iterating over map is 10x slower

[korniltsev]

func BenchmarkIntIntMapIterKeys(b *testing.B) {
	var j, v, sum int64
	var ok bool
	m := New(2048, 0.60)
	fillIntIntMap(m)
	for i := 0; i < b.N; i++ {
		sum = int64(0)
		for j = range m.Keys() {
			if v, ok = m.Get(j); ok {
				sum += j
				sum += v
			}
		}
		//log.Println("int int sum:", sum)
	}
}

func BenchmarkIntIntMapIterItems(b *testing.B) {
	var j, v, sum int64
	var kv [2]int64
	m := New(2048, 0.60)
	fillIntIntMap(m)
	for i := 0; i < b.N; i++ {
		sum = int64(0)
		for kv = range m.Items() {
			j = kv[0]
			v = kv[1]
			sum += j
			sum += v
		}
		//log.Println("int int sum:", sum)
	}
}

func BenchmarkIntIntMapIterNoChan(b *testing.B) {
	var sum int64
	m := New(2048, 0.60)
	fillIntIntMap(m)
	for i := 0; i < b.N; i++ {
		sum = int64(0)
		m.Items2(func(k, v int64) {
			sum += k
			sum += v
		})

		//log.Println("int int sum:", sum)
	}
}

func BenchmarkStdMapIter(b *testing.B) {
	var j, v, sum int64
	m := make(map[int64]int64, 2048)
	fillStdMap(m)
	for i := 0; i < b.N; i++ {
		sum = int64(0)
		for j, v = range m {
			sum += j
			sum += v
		}
		//log.Println("map sum:", sum)
	}
}

cpu: AMD Ryzen 9 5950X 16-Core Processor            
BenchmarkIntIntMapIterKeys
BenchmarkIntIntMapIterKeys-32      	       9	 119676935 ns/op
BenchmarkIntIntMapIterItems
BenchmarkIntIntMapIterItems-32     	       8	 127800299 ns/op
BenchmarkIntIntMapIterNoChan
BenchmarkIntIntMapIterNoChan-32    	      76	  14489078 ns/op
BenchmarkStdMapIter
BenchmarkStdMapIter-32             	      69	  15238876 ns/op

[brentp]

If I understand correctly, you're showing that iterating over a(n intint)map using a channel is much slower.
care to make a PR with Items2? Perhaps each can name it Each ?

[korniltsev]

@brentp ptal #10

[brentp]

closed by #10