func (ts *Source) refreshToken() error {
log.Debugf("refreshing the token from %q", refreshURL)
data, err := json.Marshal(ts.token)
if err != nil {
log.Errorf("%s: %s", constants.ErrJSONEncoding, err)
return constants.ErrJSONEncoding
}
req, err := http.NewRequest("POST", refreshURL, bytes.NewBuffer(data))
if err != nil {
log.Errorf("%s: %s", constants.ErrCreatingHTTPRequest, err)
return constants.ErrCreatingHTTPRequest
}
req.Header.Set("Content-Type", "application/json")
res, err := (&http.Client{}).Do(req)
if err != nil {
log.Errorf("%s: %s", constants.ErrDoingHTTPRequest, err)
return constants.ErrDoingHTTPRequest
}
defer res.Body.Close()
if err := json.NewDecoder(res.Body).Decode(ts.token); err != nil {
log.Errorf("%s: %s", constants.ErrJSONDecodingResponseBody, err)
return constants.ErrJSONDecodingResponseBody
}
log.Debug("token was refreshed successfully")
return nil
}
// Sync syncs the tree with the server.
func (nt *Tree) Sync() error {
postURL := nt.client.GetMetadataURL("changes")
c := &changes{
Checkpoint: nt.Checkpoint,
}
jsonBytes, err := json.Marshal(c)
if err != nil {
log.Errorf("%s: %s", constants.ErrJSONEncoding, err)
return constants.ErrJSONEncoding
}
req, err := http.NewRequest("POST", postURL, bytes.NewBuffer(jsonBytes))
if err != nil {
log.Errorf("%s: %s", constants.ErrCreatingHTTPRequest, err)
return constants.ErrCreatingHTTPRequest
}
req.Header.Set("Content-Type", "application/json")
res, err := nt.client.Do(req)
if err != nil {
log.Errorf("%s: %s", constants.ErrDoingHTTPRequest, err)
return constants.ErrDoingHTTPRequest
}
if err := nt.client.CheckResponse(res); err != nil {
return err
}
// return format should be:
// {"checkpoint": str, "reset": bool, "nodes": []}
// {"checkpoint": str, "reset": false, "nodes": []}
// {"end": true}
defer res.Body.Close()
bodyBytes, err := ioutil.ReadAll(res.Body)
if err != nil {
log.Errorf("%s: %s", constants.ErrReadingResponseBody, err)
return constants.ErrReadingResponseBody
}
for _, lineBytes := range bytes.Split(bodyBytes, []byte("\n")) {
var cr changesResponse
if err := json.Unmarshal(lineBytes, &cr); err != nil {
log.Errorf("%s: %s", constants.ErrJSONDecodingResponseBody, err)
return constants.ErrJSONDecodingResponseBody
}
if cr.Checkpoint != "" {
log.Debugf("changes returned Checkpoint: %s", cr.Checkpoint)
nt.Checkpoint = cr.Checkpoint
}
if cr.Reset {
log.Debug("reset is required")
return constants.ErrMustFetchFresh
}
if cr.End {
break
}
if err := nt.updateNodes(cr.Nodes); err != nil {
return err
}
}
return nil
}
// Token returns an oauth2.Token. If the cached token (in (*Source).path) has
// expired, it will fetch the token from the server and cache it before
// returning it.
func (ts *Source) Token() (*oauth2.Token, error) {
if !ts.token.Valid() {
log.Debug("token is not valid, it has probably expired")
if err := ts.refreshToken(); err != nil {
return nil, err
}
if err := ts.saveToken(); err != nil {
return nil, err
}
}
return ts.token, nil
}
func (ts *Source) saveToken() error {
log.Debugf("saving the token to %s", ts.path)
f, err := os.Create(ts.path)
if err != nil {
log.Errorf("%s: %s", constants.ErrCreateFile, ts.path)
return constants.ErrCreateFile
}
if err := json.NewEncoder(f).Encode(ts.token); err != nil {
log.Errorf("%s: %s", constants.ErrJSONEncoding, err)
return constants.ErrJSONEncoding
}
log.Debug("token saved successfully")
return nil
}
func (ts *Source) readToken() error {
log.Debugf("reading the token from %s", ts.path)
f, err := os.Open(ts.path)
if err != nil {
log.Errorf("%s: %s", constants.ErrOpenFile, ts.path)
return constants.ErrOpenFile
}
if err := json.NewDecoder(f).Decode(ts.token); err != nil {
log.Errorf("%s: %s", constants.ErrJSONDecoding, err)
return constants.ErrJSONDecoding
}
log.Debug("token loaded successfully")
return nil
}
func (nt *Tree) loadOrFetch() error {
var err error
if err = nt.loadCache(); err != nil {
log.Debug(err)
if err = nt.fetchFresh(); err != nil {
return err
}
}
if err = nt.Sync(); err != nil {
switch err {
case constants.ErrMustFetchFresh:
if err = nt.fetchFresh(); err != nil {
return err
}
return nt.Sync()
default:
return err
}
}
return nil
}