add other session providers (#5963)

vendor/github.com/lunny/log/dbwriter.go

@@ -0,0 +1,36 @@
+package log
+
+import (
+	"database/sql"
+	"time"
+)
+
+type DBWriter struct {
+	db      *sql.DB
+	stmt    *sql.Stmt
+	content chan []byte
+}
+
+func NewDBWriter(db *sql.DB) (*DBWriter, error) {
+	_, err := db.Exec("CREATE TABLE IF NOT EXISTS log (id int, content text, created datetime)")
+	if err != nil {
+		return nil, err
+	}
+	stmt, err := db.Prepare("INSERT INTO log (content, created) values (?, ?)")
+	if err != nil {
+		return nil, err
+	}
+	return &DBWriter{db, stmt, make(chan []byte, 1000)}, nil
+}
+
+func (w *DBWriter) Write(p []byte) (n int, err error) {
+	_, err = w.stmt.Exec(string(p), time.Now())
+	if err == nil {
+		n = len(p)
+	}
+	return
+}
+
+func (w *DBWriter) Close() {
+	w.stmt.Close()
+}