash 请求钱包来给传入的hash进行签名。
// It looks up the account specified either solely via its address contained within,
// or optionally with the aid of any location metadata from the embedded URL field.
//它可以通过其中包含的地址（或可选地借助嵌入式URL字段中的任何位置元数据）来查找指定的帐户。
// If the wallet requires additional authentication to sign the request (e.g.
// a password to decrypt the account, or a PIN code o verify the transaction),
// an AuthNeededError instance will be returned, containing infos for the user
// about which fields or actions are needed. The user may retry by providing
// the needed details via SignHashWithPassphrase, or by other means (e.g. unlock
// the account in a keystore).
// 如果钱包需要额外的验证才能签名(比如说 需要密码来解锁账号， 或者是需要一个PIN 代码来验证交易。)
// 会返回一个AuthNeededError的错误，里面包含了用户的信息，以及哪些字段或者操作需要提供。
// 用户可以通过 SignHashWithPassphrase来签名或者通过其他手段(在keystore里面解锁账号)
SignHash(account Account, hash []byte) ([]byte, error)
// SignTx requests the wallet to sign the given transaction.
// SignTx 请求钱包对指定的交易进行签名。
// It looks up the account specified either solely via its address contained within,
// or optionally with the aid of any location metadata from the embedded URL field.
//
// If the wallet requires additional authentication to sign the request (e.g.
// a password to decrypt the account, or a PIN code o verify the transaction),
// an AuthNeededError instance will be returned, containing infos for the user
// about which fields or actions are needed. The user may retry by providing
// the needed details via SignTxWithPassphrase, or by other means (e.g. unlock
// the account in a keystore).
SignTx(account Account, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
// SignHashWithPassphrase requests the wallet to sign the given hash with the
// given passphrase as extra authentication information.
// SignHashWithPassphrase请求钱包使用给定的passphrase来签名给定的hash
// It looks up the account specified either solely via its address contained within,
// or optionally with the aid of any location metadata from the embedded URL field.
SignHashWithPassphrase(account Account, passphrase string, hash []byte) ([]byte, error)
// SignTxWithPassphrase requests the wallet to sign the given transaction, with the
// given passphrase as extra authentication information.
// SignHashWithPassphrase请求钱包使用给定的passphrase来签名给定的transaction
// It looks up the account specified either solely via its address contained within,
// or optionally with the aid of any location metadata from the embedded URL field.
SignTxWithPassphrase(account Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
}
后端 Backend
// Backend is a "wallet provider" that may contain a batch of accounts they can
// sign transactions with and upon request, do so.
// Backend是一个钱包提供器。 可以包含一批账号。他们可以根据请求签署交易，这样做。
type Backend interface {
// Wallets retrieves the list of wallets the backend is currently aware of.
// Wallets获取当前能够查找到的钱包
// The returned wallets are not opened by default. For software HD wallets this
// means that no base seeds are decrypted, and for hardware wallets that no actual
// connection is established.
// 返回的钱包默认是没有打开的。
// The resulting wallet list will be sorted alphabetically based on its internal
// URL assigned by the backend. Since wallets (especially hardware) may come and
// go, the same wallet might appear at a different positions in the list during
// subsequent retrievals.
//所产生的钱包列表将根据后端分配的内部URL按字母顺序排序。 由于钱包（特别是硬件钱包）可能会打开和关闭，所以在随后的检索过程中，相同的钱包可能会出现在列表中的不同位置。
Wallets() []Wallet
// Subscribe creates an async subscription to receive notifications when the
// backend detects the arrival or departure of a wallet.
// 订阅创建异步订阅，以便在后端检测到钱包的到达或离开时接收通知。
Subscribe(sink chan<- WalletEvent) event.Subscription
}
Manager是一个包含所有东西的账户管理工具。 可以和所有的Backends来通信来签署交易。
数据结构
// Manager is an overarching account manager that can communicate with various
// backends for signing transactions.
type Manager struct {
// 所有已经注册的Backend
backends map[reflect.Type][]Backend // Index of backends currently registered
// 所有Backend的更新订阅器
updaters []event.Subscription // Wallet update subscriptions for all backends
// backend更新的订阅槽
updates chan WalletEvent // Subscription sink for backend wallet changes
// 所有已经注册的Backends的钱包的缓存
wallets []Wallet // Cache of all wallets from all registered backends
// 钱包到达和离开的通知
feed event.Feed // Wallet feed notifying of arrivals/departures
// 退出队列
quit chan chan error
lock sync.RWMutex
}
创建Manager
// NewManager creates a generic account manager to sign transaction via various
// supported backends.
func NewManager(backends ...Backend) *Manager {
// Subscribe to wallet notifications from all backends
updates := make(chan WalletEvent, 4*len(backends))
subs := make([]event.Subscription, len(backends))
for i, backend := range backends {
subs[i] = backend.Subscribe(updates)
}
// Retrieve the initial list of wallets from the backends and sort by URL
var wallets []Wallet
for _, backend := range backends {
wallets = merge(wallets, backend.Wallets()...)
}
// Assemble the account manager and return
am := &Manager{
backends: make(map[reflect.Type][]Backend),
updaters: subs,
updates: updates,
wallets: wallets,
quit: make(chan chan error),
}
for _, backend := range backends {
kind := reflect.TypeOf(backend)
am.backends[kind] = append(am.backends[kind], backend)
}
go am.update()
return am
}
update方法。 是一个goroutine。会监听所有backend触发的更新信息。 然后转发给feed.
// update is the wallet event loop listening for notifications from the backends
// and updating the cache of wallets.
func (am *Manager) update() {
// Close all subscriptions when the manager terminates
defer func() {
am.lock.Lock()
for _, sub := range am.updaters {
sub.Unsubscribe()
}
am.updaters = nil
am.lock.Unlock()
}()
// Loop until termination
for {
select {
case event := <-am.updates:
// Wallet event arrived, update local cache
am.lock.Lock()
switch event.Kind {
case WalletArrived:
am.wallets = merge(am.wallets, event.Wallet)
case WalletDropped:
am.wallets = drop(am.wallets, event.Wallet)
}
am.lock.Unlock()
// Notify any listeners of the event
am.feed.Send(event)
case errc := <-am.quit:
// Manager terminating, return
errc <- nil
return
}
}
}
返回backend
// Backends retrieves the backend(s) with the given type from the account manager.
func (am *Manager) Backends(kind reflect.Type) []Backend {
return am.backends[kind]
}
订阅消息
// Subscribe creates an async subscription to receive notifications when the
// manager detects the arrival or departure of a wallet from any of its backends.
func (am *Manager) Subscribe(sink chan<- WalletEvent) event.Subscription {
return am.feed.Subscribe(sink)
}
对于node来说。是什么时候创建的账号管理器。
// New creates a new P2P node, ready for protocol registration.
func New(conf *Config) (*Node, error) {
...
am, ephemeralKeystore, err := makeAccountManager(conf)
func makeAccountManager(conf *Config) (*accounts.Manager, string, error) {
scryptN := keystore.StandardScryptN
scryptP := keystore.StandardScryptP
if conf.UseLightweightKDF {
scryptN = keystore.LightScryptN
scryptP = keystore.LightScryptP
}
var (
keydir string
ephemeral string
err error
)
switch {
case filepath.IsAbs(conf.KeyStoreDir):
keydir = conf.KeyStoreDir
case conf.DataDir != "":
if conf.KeyStoreDir == "" {
keydir = filepath.Join(conf.DataDir, datadirDefaultKeyStore)
} else {
keydir, err = filepath.Abs(conf.KeyStoreDir)
}
case conf.KeyStoreDir != "":
keydir, err = filepath.Abs(conf.KeyStoreDir)
default:
// There is no datadir.
keydir, err = ioutil.TempDir("", "go-ethereum-keystore")
ephemeral = keydir
}
if err != nil {
return nil, "", err
}
if err := os.MkdirAll(keydir, 0700); err != nil {
return nil, "", err
}
// Assemble the account manager and supported backends
// 创建了一个KeyStore的backend
backends := []accounts.Backend{
keystore.NewKeyStore(keydir, scryptN, scryptP),
}
// 如果是USB钱包。 需要做一些额外的操作。
if !conf.NoUSB {
// Start a USB hub for Ledger hardware wallets
if ledgerhub, err := usbwallet.NewLedgerHub(); err != nil {
log.Warn(fmt.Sprintf("Failed to start Ledger hub, disabling: %v", err))
} else {
backends = append(backends, ledgerhub)
}
// Start a USB hub for Trezor hardware wallets
if trezorhub, err := usbwallet.NewTrezorHub(); err != nil {
log.Warn(fmt.Sprintf("Failed to start Trezor hub, disabling: %v", err))
} else {
backends = append(backends, trezorhub)
}
}
return accounts.NewManager(backends...), ephemeral, nil
}