GODT-1840: Safe map for mailboxID cache

internal/imap/map.go

@@ -0,0 +1,44 @@
+// Copyright (c) 2022 Proton AG
+//
+// This file is part of Proton Mail Bridge.
+//
+// Proton Mail Bridge is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Proton Mail Bridge 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 General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Proton Mail Bridge. If not, see <https://www.gnu.org/licenses/>.
+
+package imap
+
+import "sync"
+
+type safeMapOfStrings struct {
+	data  map[string]string
+	mutex sync.RWMutex
+}
+
+func newSafeMapOfString() safeMapOfStrings {
+	return safeMapOfStrings{
+		data:  map[string]string{},
+		mutex: sync.RWMutex{},
+	}
+}
+
+func (m *safeMapOfStrings) get(key string) string {
+	m.mutex.RLock()
+	defer m.mutex.RUnlock()
+	return m.data[key]
+}
+
+func (m *safeMapOfStrings) set(key, value string) {
+	m.mutex.Lock()
+	defer m.mutex.Unlock()
+	m.data[key] = value
+}