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feat: first (nonsensical) Deltas showin' up
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@b5
b5 committed Feb 14, 2019
1 parent d84c363 commit fc9f884
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Showing 2 changed files with 111 additions and 44 deletions.
125 changes: 93 additions & 32 deletions difff.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -54,7 +54,7 @@ var (

// Diff computes a slice of deltas that define an edit script for turning the
// value at d1 into d2
func Diff(d1, d2 interface{}) ([]Delta, error) {
func Diff(d1, d2 interface{}) ([]*Delta, error) {
var (
wg sync.WaitGroup
t1, t2 Node
Expand Down Expand Up @@ -94,8 +94,8 @@ func Diff(d1, d2 interface{}) ([]Delta, error) {
// if err != nil {
// return nil, err
// }
fmt.Println("weights", t1.Weight(), t2.Weight())
queueMatch(t1Nodes, t2)
dts := computeDeltas(t1, t2)
// fmt.Printf("%d %d\n", matches[0].left.Parent().Hash(), matches[0].right.Parent().Hash())
// for i, m := range matches {
// fmt.Printf("%d. %s %s\n", i, path(m[0]), path(m[1]))
Expand All @@ -104,20 +104,20 @@ func Diff(d1, d2 interface{}) ([]Delta, error) {
// fmt.Println(hex.EncodeToString(t1.Hash()), t1.Weight())
// fmt.Println(hex.EncodeToString(t2.Hash()), t2.Weight())
// fmt.Println(t1SubTrees, t2SubTrees)
for key, ns := range t1Nodes {
str := ""
for _, n := range ns {
str += fmt.Sprintf(" %s", path(n))
}
fmt.Printf("%s [%s]\n", key, str)
}
fmt.Printf("\n")
// for key, ns := range t1Nodes {
// str := ""
// for _, n := range ns {
// str += fmt.Sprintf(" %s", path(n))
// }
// fmt.Printf("%s [%s]\n", key, str)
// }
// fmt.Printf("\n")

// for _, n := range t2SubTrees {
// fmt.Printf("[%s %d] ", hex.EncodeToString(n.Hash()), n.Weight())
// }
// fmt.Printf("\n")
return nil, nil
return dts, nil
}

// DeltaType defines the types of changes xydiff can create
Expand All @@ -141,12 +141,27 @@ const (
DTChange
)

func (d DeltaType) String() string {
switch d {
case DTRemove:
return "remove"
case DTInsert:
return "insert"
case DTMove:
return "move"
case DTChange:
return "change"
default:
return "unknown"
}
}

// Delta represents a change between two documents
type Delta struct {
Type DeltaType

SrcPath []string
DstPath []string
SrcPath string
DstPath string

SrcVal interface{}
DstVal interface{}
Expand Down Expand Up @@ -391,14 +406,10 @@ func queueMatch(t1Nodes map[string][]Node, t2 Node) {
case 1:
// connect an exact match. yay!
n1 := candidates[0]
n1.SetMatch(n2)
n2.SetMatch(n1)
matchNodes(n1, n2)
default:
// choose a best candidate. let the sketchiness begin.
if n1BestMatch := bestCandidate(candidates, n2, t2Weight); n1BestMatch != nil {
n1BestMatch.SetMatch(n2)
n2.SetMatch(n1BestMatch)
}
bestCandidate(candidates, n2, t2Weight)
}

considering--
Expand All @@ -415,20 +426,40 @@ func queueMatch(t1Nodes map[string][]Node, t2 Node) {
return
}

// matchNodes connects two nodes & tries to propagate that match upward to
// ancestors so long as labels match
func matchNodes(n1, n2 Node) {
n1.SetMatch(n2)
n2.SetMatch(n1)
n1p := n1.Parent()
n2p := n2.Parent()
for n1p != nil && n2p != nil {
// TODO - root name is coming back as "", need to think about why this is
// and weather it's ok to match roots
if n1p.Name() == n2p.Name() && n1p.Name() != "" && n2p.Name() != "" {
// fmt.Printf("also matching %s %s %s %d\n", path(n1p), path(n2p), n1p.Name(), n1p.Type())
n1p.SetMatch(n2p)
n2p.SetMatch(n1p)
n1p = n1p.Parent()
n2p = n2p.Parent()
}
break
}
}

// bestCandidate is the one who's parent
func bestCandidate(t1Candidates []Node, n2 Node, t2Weight int) Node {
func bestCandidate(t1Candidates []Node, n2 Node, t2Weight int) {
maxDist := 1 + float32(n2.Weight())/float32(t2Weight)
dist := 1 + float32(n2.Parent().Weight()-n2.Weight())/float32(t2Weight)
n2 = n2.Parent()
DISTLOOP:

for dist < maxDist {
for i, can := range t1Candidates {
if cp := can.Parent(); cp != nil {
if n2.Name() == cp.Name() {
// fmt.Printf("matching: %s and %s\n", path(n2), path(cp))
n2.SetMatch(cp)
cp.SetMatch(n2)
break DISTLOOP
matchNodes(cp, n2)
return
}
}
t1Candidates[i] = can.Parent()
Expand All @@ -440,7 +471,6 @@ DISTLOOP:
n2 = n2.Parent()
}
// fmt.Println("dist", dist, "maxDist:", maxDist, "n2Weight:", n2.Weight(), "n2path:", path(n2), "treeWeight:", t2Weight)
return nil
}

func optimize() {
Expand Down Expand Up @@ -493,23 +523,54 @@ func propagateMatchToChildren(n Node) {
}
}

func computeDeltas(t1, t2 Node) []Delta {
ds := calcIUDs(t1, t2)
func computeDeltas(t1, t2 Node) []*Delta {
ds := calcICDs(t1, t2)
calcMoves(ds)
organize(ds)
return ds
}

// calculate inserts, updates, & deletes
func calcIUDs(t1, t2 Node) []Delta {
return nil
func walk(tree Node, path string, fn func(path string, n Node)) {
path = fmt.Sprintf("%s.%s", path, tree.Name())
fn(path, tree)
if cmp, ok := tree.(Compound); ok {
for _, n := range cmp.Children() {
walk(n, path, fn)
}
}
}

// calculate inserts, changes, & deletes
func calcICDs(t1, t2 Node) (dts []*Delta) {
walk(t1, "", func(path string, n Node) {
if t1.Match() == nil {
delta := &Delta{
Type: DTRemove,
SrcPath: path,
SrcVal: n.Value(),
}
dts = append(dts, delta)
}
})

walk(t2, "", func(path string, n Node) {
if t1.Match() == nil {
delta := &Delta{
Type: DTInsert,
DstPath: path,
DstVal: n.Value(),
}
dts = append(dts, delta)
}
})
return dts
}

func calcMoves(ds []Delta) {
func calcMoves(ds []*Delta) {

}

func organize([]Delta) {
func organize([]*Delta) {
}

// lcss calculates the longest common subsequence
Expand Down
30 changes: 18 additions & 12 deletions difff_test.go
View file
Original file line number Diff line number Diff line change
Expand Up @@ -49,12 +49,18 @@ func TestBasicDiff(t *testing.T) {
}

Diff(a, b)
// ds, err := Diff(a, b)
// if err != nil {
// t.Fatal(err)
// }
// data, _ := json.MarshalIndent(ds, "", " ")
// fmt.Println(string(data))
}

type TestCase struct {
description string
src, dst string // express test cases as json strings
expect []Delta
expect []*Delta
}

func RunTestCases(t *testing.T, cases []TestCase) {
Expand Down Expand Up @@ -82,7 +88,7 @@ func RunTestCases(t *testing.T, cases []TestCase) {
}
}

func CompareDiffs(a, b []Delta) error {
func CompareDiffs(a, b []*Delta) error {
if len(a) != len(b) {
return fmt.Errorf("length mismatch: %d != %d", len(a), len(b))
}
Expand All @@ -96,7 +102,7 @@ func CompareDiffs(a, b []Delta) error {
return nil
}

func CompareDeltas(a, b Delta) error {
func CompareDeltas(a, b *Delta) error {
if a.Type != b.Type {
return fmt.Errorf("Type mismatch. %T != %T", a.Type, b.Type)
}
Expand All @@ -116,40 +122,40 @@ func TestQriUseCases(t *testing.T) {
"detect scalar change",
`[[0,1,2]]`,
`[[0,1,3]]`,
[]Delta{
{Type: DTChange, SrcPath: []string{"0", "2"}, DstPath: []string{"0", "2"}, SrcVal: 2, DstVal: 3},
[]*Delta{
{Type: DTChange, SrcPath: "0.2", DstPath: "0.2", SrcVal: 2, DstVal: 3},
},
},
{
"detect insert",
`[[1]]`,
`[[1],[2]]`,
[]Delta{
{Type: DTInsert, SrcPath: []string{"0", "0"}, DstPath: []string{"0", "1"}, SrcVal: nil, DstVal: []interface{}{2}},
[]*Delta{
{Type: DTInsert, SrcPath: "0.0", DstPath: "0.1", SrcVal: "", DstVal: []interface{}{2}},
},
},
{
"detect remove",
`[[1],[2],[3]]`,
`[[1],[3]]`,
[]Delta{
{Type: DTRemove, SrcPath: []string{"0", "1"}, DstPath: nil, SrcVal: []interface{}{2}, DstVal: nil},
[]*Delta{
{Type: DTRemove, SrcPath: "0.1", DstPath: "", SrcVal: []interface{}{2}, DstVal: nil},
},
},
{
"detect move",
`[[1],[2],[3]]`,
`[[1],[3],[2]]`,
[]Delta{
{Type: DTMove, SrcPath: []string{"0", "1"}, DstPath: []string{"0", "2"}, SrcVal: []interface{}{2}, DstVal: []interface{}{2}},
[]*Delta{
{Type: DTMove, SrcPath: "0.1", DstPath: "0.2", SrcVal: []interface{}{2}, DstVal: []interface{}{2}},
},
},
}

RunTestCases(t, cases)
}

func BenchmarkDiff(b *testing.B) {
func BenchmarkDiff1(b *testing.B) {
srcData := `{
"foo" : {
"bar" : [1,2,3]
Expand Down

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