// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package accounts
import (
"bufio"
"encoding/json"
"fmt"
"io/ioutil"
"os"
"path/filepath"
"sort"
"strings"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
)
// Minimum amount of time between cache reloads. This limit applies if the platform does
// not support change notifications. It also applies if the keystore directory does not
// exist yet, the code will attempt to create a watcher at most this often.
const minReloadInterval = 2 * time.Second
type accountsByFile []Account
func (s accountsByFile) Len() int { return len(s) }
func (s accountsByFile) Less(i, j int) bool { return s[i].File < s[j].File }
func (s accountsByFile) Swap(i, j int) { s[i], s[j] = s[j], s[i] }
// AmbiguousAddrError is returned when attempting to unlock
// an address for which more than one file exists.
type AmbiguousAddrError struct {
Addr common.Address
Matches []Account
}
func (err *AmbiguousAddrError) Error() string {
files := ""
for i, a := range err.Matches {
files += a.File
if i < len(err.Matches)-1 {
files += ", "
}
}
return fmt.Sprintf("multiple keys match address (%s)", files)
}
// addrCache is a live index of all accounts in the keystore.
type addrCache struct {
keydir string
watcher *watcher
mu sync.Mutex
all accountsByFile
byAddr map[common.Address][]Account
throttle *time.Timer
}
func newAddrCache(keydir string) *addrCache {
ac := &addrCache{
keydir: keydir,
byAddr: make(map[common.Address][]Account),
}
ac.watcher = newWatcher(ac)
return ac
}
func (ac *addrCache) accounts() []Account {
ac.maybeReload()
ac.mu.Lock()
defer ac.mu.Unlock()
cpy := make([]Account, len(ac.all))
copy(cpy, ac.all)
return cpy
}
func (ac *addrCache) hasAddress(addr common.Address) bool {
ac.maybeReload()
ac.mu.Lock()
defer ac.mu.Unlock()
return len(ac.byAddr[addr]) > 0
}
func (ac *addrCache) add(newAccount Account) {
ac.mu.Lock()
defer ac.mu.Unlock()
i := sort.Search(len(ac.all), func(i int) bool { return ac.all[i].File >= newAccount.File })
if i < len(ac.all) && ac.all[i] == newAccount {
return
}
// newAccount is not in the cache.
ac.all = append(ac.all, Account{})
copy(ac.all[i+1:], ac.all[i:])
ac.all[i] = newAccount
ac.byAddr[newAccount.Address] = append(ac.byAddr[newAccount.Address], newAccount)
}
// note: removed needs to be unique here (i.e. both File and Address must be set).
func (ac *addrCache) delete(removed Account) {
ac.mu.Lock()
defer ac.mu.Unlock()
ac.all = removeAccount(ac.all, removed)
if ba := removeAccount(ac.byAddr[removed.Address], removed); len(ba) == 0 {
delete(ac.byAddr, removed.Address)
} else {
ac.byAddr[removed.Address] = ba
}
}
func removeAccount(slice []Account, elem Account) []Account {
for i := range slice {
if slice[i] == elem {
return append(slice[:i], slice[i+1:]...)
}
}
return slice
}
// find returns the cached account for address if there is a unique match.
// The exact matching rules are explained by the documentation of Account.
// Callers must hold ac.mu.
func (ac *addrCache) find(a Account) (Account, error) {
// Limit search to address candidates if possible.
matches := ac.all
if (a.Address != common.Address{}) {
matches = ac.byAddr[a.Address]
}
if a.File != "" {
// If only the basename is specified, complete the path.
if !strings.ContainsRune(a.File, filepath.Separator) {
a.File = filepath.Join(ac.keydir, a.File)
}
for i := range matches {
if matches[i].File == a.File {
return matches[i], nil
}
}
if (a.Address == common.Address{}) {
return Account{}, ErrNoMatch
}
}
switch len(matches) {
case 1:
return matches[0], nil
case 0:
return Account{}, ErrNoMatch
default:
err := &AmbiguousAddrError{Addr: a.Address, Matches: make([]Account, len(matches))}
copy(err.Matches, matches)
return Account{}, err
}
}
func (ac *addrCache) maybeReload() {
ac.mu.Lock()
defer ac.mu.Unlock()
if ac.watcher.running {
return // A watcher is running and will keep the cache up-to-date.
}
if ac.throttle == nil {
ac.throttle = time.NewTimer(0)
} else {
select {
case <-ac.throttle.C:
default:
return // The cache was reloaded recently.
}
}
ac.watcher.start()
ac.reload()
ac.throttle.Reset(minReloadInterval)
}
func (ac *addrCache) close() {
ac.mu.Lock()
ac.watcher.close()
if ac.throttle != nil {
ac.throttle.Stop()
}
ac.mu.Unlock()
}
// reload caches addresses of existing accounts.
// Callers must hold ac.mu.
func (ac *addrCache) reload() {
accounts, err := ac.scan()
if err != nil && glog.V(logger.Debug) {
glog.Errorf("can't load keys: %v", err)
}
ac.all = accounts
sort.Sort(ac.all)
for k := range ac.byAddr {
delete(ac.byAddr, k)
}
for _, a := range accounts {
ac.byAddr[a.Address] = append(ac.byAddr[a.Address], a)
}
glog.V(logger.Debug).Infof("reloaded keys, cache has %d accounts", len(ac.all))
}
func (ac *addrCache) scan() ([]Account, error) {
files, err := ioutil.ReadDir(ac.keydir)
if err != nil {
return nil, err
}
var (
buf = new(bufio.Reader)
addrs []Account
keyJSON struct {
Address common.Address `json:"address"`
}
)
for _, fi := range files {
path := filepath.Join(ac.keydir, fi.Name())
if skipKeyFile(fi) {
glog.V(logger.Detail).Infof("ignoring file %s", path)
continue
}
fd, err := os.Open(path)
if err != nil {
glog.V(logger.Detail).Infoln(err)
continue
}
buf.Reset(fd)
// Parse the address.
keyJSON.Address = common.Address{}
err = json.NewDecoder(buf).Decode(&keyJSON)
switch {
case err != nil:
glog.V(logger.Debug).Infof("can't decode key %s: %v", path, err)
case (keyJSON.Address == common.Address{}):
glog.V(logger.Debug).Infof("can't decode key %s: missing or zero address", path)
default:
addrs = append(addrs, Account{Address: keyJSON.Address, File: path})
}
fd.Close()
}
return addrs, err
}
func skipKeyFile(fi os.FileInfo) bool {
// Skip editor backups and UNIX-style hidden files.
if strings.HasSuffix(fi.Name(), "~") || strings.HasPrefix(fi.Name(), ".") {
return true
}
// Skip misc special files, directories (yes, symlinks too).
if fi.IsDir() || fi.Mode()&os.ModeType != 0 {
return true
}
return false
}
