package storage import ( "bytes" "code.laria.me/petrific/config" "code.laria.me/petrific/logging" "code.laria.me/petrific/objects" "errors" "fmt" "io" "time" ) var ( ObjectNotFound = errors.New("Object not found") ) type StorageSubcmd func(args []string, log *logging.Log, conf config.Config) int type Storage interface { Get(id objects.ObjectId) ([]byte, error) Has(id objects.ObjectId) (bool, error) Set(id objects.ObjectId, typ objects.ObjectType, raw []byte) error List(typ objects.ObjectType) ([]objects.ObjectId, error) Subcmds() map[string]StorageSubcmd Close() error } type CreateStorageFromConfig func(conf config.Config, name string) (Storage, error) func SetObject(s Storage, o objects.RawObject) (id objects.ObjectId, err error) { buf := new(bytes.Buffer) id, err = o.SerializeAndId(buf, objects.OIdAlgoDefault) if err != nil { return } ok, err := s.Has(id) if err != nil { return } if !ok { err = s.Set(id, o.Type, buf.Bytes()) } return } type IdMismatchErr struct { Want, Have objects.ObjectId } func (iderr IdMismatchErr) Error() string { return fmt.Sprintf("ID verification failed: want %s, have %s", iderr.Want, iderr.Have) } // GetObjects gets an object from a Storage and parses and verifies it (check it's checksum/id) func GetObject(s Storage, id objects.ObjectId) (objects.RawObject, error) { raw, err := s.Get(id) if err != nil { return objects.RawObject{}, err } idgen := id.Algo.Generator() r := io.TeeReader(bytes.NewReader(raw), idgen) obj, err := objects.Unserialize(r) if err != nil { return objects.RawObject{}, err } if have_id := idgen.GetId(); !have_id.Equals(id) { return objects.RawObject{}, IdMismatchErr{id, have_id} } return obj, nil } func GetObjectOfType(s Storage, id objects.ObjectId, t objects.ObjectType) (objects.Object, error) { rawobj, err := GetObject(s, id) if err != nil { return nil, err } if rawobj.Type != t { return nil, fmt.Errorf("GetObjectOfType: Wrong object type %s (want %s)", rawobj.Type, t) } return rawobj.Object() } // FindLatestSnapshot finds the latest snapshot, optionally filtered by archive func FindLatestSnapshot(store Storage, archive string) (latestSnapshot *objects.Snapshot, err error) { ids, err := store.List(objects.OTSnapshot) if err != nil { return nil, err } var earliestTime time.Time found := false for _, id := range ids { _snapshot, err := GetObjectOfType(store, id, objects.OTSnapshot) if err != nil { return nil, err } snapshot := _snapshot.(*objects.Snapshot) if archive != "" && snapshot.Archive != archive { continue } if snapshot.Date.After(earliestTime) { earliestTime = snapshot.Date latestSnapshot = snapshot found = true } } if !found { return latestSnapshot, ObjectNotFound } return latestSnapshot, nil }