Is there interest in adding a file size criteria in tracing_appender

[ghost]

Hi, I noticed that while the tracing_appender crate rotates file based on the date, it does not (I think) support file rotation based on the file size.
The most backwards compatible implementation I can think of is adding a size: u64 field to the tracing_appender::rolling::Rotation struct. Then, logic would be updated in tracing_appender::rolling::Inner::should_rollover to check for file size if that criteria is set.

---

Another idea could be to create an new trait called Criteria which exposes the method fn should_rollover(inner: &Inner) -> bool. We could then parameterize the Inner struct with a generic bounded to that trait, and then implement should_rollever for the various rollover types which implement Criteria.
Something like

trait Criteria {
   fn should_rollover(inner: Inner) -> bool
}

#[derive(Debug)]
struct Inner<C: Critera> {
    log_directory: PathBuf,
    log_filename_prefix: Option<String>,
    log_filename_suffix: Option<String>,
    date_format: Vec<format_description::FormatItem<'static>>,
    rotation: C,
    next_date: AtomicUsize,
    max_files: Option<usize>,
}

impl<C: Criteria> for Inner<Criteria> {
   // Keep function defintions as is

  /// Keep this signature the same to minimize code change
  /// but within the method body...
  fn should_rollover(&self, date: OffsetDateTime) -> Option<usize> {
     let should_roll = self.rotation::should_rollover(self);
     // Convert to Option<usize>
  }
}

enum TemporalRotationPolicy {
   Daily,
   Monthly,
}
impl Criteria for TemporalRotationPolicy {
     fn should_rollover(inner: Inner) -> bool {
            /// get current time etc, and determine if we should rollover
      }
}
// Similarly define StorageRotationPolicy and implement Criteria for it

The above solution could prevent a runtime check in should_rollover by allowing types such TemporalRotationPolicy (which already exists in the form of the RotationKind enum) and StorageRotationPolicy to implement their version of should_rollover.

I am sure this could be improved. I am new to Rust and apologize in advance. I am interested in learning the best approach.

---

If there is interest in this feature, I can try to make a pull request.