move SFTPGo package to the internal folder

SFTPGo is a daemon and command line tool, not a library.

The public API are provided by the SDK

Signed-off-by: Nicola Murino <nicola.murino@gmail.com>

internal/common/clientsmap.go

@@ -0,0 +1,65 @@
+// Copyright (C) 2019-2022  Nicola Murino
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published
+// by the Free Software Foundation, version 3.
+//
+// This program 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 Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+package common
+
+import (
+	"sync"
+	"sync/atomic"
+
+	"github.com/drakkan/sftpgo/v2/internal/logger"
+)
+
+// clienstMap is a struct containing the map of the connected clients
+type clientsMap struct {
+	totalConnections int32
+	mu               sync.RWMutex
+	clients          map[string]int
+}
+
+func (c *clientsMap) add(source string) {
+	atomic.AddInt32(&c.totalConnections, 1)
+
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	c.clients[source]++
+}
+
+func (c *clientsMap) remove(source string) {
+	c.mu.Lock()
+	defer c.mu.Unlock()
+
+	if val, ok := c.clients[source]; ok {
+		atomic.AddInt32(&c.totalConnections, -1)
+		c.clients[source]--
+		if val > 1 {
+			return
+		}
+		delete(c.clients, source)
+	} else {
+		logger.Warn(logSender, "", "cannot remove client %v it is not mapped", source)
+	}
+}
+
+func (c *clientsMap) getTotal() int32 {
+	return atomic.LoadInt32(&c.totalConnections)
+}
+
+func (c *clientsMap) getTotalFrom(source string) int {
+	c.mu.RLock()
+	defer c.mu.RUnlock()
+
+	return c.clients[source]
+}