add name list

weed/util/skiplist/name_batch.go

@@ -0,0 +1,102 @@
+package skiplist
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/glog"
+	"github.com/golang/protobuf/proto"
+	"sort"
+	"strings"
+)
+
+type NameBatch struct {
+	key   string
+	names map[string]struct{}
+}
+
+func (nb *NameBatch) ContainsName(name string) (found bool) {
+	_, found = nb.names[name]
+	return
+}
+func (nb *NameBatch) WriteName(name string) {
+	if nb.key == "" || strings.Compare(nb.key, name) > 0 {
+		nb.key = name
+	}
+	nb.names[name] = struct{}{}
+}
+func (nb *NameBatch) DeleteName(name string) {
+	delete(nb.names, name)
+	if nb.key == name {
+		nb.key = ""
+		for n := range nb.names {
+			if nb.key == "" || strings.Compare(nb.key, n) > 0 {
+				nb.key = n
+			}
+		}
+	}
+}
+func (nb *NameBatch) ListNames(startFrom string, visitNamesFn func(name string) bool) bool {
+	var names []string
+	needFilter := startFrom == ""
+	for n := range nb.names {
+		if !needFilter || strings.Compare(n, startFrom) >= 0 {
+			names = append(names, n)
+		}
+	}
+	sort.Slice(names, func(i, j int) bool {
+		return strings.Compare(names[i], names[j]) < 0
+	})
+	for _, n := range names {
+		if !visitNamesFn(n) {
+			return false
+		}
+	}
+	return true
+}
+
+func NewNameBatch() *NameBatch {
+	return &NameBatch{
+		names: make(map[string]struct{}),
+	}
+}
+
+func LoadNameBatch(data []byte) *NameBatch {
+	t := &NameBatchData{}
+	if len(data) > 0 {
+		err := proto.Unmarshal(data, t)
+		if err != nil {
+			glog.Errorf("unmarshal into NameBatchData{} : %v", err)
+			return nil
+		}
+	}
+	nb := NewNameBatch()
+	for _, n := range t.Names {
+		name := string(n)
+		if nb.key == "" || strings.Compare(nb.key, name) > 0 {
+			nb.key = name
+		}
+		nb.names[name] = struct{}{}
+	}
+	return nb
+}
+
+func (nb *NameBatch) ToBytes() []byte {
+	t := &NameBatchData{}
+	for n := range nb.names {
+		t.Names = append(t.Names, []byte(n))
+	}
+	data, _ := proto.Marshal(t)
+	return data
+}
+
+func (nb *NameBatch) SplitBy(name string) (x, y *NameBatch) {
+	x, y = NewNameBatch(), NewNameBatch()
+
+	for n := range nb.names {
+		// there should be no equal case though
+		if strings.Compare(n, name) <= 0 {
+			x.WriteName(n)
+		} else {
+			y.WriteName(n)
+		}
+	}
+	return
+}