Function testUsage

plugins/snapshots/devmapper/snapshotter_test.go:72–110

testUsage tests devmapper's Usage implementation. This is an approximate test as it's hard to predict how many blocks will be consumed under different conditions and parameters.

(t *testing.T, snapshotter snapshots.Snapshotter)

// testUsage tests devmapper's Usage implementation. This is an approximate test as it's hard to
// predict how many blocks will be consumed under different conditions and parameters.
func testUsage(t *testing.T, snapshotter snapshots.Snapshotter) {
	ctx := context.Background()

	// Create empty base layer
	_, err := snapshotter.Prepare(ctx, "prepare-1", "")
	assert.NoError(t, err)

	emptyLayerUsage, err := snapshotter.Usage(ctx, "prepare-1")
	assert.NoError(t, err)

	// Should be > 0 as just written file system also consumes blocks
	assert.Greater(t, emptyLayerUsage.Size, int64(0))

	err = snapshotter.Commit(ctx, "layer-1", "prepare-1")
	assert.NoError(t, err)

	// Create child layer with 1MB file

	var (
		sizeBytes   int64 = 1048576 // 1MB
		baseApplier       = fstest.Apply(fstest.CreateRandomFile("/a", 12345679, sizeBytes, 0777))
	)

	mounts, err := snapshotter.Prepare(ctx, "prepare-2", "layer-1")
	assert.NoError(t, err)

	err = mount.WithTempMount(ctx, mounts, baseApplier.Apply)
	assert.NoError(t, err)

	err = snapshotter.Commit(ctx, "layer-2", "prepare-2")
	assert.NoError(t, err)

	layer2Usage, err := snapshotter.Usage(ctx, "layer-2")
	assert.NoError(t, err)

	// Should be at least 1 MB + fs metadata
	assert.GreaterOrEqual(t, layer2Usage.Size, sizeBytes,
		"%d > %d", layer2Usage.Size, sizeBytes)
}

func TestMkfsExt4(t *testing.T) {
	ctx := context.Background()