perf(metrics): reduce allocations for metrics #33699 #2037

gzliudan · 2026-02-10T07:37:42Z

Proposed changes

Ref: ethereum#33699

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coderabbitai · 2026-02-10T07:37:57Z

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Copilot

Pull request overview

This PR aims to reduce allocations in the metrics package by avoiding the generic getOrRegister helper (which required an extra closure capture) and inlining Registry.GetOrRegister calls across metric constructors.

Changes:

Inline nil-registry fallback + Registry.GetOrRegister in multiple GetOrRegister* helpers to reduce closure captures/allocations.
Remove the generic internal getOrRegister[T] helper from metrics/registry.go.
Add a new benchmark for GetOrRegister helpers and adjust a prefixed-child-registry test to use a non-default parent registry.

Reviewed changes

Copilot reviewed 12 out of 12 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
metrics/counter.go	Inline `GetOrRegisterCounter` implementation using `Registry.GetOrRegister`.
metrics/counter_float64.go	Inline `GetOrRegisterCounterFloat64` implementation using `Registry.GetOrRegister`.
metrics/gauge.go	Inline `GetOrRegisterGauge` implementation using `Registry.GetOrRegister`.
metrics/gauge_float64.go	Inline `GetOrRegisterGaugeFloat64` implementation using `Registry.GetOrRegister`.
metrics/gauge_info.go	Inline `GetOrRegisterGaugeInfo` implementation using `Registry.GetOrRegister`.
metrics/histogram.go	Inline `GetOrRegisterHistogram` / `GetOrRegisterHistogramLazy` using `Registry.GetOrRegister`.
metrics/meter.go	Inline `GetOrRegisterMeter` implementation using `Registry.GetOrRegister`.
metrics/resetting_timer.go	Inline `GetOrRegisterResettingTimer` implementation using `Registry.GetOrRegister`.
metrics/runtimehistogram.go	Inline runtime histogram registration via `Registry.GetOrRegister`.
metrics/timer.go	Inline `GetOrRegisterTimer` implementation using `Registry.GetOrRegister`.
metrics/registry.go	Remove generic `getOrRegister[T]` helper.
metrics/registry_test.go	Add benchmark for `GetOrRegister*` helpers; change one test to use `NewRegistry()` as parent.

Comments suppressed due to low confidence (1)

metrics/registry_test.go:299

TestChildPrefixedRegistryRegister calls the package-level Register("bar", c) but ignores the returned error. This test file already registers "bar" in another test, so depending on execution order this can silently hit ErrDuplicateMetric and mask failures. Please assert on the error and/or use a unique metric name (or unregister it) to avoid global DefaultRegistry pollution.

	r := NewPrefixedChildRegistry(NewRegistry(), "prefix.")
	err := r.Register("foo", NewCounter())
	c := NewCounter()
	Register("bar", c)
	if err != nil {
		t.Fatal(err.Error())

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Copilot · 2026-02-10T07:43:10Z

metrics/registry_test.go

+	sample := func() Sample { return nil }
+	tests := []struct {
+		name string
+		ctor func() any
+	}{
+		{name: "counter", ctor: func() any { return GetOrRegisterCounter("counter", DefaultRegistry) }},
+		{name: "gauge", ctor: func() any { return GetOrRegisterGauge("gauge", DefaultRegistry) }},
+		{name: "gaugefloat64", ctor: func() any { return GetOrRegisterGaugeFloat64("gaugefloat64", DefaultRegistry) }},
+		{name: "histogram", ctor: func() any { return GetOrRegisterHistogram("histogram", DefaultRegistry, sample()) }},
+		{name: "meter", ctor: func() any { return GetOrRegisterMeter("meter", DefaultRegistry) }},
+		{name: "timer", ctor: func() any { return GetOrRegisterTimer("timer", DefaultRegistry) }},
+		{name: "gaugeinfo", ctor: func() any { return GetOrRegisterGaugeInfo("gaugeinfo", DefaultRegistry) }},
+		{name: "resettingtimer", ctor: func() any { return GetOrRegisterResettingTimer("resettingtimer", DefaultRegistry) }},
+		{name: "runtimehistogramlazy", ctor: func() any { return GetOrRegisterHistogramLazy("runtimehistogramlazy", DefaultRegistry, sample) }},


In BenchmarkRegistryGetOrRegister, the histogram and histogram-lazy cases construct a Histogram with a nil Sample (sample() returns nil). That creates a StandardHistogram with a nil backing sample, which will panic if any histogram method (Update/Snapshot/Clear/etc.) is used and also leaves an invalid metric registered in the registry. Use a real Sample implementation (e.g., NewUniformSample/NewExpDecaySample) for the benchmark inputs.

Copilot · 2026-02-10T07:43:11Z

metrics/registry_test.go

+		ctor func() any
+	}{
+		{name: "counter", ctor: func() any { return GetOrRegisterCounter("counter", DefaultRegistry) }},
+		{name: "gauge", ctor: func() any { return GetOrRegisterGauge("gauge", DefaultRegistry) }},
+		{name: "gaugefloat64", ctor: func() any { return GetOrRegisterGaugeFloat64("gaugefloat64", DefaultRegistry) }},
+		{name: "histogram", ctor: func() any { return GetOrRegisterHistogram("histogram", DefaultRegistry, sample()) }},
+		{name: "meter", ctor: func() any { return GetOrRegisterMeter("meter", DefaultRegistry) }},
+		{name: "timer", ctor: func() any { return GetOrRegisterTimer("timer", DefaultRegistry) }},
+		{name: "gaugeinfo", ctor: func() any { return GetOrRegisterGaugeInfo("gaugeinfo", DefaultRegistry) }},
+		{name: "resettingtimer", ctor: func() any { return GetOrRegisterResettingTimer("resettingtimer", DefaultRegistry) }},
+		{name: "runtimehistogramlazy", ctor: func() any { return GetOrRegisterHistogramLazy("runtimehistogramlazy", DefaultRegistry, sample) }},
+	}
+	for _, test := range tests {
+		b.Run(test.name, func(b *testing.B) {
+			for i := 0; i < b.N; i++ {
+				test.ctor()


BenchmarkRegistryGetOrRegister uses DefaultRegistry for all subbenchmarks, which introduces shared global state and can skew results (e.g., if other tests/benchmarks register the same names) and leaves registered metrics behind. Prefer using a fresh Registry per sub-benchmark (or explicitly Unregister/replace the registry) to keep the benchmark isolated and repeatable.

Suggested change

ctor func() any

}{

{name: "counter", ctor: func() any { return GetOrRegisterCounter("counter", DefaultRegistry) }},

{name: "gauge", ctor: func() any { return GetOrRegisterGauge("gauge", DefaultRegistry) }},

{name: "gaugefloat64", ctor: func() any { return GetOrRegisterGaugeFloat64("gaugefloat64", DefaultRegistry) }},

{name: "histogram", ctor: func() any { return GetOrRegisterHistogram("histogram", DefaultRegistry, sample()) }},

{name: "meter", ctor: func() any { return GetOrRegisterMeter("meter", DefaultRegistry) }},

{name: "timer", ctor: func() any { return GetOrRegisterTimer("timer", DefaultRegistry) }},

{name: "gaugeinfo", ctor: func() any { return GetOrRegisterGaugeInfo("gaugeinfo", DefaultRegistry) }},

{name: "resettingtimer", ctor: func() any { return GetOrRegisterResettingTimer("resettingtimer", DefaultRegistry) }},

{name: "runtimehistogramlazy", ctor: func() any { return GetOrRegisterHistogramLazy("runtimehistogramlazy", DefaultRegistry, sample) }},

}

for _, test := range tests {

b.Run(test.name, func(b *testing.B) {

for i := 0; i < b.N; i++ {

test.ctor()

ctor func(r Registry) any

}{

{name: "counter", ctor: func(r Registry) any { return GetOrRegisterCounter("counter", r) }},

{name: "gauge", ctor: func(r Registry) any { return GetOrRegisterGauge("gauge", r) }},

{name: "gaugefloat64", ctor: func(r Registry) any { return GetOrRegisterGaugeFloat64("gaugefloat64", r) }},

{name: "histogram", ctor: func(r Registry) any { return GetOrRegisterHistogram("histogram", r, sample()) }},

{name: "meter", ctor: func(r Registry) any { return GetOrRegisterMeter("meter", r) }},

{name: "timer", ctor: func(r Registry) any { return GetOrRegisterTimer("timer", r) }},

{name: "gaugeinfo", ctor: func(r Registry) any { return GetOrRegisterGaugeInfo("gaugeinfo", r) }},

{name: "resettingtimer", ctor: func(r Registry) any { return GetOrRegisterResettingTimer("resettingtimer", r) }},

{name: "runtimehistogramlazy", ctor: func(r Registry) any { return GetOrRegisterHistogramLazy("runtimehistogramlazy", r, sample) }},

}

for _, test := range tests {

b.Run(test.name, func(b *testing.B) {

r := NewRegistry()

b.ResetTimer()

for i := 0; i < b.N; i++ {

test.ctor(r)

Copilot · 2026-02-10T07:43:11Z

metrics/registry.go

 // GetOrRegister gets an existing metric or creates and registers a new one. Threadsafe
 // alternative to calling Get and Register on failure.
 func GetOrRegister(name string, i func() interface{}) interface{} {
 	return DefaultRegistry.GetOrRegister(name, i)
 }

-func getOrRegister[T any](name string, ctor func() T, r Registry) T {
-	if r == nil {
-		r = DefaultRegistry
-	}
-	return r.GetOrRegister(name, func() any { return ctor() }).(T)
-}
-
 // Register the given metric under the given name.  Returns a ErrDuplicateMetric
 // if a metric by the given name is already registered.
 func Register(name string, i interface{}) error {


Removing the shared getOrRegister helper has introduced repeated "if r == nil { r = DefaultRegistry }" blocks across many metric types. To keep the allocation improvement while avoiding duplication and future inconsistency, consider adding a small non-generic internal helper that takes ctor func() interface{} (so callers can pass non-capturing func literals) and centralizes the nil->DefaultRegistry behavior.

perf(metrics): reduce allocations for metrics ethereum#33699

392be5e

gzliudan requested review from AnilChinchawale, anunay-xin, benjamin202410, Copilot, liam-lai and wanwiset25 February 10, 2026 07:37

Copilot started reviewing on behalf of gzliudan February 10, 2026 07:38 View session

Copilot AI reviewed Feb 10, 2026

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gzliudan commented Feb 10, 2026

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