Add Configuration for Higher Time Precision with Decimals

[hrmsk66]

To address #67, add a new configuration option, with_higher_precision. When this option is enabled, the time is displayed with higher precision, including decimal points.

• Added with_higher_precision as a configuration option.
• Refactored the existing code in the on_event method to separate methods for code reusability¹

Example Output:
With higher_precision enabled, the output will look like this.

┐run{hostname="localhost"}
├─ 45.96μs TRACE Request received
├─┐fetch_httpbin{method=GET, path="/"}
│ ├─ 3.70s  DEBUG Response received, backend=httpbin, status=200 OK, cache_status=MISS
├─┘
├─┐fetch_example{method=GET, path="/"}
│ ├─ 587.93ms DEBUG Response received from example, backend=example, status=200 OK, cache_status=HIT
│ ├─┐open_datastore{name="subscriptions"}
│ ├─┘
│ ├─┐read_from_datastore{key="foo@example.com"}
│ │ ├─ 43.04μs  WARN Item found, key=foo@example.com
│ ├─┘
├─┘
├─ 4.29s  TRACE Returning response, status=200 OK
┘

Footnotes

1. If this PR looks good, I'd like to propose an implementation to address Issue 17 based on this as a foundation. ↩

[oli-obk]

Just some style nits, then this lgtm

[oli-obk]

Tip for the future: when moving things out into a new function, do that in a separate commit, and then modify it in other commits. This makes it easier to track for reviewers to see what changes you made in detail

[hrmsk66]

Thanks for the advice. Will separate commits for clarity moving forward.

[oli-obk]

lgtm, unfortunately you also need to rebase over the latest changes

[hrmsk66]

Hi @oli-obk
Rebased to resolve conflicts and noticed my PR needed updates to align with the main branch. In the "concurrent span switching detection (8ccafe8)" commit by @ten3roberts, the steps for retrieving Span's Extensions seemed to have been simplified in the on_event method.

tracing-tree/src/lib.rs

Lines 476 to 487 in 8aa51bc

	// check if this event occurred in the context of a span.
	// if it has, get the start time of this span.
	let start = match span {
	Some(span) => {
	// if the event is in a span, get the span's starting point.
	let ext = span.extensions();
	let data = ext
	.get::<Data>()
	.expect("Data cannot be found in extensions");
	Some(data.start)
	}

I've adjusted this PR accordingly in 4c66dca.

[oli-obk]

Thanks!