Remove legacyStorage in favor of namespaced storages

[bm1549]

What does this PR do?

• Removes legacyStorage in favor of a namespaced 'legacy' storage
• Adds JSDoc comments to storage.js so my IDE knows how to code for me

Motivation

This gets us one step closer to getting rid of getHandle as we are now fully converted to namespaced storages

Plugin Checklist

• Unit tests.
• TypeScript definitions.
• TypeScript tests.
• API documentation.
• CircleCI jobs/workflows.
• Plugin is exported.

Additional Notes

[github-actions]

Overall package size

Self size: 8.63 MB
Deduped: 95.03 MB
No deduping: 95.55 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 | 3.2.0 | 13.9 MB | 13.91 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 | 826.22 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 | | semver | 7.6.3 | 95.82 kB | 95.82 kB | | lodash.sortby | 4.7.0 | 75.76 kB | 75.76 kB | | ignore | 5.3.1 | 51.46 kB | 51.46 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 | | 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 84.61538% with 18 lines in your changes missing coverage. Please review.

Project coverage is 81.12%. Comparing base (3b782cd) to head (7b79ef7).
Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
packages/datadog-plugin-mocha/src/index.js	0.00%	8 Missing ⚠️
packages/datadog-plugin-cucumber/src/index.js	0.00%	5 Missing ⚠️
packages/dd-trace/src/appsec/index.js	50.00%	2 Missing ⚠️
packages/dd-trace/src/plugins/plugin.js	75.00%	2 Missing ⚠️
packages/datadog-plugin-mariadb/src/index.js	66.66%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##           master    #5206      +/-   ##
==========================================
- Coverage   81.16%   81.12%   -0.05%     
==========================================
  Files         482      481       -1     
  Lines       21522    21448      -74     
==========================================
- Hits        17468    17399      -69     
+ Misses       4054     4049       -5     

☔ View full report in Codecov by Sentry.
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[datadog-datadog-prod-us1]

Datadog Report

Branch report: brian.marks/remove-legacy-storage
Commit report: f0755fc
Test service: dd-trace-js-integration-tests

✅ 0 Failed, 628 Passed, 0 Skipped, 12m 19.57s Total Time

[pr-commenter]

Benchmarks

Benchmark execution time: 2025-02-06 02:02:04

Comparing candidate commit 7b79ef7 in PR branch brian.marks/remove-legacy-storage with baseline commit 3b782cd in branch master.

Found 0 performance improvements and 0 performance regressions! Performance is the same for 911 metrics, 22 unstable metrics.

[rochdev]

First thank you for taking on this massive PR to address tech debt.

With that said, one of the goals of this API is to decouple storages. Using a shared constant actually introduces coupling. It also differs of usage in other places for the similar channel API. A more consistent pattern would be to simply use a string, and possibly combining that with a single instance per file (or even an instance shared in multiple files of the same component). This would also help with performance by avoiding multiple lookups at runtime. Basically, a storage instance should be ideally looked up only at most once per file, and it should not pollute a core module with information about the caller.

It's also worth noting that removing getHandle would require an actual span store, which this isn't. In that sense even the namespace name is incorrect. It would be called something like "default" or "global", but I think calling it "legacy" explicitly would be better to make it obvious that its usage going forward is discouraged and alternatives are to be considered.

[bm1549]

Bypassing merge protections bc mongoose is a broken test (cc @rochdev )