func (c *ConsulClient) GASNewSecLabelID(basePath string, baseID uint32, secCtxLabels *labels.SecCtxLabel) error {
setID2Label := func(lockPair *consulAPI.KVPair) error {
defer c.KV().Release(lockPair, nil)
secCtxLabels.ID = baseID
keyPath := path.Join(basePath, strconv.FormatUint(uint64(secCtxLabels.ID), 10))
if err := c.SetValue(keyPath, secCtxLabels); err != nil {
return err
}
return c.setMaxLabelID(baseID + 1)
}
session, _, err := c.Session().CreateNoChecks(nil, nil)
if err != nil {
return err
}
beginning := baseID
for {
log.Debugf("Trying to acquire a new free ID %d", baseID)
keyPath := path.Join(basePath, strconv.FormatUint(uint64(baseID), 10))
lockPair := &consulAPI.KVPair{Key: GetLockPath(keyPath), Session: session}
acq, _, err := c.KV().Acquire(lockPair, nil)
if err != nil {
return err
}
if acq {
lblKey, _, err := c.KV().Get(keyPath, nil)
if err != nil {
c.KV().Release(lockPair, nil)
return err
}
if lblKey == nil {
return setID2Label(lockPair)
}
var consulLabels labels.SecCtxLabel
if err := json.Unmarshal(lblKey.Value, &consulLabels); err != nil {
c.KV().Release(lockPair, nil)
return err
}
if consulLabels.RefCount() == 0 {
log.Infof("Recycling ID %d", baseID)
return setID2Label(lockPair)
}
c.KV().Release(lockPair, nil)
}
baseID++
if baseID > common.MaxSetOfLabels {
baseID = common.FirstFreeLabelID
}
if beginning == baseID {
return fmt.Errorf("reached maximum set of labels available.")
}
}
}
// GASNewSecLabelID gets the next available LabelID and sets it in secCtxLabels. After
// assigning the LabelID to secCtxLabels it sets the LabelID + 1 in
// common.LastFreeLabelIDKeyPath path.
func (e *EtcdClient) GASNewSecLabelID(basePath string, baseID uint32, secCtxLabels *labels.SecCtxLabel) error {
setID2Label := func(id uint32) error {
secCtxLabels.ID = id
keyPath := path.Join(basePath, strconv.FormatUint(uint64(secCtxLabels.ID), 10))
if err := e.SetValue(keyPath, secCtxLabels); err != nil {
return err
}
return e.setMaxLabelID(id + 1)
}
acquireFreeID := func(firstID uint32, incID *uint32) (bool, error) {
log.Debugf("Trying to acquire a new free ID %d", *incID)
keyPath := path.Join(basePath, strconv.FormatUint(uint64(*incID), 10))
locker, err := e.LockPath(GetLockPath(keyPath))
if err != nil {
return false, err
}
defer locker.Unlock()
value, err := e.GetValue(keyPath)
if err != nil {
return false, err
}
if value == nil {
return false, setID2Label(*incID)
}
var consulLabels labels.SecCtxLabel
if err := json.Unmarshal(value, &consulLabels); err != nil {
return false, err
}
if consulLabels.RefCount() == 0 {
log.Infof("Recycling ID %d", *incID)
return false, setID2Label(*incID)
}
*incID++
if *incID > common.MaxSetOfLabels {
*incID = common.FirstFreeLabelID
}
if firstID == *incID {
return false, fmt.Errorf("reached maximum set of labels available.")
}
return true, nil
}
beginning := baseID
for {
retry, err := acquireFreeID(beginning, &baseID)
if err != nil {
return err
} else if !retry {
return nil
}
}
}