zfs: implement DatasetPath top down walk

zfs/datasetpath_visitor_test.go

@@ -0,0 +1,95 @@
+package zfs
+
+import (
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestNewDatasetPathTree(t *testing.T) {
+
+	r := newDatasetPathTree(toDatasetPath("pool1/foo/bar"))
+
+	assert.Equal(t, "pool1", r.Component)
+	assert.True(t, len(r.Children) == 1)
+	cr := r.Children[0]
+	assert.Equal(t, "foo", cr.Component)
+	assert.True(t, len(cr.Children) == 1)
+	ccr := cr.Children[0]
+	assert.Equal(t, "bar", ccr.Component)
+
+}
+
+type visitRecorder struct {
+	visits []DatasetPathVisit
+}
+
+func makeVisitRecorder() (v DatasetPathsVisitor, rec *visitRecorder) {
+	rec = &visitRecorder{
+		visits: make([]DatasetPathVisit, 0),
+	}
+	v = func(v DatasetPathVisit) error {
+		rec.visits = append(rec.visits, v)
+		return nil
+	}
+	return
+}
+
+func buildForest(paths []DatasetPath) (f *DatasetPathForest) {
+	f = NewDatasetPathForest()
+	for _, p := range paths {
+		f.Add(p)
+	}
+	return
+}
+
+func TestDatasetPathForestWalkTopDown(t *testing.T) {
+
+	paths := []DatasetPath{
+		toDatasetPath("pool1"),
+		toDatasetPath("pool1/foo/bar"),
+		toDatasetPath("pool1/foo/bar/looloo"),
+		toDatasetPath("pool2/test/bar"),
+	}
+
+	v, rec := makeVisitRecorder()
+
+	buildForest(paths).WalkTopDown(v)
+
+	expectedVisists := []DatasetPathVisit{
+		{toDatasetPath("pool1"), false},
+		{toDatasetPath("pool1/foo"), true},
+		{toDatasetPath("pool1/foo/bar"), false},
+		{toDatasetPath("pool1/foo/bar/looloo"), false},
+		{toDatasetPath("pool2"), true},
+		{toDatasetPath("pool2/test"), true},
+		{toDatasetPath("pool2/test/bar"), false},
+	}
+	assert.Equal(t, expectedVisists, rec.visits)
+
+}
+
+func TestDatasetPathWalkTopDownWorksUnordered(t *testing.T) {
+
+	paths := []DatasetPath{
+		toDatasetPath("pool1"),
+		toDatasetPath("pool1/foo/bar/looloo"),
+		toDatasetPath("pool1/foo/bar"),
+		toDatasetPath("pool1/bang/baz"),
+	}
+
+	v, rec := makeVisitRecorder()
+
+	buildForest(paths).WalkTopDown(v)
+
+	expectedVisists := []DatasetPathVisit{
+		{toDatasetPath("pool1"), false},
+		{toDatasetPath("pool1/foo"), true},
+		{toDatasetPath("pool1/foo/bar"), false},
+		{toDatasetPath("pool1/foo/bar/looloo"), false},
+		{toDatasetPath("pool1/bang"), true},
+		{toDatasetPath("pool1/bang/baz"), false},
+	}
+
+	assert.Equal(t, expectedVisists, rec.visits)
+
+}