add difftree for noders (#262)

difftree for noders

1 files changed, 429 insertions, 0 deletions

diff --git a/utils/merkletrie/difftree_test.go b/utils/merkletrie/difftree_test.go
new file mode 100644
index 0000000..6a193af
--- /dev/null
+++ b/utils/merkletrie/difftree_test.go
@@ -0,0 +1,429 @@
+package merkletrie_test
+
+import (
+	"bytes"
+	"fmt"
+	"reflect"
+	"sort"
+	"strings"
+	"testing"
+	"unicode"
+
+	"srcd.works/go-git.v4/utils/merkletrie"
+	"srcd.works/go-git.v4/utils/merkletrie/internal/fsnoder"
+
+	. "gopkg.in/check.v1"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type DiffTreeSuite struct{}
+
+var _ = Suite(&DiffTreeSuite{})
+
+type diffTreeTest struct {
+	from     string
+	to       string
+	expected string
+}
+
+func (t diffTreeTest) innerRun(c *C, context string, reverse bool) {
+	comment := Commentf("\n%s", context)
+	if reverse {
+		comment = Commentf("%s [REVERSED]", comment.CheckCommentString())
+	}
+
+	a, err := fsnoder.New(t.from)
+	c.Assert(err, IsNil, comment)
+	comment = Commentf("%s\n\t    from = %s", comment.CheckCommentString(), a)
+
+	b, err := fsnoder.New(t.to)
+	c.Assert(err, IsNil, comment)
+	comment = Commentf("%s\n\t      to = %s", comment.CheckCommentString(), b)
+
+	expected, err := newChangesFromString(t.expected)
+	c.Assert(err, IsNil, comment)
+
+	if reverse {
+		a, b = b, a
+		expected = expected.reverse()
+	}
+	comment = Commentf("%s\n\texpected = %s", comment.CheckCommentString(), expected)
+
+	results, err := merkletrie.DiffTree(a, b, fsnoder.HashEqual)
+	c.Assert(err, IsNil, comment)
+
+	obtained, err := newChanges(results)
+	c.Assert(err, IsNil, comment)
+
+	comment = Commentf("%s\n\tobtained = %s", comment.CheckCommentString(), obtained)
+
+	c.Assert(obtained, changesEquals, expected, comment)
+}
+
+func (t diffTreeTest) run(c *C, context string) {
+	t.innerRun(c, context, false)
+	t.innerRun(c, context, true)
+}
+
+type change struct {
+	merkletrie.Action
+	path string
+}
+
+func (c change) String() string {
+	return fmt.Sprintf("<%s %s>", c.Action, c.path)
+}
+
+func (c change) reverse() change {
+	ret := change{
+		path: c.path,
+	}
+
+	switch c.Action {
+	case merkletrie.Insert:
+		ret.Action = merkletrie.Delete
+	case merkletrie.Delete:
+		ret.Action = merkletrie.Insert
+	case merkletrie.Modify:
+		ret.Action = merkletrie.Modify
+	default:
+		panic(fmt.Sprintf("unknown action type: %d", c.Action))
+	}
+
+	return ret
+}
+
+type changes []change
+
+func newChanges(original merkletrie.Changes) (changes, error) {
+	ret := make(changes, len(original))
+	for i, c := range original {
+		action, err := c.Action()
+		if err != nil {
+			return nil, err
+		}
+		switch action {
+		case merkletrie.Insert:
+			ret[i] = change{
+				Action: merkletrie.Insert,
+				path:   c.To.String(),
+			}
+		case merkletrie.Delete:
+			ret[i] = change{
+				Action: merkletrie.Delete,
+				path:   c.From.String(),
+			}
+		case merkletrie.Modify:
+			ret[i] = change{
+				Action: merkletrie.Modify,
+				path:   c.From.String(),
+			}
+		default:
+			panic(fmt.Sprintf("unsupported action %d", c.Action))
+		}
+	}
+
+	return ret, nil
+}
+
+func newChangesFromString(s string) (changes, error) {
+	ret := make([]change, 0)
+
+	s = strings.TrimSpace(s)
+	s = removeDuplicatedSpace(s)
+	s = turnSpaceIntoLiteralSpace(s)
+
+	if s == "" {
+		return ret, nil
+	}
+
+	for _, chunk := range strings.Split(s, " ") {
+		change := change{
+			path: string(chunk[1:]),
+		}
+
+		switch chunk[0] {
+		case '+':
+			change.Action = merkletrie.Insert
+		case '-':
+			change.Action = merkletrie.Delete
+		case '*':
+			change.Action = merkletrie.Modify
+		default:
+			panic(fmt.Sprintf("unsupported action descriptor %q", chunk[0]))
+		}
+
+		ret = append(ret, change)
+	}
+
+	return ret, nil
+}
+
+func removeDuplicatedSpace(s string) string {
+	var buf bytes.Buffer
+
+	var lastWasSpace, currentIsSpace bool
+	for _, r := range s {
+		currentIsSpace = unicode.IsSpace(r)
+
+		if lastWasSpace && currentIsSpace {
+			continue
+		}
+		lastWasSpace = currentIsSpace
+
+		buf.WriteRune(r)
+	}
+
+	return buf.String()
+}
+
+func turnSpaceIntoLiteralSpace(s string) string {
+	return strings.Map(
+		func(r rune) rune {
+			if unicode.IsSpace(r) {
+				return ' '
+			}
+			return r
+		}, s)
+}
+
+func (cc changes) Len() int           { return len(cc) }
+func (cc changes) Swap(i, j int)      { cc[i], cc[j] = cc[j], cc[i] }
+func (cc changes) Less(i, j int) bool { return strings.Compare(cc[i].String(), cc[j].String()) < 0 }
+
+func (cc changes) equals(other changes) bool {
+	sort.Sort(cc)
+	sort.Sort(other)
+	return reflect.DeepEqual(cc, other)
+}
+
+func (cc changes) String() string {
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "len(%d) [", len(cc))
+	sep := ""
+	for _, c := range cc {
+		fmt.Fprintf(&buf, "%s%s", sep, c)
+		sep = ", "
+	}
+	buf.WriteByte(']')
+	return buf.String()
+}
+
+func (cc changes) reverse() changes {
+	ret := make(changes, len(cc))
+	for i, c := range cc {
+		ret[i] = c.reverse()
+	}
+
+	return ret
+}
+
+type changesEqualsChecker struct {
+	*CheckerInfo
+}
+
+var changesEquals Checker = &changesEqualsChecker{
+	&CheckerInfo{Name: "changesEquals", Params: []string{"obtained", "expected"}},
+}
+
+func (checker *changesEqualsChecker) Check(params []interface{}, names []string) (result bool, error string) {
+	a, ok := params[0].(changes)
+	if !ok {
+		return false, "first parameter must be a changes"
+	}
+	b, ok := params[1].(changes)
+	if !ok {
+		return false, "second parameter must be a changes"
+	}
+
+	return a.equals(b), ""
+}
+
+func do(c *C, list []diffTreeTest) {
+	for i, t := range list {
+		t.run(c, fmt.Sprintf("test #%d:", i))
+	}
+}
+
+func (s *DiffTreeSuite) TestEmptyVsEmpty(c *C) {
+	do(c, []diffTreeTest{
+		{"()", "()", ""},
+		{"A()", "A()", ""},
+		{"A()", "()", ""},
+		{"A()", "B()", ""},
+	})
+}
+
+func (s *DiffTreeSuite) TestBasicCases(c *C) {
+	do(c, []diffTreeTest{
+		{"()", "()", ""},
+		{"()", "(a<>)", "+a"},
+		{"()", "(a<1>)", "+a"},
+		{"()", "(a())", ""},
+		{"()", "(a(b()))", ""},
+		{"()", "(a(b<>))", "+a/b"},
+		{"()", "(a(b<1>))", "+a/b"},
+		{"(a<>)", "(a<>)", ""},
+		{"(a<>)", "(a<1>)", "*a"},
+		{"(a<>)", "(a())", "-a"},
+		{"(a<>)", "(a(b()))", "-a"},
+		{"(a<>)", "(a(b<>))", "-a +a/b"},
+		{"(a<>)", "(a(b<1>))", "-a +a/b"},
+		{"(a<>)", "(c())", "-a"},
+		{"(a<>)", "(c(b()))", "-a"},
+		{"(a<>)", "(c(b<>))", "-a +c/b"},
+		{"(a<>)", "(c(b<1>))", "-a +c/b"},
+		{"(a<>)", "(c(a()))", "-a"},
+		{"(a<>)", "(c(a<>))", "-a +c/a"},
+		{"(a<>)", "(c(a<1>))", "-a +c/a"},
+		{"(a<1>)", "(a<1>)", ""},
+		{"(a<1>)", "(a<2>)", "*a"},
+		{"(a<1>)", "(b<1>)", "-a +b"},
+		{"(a<1>)", "(b<2>)", "-a +b"},
+		{"(a<1>)", "(a())", "-a"},
+		{"(a<1>)", "(a(b()))", "-a"},
+		{"(a<1>)", "(a(b<>))", "-a +a/b"},
+		{"(a<1>)", "(a(b<1>))", "-a +a/b"},
+		{"(a<1>)", "(a(b<2>))", "-a +a/b"},
+		{"(a<1>)", "(c())", "-a"},
+		{"(a<1>)", "(c(b()))", "-a"},
+		{"(a<1>)", "(c(b<>))", "-a +c/b"},
+		{"(a<1>)", "(c(b<1>))", "-a +c/b"},
+		{"(a<1>)", "(c(b<2>))", "-a +c/b"},
+		{"(a<1>)", "(c())", "-a"},
+		{"(a<1>)", "(c(a()))", "-a"},
+		{"(a<1>)", "(c(a<>))", "-a +c/a"},
+		{"(a<1>)", "(c(a<1>))", "-a +c/a"},
+		{"(a<1>)", "(c(a<2>))", "-a +c/a"},
+		{"(a())", "(a())", ""},
+		{"(a())", "(b())", ""},
+		{"(a())", "(a(b()))", ""},
+		{"(a())", "(b(a()))", ""},
+		{"(a())", "(a(b<>))", "+a/b"},
+		{"(a())", "(a(b<1>))", "+a/b"},
+		{"(a())", "(b(a<>))", "+b/a"},
+		{"(a())", "(b(a<1>))", "+b/a"},
+	})
+}
+
+func (s *DiffTreeSuite) TestHorizontals(c *C) {
+	do(c, []diffTreeTest{
+		{"()", "(a<> b<>)", "+a +b"},
+		{"()", "(a<> b<1>)", "+a +b"},
+		{"()", "(a<> b())", "+a"},
+		{"()", "(a() b<>)", "+b"},
+		{"()", "(a<1> b<>)", "+a +b"},
+		{"()", "(a<1> b<1>)", "+a +b"},
+		{"()", "(a<1> b<2>)", "+a +b"},
+		{"()", "(a<1> b())", "+a"},
+		{"()", "(a() b<1>)", "+b"},
+		{"()", "(a() b())", ""},
+		{"()", "(a<> b<> c<> d<>)", "+a +b +c +d"},
+		{"()", "(a<> b<1> c() d<> e<2> f())", "+a +b +d +e"},
+	})
+}
+
+func (s *DiffTreeSuite) TestVerticals(c *C) {
+	do(c, []diffTreeTest{
+		{"()", "(z<>)", "+z"},
+		{"()", "(a(z<>))", "+a/z"},
+		{"()", "(a(b(z<>)))", "+a/b/z"},
+		{"()", "(a(b(c(z<>))))", "+a/b/c/z"},
+		{"()", "(a(b(c(d(z<>)))))", "+a/b/c/d/z"},
+		{"()", "(a(b(c(d(z<1>)))))", "+a/b/c/d/z"},
+	})
+}
+
+func (s *DiffTreeSuite) TestSingleInserts(c *C) {
+	do(c, []diffTreeTest{
+		{"()", "(z<>)", "+z"},
+		{"(a())", "(a(z<>))", "+a/z"},
+		{"(a())", "(a(b(z<>)))", "+a/b/z"},
+		{"(a(b(c())))", "(a(b(c(z<>))))", "+a/b/c/z"},
+		{"(a<> b<> c<>)", "(a<> b<> c<> z<>)", "+z"},
+		{"(a(b<> c<> d<>))", "(a(b<> c<> d<> z<>))", "+a/z"},
+		{"(a(b(c<> d<> e<>)))", "(a(b(c<> d<> e<> z<>)))", "+a/b/z"},
+		{"(a(b<>) f<>)", "(a(b<>) f<> z<>)", "+z"},
+		{"(a(b<>) f<>)", "(a(b<> z<>) f<>)", "+a/z"},
+	})
+}
+
+func (s *DiffTreeSuite) TestDebug(c *C) {
+	do(c, []diffTreeTest{
+		{"(a(b<>) f<>)", "(a(b<> z<>) f<>)", "+a/z"},
+	})
+}
+
+//      root
+//      / | \
+//     /  |  ----
+//    f   d      h --------
+//   /\         /  \      |
+//  e   a      j   b/      g
+//  |  / \     |
+//  l  n  k    icm
+//     |
+//     o
+//     |
+//     p/
+func (s *DiffTreeSuite) TestCrazy(c *C) {
+	crazy := "(f(e(l<1>) a(n(o(p())) k<1>)) d<1> h(j(i<1> c<2> m<>) b() g<>))"
+	do(c, []diffTreeTest{
+		{
+			crazy,
+			"()",
+			"-d -f/e/l -f/a/k -h/j/i -h/j/c -h/j/m -h/g",
+		}, {
+			crazy,
+			crazy,
+			"",
+		}, {
+			crazy,
+			"(d<1>)",
+			"-f/e/l -f/a/k -h/j/i -h/j/c -h/j/m -h/g",
+		}, {
+			crazy,
+			"(d<1> h(b() g<>))",
+			"-f/e/l -f/a/k -h/j/i -h/j/c -h/j/m",
+		}, {
+			crazy,
+			"(d<1> f(e(l()) a()) h(b() g<>))",
+			"-f/e/l -f/a/k -h/j/i -h/j/c -h/j/m",
+		}, {
+			crazy,
+			"(d<1> f(e(l<1>) a()) h(b() g<>))",
+			"-f/a/k -h/j/i -h/j/c -h/j/m",
+		}, {
+			crazy,
+			"(d<2> f(e(l<2>) a(s(t<1>))) h(b() g<> r<> j(i<> c<3> m<>)))",
+			"+f/a/s/t +h/r -f/a/k *d *f/e/l *h/j/c *h/j/i",
+		}, {
+			crazy,
+			"(f(e(l<2>) a(n(o(p<1>)) k<>)) h(j(i<1> c<2> m<>) b() g<>))",
+			"*f/e/l +f/a/n/o/p *f/a/k -d",
+		}, {
+			crazy,
+			"(f(e(l<1>) a(n(o(p(r<1>))) k<1>)) d<1> h(j(i<1> c<2> b() m<>) g<1>))",
+			"+f/a/n/o/p/r *h/g",
+		},
+	})
+}
+
+func (s *DiffTreeSuite) TestSameNames(c *C) {
+	do(c, []diffTreeTest{
+		{
+			"(a(a(a<>)))",
+			"(a(a(a<1>)))",
+			"*a/a/a",
+		}, {
+			"(a(b(a<>)))",
+			"(a(b(a<>)) b(a<>))",
+			"+b/a",
+		}, {
+			"(a(b(a<>)))",
+			"(a(b()) b(a<>))",
+			"-a/b/a +b/a",
+		},
+	})
+}