refactor(tracing): make function a span property

[P403n1x87]

We turn a utility function into a span property.

Checklist

• PR author has checked that all the criteria below are met
• The PR description includes an overview of the change
• The PR description articulates the motivation for the change
• The change includes tests OR the PR description describes a testing strategy
• The PR description notes risks associated with the change, if any
• Newly-added code is easy to change
• The change follows the library release note guidelines
• The change includes or references documentation updates if necessary
• Backport labels are set (if applicable)

Reviewer Checklist

• Reviewer has checked that all the criteria below are met
• Title is accurate
• All changes are related to the pull request's stated goal
• Avoids breaking API changes
• Testing strategy adequately addresses listed risks
• Newly-added code is easy to change
• Release note makes sense to a user of the library
• If necessary, author has acknowledged and discussed the performance implications of this PR as reported in the benchmarks PR comment
• Backport labels are set in a manner that is consistent with the release branch maintenance policy

[github-actions]

CODEOWNERS have been resolved as:

ddtrace/_trace/processor/__init__.py                                    @DataDog/apm-sdk-api-python
ddtrace/_trace/span.py                                                  @DataDog/apm-sdk-api-python
ddtrace/internal/processor/stats.py                                     @DataDog/apm-core-python
tests/tracer/test_tracer.py                                             @DataDog/apm-sdk-api-python

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-04-10 13:06:42

Comparing candidate commit 6e66b30 in PR branch refactor/span-is-top-level-method with baseline commit 9d2d4e6 in branch main.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 496 metrics, 2 unstable metrics.

[github-actions]

CODEOWNERS have been resolved as:

ddtrace/_trace/processor/__init__.py                                    @DataDog/apm-sdk-api-python
ddtrace/_trace/span.py                                                  @DataDog/apm-sdk-api-python
ddtrace/internal/processor/stats.py                                     @DataDog/apm-core-python
tests/tracer/test_tracer.py                                             @DataDog/apm-sdk-api-python

[github-actions]

Bootstrap import analysis

Comparison of import times between this PR and base.

Summary

The average import time from this PR is: 230 ± 2 ms.

The average import time from base is: 233 ± 2 ms.

The import time difference between this PR and base is: -2.55 ± 0.09 ms.

Import time breakdown

The following import paths have shrunk:

ddtrace.auto 2.034 ms (0.88%)

ddtrace.bootstrap.sitecustomize 1.367 ms (0.59%)

ddtrace.bootstrap.preload 1.367 ms (0.59%)

ddtrace.internal.products 1.367 ms (0.59%)

ddtrace.internal.remoteconfig.client 0.644 ms (0.28%)

ddtrace 0.667 ms (0.29%)