[feature] Add MySQL storage engine

engine/mysqlstore/mysqlstore.go

@@ -0,0 +1,75 @@
+package mysqlstore
+
+import (
+	"database/sql"
+	"log"
+	"time"
+
+	_ "github.com/go-sql-driver/mysql"
+)
+
+type MySQLStore struct {
+	*sql.DB
+	stopSweeper chan bool
+}
+
+func New(db *sql.DB, sweepInterval time.Duration) *MySQLStore {
+	m := &MySQLStore{DB: db}
+	if sweepInterval > 0 {
+		go m.startSweeper(sweepInterval)
+	}
+	return m
+}
+
+func (m *MySQLStore) Find(token string) ([]byte, bool, error) {
+	var b []byte
+	row := m.DB.QueryRow("SELECT data FROM sessions WHERE token = ? AND UTC_TIMESTAMP(6) < expiry", token)
+	err := row.Scan(&b)
+	if err == sql.ErrNoRows {
+		return nil, false, nil
+	} else if err != nil {
+		return nil, false, err
+	}
+	return b, true, nil
+}
+
+func (m *MySQLStore) Save(token string, b []byte, expiry time.Time) error {
+	_, err := m.DB.Exec("INSERT INTO sessions (token, data, expiry) VALUES (?, ?, ?) ON DUPLICATE KEY UPDATE data = VALUES(data), expiry = VALUES(expiry)", token, b, expiry.UTC())
+	if err != nil {
+		return err
+	}
+	return nil
+}
+
+func (m *MySQLStore) Delete(token string) error {
+	_, err := m.DB.Exec("DELETE FROM sessions WHERE token = ?", token)
+	return err
+}
+
+func (m *MySQLStore) startSweeper(interval time.Duration) {
+	m.stopSweeper = make(chan bool)
+	ticker := time.NewTicker(interval)
+	for {
+		select {
+		case <-ticker.C:
+			err := m.deleteExpired()
+			if err != nil {
+				log.Println(err)
+			}
+		case <-m.stopSweeper:
+			ticker.Stop()
+			return
+		}
+	}
+}
+
+func (m *MySQLStore) StopSweeper() {
+	if m.stopSweeper != nil {
+		m.stopSweeper <- true
+	}
+}
+
+func (m *MySQLStore) deleteExpired() error {
+	_, err := m.DB.Exec("DELETE FROM sessions WHERE expiry < UTC_TIMESTAMP(6)")
+	return err
+}