ringbuffer添加copy接口

general/src/pattern/lockfree.hpp

@@ -17,7 +17,14 @@ class LockfreeList
         int lock;
         int unlock;
     public:
-        LockfreeList():mutex(0),lock(0),unlock(1){};
+        LockfreeList():
+        mutex(0),
+        lock(0),
+        unlock(1)
+        {
+
+        };
+        
         ~LockfreeList(){};
         void Lock()
         {

general/src/pattern/ringbuffer.hpp

@@ -13,6 +13,8 @@ public:
     RingBuffer(uint64_t size);
     int Add(T *data,uint64_t len);
     int Take(T *data,uint64_t len);
+    int Copy(T *data,uint64_t len);
+
     void SetEmpty();
     uint32_t CanReadCount();
     uint32_t CanWriteCount();
@@ -48,12 +50,47 @@ template<typename T>
 RingBuffer<T>::~RingBuffer(){
     delete[] mData;
 }
+
 template<typename T>
 void RingBuffer<T>::SetEmpty(){
     this->mCurrentHead = this->mCurrentTail;
     this->mRemain = this->mSize;
 }
 
+template<typename T>
+int RingBuffer<T>::Copy(T *data,uint64_t len){
+        if(data == nullptr)
+        return -1;
+    if(mRemain == mSize)
+        return 0;
+    int bytes_read = 0;
+    if(len > (mSize - mRemain)){
+        bytes_read = mSize - mRemain;
+    }else{
+        bytes_read = len;
+    }
+    /// |start|head|.....|tail|end|
+    if(mCurrentTail >= mCurrentHead){
+        memcpy(data,&mData[mCurrentHead],sizeof(T)*bytes_read);
+        return bytes_read;
+    }
+    /// |start|...|tail|.....|head|...|end|  
+    if(mCurrentHead > mCurrentTail){
+        int off = mCurrentHead + bytes_read;
+        if(off > mSize){
+            int tmp = mSize - mCurrentHead;
+            memcpy(data,&mData[mCurrentHead],(mSize - mCurrentHead)*sizeof(T));
+            memcpy(&data[mSize - mCurrentHead],&mData[0],(bytes_read - tmp)*sizeof(T));
+            return bytes_read;
+        }
+        if(off <= mSize){
+            memcpy(data,&mData[mCurrentHead],sizeof(T)*bytes_read);
+            return bytes_read;
+        }
+    }
+
+}
+
 template<typename T>
 uint32_t RingBuffer<T>::Size(){
     return mSize;