Function BenchmarkUnionInPlaceCopyOnWrite

benchmark_test.go:350–389

BenchmarkUnionInPlaceCopyOnWrite tests the performance of bitmap.Or() when the bitmap was generated via FromBuffer. In this case all left containers need to be copied in order to be updated. The nested for-loops test a number of different scenarios with respect to the ranges and densities of bitmaps

(b *testing.B)

// The nested for-loops test a number of different scenarios
// with respect to the ranges and densities of bitmaps.
func BenchmarkUnionInPlaceCopyOnWrite(b *testing.B) {
	// uint32s to maintain 1.12 compatibility, which requires unsigned shifts.
	startingContainerPower := uint32(4)
	finalContainerPower := uint32(10)
	containerIncrement := uint32(3)
	startingItemsPower := uint32(3)
	finalItemsPower := uint32(10)
	itemsIncrement := uint32(7)
	for leftContainerPower := startingContainerPower; leftContainerPower <= finalContainerPower; leftContainerPower += containerIncrement {
		for rightContainerPower := startingContainerPower; rightContainerPower <= finalContainerPower; rightContainerPower += containerIncrement {
			for leftItemsPerContainerPower := startingItemsPower; leftItemsPerContainerPower <= finalItemsPower; leftItemsPerContainerPower += itemsIncrement {
				for rightItemsPerContainerPower := startingItemsPower; rightItemsPerContainerPower <= finalItemsPower; rightItemsPerContainerPower += itemsIncrement {
					b.Run(fmt.Sprintf("%d-%d-%d-%d", leftContainerPower, rightContainerPower, leftItemsPerContainerPower, rightItemsPerContainerPower),
						func(b *testing.B) {
							leftMax := (1 << 16) << leftContainerPower
							rightMax := (1 << 16) << rightContainerPower
							leftItems := 1 << (leftContainerPower + leftItemsPerContainerPower)
							rightItems := 1 << (rightContainerPower + rightItemsPerContainerPower)
							left := make([][]byte, 10)
							right := make([]*Bitmap, 10)
							for i := 0; i < 10; i++ {
								right[i] = NewBitmap()
								left[i] = generateRandomBitmap(b, leftMax, leftItems)
								_, err := right[i].FromBuffer(generateRandomBitmap(b, rightMax, rightItems))
								require.NoError(b, err)
							}
							// This tests a destructive operation, Or() so have to have a fresh bitmap per test.
							targetLefts := make([]*Bitmap, b.N)
							for i := 0; i < b.N; i++ {
								targetLefts[i] = NewBitmap()
								_, err := targetLefts[i].FromBuffer(left[i%10])
								require.NoError(b, err)
							}
							runActualBenchmark(b, targetLefts, right)
						})
				}
			}
		}
	}
}

// runActualBenchmark is broken out primarily so you can profile the tests,
// as otherwise the generation overwhelms the actual test.