一、Account
// Account represents an Ethereum account located at a specific location defined
// by the optional URL field.
// Account，代表一个位于由可选的URL字段定义的具体位置的以太坊账户
// Address，地址是20个字节，由私钥衍生。。URL，可选字段，后端的资源位置
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
}
二、Wallet
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。被上层使用，为所有来自于各种backend的钱包定义一个排序
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.
// Status 返回钱包的当前状态的文本来帮助使用者。同时返回一个错误来指示钱包可能会遇到的任何错误
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.
//
// 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.
//
// Please note, if you open a wallet, you must close it to release any allocated
// resources (especially important when working with hardware wallets).
// 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秘钥，而是简单地建立与硬件钱包的连接和/或访问衍生种子。
// 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 释放一个打开的钱包实例的占用的任何资源。
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 用来获取钱包正发现的账户列表。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.
//
// 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.
//
// You can disable automatic account discovery by calling SelfDerive with a nil
// chain state reader.
// 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。
// 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。
// 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.
//
// 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 SignHashWithPassphrase, or by other means (e.g. unlock
// the account in a keystore).
// SignHash 请求钱包来给传入的hash进行签名。
// 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。
// 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.
//
// 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 to 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 请求钱包对指定的交易进行签名。
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.
//
// 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 请求钱包使用给定的passphrase来作为额外的认证信息去签名给定的hash
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.
//
// 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 请求钱包使用给定的passphrase来作为额外的认证信息去签名给定的transaction
SignTxWithPassphrase(account Account, passphrase string, tx *types.Transaction, chainID *big.Int) (*types.Transaction, error)
}
三、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，包含一批账号。他们可以根据请求签署交易
type Backend interface {
// Wallets retrieves the list of wallets the backend is currently aware of.
//
// 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.
//
// 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.
// 检索backend当前知道的一批钱包，返回的钱包默认是关闭的
// 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.
// 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
}