// decodeList decodes a list of values into a list of objects, with resource version set to corresponding rev.
// On success, ListPtr would be set to the list of objects.
func decodeList(elems []*elemForDecode, filter storage.Filter, ListPtr interface{}, codec runtime.Codec, versioner storage.Versioner) error {
v, err := conversion.EnforcePtr(ListPtr)
if err != nil || v.Kind() != reflect.Slice {
panic("need ptr to slice")
}
for _, elem := range elems {
obj, _, err := codec.Decode(elem.data, nil, reflect.New(v.Type().Elem()).Interface().(runtime.Object))
if err != nil {
return err
}
// being unable to set the version does not prevent the object from being extracted
versioner.UpdateObject(obj, elem.rev)
if filter.Filter(obj) {
v.Set(reflect.Append(v, reflect.ValueOf(obj).Elem()))
}
}
return nil
}
// decodeNodeList walks the tree of each node in the list and decodes into the specified object
func (h *etcdHelper) decodeNodeList(nodes []*etcd.Node, filter storage.Filter, slicePtr interface{}) error {
trace := util.NewTrace("decodeNodeList " + getTypeName(slicePtr))
defer trace.LogIfLong(400 * time.Millisecond)
v, err := conversion.EnforcePtr(slicePtr)
if err != nil || v.Kind() != reflect.Slice {
// This should not happen at runtime.
panic("need ptr to slice")
}
for _, node := range nodes {
if node.Dir {
trace.Step("Decoding dir " + node.Key + " START")
if err := h.decodeNodeList(node.Nodes, filter, slicePtr); err != nil {
return err
}
trace.Step("Decoding dir " + node.Key + " END")
continue
}
if obj, found := h.getFromCache(node.ModifiedIndex, filter); found {
// obj != nil iff it matches the filter function.
if obj != nil {
v.Set(reflect.Append(v, reflect.ValueOf(obj).Elem()))
}
} else {
obj, _, err := h.codec.Decode([]byte(node.Value), nil, reflect.New(v.Type().Elem()).Interface().(runtime.Object))
if err != nil {
return err
}
// being unable to set the version does not prevent the object from being extracted
_ = h.versioner.UpdateObject(obj, node.ModifiedIndex)
if filter.Filter(obj) {
v.Set(reflect.Append(v, reflect.ValueOf(obj).Elem()))
}
if node.ModifiedIndex != 0 {
h.addToCache(node.ModifiedIndex, obj)
}
}
}
trace.Step(fmt.Sprintf("Decoded %v nodes", len(nodes)))
return nil
}
func (h *etcdHelper) getFromCache(index uint64, filter storage.Filter) (runtime.Object, bool) {
startTime := time.Now()
defer func() {
metrics.ObserveGetCache(startTime)
}()
obj, found := h.cache.Get(index)
if found {
if !filter.Filter(obj.(runtime.Object)) {
return nil, true
}
// We should not return the object itself to avoid polluting the cache if someone
// modifies returned values.
objCopy, err := h.copier.Copy(obj.(runtime.Object))
if err != nil {
glog.Errorf("Error during DeepCopy of cached object: %q", err)
// We can't return a copy, thus we report the object as not found.
return nil, false
}
metrics.ObserveCacheHit()
return objCopy.(runtime.Object), true
}
metrics.ObserveCacheMiss()
return nil, false
}