opentofu/dag/dag_test.go
James Bardin 8cf0a8ca9c faster DAG transitive reduction
In the case of highly-connected graphs, the TransitiveReduction process
was far too computationally intensive. Since no operations are applied
to the nodes, and the walk order is not even user visible, we don't need
to sort them n^2 times.
2017-10-03 11:24:59 -04:00

382 lines
6.8 KiB
Go

package dag
import (
"flag"
"fmt"
"io/ioutil"
"log"
"os"
"reflect"
"strconv"
"strings"
"sync"
"testing"
"github.com/hashicorp/terraform/helper/logging"
)
func TestMain(m *testing.M) {
flag.Parse()
if testing.Verbose() {
// if we're verbose, use the logging requested by TF_LOG
logging.SetOutput()
} else {
// otherwise silence all logs
log.SetOutput(ioutil.Discard)
}
os.Exit(m.Run())
}
func TestAcyclicGraphRoot(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(BasicEdge(3, 2))
g.Connect(BasicEdge(3, 1))
if root, err := g.Root(); err != nil {
t.Fatalf("err: %s", err)
} else if root != 3 {
t.Fatalf("bad: %#v", root)
}
}
func TestAcyclicGraphRoot_cycle(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(BasicEdge(1, 2))
g.Connect(BasicEdge(2, 3))
g.Connect(BasicEdge(3, 1))
if _, err := g.Root(); err == nil {
t.Fatal("should error")
}
}
func TestAcyclicGraphRoot_multiple(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(BasicEdge(3, 2))
if _, err := g.Root(); err == nil {
t.Fatal("should error")
}
}
func TestAyclicGraphTransReduction(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(BasicEdge(1, 2))
g.Connect(BasicEdge(1, 3))
g.Connect(BasicEdge(2, 3))
g.TransitiveReduction()
actual := strings.TrimSpace(g.String())
expected := strings.TrimSpace(testGraphTransReductionStr)
if actual != expected {
t.Fatalf("bad: %s", actual)
}
}
func TestAyclicGraphTransReduction_more(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Add(4)
g.Connect(BasicEdge(1, 2))
g.Connect(BasicEdge(1, 3))
g.Connect(BasicEdge(1, 4))
g.Connect(BasicEdge(2, 3))
g.Connect(BasicEdge(2, 4))
g.Connect(BasicEdge(3, 4))
g.TransitiveReduction()
actual := strings.TrimSpace(g.String())
expected := strings.TrimSpace(testGraphTransReductionMoreStr)
if actual != expected {
t.Fatalf("bad: %s", actual)
}
}
// use this to simulate slow sort operations
type counter struct {
Name string
Calls int64
}
func (s *counter) String() string {
s.Calls++
return s.Name
}
// Make sure we can reduce a sizable, fully-connected graph.
func TestAyclicGraphTransReduction_fullyConnected(t *testing.T) {
var g AcyclicGraph
const nodeCount = 200
nodes := make([]*counter, nodeCount)
for i := 0; i < nodeCount; i++ {
nodes[i] = &counter{Name: strconv.Itoa(i)}
}
// Add them all to the graph
for _, n := range nodes {
g.Add(n)
}
// connect them all
for i := range nodes {
for j := range nodes {
if i == j {
continue
}
g.Connect(BasicEdge(nodes[i], nodes[j]))
}
}
g.TransitiveReduction()
vertexNameCalls := int64(0)
for _, n := range nodes {
vertexNameCalls += n.Calls
}
switch {
case vertexNameCalls > 2*nodeCount:
// Make calling it more the 2x per node fatal.
// If we were sorting this would give us roughly ln(n)(n^3) calls, or
// >59000000 calls for 200 vertices.
t.Fatalf("VertexName called %d times", vertexNameCalls)
case vertexNameCalls > 0:
// we don't expect any calls, but a change here isn't necessarily fatal
t.Logf("WARNING: VertexName called %d times", vertexNameCalls)
}
}
func TestAcyclicGraphValidate(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(BasicEdge(3, 2))
g.Connect(BasicEdge(3, 1))
if err := g.Validate(); err != nil {
t.Fatalf("err: %s", err)
}
}
func TestAcyclicGraphValidate_cycle(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(BasicEdge(3, 2))
g.Connect(BasicEdge(3, 1))
g.Connect(BasicEdge(1, 2))
g.Connect(BasicEdge(2, 1))
if err := g.Validate(); err == nil {
t.Fatal("should error")
}
}
func TestAcyclicGraphValidate_cycleSelf(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Connect(BasicEdge(1, 1))
if err := g.Validate(); err == nil {
t.Fatal("should error")
}
}
func TestAcyclicGraphAncestors(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Add(4)
g.Add(5)
g.Connect(BasicEdge(0, 1))
g.Connect(BasicEdge(1, 2))
g.Connect(BasicEdge(2, 3))
g.Connect(BasicEdge(3, 4))
g.Connect(BasicEdge(4, 5))
actual, err := g.Ancestors(2)
if err != nil {
t.Fatalf("err: %#v", err)
}
expected := []Vertex{3, 4, 5}
if actual.Len() != len(expected) {
t.Fatalf("bad length! expected %#v to have len %d", actual, len(expected))
}
for _, e := range expected {
if !actual.Include(e) {
t.Fatalf("expected: %#v to include: %#v", expected, actual)
}
}
}
func TestAcyclicGraphDescendents(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Add(4)
g.Add(5)
g.Connect(BasicEdge(0, 1))
g.Connect(BasicEdge(1, 2))
g.Connect(BasicEdge(2, 3))
g.Connect(BasicEdge(3, 4))
g.Connect(BasicEdge(4, 5))
actual, err := g.Descendents(2)
if err != nil {
t.Fatalf("err: %#v", err)
}
expected := []Vertex{0, 1}
if actual.Len() != len(expected) {
t.Fatalf("bad length! expected %#v to have len %d", actual, len(expected))
}
for _, e := range expected {
if !actual.Include(e) {
t.Fatalf("expected: %#v to include: %#v", expected, actual)
}
}
}
func TestAcyclicGraphWalk(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(BasicEdge(3, 2))
g.Connect(BasicEdge(3, 1))
var visits []Vertex
var lock sync.Mutex
err := g.Walk(func(v Vertex) error {
lock.Lock()
defer lock.Unlock()
visits = append(visits, v)
return nil
})
if err != nil {
t.Fatalf("err: %s", err)
}
expected := [][]Vertex{
{1, 2, 3},
{2, 1, 3},
}
for _, e := range expected {
if reflect.DeepEqual(visits, e) {
return
}
}
t.Fatalf("bad: %#v", visits)
}
func TestAcyclicGraphWalk_error(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Add(4)
g.Connect(BasicEdge(4, 3))
g.Connect(BasicEdge(3, 2))
g.Connect(BasicEdge(2, 1))
var visits []Vertex
var lock sync.Mutex
err := g.Walk(func(v Vertex) error {
lock.Lock()
defer lock.Unlock()
if v == 2 {
return fmt.Errorf("error")
}
visits = append(visits, v)
return nil
})
if err == nil {
t.Fatal("should error")
}
expected := [][]Vertex{
{1},
}
for _, e := range expected {
if reflect.DeepEqual(visits, e) {
return
}
}
t.Fatalf("bad: %#v", visits)
}
func TestAcyclicGraph_ReverseDepthFirstWalk_WithRemoval(t *testing.T) {
var g AcyclicGraph
g.Add(1)
g.Add(2)
g.Add(3)
g.Connect(BasicEdge(3, 2))
g.Connect(BasicEdge(2, 1))
var visits []Vertex
var lock sync.Mutex
err := g.ReverseDepthFirstWalk([]Vertex{1}, func(v Vertex, d int) error {
lock.Lock()
defer lock.Unlock()
visits = append(visits, v)
g.Remove(v)
return nil
})
if err != nil {
t.Fatalf("err: %s", err)
}
expected := []Vertex{1, 2, 3}
if !reflect.DeepEqual(visits, expected) {
t.Fatalf("expected: %#v, got: %#v", expected, visits)
}
}
const testGraphTransReductionStr = `
1
2
2
3
3
`
const testGraphTransReductionMoreStr = `
1
2
2
3
3
4
4
`