add redis3

weed/util/skiplist/name_batch.go

@@ -35,7 +35,7 @@ func (nb *NameBatch) DeleteName(name string) {
 }
 func (nb *NameBatch) ListNames(startFrom string, visitNamesFn func(name string) bool) bool {
 	var names []string
-	needFilter := startFrom == ""
+	needFilter := startFrom != ""
 	for n := range nb.names {
 		if !needFilter || strings.Compare(n, startFrom) >= 0 {
 			names = append(names, n)

weed/util/skiplist/name_list.go

@@ -9,7 +9,7 @@ type NameList struct {
 	batchSize int
 }
 
-func NewNameList(store ListStore, batchSize int) *NameList {
+func newNameList(store ListStore, batchSize int) *NameList {
 	return &NameList{
 		skipList:  New(store),
 		batchSize: batchSize,
@@ -59,6 +59,7 @@ There are multiple cases after finding the name for greater or equal node
 
 */
 func (nl *NameList) WriteName(name string) error {
+
 	lookupKey := []byte(name)
 	prevNode, nextNode, found, err := nl.skipList.FindGreaterOrEqual(lookupKey)
 	if err != nil {
@@ -301,3 +302,25 @@ func (nl *NameList) ListNames(startFrom string, visitNamesFn func(name string) b
 
 	return nil
 }
+
+func (nl *NameList) RemoteAllListElement() error {
+
+	t := nl.skipList
+
+	nodeRef := t.startLevels[0]
+	for nodeRef != nil {
+		node, err := t.loadElement(nodeRef)
+		if err != nil {
+			return err
+		}
+		if node == nil {
+			return nil
+		}
+		if err := t.deleteElement(node); err != nil {
+			return err
+		}
+		nodeRef = node.Next[0]
+	}
+	return nil
+
+}

weed/util/skiplist/name_list_serde.go

@@ -0,0 +1,71 @@
+package skiplist
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/golang/protobuf/proto"
+)
+
+func LoadNameList(data []byte, store ListStore, batchSize int) *NameList {
+
+	nl := &NameList{
+		skipList:  New(store),
+		batchSize: batchSize,
+	}
+
+	if len(data) == 0 {
+		return nl
+	}
+
+	message := &SkipListProto{}
+	if err := proto.Unmarshal(data, message); err != nil {
+		glog.Errorf("loading skiplist: %v", err)
+	}
+	nl.skipList.maxNewLevel = int(message.MaxNewLevel)
+	nl.skipList.maxLevel = int(message.MaxLevel)
+	for i, ref := range message.StartLevels {
+		nl.skipList.startLevels[i] = &SkipListElementReference{
+			ElementPointer: ref.ElementPointer,
+			Key:            ref.Key,
+		}
+	}
+	for i, ref := range message.EndLevels {
+		nl.skipList.endLevels[i] = &SkipListElementReference{
+			ElementPointer: ref.ElementPointer,
+			Key:            ref.Key,
+		}
+	}
+	return nl
+}
+
+func (nl *NameList) HasChanges() bool {
+	return nl.skipList.hasChanges
+}
+
+func (nl *NameList) ToBytes() []byte {
+	message := &SkipListProto{}
+	message.MaxNewLevel = int32(nl.skipList.maxNewLevel)
+	message.MaxLevel = int32(nl.skipList.maxLevel)
+	for _, ref := range nl.skipList.startLevels {
+		if ref == nil {
+			break
+		}
+		message.StartLevels = append(message.StartLevels, &SkipListElementReference{
+			ElementPointer: ref.ElementPointer,
+			Key:            ref.Key,
+		})
+	}
+	for _, ref := range nl.skipList.endLevels {
+		if ref == nil {
+			break
+		}
+		message.EndLevels = append(message.EndLevels, &SkipListElementReference{
+			ElementPointer: ref.ElementPointer,
+			Key:            ref.Key,
+		})
+	}
+	data, err := proto.Marshal(message)
+	if err != nil {
+		glog.Errorf("marshal skiplist: %v", err)
+	}
+	return data
+}

weed/util/skiplist/name_list_test.go

@@ -15,7 +15,7 @@ func String(x int) string {
 }
 
 func TestNameList(t *testing.T) {
-	list := NewNameList(memStore, 7)
+	list := newNameList(memStore, 7)
 
 	for i := 0; i < maxNameCount; i++ {
 		list.WriteName(String(i))
@@ -51,7 +51,7 @@ func TestNameList(t *testing.T) {
 	}
 
 	// randomized deletion
-	list = NewNameList(memStore, 7)
+	list = newNameList(memStore, 7)
 	// Delete elements at random positions in the list.
 	rList := rand.Perm(maxN)
 	for _, i := range rList {

weed/util/skiplist/skiplist.go

@@ -22,6 +22,7 @@ type SkipList struct {
 	maxNewLevel int
 	maxLevel    int
 	listStore   ListStore
+	hasChanges  bool
 	// elementCount int
 }
 
@@ -93,6 +94,9 @@ func (t *SkipList) findExtended(key []byte, findGreaterOrEqual bool) (prevElemen
 	if err != nil {
 		return
 	}
+	if currentNode == nil {
+		return
+	}
 
 	// In case, that our first element is already greater-or-equal!
 	if findGreaterOrEqual && compareElement(currentNode, key) > 0 {
@@ -115,6 +119,9 @@ func (t *SkipList) findExtended(key []byte, findGreaterOrEqual bool) (prevElemen
 			if err != nil {
 				return
 			}
+			if currentNode == nil {
+				return
+			}
 		} else {
 			if index > 0 {
 
@@ -126,6 +133,9 @@ func (t *SkipList) findExtended(key []byte, findGreaterOrEqual bool) (prevElemen
 					if err != nil {
 						return
 					}
+					if currentNodeNext == nil {
+						return
+					}
 					foundElem = currentNodeNext
 					ok = true
 					return
@@ -216,9 +226,11 @@ func (t *SkipList) Delete(key []byte) (err error) {
 					if err != nil {
 						return err
 					}
-					nextNextNode.Prev = currentNode.Reference()
-					if err = t.saveElement(nextNextNode); err != nil {
-						return err
+					if nextNextNode != nil {
+						nextNextNode.Prev = currentNode.Reference()
+						if err = t.saveElement(nextNextNode); err != nil {
+							return err
+						}
 					}
 				}
 				// t.elementCount--
@@ -230,6 +242,7 @@ func (t *SkipList) Delete(key []byte) (err error) {
 			// Link from start needs readjustments.
 			startNextKey := t.startLevels[index].Key
 			if compareElement(nextNode, startNextKey) == 0 {
+				t.hasChanges = true
 				t.startLevels[index] = nextNode.Next[index]
 				// This was our currently highest node!
 				if t.startLevels[index] == nil {
@@ -240,6 +253,7 @@ func (t *SkipList) Delete(key []byte) (err error) {
 			// Link from end needs readjustments.
 			if nextNode.Next[index] == nil {
 				t.endLevels[index] = currentNode.Reference()
+				t.hasChanges = true
 			}
 			nextNode.Next[index] = nil
 		}
@@ -260,7 +274,7 @@ func (t *SkipList) Delete(key []byte) (err error) {
 
 // Insert inserts the given ListElement into the skiplist.
 // Insert runs in approx. O(log(n))
-func (t *SkipList) Insert(key, value []byte) (err error){
+func (t *SkipList) Insert(key, value []byte) (err error) {
 
 	if t == nil || key == nil {
 		return
@@ -272,6 +286,7 @@ func (t *SkipList) Insert(key, value []byte) (err error){
 	if level > t.maxLevel {
 		level = t.maxLevel + 1
 		t.maxLevel = level
+		t.hasChanges = true
 	}
 
 	elem := &SkipListElement{
@@ -326,9 +341,11 @@ func (t *SkipList) Insert(key, value []byte) (err error){
 						if nextNode, err = t.loadElement(nextNodeRef); err != nil {
 							return
 						}
-						nextNode.Prev = elem.Reference()
-						if err = t.saveElement(nextNode); err != nil {
-							return
+						if nextNode != nil {
+							nextNode.Prev = elem.Reference()
+							if err = t.saveElement(nextNode); err != nil {
+								return
+							}
 						}
 					}
 				}
@@ -343,6 +360,9 @@ func (t *SkipList) Insert(key, value []byte) (err error){
 					}
 				}
 				currentNode = nextNode
+				if currentNode == nil {
+					return
+				}
 			} else {
 				// Go down
 				index--
@@ -366,18 +386,22 @@ func (t *SkipList) Insert(key, value []byte) (err error){
 					if err != nil {
 						return err
 					}
-					startLevelElement.Prev = elem.Reference()
-					if err = t.saveElement(startLevelElement); err != nil {
-						return err
+					if startLevelElement != nil {
+						startLevelElement.Prev = elem.Reference()
+						if err = t.saveElement(startLevelElement); err != nil {
+							return err
+						}
 					}
 				}
 				elem.Next[i] = t.startLevels[i]
 				t.startLevels[i] = elem.Reference()
+				t.hasChanges = true
 			}
 
 			// link the endLevels to this element!
 			if elem.Next[i] == nil {
 				t.endLevels[i] = elem.Reference()
+				t.hasChanges = true
 			}
 
 			didSomething = true
@@ -392,20 +416,24 @@ func (t *SkipList) Insert(key, value []byte) (err error){
 					if err != nil {
 						return err
 					}
-					endLevelElement.Next[i] = elem.Reference()
-					if err = t.saveElement(endLevelElement); err != nil {
-						return err
+					if endLevelElement != nil {
+						endLevelElement.Next[i] = elem.Reference()
+						if err = t.saveElement(endLevelElement); err != nil {
+							return err
+						}
 					}
 				}
 				if i == 0 {
 					elem.Prev = t.endLevels[i]
 				}
 				t.endLevels[i] = elem.Reference()
+				t.hasChanges = true
 			}
 
 			// Link the startLevels to this element!
 			if t.startLevels[i] == nil || bytes.Compare(t.startLevels[i].Key, key) > 0 {
 				t.startLevels[i] = elem.Reference()
+				t.hasChanges = true
 			}
 
 			didSomething = true
@@ -486,6 +514,9 @@ func (t *SkipList) println() {
 	for nodeRef != nil {
 		print(fmt.Sprintf("%v: ", string(nodeRef.Key)))
 		node, _ := t.loadElement(nodeRef)
+		if node == nil {
+			break
+		}
 		for i := 0; i <= int(node.Level); i++ {
 
 			l := node.Next[i]
@@ -510,8 +541,8 @@ func (t *SkipList) println() {
 			}
 
 		}
-		println()
 		nodeRef = node.Next[0]
+		println()
 	}
 
 	print("end --> ")