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Address remaining comments from #756

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Rename Encoding to Codec, Versioning to ResourceVersioner.  Add
GoDoc.  Add Delete(key, recursive) to EtcdHelper
This commit is contained in:
Clayton Coleman
2014-08-05 22:23:22 -04:00
parent 91b31c5552
commit 67dbd15929
6 changed files with 88 additions and 71 deletions
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54
pkg/tools/etcd_tools.go
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@@ -42,13 +42,15 @@ var (
EtcdErrorValueRequired = &etcd.EtcdError{ErrorCode: EtcdErrorCodeValueRequired}
)
type Encoding interface {
// Codec provides methods for transforming Etcd values into objects and back
type Codec interface {
Encode(obj interface{}) (data []byte, err error)
Decode(data []byte) (interface{}, error)
DecodeInto(data []byte, obj interface{}) error
}
type Versioning interface {
// ResourceVersioner provides methods for managing object modification tracking
type ResourceVersioner interface {
SetResourceVersion(obj interface{}, version uint64) error
ResourceVersion(obj interface{}) (uint64, error)
}
@@ -71,16 +73,17 @@ type EtcdGetSet interface {
Get(key string, sort, recursive bool) (*etcd.Response, error)
Set(key, value string, ttl uint64) (*etcd.Response, error)
Create(key, value string, ttl uint64) (*etcd.Response, error)
Delete(key string, recursive bool) (*etcd.Response, error)
CompareAndSwap(key, value string, ttl uint64, prevValue string, prevIndex uint64) (*etcd.Response, error)
Watch(prefix string, waitIndex uint64, recursive bool, receiver chan *etcd.Response, stop chan bool) (*etcd.Response, error)
}
// EtcdHelper offers common object marshalling/unmarshalling operations on an etcd client.
type EtcdHelper struct {
Client EtcdGetSet
Encoding Encoding
// optional
Versioning Versioning
Client EtcdGetSet
Codec Codec
// optional, no atomic operations can be performed without this interface
ResourceVersioner ResourceVersioner
}
// IsEtcdNotFound returns true iff err is an etcd not found error.
@@ -136,7 +139,7 @@ func (h *EtcdHelper) ExtractList(key string, slicePtr interface{}) error {
v := pv.Elem()
for _, node := range nodes {
obj := reflect.New(v.Type().Elem())
err = h.Encoding.DecodeInto([]byte(node.Value), obj.Interface())
err = h.Codec.DecodeInto([]byte(node.Value), obj.Interface())
if err != nil {
return err
}
@@ -145,7 +148,7 @@ func (h *EtcdHelper) ExtractList(key string, slicePtr interface{}) error {
return nil
}
// Unmarshals json found at key into objPtr. On a not found error, will either return
// ExtractObj unmarshals json found at key into objPtr. On a not found error, will either return
// a zero object of the requested type, or an error, depending on ignoreNotFound. Treats
// empty responses and nil response nodes exactly like a not found error.
func (h *EtcdHelper) ExtractObj(key string, objPtr interface{}, ignoreNotFound bool) error {
@@ -170,21 +173,22 @@ func (h *EtcdHelper) bodyAndExtractObj(key string, objPtr interface{}, ignoreNot
return "", 0, fmt.Errorf("key '%v' found no nodes field: %#v", key, response)
}
body = response.Node.Value
err = h.Encoding.DecodeInto([]byte(body), objPtr)
if h.Versioning != nil {
_ = h.Versioning.SetResourceVersion(objPtr, response.Node.ModifiedIndex)
err = h.Codec.DecodeInto([]byte(body), objPtr)
if h.ResourceVersioner != nil {
_ = h.ResourceVersioner.SetResourceVersion(objPtr, response.Node.ModifiedIndex)
// being unable to set the version does not prevent the object from being extracted
}
return body, response.Node.ModifiedIndex, err
}
// Create adds a new object at a key unless it already exists
func (h *EtcdHelper) CreateObj(key string, obj interface{}) error {
data, err := h.Encoding.Encode(obj)
data, err := h.Codec.Encode(obj)
if err != nil {
return err
}
if h.Versioning != nil {
if version, err := h.Versioning.ResourceVersion(obj); err == nil && version != 0 {
if h.ResourceVersioner != nil {
if version, err := h.ResourceVersioner.ResourceVersion(obj); err == nil && version != 0 {
return errors.New("resourceVersion may not be set on objects to be created")
}
}
@@ -193,15 +197,21 @@ func (h *EtcdHelper) CreateObj(key string, obj interface{}) error {
return err
}
// Delete removes the specified key
func (h *EtcdHelper) Delete(key string, recursive bool) error {
_, err := h.Client.Delete(key, recursive)
return err
}
// SetObj marshals obj via json, and stores under key. Will do an
// atomic update if obj's ResourceVersion field is set.
func (h *EtcdHelper) SetObj(key string, obj interface{}) error {
data, err := h.Encoding.Encode(obj)
data, err := h.Codec.Encode(obj)
if err != nil {
return err
}
if h.Versioning != nil {
if version, err := h.Versioning.ResourceVersion(obj); err == nil && version != 0 {
if h.ResourceVersioner != nil {
if version, err := h.ResourceVersioner.ResourceVersion(obj); err == nil && version != 0 {
_, err = h.Client.CompareAndSwap(key, string(data), 0, "", version)
return err // err is shadowed!
}
@@ -253,7 +263,7 @@ func (h *EtcdHelper) AtomicUpdate(key string, ptrToType interface{}, tryUpdate E
return err
}
data, err := h.Encoding.Encode(ret)
data, err := h.Codec.Encode(ret)
if err != nil {
return err
}
@@ -288,7 +298,7 @@ func Everything(interface{}) bool {
// API objects, and any items passing 'filter' are sent down the returned
// watch.Interface.
func (h *EtcdHelper) WatchList(key string, filter FilterFunc) (watch.Interface, error) {
w := newEtcdWatcher(true, filter, h.Encoding)
w := newEtcdWatcher(true, filter, h.Codec)
go w.etcdWatch(h.Client, key)
return w, nil
}
@@ -296,14 +306,14 @@ func (h *EtcdHelper) WatchList(key string, filter FilterFunc) (watch.Interface,
// Watch begins watching the specified key. Events are decoded into
// API objects and sent down the returned watch.Interface.
func (h *EtcdHelper) Watch(key string) (watch.Interface, error) {
w := newEtcdWatcher(false, nil, h.Encoding)
w := newEtcdWatcher(false, nil, h.Codec)
go w.etcdWatch(h.Client, key)
return w, nil
}
// etcdWatcher converts a native etcd watch to a watch.Interface.
type etcdWatcher struct {
encoding Encoding
encoding Codec
list bool // If we're doing a recursive watch, should be true.
filter FilterFunc
@@ -322,7 +332,7 @@ type etcdWatcher struct {
}
// Returns a new etcdWatcher; if list is true, watch sub-nodes.
func newEtcdWatcher(list bool, filter FilterFunc, encoding Encoding) *etcdWatcher {
func newEtcdWatcher(list bool, filter FilterFunc, encoding Codec) *etcdWatcher {
w := &etcdWatcher{
encoding: encoding,
list: list,