lazy load fetch instrumentation only when needed

[rochdev]

What does this PR do?

Lazy load fetch instrumentation only when needed.

Motivation

This was a significant part of the remaining startup time. I'm not sure why as this instrumentation doesn't do much, but it still makes things a lot faster.

[github-actions]

Overall package size

Self size: 8.79 MB
Deduped: 94.99 MB
No deduping: 95.5 MB

Dependency sizes

| name | version | self size | total size | |------|---------|-----------|------------| | @datadog/libdatadog | 0.4.0 | 29.44 MB | 29.44 MB | | @datadog/native-appsec | 8.4.0 | 19.25 MB | 19.26 MB | | @datadog/native-iast-taint-tracking | 3.3.0 | 13.77 MB | 13.78 MB | | @datadog/pprof | 5.5.1 | 9.79 MB | 10.17 MB | | protobufjs | 7.2.5 | 2.77 MB | 5.16 MB | | @datadog/native-iast-rewriter | 2.8.0 | 2.6 MB | 2.74 MB | | @opentelemetry/core | 1.14.0 | 872.87 kB | 1.47 MB | | @datadog/native-metrics | 3.1.0 | 1.06 MB | 1.46 MB | | @opentelemetry/api | 1.8.0 | 1.21 MB | 1.21 MB | | import-in-the-middle | 1.11.2 | 112.74 kB | 835.4 kB | | source-map | 0.7.4 | 226 kB | 226 kB | | opentracing | 0.14.7 | 194.81 kB | 194.81 kB | | lru-cache | 7.18.3 | 133.92 kB | 133.92 kB | | pprof-format | 2.1.0 | 111.69 kB | 111.69 kB | | @datadog/sketches-js | 2.1.0 | 109.9 kB | 109.9 kB | | lodash.sortby | 4.7.0 | 75.76 kB | 75.76 kB | | ignore | 5.3.2 | 53.63 kB | 53.63 kB | | shell-quote | 1.8.1 | 44.96 kB | 44.96 kB | | istanbul-lib-coverage | 3.2.0 | 29.34 kB | 29.34 kB | | rfdc | 1.3.1 | 25.21 kB | 25.21 kB | | @isaacs/ttlcache | 1.4.1 | 25.2 kB | 25.2 kB | | tlhunter-sorted-set | 0.1.0 | 24.94 kB | 24.94 kB | | limiter | 1.1.5 | 23.17 kB | 23.17 kB | | dc-polyfill | 0.1.4 | 23.1 kB | 23.1 kB | | retry | 0.13.1 | 18.85 kB | 18.85 kB | | semifies | 1.0.0 | 15.84 kB | 15.84 kB | | jest-docblock | 29.7.0 | 8.99 kB | 12.76 kB | | crypto-randomuuid | 1.0.0 | 11.18 kB | 11.18 kB | | ttl-set | 1.0.0 | 4.61 kB | 9.69 kB | | path-to-regexp | 0.1.12 | 6.6 kB | 6.6 kB | | koalas | 1.0.2 | 6.47 kB | 6.47 kB | | module-details-from-path | 1.0.3 | 4.47 kB | 4.47 kB |

_{🤖 This report was automatically generated by heaviest-objects-in-the-universe}

[codecov]

Codecov Report

Attention: Patch coverage is 90.47619% with 2 lines in your changes missing coverage. Please review.

Project coverage is 80.42%. Comparing base (a1cd027) to head (3f2b2a8).
Report is 6 commits behind head on master.

Files with missing lines	Patch %	Lines
packages/datadog-instrumentations/src/fetch.js	86.66%	2 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5317      +/-   ##
==========================================
- Coverage   80.42%   80.42%   -0.01%     
==========================================
  Files         491      491              
  Lines       21847    21856       +9     
==========================================
+ Hits        17570    17577       +7     
- Misses       4277     4279       +2     

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📢 Have feedback on the report? Share it here.

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-02-25 23:36:43

Comparing candidate commit 3f2b2a8 in PR branch lazy-fetch-instrumentation with baseline commit a1cd027 in branch master.

Found 0 performance improvements and 6 performance regressions! Performance is the same for 912 metrics, 15 unstable metrics.

scenario:log-skip-log-22

• 🟥 cpu_user_time [+17.144ms; +21.723ms] or [+6.587%; +8.346%]
• 🟥 execution_time [+18.380ms; +20.548ms] or [+6.093%; +6.812%]

scenario:log-with-debug-22

• 🟥 cpu_user_time [+13.714ms; +19.989ms] or [+5.256%; +7.662%]
• 🟥 execution_time [+15.592ms; +20.185ms] or [+5.174%; +6.698%]

scenario:log-with-error-22

• 🟥 cpu_user_time [+14.641ms; +19.708ms] or [+5.707%; +7.683%]
• 🟥 execution_time [+18.711ms; +20.313ms] or [+6.320%; +6.861%]

[datadog-datadog-prod-us1]

Datadog Report

Branch report: lazy-fetch-instrumentation
Commit report: 15bb6db
Test service: dd-trace-js-integration-tests

✅ 0 Failed, 674 Passed, 0 Skipped, 17m 16.17s Total Time

[szegedi]

LGTM, some very speculative suggestions for saving few nanos here and there.

[szegedi]

How about we have this folded into the final expression, so it short-circuits. (getIsGCPFunction could be rewritten so it short circuits too, possibly first evaluating isNewerGCPFunction as I imagine that's more frequent.) I figure microoptimizations are on topic in a PR that deals with startup time :-)

[rochdev]

Worth looking into, but for the purpose of this PR, existing code was just copied over so I would consider it out of scope.