diff options
Diffstat (limited to 'accounts/keystore/account_cache.go')
-rw-r--r-- | accounts/keystore/account_cache.go | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/accounts/keystore/account_cache.go b/accounts/keystore/account_cache.go new file mode 100644 index 000000000..3fae3ef5b --- /dev/null +++ b/accounts/keystore/account_cache.go @@ -0,0 +1,283 @@ +// 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 keystore + +import ( + "bufio" + "encoding/json" + "fmt" + "io/ioutil" + "os" + "path/filepath" + "sort" + "strings" + "sync" + "time" + + "github.com/ethereum/go-ethereum/accounts" + "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 accountsByURL []accounts.Account + +func (s accountsByURL) Len() int { return len(s) } +func (s accountsByURL) Less(i, j int) bool { return s[i].URL.Cmp(s[j].URL) < 0 } +func (s accountsByURL) 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 []accounts.Account +} + +func (err *AmbiguousAddrError) Error() string { + files := "" + for i, a := range err.Matches { + files += a.URL.Path + if i < len(err.Matches)-1 { + files += ", " + } + } + return fmt.Sprintf("multiple keys match address (%s)", files) +} + +// accountCache is a live index of all accounts in the keystore. +type accountCache struct { + keydir string + watcher *watcher + mu sync.Mutex + all accountsByURL + byAddr map[common.Address][]accounts.Account + throttle *time.Timer + notify chan struct{} +} + +func newAccountCache(keydir string) (*accountCache, chan struct{}) { + ac := &accountCache{ + keydir: keydir, + byAddr: make(map[common.Address][]accounts.Account), + notify: make(chan struct{}, 1), + } + ac.watcher = newWatcher(ac) + return ac, ac.notify +} + +func (ac *accountCache) accounts() []accounts.Account { + ac.maybeReload() + ac.mu.Lock() + defer ac.mu.Unlock() + cpy := make([]accounts.Account, len(ac.all)) + copy(cpy, ac.all) + return cpy +} + +func (ac *accountCache) hasAddress(addr common.Address) bool { + ac.maybeReload() + ac.mu.Lock() + defer ac.mu.Unlock() + return len(ac.byAddr[addr]) > 0 +} + +func (ac *accountCache) add(newAccount accounts.Account) { + ac.mu.Lock() + defer ac.mu.Unlock() + + i := sort.Search(len(ac.all), func(i int) bool { return ac.all[i].URL.Cmp(newAccount.URL) >= 0 }) + if i < len(ac.all) && ac.all[i] == newAccount { + return + } + // newAccount is not in the cache. + ac.all = append(ac.all, accounts.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 *accountCache) delete(removed accounts.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 []accounts.Account, elem accounts.Account) []accounts.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 accounts.Account. +// Callers must hold ac.mu. +func (ac *accountCache) find(a accounts.Account) (accounts.Account, error) { + // Limit search to address candidates if possible. + matches := ac.all + if (a.Address != common.Address{}) { + matches = ac.byAddr[a.Address] + } + if a.URL.Path != "" { + // If only the basename is specified, complete the path. + if !strings.ContainsRune(a.URL.Path, filepath.Separator) { + a.URL.Path = filepath.Join(ac.keydir, a.URL.Path) + } + for i := range matches { + if matches[i].URL == a.URL { + return matches[i], nil + } + } + if (a.Address == common.Address{}) { + return accounts.Account{}, ErrNoMatch + } + } + switch len(matches) { + case 1: + return matches[0], nil + case 0: + return accounts.Account{}, ErrNoMatch + default: + err := &AmbiguousAddrError{Addr: a.Address, Matches: make([]accounts.Account, len(matches))} + copy(err.Matches, matches) + return accounts.Account{}, err + } +} + +func (ac *accountCache) 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 *accountCache) close() { + ac.mu.Lock() + ac.watcher.close() + if ac.throttle != nil { + ac.throttle.Stop() + } + if ac.notify != nil { + close(ac.notify) + ac.notify = nil + } + ac.mu.Unlock() +} + +// reload caches addresses of existing accounts. +// Callers must hold ac.mu. +func (ac *accountCache) 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) + } + select { + case ac.notify <- struct{}{}: + default: + } + glog.V(logger.Debug).Infof("reloaded keys, cache has %d accounts", len(ac.all)) +} + +func (ac *accountCache) scan() ([]accounts.Account, error) { + files, err := ioutil.ReadDir(ac.keydir) + if err != nil { + return nil, err + } + + var ( + buf = new(bufio.Reader) + addrs []accounts.Account + keyJSON struct { + Address string `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 = "" + err = json.NewDecoder(buf).Decode(&keyJSON) + addr := common.HexToAddress(keyJSON.Address) + switch { + case err != nil: + glog.V(logger.Debug).Infof("can't decode key %s: %v", path, err) + case (addr == common.Address{}): + glog.V(logger.Debug).Infof("can't decode key %s: missing or zero address", path) + default: + addrs = append(addrs, accounts.Account{Address: addr, URL: accounts.URL{Scheme: KeyStoreScheme, Path: 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 +} |