// ExtractList returns obj's Items element as an array of runtime.Objects.
// Returns an error if obj is not a List type (does not have an Items member).
func ExtractList(obj runtime.Object) ([]runtime.Object, error) {
itemsPtr, err := GetItemsPtr(obj)
if err != nil {
return nil, err
}
items, err := conversion.EnforcePtr(itemsPtr)
if err != nil {
return nil, err
}
list := make([]runtime.Object, items.Len())
for i := range list {
raw := items.Index(i)
switch item := raw.Interface().(type) {
case runtime.RawExtension:
switch {
case item.Object != nil:
list[i] = item.Object
case item.Raw != nil:
// TODO: Set ContentEncoding and ContentType correctly.
list[i] = &runtime.Unknown{Raw: item.Raw}
default:
list[i] = nil
}
case runtime.Object:
list[i] = item
default:
var found bool
if list[i], found = raw.Addr().Interface().(runtime.Object); !found {
return nil, fmt.Errorf("%v: item[%v]: Expected object, got %#v(%s)", obj, i, raw.Interface(), raw.Kind())
}
}
}
return list, nil
}
func (h *etcdHelper) extractObj(response *etcd.Response, inErr error, objPtr runtime.Object, ignoreNotFound, prevNode bool) (body string, node *etcd.Node, err error) {
if response != nil {
if prevNode {
node = response.PrevNode
} else {
node = response.Node
}
}
if inErr != nil || node == nil || len(node.Value) == 0 {
if ignoreNotFound {
v, err := conversion.EnforcePtr(objPtr)
if err != nil {
return "", nil, err
}
v.Set(reflect.Zero(v.Type()))
return "", nil, nil
} else if inErr != nil {
return "", nil, inErr
}
return "", nil, fmt.Errorf("unable to locate a value on the response: %#v", response)
}
body = node.Value
out, gvk, err := h.codec.Decode([]byte(body), nil, objPtr)
if err != nil {
return body, nil, err
}
if out != objPtr {
return body, nil, fmt.Errorf("unable to decode object %s into %v", gvk.String(), reflect.TypeOf(objPtr))
}
// being unable to set the version does not prevent the object from being extracted
_ = h.versioner.UpdateObject(objPtr, node.ModifiedIndex)
return body, node, err
}
// Implements storage.Interface.
func (c *Cacher) List(ctx context.Context, key string, resourceVersion string, pred SelectionPredicate, listObj runtime.Object) error {
if resourceVersion == "" {
// If resourceVersion is not specified, serve it from underlying
// storage (for backward compatibility).
return c.storage.List(ctx, key, resourceVersion, pred, listObj)
}
// If resourceVersion is specified, serve it from cache.
// It's guaranteed that the returned value is at least that
// fresh as the given resourceVersion.
listRV, err := ParseListResourceVersion(resourceVersion)
if err != nil {
return err
}
trace := util.NewTrace(fmt.Sprintf("cacher %v: List", c.objectType.String()))
defer trace.LogIfLong(500 * time.Millisecond)
c.ready.wait()
trace.Step("Ready")
// List elements with at least 'listRV' from cache.
listPtr, err := meta.GetItemsPtr(listObj)
if err != nil {
return err
}
listVal, err := conversion.EnforcePtr(listPtr)
if err != nil || listVal.Kind() != reflect.Slice {
return fmt.Errorf("need a pointer to slice, got %v", listVal.Kind())
}
filter := filterFunction(key, pred)
objs, readResourceVersion, err := c.watchCache.WaitUntilFreshAndList(listRV, trace)
if err != nil {
return err
}
trace.Step(fmt.Sprintf("Listed %d items from cache", len(objs)))
if len(objs) > listVal.Cap() && pred.Label.Empty() && pred.Field.Empty() {
// Resize the slice appropriately, since we already know that none
// of the elements will be filtered out.
listVal.Set(reflect.MakeSlice(reflect.SliceOf(c.objectType.Elem()), 0, len(objs)))
trace.Step("Resized result")
}
for _, obj := range objs {
elem, ok := obj.(*storeElement)
if !ok {
return fmt.Errorf("non *storeElement returned from storage: %v", obj)
}
if filter(elem.Key, elem.Object) {
listVal.Set(reflect.Append(listVal, reflect.ValueOf(elem.Object).Elem()))
}
}
trace.Step(fmt.Sprintf("Filtered %d items", listVal.Len()))
if c.versioner != nil {
if err := c.versioner.UpdateList(listObj, readResourceVersion); err != nil {
return err
}
}
return nil
}
// SetZeroValue would set the object of objPtr to zero value of its type.
func SetZeroValue(objPtr Object) error {
v, err := conversion.EnforcePtr(objPtr)
if err != nil {
return err
}
v.Set(reflect.Zero(v.Type()))
return nil
}
// ListMetaFor returns a pointer to a provided object's ListMeta,
// or an error if the object does not have that pointer.
// TODO: allow runtime.Unknown to extract this object
// TODO: Remove this function and use meta.ObjectMetaAccessor() instead.
func ListMetaFor(obj runtime.Object) (*ListMeta, error) {
v, err := conversion.EnforcePtr(obj)
if err != nil {
return nil, err
}
var meta *ListMeta
err = runtime.FieldPtr(v, "ListMeta", &meta)
return meta, err
}
// Implements storage.Interface.
func (h *etcdHelper) Delete(ctx context.Context, key string, out runtime.Object, preconditions *storage.Preconditions) error {
if ctx == nil {
glog.Errorf("Context is nil")
}
key = path.Join(h.pathPrefix, key)
v, err := conversion.EnforcePtr(out)
if err != nil {
panic("unable to convert output object to pointer")
}
if preconditions == nil {
startTime := time.Now()
response, err := h.etcdKeysAPI.Delete(ctx, key, nil)
metrics.RecordEtcdRequestLatency("delete", getTypeName(out), startTime)
if !etcdutil.IsEtcdNotFound(err) {
// if the object that existed prior to the delete is returned by etcd, update the out object.
if err != nil || response.PrevNode != nil {
_, _, err = h.extractObj(response, err, out, false, true)
}
}
return toStorageErr(err, key, 0)
}
// Check the preconditions match.
obj := reflect.New(v.Type()).Interface().(runtime.Object)
for {
_, node, res, err := h.bodyAndExtractObj(ctx, key, obj, false)
if err != nil {
return toStorageErr(err, key, 0)
}
if err := checkPreconditions(key, preconditions, obj); err != nil {
return toStorageErr(err, key, 0)
}
index := uint64(0)
if node != nil {
index = node.ModifiedIndex
} else if res != nil {
index = res.Index
}
opt := etcd.DeleteOptions{PrevIndex: index}
startTime := time.Now()
response, err := h.etcdKeysAPI.Delete(ctx, key, &opt)
metrics.RecordEtcdRequestLatency("delete", getTypeName(out), startTime)
if etcdutil.IsEtcdTestFailed(err) {
glog.Infof("deletion of %s failed because of a conflict, going to retry", key)
} else {
if !etcdutil.IsEtcdNotFound(err) {
// if the object that existed prior to the delete is returned by etcd, update the out object.
if err != nil || response.PrevNode != nil {
_, _, err = h.extractObj(response, err, out, false, true)
}
}
return toStorageErr(err, key, 0)
}
}
}
// Implements storage.Interface.
func (c *Cacher) GetToList(ctx context.Context, key string, resourceVersion string, pred SelectionPredicate, listObj runtime.Object) error {
if resourceVersion == "" {
// If resourceVersion is not specified, serve it from underlying
// storage (for backward compatibility).
return c.storage.GetToList(ctx, key, resourceVersion, pred, listObj)
}
// If resourceVersion is specified, serve it from cache.
// It's guaranteed that the returned value is at least that
// fresh as the given resourceVersion.
listRV, err := ParseListResourceVersion(resourceVersion)
if err != nil {
return err
}
trace := util.NewTrace(fmt.Sprintf("cacher %v: List", c.objectType.String()))
defer trace.LogIfLong(500 * time.Millisecond)
c.ready.wait()
trace.Step("Ready")
// List elements with at least 'listRV' from cache.
listPtr, err := meta.GetItemsPtr(listObj)
if err != nil {
return err
}
listVal, err := conversion.EnforcePtr(listPtr)
if err != nil || listVal.Kind() != reflect.Slice {
return fmt.Errorf("need a pointer to slice, got %v", listVal.Kind())
}
filter := filterFunction(key, pred)
obj, exists, readResourceVersion, err := c.watchCache.WaitUntilFreshAndGet(listRV, key, trace)
if err != nil {
return err
}
trace.Step("Got from cache")
if exists {
elem, ok := obj.(*storeElement)
if !ok {
return fmt.Errorf("non *storeElement returned from storage: %v", obj)
}
if filter(elem.Key, elem.Object) {
listVal.Set(reflect.Append(listVal, reflect.ValueOf(elem.Object).Elem()))
}
}
if c.versioner != nil {
if err := c.versioner.UpdateList(listObj, readResourceVersion); err != nil {
return err
}
}
return nil
}
// Delete implements storage.Interface.Delete.
func (s *store) Delete(ctx context.Context, key string, out runtime.Object, precondtions *storage.Preconditions) error {
v, err := conversion.EnforcePtr(out)
if err != nil {
panic("unable to convert output object to pointer")
}
key = path.Join(s.pathPrefix, key)
if precondtions == nil {
return s.unconditionalDelete(ctx, key, out)
}
return s.conditionalDelete(ctx, key, out, v, precondtions)
}
// decode decodes value of bytes into object. It will also set the object resource version to rev.
// On success, objPtr would be set to the object.
func decode(codec runtime.Codec, versioner storage.Versioner, value []byte, objPtr runtime.Object, rev int64) error {
if _, err := conversion.EnforcePtr(objPtr); err != nil {
panic("unable to convert output object to pointer")
}
_, _, err := codec.Decode(value, nil, objPtr)
if err != nil {
return err
}
// being unable to set the version does not prevent the object from being extracted
versioner.UpdateObject(objPtr, uint64(rev))
return nil
}
func (s *Scheme) IsUnversioned(obj Object) (bool, bool) {
v, err := conversion.EnforcePtr(obj)
if err != nil {
return false, false
}
t := v.Type()
if _, ok := s.typeToGVK[t]; !ok {
return false, false
}
_, ok := s.unversionedTypes[t]
return ok, true
}
// SetList sets the given list object's Items member have the elements given in
// objects.
// Returns an error if list is not a List type (does not have an Items member),
// or if any of the objects are not of the right type.
func SetList(list runtime.Object, objects []runtime.Object) error {
itemsPtr, err := GetItemsPtr(list)
if err != nil {
return err
}
items, err := conversion.EnforcePtr(itemsPtr)
if err != nil {
return err
}
if items.Type() == objectSliceType {
items.Set(reflect.ValueOf(objects))
return nil
}
slice := reflect.MakeSlice(items.Type(), len(objects), len(objects))
for i := range objects {
dest := slice.Index(i)
// check to see if you're directly assignable
if reflect.TypeOf(objects[i]).AssignableTo(dest.Type()) {
dest.Set(reflect.ValueOf(objects[i]))
continue
}
src, err := conversion.EnforcePtr(objects[i])
if err != nil {
return err
}
if src.Type().AssignableTo(dest.Type()) {
dest.Set(src)
} else if src.Type().ConvertibleTo(dest.Type()) {
dest.Set(src.Convert(dest.Type()))
} else {
return fmt.Errorf("item[%d]: can't assign or convert %v into %v", i, src.Type(), dest.Type())
}
}
items.Set(slice)
return nil
}
// ObjectKinds returns all possible group,version,kind of the go object, true if the
// object is considered unversioned, or an error if it's not a pointer or is unregistered.
func (s *Scheme) ObjectKinds(obj Object) ([]schema.GroupVersionKind, bool, error) {
v, err := conversion.EnforcePtr(obj)
if err != nil {
return nil, false, err
}
t := v.Type()
gvks, ok := s.typeToGVK[t]
if !ok {
return nil, false, NewNotRegisteredErr(schema.GroupVersionKind{}, t)
}
_, unversionedType := s.unversionedTypes[t]
return gvks, unversionedType, nil
}
// EachListItem invokes fn on each runtime.Object in the list. Any error immediately terminates
// the loop.
func EachListItem(obj runtime.Object, fn func(runtime.Object) error) error {
// TODO: Change to an interface call?
itemsPtr, err := GetItemsPtr(obj)
if err != nil {
return err
}
items, err := conversion.EnforcePtr(itemsPtr)
if err != nil {
return err
}
len := items.Len()
if len == 0 {
return nil
}
takeAddr := false
if elemType := items.Type().Elem(); elemType.Kind() != reflect.Ptr && elemType.Kind() != reflect.Interface {
if !items.Index(0).CanAddr() {
return fmt.Errorf("unable to take address of items in %T for EachListItem", obj)
}
takeAddr = true
}
for i := 0; i < len; i++ {
raw := items.Index(i)
if takeAddr {
raw = raw.Addr()
}
switch item := raw.Interface().(type) {
case *runtime.RawExtension:
if err := fn(item.Object); err != nil {
return err
}
case runtime.Object:
if err := fn(item); err != nil {
return err
}
default:
obj, ok := item.(runtime.Object)
if !ok {
return fmt.Errorf("%v: item[%v]: Expected object, got %#v(%s)", obj, i, raw.Interface(), raw.Kind())
}
if err := fn(obj); err != nil {
return err
}
}
}
return nil
}
func listToItems(listObj runtime.Object) ([]runtime.Object, error) {
v, err := conversion.EnforcePtr(listObj)
if err != nil {
return nil, fmt.Errorf("unexpected error: %v", err)
}
items := v.FieldByName("Items")
if !items.IsValid() {
return nil, fmt.Errorf("unexpected Items field in %v", listObj)
}
if items.Type().Kind() != reflect.Slice {
return nil, fmt.Errorf("unexpected Items field type: %v", items.Type().Kind())
}
result := make([]runtime.Object, items.Len())
for i := 0; i < items.Len(); i++ {
result[i] = items.Index(i).Addr().Interface().(runtime.Object)
}
return result, nil
}
// 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.FilterFunc, 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(obj) {
v.Set(reflect.Append(v, reflect.ValueOf(obj).Elem()))
}
}
return nil
}
// Field puts the value of fieldName, which must be a member of v, into dest,
// which must be a variable to which this field's value can be assigned.
func Field(v reflect.Value, fieldName string, dest interface{}) error {
field := v.FieldByName(fieldName)
if !field.IsValid() {
return fmt.Errorf("couldn't find %v field in %#v", fieldName, v.Interface())
}
destValue, err := conversion.EnforcePtr(dest)
if err != nil {
return err
}
if field.Type().AssignableTo(destValue.Type()) {
destValue.Set(field)
return nil
}
if field.Type().ConvertibleTo(destValue.Type()) {
destValue.Set(field.Convert(destValue.Type()))
return nil
}
return fmt.Errorf("couldn't assign/convert %v to %v", field.Type(), destValue.Type())
}
// Implements storage.Interface.
func (c *Cacher) Get(ctx context.Context, key string, resourceVersion string, objPtr runtime.Object, ignoreNotFound bool) error {
if resourceVersion == "" {
// If resourceVersion is not specified, serve it from underlying
// storage (for backward compatibility).
return c.storage.Get(ctx, key, resourceVersion, objPtr, ignoreNotFound)
}
// If resourceVersion is specified, serve it from cache.
// It's guaranteed that the returned value is at least that
// fresh as the given resourceVersion.
getRV, err := ParseListResourceVersion(resourceVersion)
if err != nil {
return err
}
// Do not create a trace - it's not for free and there are tons
// of Get requests. We can add it if it will be really needed.
c.ready.wait()
objVal, err := conversion.EnforcePtr(objPtr)
if err != nil {
return err
}
obj, exists, readResourceVersion, err := c.watchCache.WaitUntilFreshAndGet(getRV, key, nil)
if err != nil {
return err
}
if exists {
elem, ok := obj.(*storeElement)
if !ok {
return fmt.Errorf("non *storeElement returned from storage: %v", obj)
}
objVal.Set(reflect.ValueOf(elem.Object).Elem())
} else {
objVal.Set(reflect.Zero(objVal.Type()))
if !ignoreNotFound {
return NewKeyNotFoundError(key, int64(readResourceVersion))
}
}
return nil
}
// addObjectParams converts a runtime.Object into a set of go-restful Param() definitions on the route.
// The object must be a pointer to a struct; only fields at the top level of the struct that are not
// themselves interfaces or structs are used; only fields with a json tag that is non empty (the standard
// Go JSON behavior for omitting a field) become query parameters. The name of the query parameter is
// the JSON field name. If a description struct tag is set on the field, that description is used on the
// query parameter. In essence, it converts a standard JSON top level object into a query param schema.
func addObjectParams(ws *restful.WebService, route *restful.RouteBuilder, obj interface{}) error {
sv, err := conversion.EnforcePtr(obj)
if err != nil {
return err
}
st := sv.Type()
switch st.Kind() {
case reflect.Struct:
for i := 0; i < st.NumField(); i++ {
name := st.Field(i).Name
sf, ok := st.FieldByName(name)
if !ok {
continue
}
switch sf.Type.Kind() {
case reflect.Interface, reflect.Struct:
case reflect.Ptr:
// TODO: This is a hack to let metav1.Time through. This needs to be fixed in a more generic way eventually. bug #36191
if (sf.Type.Elem().Kind() == reflect.Interface || sf.Type.Elem().Kind() == reflect.Struct) && strings.TrimPrefix(sf.Type.String(), "*") != "metav1.Time" {
continue
}
fallthrough
default:
jsonTag := sf.Tag.Get("json")
if len(jsonTag) == 0 {
continue
}
jsonName := strings.SplitN(jsonTag, ",", 2)[0]
if len(jsonName) == 0 {
continue
}
var desc string
if docable, ok := obj.(documentable); ok {
desc = docable.SwaggerDoc()[jsonName]
}
route.Param(ws.QueryParameter(jsonName, desc).DataType(typeToJSON(sf.Type.String())))
}
}
}
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.FilterFunc, 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(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
}
// TypeAccessor returns an interface that allows retrieving and modifying the APIVersion
// and Kind of an in-memory internal object.
// TODO: this interface is used to test code that does not have ObjectMeta or ListMeta
// in round tripping (objects which can use apiVersion/kind, but do not fit the Kube
// api conventions).
func TypeAccessor(obj interface{}) (Type, error) {
if typed, ok := obj.(runtime.Object); ok {
return objectAccessor{typed}, nil
}
v, err := conversion.EnforcePtr(obj)
if err != nil {
return nil, err
}
t := v.Type()
if v.Kind() != reflect.Struct {
return nil, fmt.Errorf("expected struct, but got %v: %v (%#v)", v.Kind(), t, v.Interface())
}
typeMeta := v.FieldByName("TypeMeta")
if !typeMeta.IsValid() {
return nil, fmt.Errorf("struct %v lacks embedded TypeMeta type", t)
}
a := &genericAccessor{}
if err := extractFromTypeMeta(typeMeta, a); err != nil {
return nil, fmt.Errorf("unable to find type fields on %#v: %v", typeMeta, err)
}
return a, nil
}
// GetItemsPtr returns a pointer to the list object's Items member.
// If 'list' doesn't have an Items member, it's not really a list type
// and an error will be returned.
// This function will either return a pointer to a slice, or an error, but not both.
func GetItemsPtr(list runtime.Object) (interface{}, error) {
v, err := conversion.EnforcePtr(list)
if err != nil {
return nil, err
}
items := v.FieldByName("Items")
if !items.IsValid() {
return nil, fmt.Errorf("no Items field in %#v", list)
}
switch items.Kind() {
case reflect.Interface, reflect.Ptr:
target := reflect.TypeOf(items.Interface()).Elem()
if target.Kind() != reflect.Slice {
return nil, fmt.Errorf("items: Expected slice, got %s", target.Kind())
}
return items.Interface(), nil
case reflect.Slice:
return items.Addr().Interface(), nil
default:
return nil, fmt.Errorf("items: Expected slice, got %s", items.Kind())
}
}
// Implements storage.Interface.
func (h *etcdHelper) Create(ctx context.Context, key string, obj, out runtime.Object, ttl uint64) error {
trace := util.NewTrace("etcdHelper::Create " + getTypeName(obj))
defer trace.LogIfLong(250 * time.Millisecond)
if ctx == nil {
glog.Errorf("Context is nil")
}
key = path.Join(h.pathPrefix, key)
data, err := runtime.Encode(h.codec, obj)
trace.Step("Object encoded")
if err != nil {
return err
}
if version, err := h.versioner.ObjectResourceVersion(obj); err == nil && version != 0 {
return errors.New("resourceVersion may not be set on objects to be created")
}
trace.Step("Version checked")
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)
trace.Step("Object created")
metrics.RecordEtcdRequestLatency("create", getTypeName(obj), startTime)
if err != nil {
return toStorageErr(err, key, 0)
}
if out != nil {
if _, err := conversion.EnforcePtr(out); err != nil {
panic("unable to convert output object to pointer")
}
_, _, err = h.extractObj(response, err, out, false, false)
}
return err
}
// GuaranteedUpdate implements storage.Interface.GuaranteedUpdate.
func (s *store) GuaranteedUpdate(
ctx context.Context, key string, out runtime.Object, ignoreNotFound bool,
precondtions *storage.Preconditions, tryUpdate storage.UpdateFunc, suggestion ...runtime.Object) error {
trace := util.NewTrace(fmt.Sprintf("GuaranteedUpdate etcd3: %s", reflect.TypeOf(out).String()))
defer trace.LogIfLong(500 * time.Millisecond)
v, err := conversion.EnforcePtr(out)
if err != nil {
panic("unable to convert output object to pointer")
}
key = path.Join(s.pathPrefix, key)
var origState *objState
if len(suggestion) == 1 && suggestion[0] != nil {
origState, err = s.getStateFromObject(suggestion[0])
if err != nil {
return err
}
} else {
getResp, err := s.client.KV.Get(ctx, key, s.getOps...)
if err != nil {
return err
}
origState, err = s.getState(getResp, key, v, ignoreNotFound)
if err != nil {
return err
}
}
trace.Step("initial value restored")
for {
if err := checkPreconditions(key, precondtions, origState.obj); err != nil {
return err
}
ret, ttl, err := s.updateState(origState, tryUpdate)
if err != nil {
return err
}
data, err := runtime.Encode(s.codec, ret)
if err != nil {
return err
}
if bytes.Equal(data, origState.data) {
return decode(s.codec, s.versioner, origState.data, out, origState.rev)
}
opts, err := s.ttlOpts(ctx, int64(ttl))
if err != nil {
return err
}
trace.Step("Transaction prepared")
txnResp, err := s.client.KV.Txn(ctx).If(
clientv3.Compare(clientv3.ModRevision(key), "=", origState.rev),
).Then(
clientv3.OpPut(key, string(data), opts...),
).Else(
clientv3.OpGet(key),
).Commit()
if err != nil {
return err
}
trace.Step("Transaction committed")
if !txnResp.Succeeded {
getResp := (*clientv3.GetResponse)(txnResp.Responses[0].GetResponseRange())
glog.V(4).Infof("GuaranteedUpdate of %s failed because of a conflict, going to retry", key)
origState, err = s.getState(getResp, key, v, ignoreNotFound)
if err != nil {
return err
}
trace.Step("Retry value restored")
continue
}
putResp := txnResp.Responses[0].GetResponsePut()
return decode(s.codec, s.versioner, data, out, putResp.Header.Revision)
}
}
// Implements storage.Interface.
func (h *etcdHelper) GuaranteedUpdate(
ctx context.Context, key string, ptrToType runtime.Object, ignoreNotFound bool,
preconditions *storage.Preconditions, tryUpdate storage.UpdateFunc, _ ...runtime.Object) error {
// Ignore the suggestion about current object.
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 = path.Join(h.pathPrefix, key)
for {
obj := reflect.New(v.Type()).Interface().(runtime.Object)
origBody, node, res, err := h.bodyAndExtractObj(ctx, key, obj, ignoreNotFound)
if err != nil {
return toStorageErr(err, key, 0)
}
if err := checkPreconditions(key, preconditions, obj); err != nil {
return toStorageErr(err, key, 0)
}
meta := storage.ResponseMeta{}
if node != nil {
meta.TTL = node.TTL
meta.ResourceVersion = node.ModifiedIndex
}
// Get the object to be written by calling tryUpdate.
ret, newTTL, err := tryUpdate(obj, meta)
if err != nil {
return toStorageErr(err, key, 0)
}
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, 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 toStorageErr(err, key, 0)
}
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{
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 toStorageErr(err, key, int64(index))
}
}
