1 files changed, 271 insertions, 0 deletions
diff --git a/accounts/keystore/address_cache.go b/accounts/keystore/address_cache.go
new file mode 100644
index 000000000..eb3e3263b
--- /dev/null
+++ b/accounts/keystore/address_cache.go
@@ -0,0 +1,271 @@
+// 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 accountsByFile []accounts.Account
+
+func (s accountsByFile) Len() int           { return len(s) }
+func (s accountsByFile) Less(i, j int) bool { return s[i].URL < s[j].URL }
+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 []accounts.Account
+}
+
+func (err *AmbiguousAddrError) Error() string {
+	files := ""
+	for i, a := range err.Matches {
+		files += a.URL
+		if i < len(err.Matches)-1 {
+			files += ", "
+		}
+	}
+	return fmt.Sprintf("multiple keys match address (%s)", files)
+}
+
+// addressCache is a live index of all accounts in the keystore.
+type addressCache struct {
+	keydir   string
+	watcher  *watcher
+	mu       sync.Mutex
+	all      accountsByFile
+	byAddr   map[common.Address][]accounts.Account
+	throttle *time.Timer
+}
+
+func newAddrCache(keydir string) *addressCache {
+	ac := &addressCache{
+		keydir: keydir,
+		byAddr: make(map[common.Address][]accounts.Account),
+	}
+	ac.watcher = newWatcher(ac)
+	return ac
+}
+
+func (ac *addressCache) 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 *addressCache) hasAddress(addr common.Address) bool {
+	ac.maybeReload()
+	ac.mu.Lock()
+	defer ac.mu.Unlock()
+	return len(ac.byAddr[addr]) > 0
+}
+
+func (ac *addressCache) 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 >= newAccount.URL })
+	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 *addressCache) 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 *addressCache) 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 != "" {
+		// If only the basename is specified, complete the path.
+		if !strings.ContainsRune(a.URL, filepath.Separator) {
+			a.URL = filepath.Join(ac.keydir, a.URL)
+		}
+		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 *addressCache) 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 *addressCache) 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 *addressCache) 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 *addressCache) 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: 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
+}