Benchmark interface

benchmarkinterface.go

type foo interface {
	increment()
}

type X struct {
	i int
}

func (x *X) increment() {
	x.i++
}

func BenchmarkInterface(b *testing.B) {
	var a foo = new(X)
	for i := 0; i < b.N; i++ {
		a.increment()
	}
}

func BenchmarkConcreteType(b *testing.B) {
	var a = new(X)
	for i := 0; i < b.N; i++ {
		a.increment()
	}
}

goos: linux
goarch: amd64
pkg: github.com/dgraph-io/badger/table
BenchmarkInterface-8   	2000000000	         2.01 ns/op	       0 B/op	       0 allocs/op
PASS
ok  	github.com/dgraph-io/badger/table	4.224s
Success: Benchmarks passed.

goos: linux
goarch: amd64
pkg: github.com/dgraph-io/badger/table
BenchmarkConcreteType-8   	2000000000	         1.50 ns/op	       0 B/op	       0 allocs/op
PASS
ok  	github.com/dgraph-io/badger/table	3.158s
Success: Benchmarks passed.