add safemap and test

+package beego
+
+import (
+	"sync"
+)
+
+type BeeMap struct {
+	lock *sync.RWMutex
+	bm   map[interface{}]interface{}
+}
+
+func NewBeeMap() *BeeMap {
+	return &BeeMap{
+		lock: new(sync.RWMutex),
+		bm:   make(map[interface{}]interface{}),
+	}
+}
+
+//Get from maps return the k's value
+func (m *BeeMap) Get(k interface{}) interface{} {
+	m.lock.RLock()
+	defer m.lock.RUnlock()
+	if val, ok := m.bm[k]; ok {
+		return val
+	}
+	return nil
+}
+
+// Maps the given key and value. Returns false
+// if the key is already in the map and changes nothing.
+func (m *BeeMap) Set(k interface{}, v interface{}) bool {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	if val, ok := m.bm[k]; !ok {
+		m.bm[k] = v
+	} else if val != v {
+		m.bm[k] = v
+	} else {
+		return false
+	}
+	return true
+}
+
+// Returns true if k is exist in the map.
+func (m *BeeMap) Check(k interface{}) bool {
+	m.lock.RLock()
+	defer m.lock.RUnlock()
+	if _, ok := m.bm[k]; !ok {
+		return false
+	}
+	return true
+}
+
+func (m *BeeMap) Delete(k interface{}) {
+	m.lock.Lock()
+	defer m.lock.Unlock()
+	delete(m.bm, k)
+}

+package beego
+
+import (
+	"testing"
+)
+
+func Test_beemap(t *testing.T) {
+	bm := NewBeeMap()
+	if !bm.Set("astaxie", 1) {
+		t.Error("set Error")
+	}
+	if !bm.Check("astaxie") {
+		t.Error("check err")
+	}
+
+	if v := bm.Get("astaxie"); v.(int) != 1 {
+		t.Error("get err")
+	}
+
+	bm.Delete("astaxie")
+	if bm.Check("astaxie") {
+		t.Error("delete err")
+	}
+}