Golang Benchmark Map Allocations

README.md

> go test -bench=. -test.benchtime=10s

BenchmarkMapIntZero-12             	389632792	        30.6 ns/op	      48 B/op	       1 allocs/op
BenchmarkMapInt100-12              	16012993	       824 ns/op	    4176 B/op	       3 allocs/op
BenchmarkMapInt1000-12             	 1420974	      8083 ns/op	   57424 B/op	       3 allocs/op
BenchmarkMapInt10000-12            	  149038	     83019 ns/op	  458833 B/op	       3 allocs/op
BenchmarkMapSliceStringZero-12     	365958336	        32.7 ns/op	      48 B/op	       1 allocs/op
BenchmarkMapSliceString100-12      	10588574	      1074 ns/op	    6224 B/op	       3 allocs/op
BenchmarkMapSliceString1000-12     	  809688	     14690 ns/op	   98385 B/op	       3 allocs/op
BenchmarkMapSliceString10000-12    	  107524	    110891 ns/op	  737363 B/op	       3 allocs/op
PASS

benchmark_test.go

package main

import (
	"testing"
)

var mapInt map[string]int

func BenchmarkMapIntZero(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		mapInt = make(map[string]int)
	}
}

func BenchmarkMapInt100(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		mapInt = make(map[string]int, 100)
	}
}

func BenchmarkMapInt1000(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		mapInt = make(map[string]int, 1000)
	}
}

func BenchmarkMapInt10000(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		mapInt = make(map[string]int, 10000)
	}
}

var mapSliceString map[string][]string

func BenchmarkMapSliceStringZero(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		mapSliceString = make(map[string][]string)
	}
}

func BenchmarkMapSliceString100(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		mapSliceString = make(map[string][]string, 100)
	}
}

func BenchmarkMapSliceString1000(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		mapSliceString = make(map[string][]string, 1000)
	}
}

func BenchmarkMapSliceString10000(b *testing.B) {
	b.ReportAllocs()
	for i := 0; i < b.N; i++ {
		mapSliceString = make(map[string][]string, 10000)
	}
}