1 files changed, 112 insertions, 0 deletions
diff --git a/auth/session.go b/auth/session.go
new file mode 100644
index 0000000..1524e6b
--- /dev/null
+++ b/auth/session.go
@@ -0,0 +1,112 @@
+package auth
+
+import (
+	"fmt"
+	"time"
+	"sync"
+	"crypto/rand"
+	"encoding/base64"
+)
+
+
+type Session struct {
+	Created time.Time
+	Modified time.Time
+}
+
+
+type Sessions struct {
+	s map[string]Session
+	lock sync.Mutex
+}
+
+
+func NewSessionContainer() *Sessions {
+	return &Sessions{
+		s: make(map[string]Session),
+	}
+}
+
+
+func createSessionId() (string, error) {
+	bytes := make([]byte, 32)
+	_, err := rand.Read(bytes)
+	if err != nil {
+		return "", err
+	}
+
+	return base64.StdEncoding.EncodeToString(bytes), nil
+}
+
+
+func (s *Sessions) NewSession() (string, error) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	id, err := createSessionId()
+	if err != nil {
+		return "", err
+	}
+
+	session := Session{
+		Created: time.Now(),
+		Modified: time.Now(),
+	}
+
+	s.s[id] = session
+	return id, nil
+}
+
+
+func (s *Sessions) IsSessionValid(id string) bool {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	_, ok := s.s[id]
+	return ok
+}
+
+
+func (s *Sessions) GetSession(id string) (Session, error) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	session, ok := s.s[id]
+	if !ok {
+		return Session{}, fmt.Errorf("invalid session id: %v", id)
+	}
+	return session, nil
+}
+
+
+func (s *Sessions) TouchSession(id string) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	session := s.s[id]
+	session.Modified = time.Now()
+	s.s[id] = session
+}
+
+
+func (s *Sessions) DeleteSession(id string) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	delete(s.s, id)
+}
+
+
+func (s *Sessions) CleanSessions(maxIdle time.Duration) {
+	s.lock.Lock()
+	defer s.lock.Unlock()
+
+	expire := time.Now().Add(-maxIdle)
+	for id, session := range s.s {
+		if session.Modified.Before(expire) {
+			// last modified before the expiration time
+			// so this session is expired
+			delete(s.s, id)
+		}
+	}
+}