store http state

storage/http.go

@@ -0,0 +1,34 @@
+package storage
+
+type HTTPState struct {
+	LastModified string
+	Etag         string
+}
+
+func (s *Storage) GetHTTPState(url string) *HTTPState {
+	row := s.db.QueryRow(`
+		select last_modified, etag
+		from http_state where url = ?
+	`, url)
+
+	if row == nil {
+		return nil
+	}
+
+	var state HTTPState
+	row.Scan(&state.LastModified, &state.Etag)
+	return &state
+}
+
+func (s *Storage) SetHTTPState(url string, state HTTPState) {
+	_, err := s.db.Exec(`
+		insert into http_state (url, last_modified, etag)
+		values (?, ?, ?)
+		on conflict (url) do update set last_modified = ?, etag = ?`,
+		url, state.LastModified, state.Etag,
+		state.LastModified, state.Etag,
+	)
+	if err != nil {
+		s.log.Print(err)
+	}
+}