// Implements storage.Interface.
func (h *etcdHelper) GuaranteedUpdate(ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool, tryUpdate storage.UpdateFunc) error {
if ctx == nil {
glog.Errorf("Context is nil")
}
v, err := conversion.EnforcePtr(ptrToType)
if err != nil {
// Panic is appropriate, because this is a programming error.
panic("need ptr to type")
}
key = h.prefixEtcdKey(key)
for {
obj := reflect.New(v.Type()).Interface().(runtime.Object)
origBody, node, res, err := h.bodyAndExtractObj(ctx, key, obj, ignoreNotFound)
if err != nil {
return err
}
meta := storage.ResponseMeta{}
if node != nil {
meta.TTL = node.TTL
if node.Expiration != nil {
meta.Expiration = node.Expiration
}
meta.ResourceVersion = node.ModifiedIndex
}
// Get the object to be written by calling tryUpdate.
ret, newTTL, err := tryUpdate(obj, meta)
if err != nil {
return err
}
index := uint64(0)
ttl := uint64(0)
if node != nil {
index = node.ModifiedIndex
if node.TTL != 0 {
ttl = uint64(node.TTL)
}
if node.Expiration != nil && ttl == 0 {
ttl = 1
}
} else if res != nil {
index = res.Index
}
if newTTL != nil {
if ttl != 0 && *newTTL == 0 {
// TODO: remove this after we have verified this is no longer an issue
glog.V(4).Infof("GuaranteedUpdate is clearing TTL for %q, may not be intentional", key)
}
ttl = *newTTL
}
// Since update object may have a resourceVersion set, we need to clear it here.
if err := h.versioner.UpdateObject(ret, meta.Expiration, 0); err != nil {
return errors.New("resourceVersion cannot be set on objects store in etcd")
}
data, err := runtime.Encode(h.codec, ret)
if err != nil {
return err
}
// First time this key has been used, try creating new value.
if index == 0 {
startTime := time.Now()
opts := etcd.SetOptions{
TTL: time.Duration(ttl) * time.Second,
PrevExist: etcd.PrevNoExist,
}
response, err := h.etcdKeysAPI.Set(ctx, key, string(data), &opts)
metrics.RecordEtcdRequestLatency("create", getTypeName(ptrToType), startTime)
if etcdutil.IsEtcdNodeExist(err) {
continue
}
_, _, err = h.extractObj(response, err, ptrToType, false, false)
return err
}
if string(data) == origBody {
// If we don't send an update, we simply return the currently existing
// version of the object.
_, _, err := h.extractObj(res, nil, ptrToType, ignoreNotFound, false)
return err
}
startTime := time.Now()
// Swap origBody with data, if origBody is the latest etcd data.
opts := etcd.SetOptions{
PrevValue: origBody,
PrevIndex: index,
TTL: time.Duration(ttl) * time.Second,
}
response, err := h.etcdKeysAPI.Set(ctx, key, string(data), &opts)
metrics.RecordEtcdRequestLatency("compareAndSwap", getTypeName(ptrToType), startTime)
if etcdutil.IsEtcdTestFailed(err) {
// Try again.
continue
}
_, _, err = h.extractObj(response, err, ptrToType, false, false)
return err
}
}
// Implements storage.Interface.
func (h *etcdHelper) GuaranteedUpdate(ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool, tryUpdate storage.UpdateFunc) error {
if ctx == nil {
glog.Errorf("Context is nil")
}
v, err := conversion.EnforcePtr(ptrToType)
if err != nil {
// Panic is appropriate, because this is a programming error.
panic("need ptr to type")
}
key = h.prefixEtcdKey(key)
for {
obj := reflect.New(v.Type()).Interface().(runtime.Object)
origBody, node, res, err := h.bodyAndExtractObj(ctx, key, obj, ignoreNotFound)
if err != nil {
return err
}
meta := storage.ResponseMeta{}
if node != nil {
meta.TTL = node.TTL
if node.Expiration != nil {
meta.Expiration = node.Expiration
}
meta.ResourceVersion = node.ModifiedIndex
}
// Get the object to be written by calling tryUpdate.
ret, newTTL, err := tryUpdate(obj, meta)
if err != nil {
return err
}
index := uint64(0)
ttl := uint64(0)
if node != nil {
index = node.ModifiedIndex
if node.TTL != 0 {
ttl = uint64(node.TTL)
}
if node.Expiration != nil && ttl == 0 {
ttl = 1
}
} else if res != nil {
index = res.EtcdIndex
}
if newTTL != nil {
if ttl != 0 && *newTTL == 0 {
// TODO: remove this after we have verified this is no longer an issue
glog.V(4).Infof("GuaranteedUpdate is clearing TTL for %q, may not be intentional", key)
}
ttl = *newTTL
}
data, err := h.codec.Encode(ret)
if err != nil {
return err
}
// First time this key has been used, try creating new value.
if index == 0 {
startTime := time.Now()
response, err := h.client.Create(key, string(data), ttl)
metrics.RecordEtcdRequestLatency("create", getTypeName(ptrToType), startTime)
if IsEtcdNodeExist(err) {
continue
}
_, _, err = h.extractObj(response, err, ptrToType, false, false)
return err
}
if string(data) == origBody {
return nil
}
startTime := time.Now()
// Swap origBody with data, if origBody is the latest etcd data.
response, err := h.client.CompareAndSwap(key, string(data), ttl, origBody, index)
metrics.RecordEtcdRequestLatency("compareAndSwap", getTypeName(ptrToType), startTime)
if IsEtcdTestFailed(err) {
// Try again.
continue
}
_, _, err = h.extractObj(response, err, ptrToType, false, false)
return err
}
}