accounts/keystore: delete the redundant keystore in filename (#17930)

* accounts/keystore: reduce file name length

* accounts/keystore: reduce code line width

accounts/keystore/plain.go

@@ -0,0 +1,61 @@
+// Copyright 2015 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 (
+	"encoding/json"
+	"fmt"
+	"os"
+	"path/filepath"
+
+	"github.com/ethereum/go-ethereum/common"
+)
+
+type keyStorePlain struct {
+	keysDirPath string
+}
+
+func (ks keyStorePlain) GetKey(addr common.Address, filename, auth string) (*Key, error) {
+	fd, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer fd.Close()
+	key := new(Key)
+	if err := json.NewDecoder(fd).Decode(key); err != nil {
+		return nil, err
+	}
+	if key.Address != addr {
+		return nil, fmt.Errorf("key content mismatch: have address %x, want %x", key.Address, addr)
+	}
+	return key, nil
+}
+
+func (ks keyStorePlain) StoreKey(filename string, key *Key, auth string) error {
+	content, err := json.Marshal(key)
+	if err != nil {
+		return err
+	}
+	return writeKeyFile(filename, content)
+}
+
+func (ks keyStorePlain) JoinPath(filename string) string {
+	if filepath.IsAbs(filename) {
+		return filename
+	}
+	return filepath.Join(ks.keysDirPath, filename)
+}