Start of snapshot work.

debian/snapshot.go

@@ -0,0 +1,52 @@
+package debian
+
+import (
+	"code.google.com/p/go-uuid/uuid"
+	"fmt"
+	"time"
+)
+
+// Snapshot is immutable state of repository: list of packages
+type Snapshot struct {
+	// Persisten internal ID
+	UUID string
+	// Human-readable name
+	Name string
+	// Date of creation
+	CreatedAt time.Time
+
+	// Source: kind + ID
+	SourceKind string
+	SourceIDs  []string
+	// Description of how snapshot was created
+	Description string
+
+	packageRefs *PackageRefList
+}
+
+// NewSnapshotFromRepository creates snapshot from current state of repository
+func NewSnapshotFromRepository(name string, repo *RemoteRepo) *Snapshot {
+	if repo.packageRefs == nil {
+		panic("repo.packageRefs == nil")
+	}
+
+	return &Snapshot{
+		UUID:        uuid.New(),
+		Name:        name,
+		CreatedAt:   time.Now(),
+		SourceKind:  "repo",
+		SourceIDs:   []string{repo.UUID},
+		Description: fmt.Sprintf("Snapshot from mirror %s", repo),
+		packageRefs: repo.packageRefs,
+	}
+}
+
+// NumPackages returns number of packages in snapshot
+func (s *Snapshot) NumPackages() int {
+	return s.packageRefs.Len()
+}
+
+// Key is a unique id in DB
+func (s *Snapshot) Key() []byte {
+	return []byte("S" + s.UUID)
+}

debian/snapshot_test.go

@@ -0,0 +1,33 @@
+package debian
+
+import (
+	. "launchpad.net/gocheck"
+)
+
+type SnapshotSuite struct {
+	PackageListMixinSuite
+	repo *RemoteRepo
+}
+
+var _ = Suite(&SnapshotSuite{})
+
+func (s *SnapshotSuite) SetUpTest(c *C) {
+	s.SetUpPackages()
+	s.repo, _ = NewRemoteRepo("yandex", "http://mirror.yandex.ru/debian/", "squeeze", []string{"main"}, []string{})
+	s.repo.packageRefs = s.reflist
+}
+
+func (s *SnapshotSuite) TestNewSnapshotFromRepository(c *C) {
+	snapshot := NewSnapshotFromRepository("snap1", s.repo)
+	c.Check(snapshot.Name, Equals, "snap1")
+	c.Check(snapshot.NumPackages(), Equals, 3)
+
+	s.repo.packageRefs = nil
+	c.Check(func() { NewSnapshotFromRepository("snap2", s.repo) }, PanicMatches, "repo.packageRefs == nil")
+}
+
+func (s *SnapshotSuite) TestKey(c *C) {
+	snapshot := NewSnapshotFromRepository("snap1", s.repo)
+	c.Assert(len(snapshot.Key()), Equals, 37)
+	c.Assert(snapshot.Key()[0], Equals, byte('S'))
+}