refactor custom metrics to be self-contained

[bengl]

This had no real business being in Proxy#init(), so I moved it to where it makes more sense.

[github-actions]

Overall package size

Self size: 8.41 MB
Deduped: 94.88 MB
No deduping: 95.39 MB

Dependency sizes

| name | version | self size | total size | |------|---------|-----------|------------| | @datadog/libdatadog | 0.3.0 | 29.43 MB | 29.43 MB | | @datadog/native-appsec | 8.3.0 | 19.37 MB | 19.38 MB | | @datadog/native-iast-taint-tracking | 3.2.0 | 13.9 MB | 13.91 MB | | @datadog/pprof | 5.4.1 | 9.76 MB | 10.13 MB | | protobufjs | 7.2.5 | 2.77 MB | 5.16 MB | | @datadog/native-iast-rewriter | 2.6.1 | 2.59 MB | 2.73 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 | | 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}

[pr-commenter]

Benchmarks

Benchmark execution time: 2024-12-31 05:42:50

Comparing candidate commit 8c89cf4 in PR branch bengl/refactor-custom-metrics with baseline commit 4d6a8e3 in branch master.

Found 0 performance improvements and 1 performance regressions! Performance is the same for 776 metrics, 21 unstable metrics.

scenario:log-without-log-20

• 🟥 cpu_user_time [+18.316ms; +23.907ms] or [+5.331%; +6.959%]

[uurien]

Why are _boundFlush and _flushInterval object level properties, and not just const boundFlush and const flushInterval?

[BridgeAR]

LGTM % comment. I would definitely prefer not to add any properties that are not absolutely needed

[BridgeAR]

Suggested change

	this._boundFlush = this.flush.bind(this)
	// TODO(bengl) this magic number should be configurable
	this._flushInterval = setInterval(this._boundFlush, 10 * 1000)
	this._flushInterval.unref()
	process.once('beforeExit', this._boundFlush)
	const flush = this.flush.bind(this)
	// TODO(bengl) this magic number should be configurable
	setInterval(flush, 10 * 1000).unref()
	process.once('beforeExit', flush)