diff --git a/general/src/pattern/ringbuffer.hpp b/general/src/pattern/ringbuffer.hpp
index 1ab22cb..28385db 100644
--- a/general/src/pattern/ringbuffer.hpp
+++ b/general/src/pattern/ringbuffer.hpp
@@ -10,7 +10,8 @@ public:
     RingBuffer(uint64_t size);
     int Add(T *data,uint64_t len);
     int TakeBack(T *data,uint64_t len);
-    int Copy(T *data,uint64_t len);
+    int TakeFront(T *data,uint64_t len);
+    int CopyBack(T *data,uint64_t len);
 
     void SetEmpty();
     uint32_t CanReadCount();
@@ -52,9 +53,35 @@ void RingBuffer<T>::SetEmpty(){
 }
 
 template<typename T>
-int RingBuffer<T>::Copy(T *data,uint64_t len){
+int RingBuffer<T>::CopyBack(T *data,uint64_t len){
     if(data == nullptr)
         return -1;
+    T *tail = nullptr;
+    if(m_len == 0)
+        return 0;
+    if((m_head + m_len) > m_data_end){
+        tail = m_head + m_len - m_size;
+    }else{
+        tail = m_head + m_len - 1;
+    }
+
+    int i = 0;
+    for(i = 0;i < len;i++){
+        T* tmp = tail;
+        if(tail > m_data) {
+            tmp--;
+        }
+        if(tail == m_data) {
+            tmp = m_data_end;
+        }
+        // next is head stop
+        if(tmp == m_head) { 
+            data[i] =  (*tail);
+            break;
+        }
+        data[i] = (*tail) ;
+        tail = tmp;
+    }
 }
 
 template<typename T>
@@ -122,7 +149,7 @@ int  RingBuffer<T>::TakeBack(T *data,uint64_t len){
     if((m_head + m_len) > m_data_end){
         tail = m_head + m_len - m_size;
     }else{
-        tail = m_head + m_len;
+        tail = m_head + m_len - 1;
     }
 
     int i = 0;
@@ -134,23 +161,58 @@ int  RingBuffer<T>::TakeBack(T *data,uint64_t len){
         if(tail == m_data) {
             tmp = m_data_end;
         }
-        if(tmp == m_head) { 
-            (*tail) = data[i];
+        // next is head stop
+        if((tmp == m_head) || (m_head == tail)) { 
+            data[len - 1 - i] =  (*tail);
+            break;
+        }
+        data[len - 1 - i] = (*tail) ;
+        tail = tmp;
+    }
+    m_len-=i;
+    return i;
+}
+
+template<typename T>
+int TakeFront(T *data,uint64_t len){
+    if(data == nullptr)
+        return -1;
+    T *tail = nullptr;
+    if(m_len == 0)
+        return 0;
+    if((m_head + m_len) > m_data_end){
+        tail = m_head + m_len - m_size;
+    }else{
+        tail = m_head + m_len - 1;
+    }
+    int i = 0;
+    for(i = 0;i < len;i++){
+        T* tmp = m_head;
+        if(m_head < m_data_end) {
+            tmp++;
+        }
+        if(m_head == m_data_end) {
+            tmp = m_data;
+        }
+        // next is head stop
+        if((tmp == tail) || (m_head == tail)) { 
+            data[i] =  (*tail);
             break;
         }
         data[i] = (*tail) ;
-        tail = tmp;
-    }    
+        m_head = tmp;
+    }
+    m_len-=i;
     return i;
 }
 
 template<typename T>
 uint32_t RingBuffer<T>::CanReadCount(){
-
+    return m_len;
 }
 
 template<typename T>
 uint32_t RingBuffer<T>::CanWriteCount(){
-
+    return m_size - m_len;
 }
 #endif
diff --git a/test/src/cpp11/template.cpp b/test/src/cpp11/template.cpp
index 5ce2296..da83727 100644
--- a/test/src/cpp11/template.cpp
+++ b/test/src/cpp11/template.cpp
@@ -25,61 +25,74 @@ void TestRingBuffer(){
     int ret = x.Add(in,512);
     std::cout<<"add "<<ret<<"  x.Length():" <<  x.Length() << " "<<std::endl;
     for(uint32_t i = 0;i < x.Length();i++){
-        printf("%d ",x.At(i));
+        std::cout<<x.At(i) <<" ";
     }
     std::cout<<"\r\n clear x----------------------------------"<<std::endl;
     x.SetEmpty();
     std::cout<<"\r\n ----------------------------------"<<std::endl;
     std::cout<<"add data :"<<std::endl;
     for(uint32_t i = 0;i < 516;i++){
-        printf("%d ",in[i]);
+        std::cout<<in[i] <<" ";
     }
     ret = x.Add(in,516);
     std::cout<<"after add "<<ret << " length: "<< x.Length()<<"\r\n"<<std::endl;
     for(uint32_t i = 0;i < x.Length();i++){
-        printf("%d ",x.At(i));
+        std::cout<<x.At(i) <<" ";
     }
     std::cout<<"\r\n----------------------------------"<<std::endl;
     clearBuffer(in,1024);
     ret = x.Add(in,20);
     std::cout<<"add "<<ret<<"\r\n"<<std::endl;
     for(uint32_t i = 0;i < x.Length();i++){
-        printf("%d ",x.At(i));
+        std::cout<<x.At(i) <<" ";
     }
     std::cout<<"\r\n----------------------------------"<<std::endl;
     clearBuffer(in,1024);
 
     std::cout<<"before take x: "<< x.Length()<<std::endl;
     for(uint32_t i = 0;i < x.Length();i++){
-        printf("%d ",x.At(i));
+        std::cout<<x.At(i) <<" ";
     }
     std::cout<<"\r\n----------------------------------"<<std::endl;
     ret = x.TakeBack(in,20);
     std::cout<<"take "<<ret<<"\r\n"<<std::endl;
     for(uint32_t i = 0;i < ret;i++){
-        printf("%d ",in[i]);
+        std::cout<<in[i] <<" ";
     }
     std::cout<<"\r\n----------------------------------"<<std::endl;
     std::cout<<"after take x: "<<x.Length()<<"\r\n"<<std::endl; 
     for(uint32_t i = 0;i < x.Length();i++){
-        printf("%d ",x.At(i));
+        std::cout<<x.At(i) <<" ";
     }
     clearBuffer(in,1024);
     std::cout<<"\r\n----------------------------------"<<std::endl;
     ret = x.TakeBack(in,20);
     std::cout<<"take "<<ret<<"\r\n"<<std::endl;
     for(uint32_t i = 0;i < ret;i++){
-        printf("%d ",in[i]);
+        std::cout<<in[i] <<" ";
     }
     std::cout<<"\r\n----------------------------------"<<std::endl;
     std::cout<<"after take x: "<<x.Length()<<"\r\n"<<std::endl; 
-    for(uint32_t i = 0;i < x.Length();i++){
-        printf("%d ",x.At(i));
+    std::cout<<"----------------------------------"<<"\r\n";
+    for(int z = 0;z < x.Length();z++){
+        std::cout<<x.At(z) <<" ";
     }
+    clearBuffer(in,1024);
+    ret = x.TakeFront(in,496);
+    std::cout<<"\r\ntake from front "<<ret<<"\r\n"<<std::endl;
+    for(uint32_t i = 0;i < ret;i++){
+        std::cout<<in[i] <<" ";
+    }
+    std::cout<<"\r\nafter take x: "<<x.Length()<<"\r\n"<<std::endl; 
+    std::cout<<"----------------------------------"<<"\r\n";
+    for(int z = 0;z < x.Length();z++){
+        std::cout<<x.At(z) <<" ";
+    }
+    fflush(stdout);
+    getchar();
 }
 
 int main() {
     std::cout<<"main"<<std::endl;
     TestRingBuffer();
-
 }
\ No newline at end of file