zfs + replication: migrate dead zfs/diff_test.go to replication/logic/diff

(and remove the dead code from package zfs)

replication/logic/diff/diff.go

@@ -1,4 +1,4 @@
-package mainfsm
+package diff
 
 import (
 	"sort"

replication/logic/diff/diff_test.go

@@ -0,0 +1,122 @@
+package diff
+
+import (
+	"strconv"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	. "github.com/zrepl/zrepl/replication/logic/pdu"
+)
+
+func fsvlist(fsv ...string) (r []*FilesystemVersion) {
+
+	r = make([]*FilesystemVersion, len(fsv))
+	for i, f := range fsv {
+
+		// parse the id from fsvlist. it is used to derivce Guid,CreateTXG and Creation attrs
+		split := strings.Split(f, ",")
+		if len(split) != 2 {
+			panic("invalid fsv spec")
+		}
+		id, err := strconv.Atoi(split[1])
+		if err != nil {
+			panic(err)
+		}
+		creation := func(id int) string {
+			return FilesystemVersionCreation(time.Unix(0, 0).Add(time.Duration(id) * time.Second))
+		}
+		if strings.HasPrefix(f, "#") {
+			r[i] = &FilesystemVersion{
+				Name:      strings.TrimPrefix(f, "#"),
+				Type:      FilesystemVersion_Bookmark,
+				Guid:      uint64(id),
+				CreateTXG: uint64(id),
+				Creation:  creation(id),
+			}
+		} else if strings.HasPrefix(f, "@") {
+			r[i] = &FilesystemVersion{
+				Name:      strings.TrimPrefix(f, "@"),
+				Type:      FilesystemVersion_Snapshot,
+				Guid:      uint64(id),
+				CreateTXG: uint64(id),
+				Creation:  creation(id),
+			}
+		} else {
+			panic("invalid character")
+		}
+	}
+	return
+}
+
+func doTest(receiver, sender []*FilesystemVersion, validate func(incpath []*FilesystemVersion, conflict error)) {
+	p, err := IncrementalPath(receiver, sender)
+	validate(p, err)
+}
+
+func TestIncrementalPath_SnapshotsOnly(t *testing.T) {
+
+	l := fsvlist
+
+	// basic functionality
+	doTest(l("@a,1", "@b,2"), l("@a,1", "@b,2", "@c,3", "@d,4"), func(path []*FilesystemVersion, conflict error) {
+		assert.Equal(t, l("@b,2", "@c,3", "@d,4"), path)
+	})
+
+	// no common ancestor
+	doTest(l(), l("@a,1"), func(path []*FilesystemVersion, conflict error) {
+		assert.Nil(t, path)
+		ca, ok := conflict.(*ConflictNoCommonAncestor)
+		require.True(t, ok)
+		assert.Equal(t, l("@a,1"), ca.SortedSenderVersions)
+	})
+	doTest(l("@a,1", "@b,2"), l("@c,3", "@d,4"), func(path []*FilesystemVersion, conflict error) {
+		assert.Nil(t, path)
+		ca, ok := conflict.(*ConflictNoCommonAncestor)
+		require.True(t, ok)
+		assert.Equal(t, l("@a,1", "@b,2"), ca.SortedReceiverVersions)
+		assert.Equal(t, l("@c,3", "@d,4"), ca.SortedSenderVersions)
+	})
+
+	// divergence is detected
+	doTest(l("@a,1", "@b1,2"), l("@a,1", "@b2,3"), func(path []*FilesystemVersion, conflict error) {
+		assert.Nil(t, path)
+		cd, ok := conflict.(*ConflictDiverged)
+		require.True(t, ok)
+		assert.Equal(t, l("@a,1")[0], cd.CommonAncestor)
+		assert.Equal(t, l("@b1,2"), cd.ReceiverOnly)
+		assert.Equal(t, l("@b2,3"), cd.SenderOnly)
+	})
+
+	// gaps before most recent common ancestor do not matter
+	doTest(l("@a,1", "@b,2", "@c,3"), l("@a,1", "@c,3", "@d,4"), func(path []*FilesystemVersion, conflict error) {
+		assert.Equal(t, l("@c,3", "@d,4"), path)
+	})
+
+}
+
+func TestIncrementalPath_BookmarkSupport(t *testing.T) {
+	l := fsvlist
+
+	// bookmarks are used
+	doTest(l("@a,1"), l("#a,1", "@b,2"), func(path []*FilesystemVersion, conflict error) {
+		assert.Equal(t, l("#a,1", "@b,2"), path)
+	})
+
+	// boomarks are stripped from IncrementalPath (cannot send incrementally)
+	doTest(l("@a,1"), l("#a,1", "#b,2", "@c,3"), func(path []*FilesystemVersion, conflict error) {
+		assert.Equal(t, l("#a,1", "@c,3"), path)
+	})
+
+	// test that snapshots are preferred over bookmarks in IncrementalPath
+	doTest(l("@a,1"), l("#a,1", "@a,1", "@b,2"), func(path []*FilesystemVersion, conflict error) {
+		assert.Equal(t, l("@a,1", "@b,2"), path)
+	})
+	doTest(l("@a,1"), l("@a,1", "#a,1", "@b,2"), func(path []*FilesystemVersion, conflict error) {
+		assert.Equal(t, l("@a,1", "@b,2"), path)
+	})
+
+}