store: Make KVEntry a struct rather than an interface.

Signed-off-by: Andrea Luzzardi <aluzzardi@gmail.com>

discovery/kv/kv.go

@@ -71,9 +71,9 @@ func (s *Discovery) Fetch() ([]*discovery.Entry, error) {
 
 // Watch is exported
 func (s *Discovery) Watch(callback discovery.WatchCallback) {
-	s.store.WatchRange(s.prefix, "", s.heartbeat, func(kvalues ...store.KVEntry) {
+	s.store.WatchRange(s.prefix, "", s.heartbeat, func(kv ...*store.KVEntry) {
 		// Traduce byte array entries to discovery.Entry
-		entries, _ := discovery.CreateEntries(convertToStringArray(kvalues))
+		entries, _ := discovery.CreateEntries(convertToStringArray(kv))
 		callback(entries)
 	})
 }
@@ -84,9 +84,9 @@ func (s *Discovery) Register(addr string) error {
 	return err
 }
 
-func convertToStringArray(entries []store.KVEntry) (addrs []string) {
+func convertToStringArray(entries []*store.KVEntry) (addrs []string) {
 	for _, entry := range entries {
-		addrs = append(addrs, string(entry.Value()))
+		addrs = append(addrs, string(entry.Value))
 	}
 	return addrs
 }

pkg/store/consul.go

@@ -118,7 +118,7 @@ func (s *Consul) Exists(key string) (bool, error) {
 }
 
 // GetRange gets a range of values at "directory"
-func (s *Consul) GetRange(prefix string) (kvi []KVEntry, err error) {
+func (s *Consul) GetRange(prefix string) ([]*KVEntry, error) {
 	pairs, _, err := s.client.KV().List(s.normalize(prefix), nil)
 	if err != nil {
 		return nil, err
@@ -126,13 +126,14 @@ func (s *Consul) GetRange(prefix string) (kvi []KVEntry, err error) {
 	if len(pairs) == 0 {
 		return nil, ErrKeyNotFound
 	}
+	kv := []*KVEntry{}
 	for _, pair := range pairs {
 		if pair.Key == prefix {
 			continue
 		}
-		kvi = append(kvi, &kviTuple{pair.Key, pair.Value, pair.ModifyIndex})
+		kv = append(kv, &KVEntry{pair.Key, pair.Value, pair.ModifyIndex})
 	}
-	return kvi, nil
+	return kv, nil
 }
 
 // DeleteRange deletes a range of values at "directory"
@@ -163,7 +164,7 @@ func (s *Consul) Watch(key string, heartbeat time.Duration, callback WatchCallba
 			s.watches[fkey] = nil
 			return err
 		}
-		callback(&kviTuple{key, entry, index})
+		callback(&KVEntry{key, entry, index})
 	}
 
 	return nil

pkg/store/etcd.go

@@ -155,7 +155,7 @@ func (s *Etcd) Watch(key string, _ time.Duration, callback WatchCallback) error
 			s.watches[key] = nil
 			return err
 		}
-		callback(&kviTuple{key, entry, index})
+		callback(&KVEntry{key, entry, index})
 	}
 	return nil
 }
@@ -204,16 +204,16 @@ func (s *Etcd) AtomicDelete(key string, oldValue []byte, index uint64) (bool, er
 }
 
 // GetRange gets a range of values at "directory"
-func (s *Etcd) GetRange(prefix string) ([]KVEntry, error) {
+func (s *Etcd) GetRange(prefix string) ([]*KVEntry, error) {
 	resp, err := s.client.Get(normalize(prefix), true, true)
 	if err != nil {
 		return nil, err
 	}
-	kvi := make([]KVEntry, len(resp.Node.Nodes))
-	for i, n := range resp.Node.Nodes {
-		kvi[i] = &kviTuple{n.Key, []byte(n.Value), n.ModifiedIndex}
+	kv := []*KVEntry{}
+	for _, n := range resp.Node.Nodes {
+		kv = append(kv, &KVEntry{n.Key, []byte(n.Value), n.ModifiedIndex})
 	}
-	return kvi, nil
+	return kv, nil
 }
 
 // DeleteRange deletes a range of values at "directory"

pkg/store/store.go

@@ -20,7 +20,7 @@ const (
 
 // WatchCallback is used for watch methods on keys
 // and is triggered on key change
-type WatchCallback func(kviTuple ...KVEntry)
+type WatchCallback func(entries ...*KVEntry)
 
 // Initialize creates a new Store object, initializing the client
 type Initialize func(addrs []string, options *Config) (Store, error)
@@ -54,7 +54,7 @@ type Store interface {
 	CreateLock(key string, value []byte) (Locker, error)
 
 	// Get range of keys based on prefix
-	GetRange(prefix string) ([]KVEntry, error)
+	GetRange(prefix string) ([]*KVEntry, error)
 
 	// Delete range of keys based on prefix
 	DeleteRange(prefix string) error
@@ -73,10 +73,10 @@ type Store interface {
 }
 
 // KVEntry represents {Key, Value, Lastindex} tuple
-type KVEntry interface {
-	Key() string
-	Value() []byte
-	LastIndex() uint64
+type KVEntry struct {
+	Key       string
+	Value     []byte
+	LastIndex uint64
 }
 
 // Locker provides locking mechanism on top of the store.

pkg/store/structs.go

@@ -28,21 +28,3 @@ type Config struct {
 	TLS     *tls.Config
 	Timeout time.Duration
 }
-
-type kviTuple struct {
-	key       string
-	value     []byte
-	lastIndex uint64
-}
-
-func (kvi *kviTuple) Key() string {
-	return kvi.key
-}
-
-func (kvi *kviTuple) Value() []byte {
-	return kvi.value
-}
-
-func (kvi *kviTuple) LastIndex() uint64 {
-	return kvi.lastIndex
-}

pkg/store/zookeeper.go

@@ -118,7 +118,7 @@ func (s *Zookeeper) Watch(key string, _ time.Duration, callback WatchCallback) e
 			log.WithField("name", "zk").Debug("Discovery watch triggered")
 			entry, index, err := s.Get(key)
 			if err == nil {
-				callback(&kviTuple{key, []byte(entry), index})
+				callback(&KVEntry{key, []byte(entry), index})
 			}
 		}
 	}
@@ -140,17 +140,18 @@ func (s *Zookeeper) CancelWatch(key string) error {
 }
 
 // GetRange gets a range of values at "directory"
-func (s *Zookeeper) GetRange(prefix string) (kvi []KVEntry, err error) {
+func (s *Zookeeper) GetRange(prefix string) ([]*KVEntry, error) {
 	prefix = normalize(prefix)
 	entries, stat, err := s.client.Children(prefix)
 	if err != nil {
 		log.Error("Cannot fetch range of keys beginning with prefix: ", prefix)
 		return nil, err
 	}
+	kv := []*KVEntry{}
 	for _, item := range entries {
-		kvi = append(kvi, &kviTuple{prefix, []byte(item), uint64(stat.Mzxid)})
+		kv = append(kv, &KVEntry{prefix, []byte(item), uint64(stat.Mzxid)})
 	}
-	return kvi, err
+	return kv, err
 }
 
 // DeleteRange deletes a range of values at "directory"