+#[derive(Debug)]
+struct Range {
+ start: SystemTime,
+ end: SystemTime,
+}
+impl Range {
+ fn new(t: &SystemTime) -> Self {
+ Self { start: *t, end: *t }
+ }
+ fn contains(&self, t: &SystemTime) -> bool {
+ t > &self.start && t < &self.end
+ }
+ fn extend(&mut self, t: &SystemTime) {
+ if t < &self.start {
+ self.start = *t;
+ }
+ if t > &self.end {
+ self.end = *t;
+ }
+ }
+}
+
+fn open_log_for_writing() -> csv::Writer<std::fs::File> {
+ let log_file_exists = std::path::Path::new(LOGFILENAME).exists();
+ let logfile = std::fs::OpenOptions::new()
+ .create_new(!log_file_exists)
+ .append(true)
+ .open(LOGFILENAME)
+ .expect("Coudln't open log file");
+ csv::WriterBuilder::new()
+ .has_headers(!log_file_exists)
+ .from_writer(logfile)
+}
+