Golang State.Get方法代码示例

// NewUser tracks a new authenticated user and saves its details in the state
func NewUser(st *state.State, username, macaroon string, discharges []string) (*UserState, error) {
	var authStateData AuthState

	err := st.Get("auth", &authStateData)
	if err == state.ErrNoState {
		authStateData = AuthState{}
	} else if err != nil {
		return nil, err
	}

	sort.Strings(discharges)
	authStateData.LastID++
	authenticatedUser := UserState{
		ID:              authStateData.LastID,
		Username:        username,
		Macaroon:        macaroon,
		Discharges:      discharges,
		StoreMacaroon:   macaroon,
		StoreDischarges: discharges,
	}
	authStateData.Users = append(authStateData.Users, authenticatedUser)

	st.Set("auth", authStateData)

	return &authenticatedUser, nil
}

// CheckMacaroon returns the UserState for the given macaroon/discharges credentials
func CheckMacaroon(st *state.State, macaroon string, discharges []string) (*UserState, error) {
	var authStateData AuthState
	err := st.Get("auth", &authStateData)
	if err != nil {
		return nil, ErrInvalidAuth
	}

NextUser:
	for _, user := range authStateData.Users {
		if user.Macaroon != macaroon {
			continue
		}
		if len(user.Discharges) != len(discharges) {
			continue
		}
		// sort discharges (stored users' discharges are already sorted)
		sort.Strings(discharges)
		for i, d := range user.Discharges {
			if d != discharges[i] {
				continue NextUser
			}
		}
		return &user, nil
	}
	return nil, ErrInvalidAuth
}

func getConns(st *state.State) (map[string]connState, error) {
	// Get information about connections from the state
	var conns map[string]connState
	err := st.Get("conns", &conns)
	if err != nil && err != state.ErrNoState {
		return nil, fmt.Errorf("cannot obtain data about existing connections: %s", err)
	}
	if conns == nil {
		conns = make(map[string]connState)
	}
	return conns, nil
}

// User returns a user from the state given its ID
func User(st *state.State, id int) (*UserState, error) {
	var authStateData AuthState

	err := st.Get("auth", &authStateData)
	if err != nil {
		return nil, err
	}

	for _, user := range authStateData.Users {
		if user.ID == id {
			return &user, nil
		}
	}
	return nil, fmt.Errorf("invalid user")
}

// All retrieves return a map from name to SnapState for all current snaps in the system state.
func All(s *state.State) (map[string]*SnapState, error) {
	// XXX: result is a map because sideloaded snaps carry no name
	// atm in their sideinfos
	var stateMap map[string]*SnapState
	if err := s.Get("snaps", &stateMap); err != nil && err != state.ErrNoState {
		return nil, err
	}
	curStates := make(map[string]*SnapState, len(stateMap))
	for snapName, snapState := range stateMap {
		if snapState.Current() != nil {
			curStates[snapName] = snapState
		}
	}
	return curStates, nil
}

// Get retrieves the SnapState of the given snap.
func Get(s *state.State, name string, snapst *SnapState) error {
	var snaps map[string]*json.RawMessage
	err := s.Get("snaps", &snaps)
	if err != nil {
		return err
	}
	raw, ok := snaps[name]
	if !ok {
		return state.ErrNoState
	}
	err = json.Unmarshal([]byte(*raw), &snapst)
	if err != nil {
		return fmt.Errorf("cannot unmarshal snap state: %v", err)
	}
	return nil
}

// ActiveInfos returns information about all active snaps.
func ActiveInfos(s *state.State) ([]*snap.Info, error) {
	var stateMap map[string]*SnapState
	var infos []*snap.Info
	if err := s.Get("snaps", &stateMap); err != nil && err != state.ErrNoState {
		return nil, err
	}
	for snapName, snapState := range stateMap {
		if !snapState.Active {
			continue
		}
		snapInfo, err := readInfo(snapName, snapState.Current())
		if err != nil {
			logger.Noticef("cannot retrieve info for snap %q: %s", snapName, err)
			continue
		}
		infos = append(infos, snapInfo)
	}
	return infos, nil
}

// Set sets the SnapState of the given snap, overwriting any earlier state.
func Set(s *state.State, name string, snapst *SnapState) {
	var snaps map[string]*json.RawMessage
	err := s.Get("snaps", &snaps)
	if err != nil && err != state.ErrNoState {
		panic("internal error: cannot unmarshal snaps state: " + err.Error())
	}
	if snaps == nil {
		snaps = make(map[string]*json.RawMessage)
	}
	if snapst == nil || (len(snapst.Sequence) == 0 && snapst.Candidate == nil) {
		delete(snaps, name)
	} else {
		data, err := json.Marshal(snapst)
		if err != nil {
			panic("internal error: cannot marshal snap state: " + err.Error())
		}
		raw := json.RawMessage(data)
		snaps[name] = &raw
	}
	s.Set("snaps", snaps)
}

// RemoveUser removes a user from the state given its ID
func RemoveUser(st *state.State, userID int) error {
	var authStateData AuthState

	err := st.Get("auth", &authStateData)
	if err != nil {
		return err
	}

	for i := range authStateData.Users {
		if authStateData.Users[i].ID == userID {
			// delete without preserving order
			n := len(authStateData.Users) - 1
			authStateData.Users[i] = authStateData.Users[n]
			authStateData.Users[n] = UserState{}
			authStateData.Users = authStateData.Users[:n]
			st.Set("auth", authStateData)
			return nil
		}
	}

	return fmt.Errorf("invalid user")
}