From f2b81eddc3cd0c0b414c6caa89790b23ee22337f Mon Sep 17 00:00:00 2001
From: kradchen <chenjuijun@realcan.cn>
Date: Wed, 13 Dec 2023 16:39:09 +0800
Subject: [PATCH] Add thrust iterator inherit from  iterator_facade

---
 src/AuroraThrustIterator.cuh | 132 +++++++++++++++++++++++++++++++++++
 1 file changed, 132 insertions(+)
 create mode 100644 src/AuroraThrustIterator.cuh

diff --git a/src/AuroraThrustIterator.cuh b/src/AuroraThrustIterator.cuh
new file mode 100644
index 0000000..cf163dc
--- /dev/null
+++ b/src/AuroraThrustIterator.cuh
@@ -0,0 +1,132 @@
+#ifndef __AURORATHRUSTITERATOR_H__
+#define __AURORATHRUSTITERATOR_H__
+#include <thrust/iterator/iterator_facade.h>
+namespace Aurora {
+
+    /**
+    * @brief 将一个向量通过循环读取来充作矩阵迭代器
+    * 
+    * @tparam ValueType 
+    */
+    template <typename ValueType>
+    class LoopVectorIterator:public thrust::iterator_facade<
+            LoopVectorIterator<ValueType>, 
+            ValueType,
+            thrust::device_system_tag,
+            thrust::random_access_traversal_tag,
+            ValueType& >{
+        public:
+        /**
+        * @brief 循环存取向量迭代器构造函数
+        * @attention 特别注意本迭代器不会有结束值！
+        *         
+        * @param ptr 原始指针
+        * @param aVectorSize 向量长度
+        */
+        __host__ __device__
+        LoopVectorIterator(ValueType* ptr, int aVectorSize=1) 
+            : ptr_(ptr),vec_size_(aVectorSize){}
+
+        __host__ __device__
+        ValueType& dereference() const{
+            return *(ptr_+offset_%vec_size_);
+        }
+
+        // 实现递增操作符
+        __host__ __device__
+        void increment() {
+            offset_++; 
+        }
+
+        // 实现递减操作符
+        __host__ __device__
+        void decrement() {
+            offset_--;
+        }
+
+        // 实现加法操作符
+        __host__ __device__
+        void advance(typename LoopVectorIterator::difference_type n) {
+            offset_+=n;
+        }
+
+        // 实现减法操作符
+        __host__ __device__
+        typename LoopVectorIterator::difference_type distance_to(const LoopVectorIterator& other) const {
+            return (other.offset_ - offset_);
+        }
+
+        // 实现比较操作符
+        __host__ __device__
+        bool equal(const LoopVectorIterator& other) const {
+            return offset_ == other.offset_;
+        }
+
+        private:
+            ValueType* ptr_;
+            int vec_size_;
+            int offset_ = 0;
+    };
+
+    /**
+    * @brief 按照行元素逐个存取的迭代去
+    * 
+    * @tparam ValueType 
+    */
+    template <typename ValueType>
+    class RowWiseIterator:public thrust::iterator_facade<
+            RowWiseIterator<ValueType>, 
+            ValueType,
+            thrust::device_system_tag,
+            thrust::random_access_traversal_tag,
+            ValueType& >{
+        public:
+
+        __host__ __device__
+        RowWiseIterator(ValueType* ptr, int aRowElementCount=1,int aColElementCount=1, int aBaseOffset=0) 
+            : ptr_(ptr), row_elements_(aRowElementCount),col_elements_(aColElementCount), offset_(aBaseOffset){}
+
+        __host__ __device__
+        ValueType& dereference() const{
+            return *(ptr_ + (offset_ / row_elements_) + (offset_ % row_elements_)*col_elements_);
+        }
+
+        // 实现递增操作符
+        __host__ __device__
+        void increment() {
+            offset_++; 
+        }
+
+        // 实现递减操作符
+        __host__ __device__
+        void decrement() {
+            offset_--;
+        }
+
+        // 实现加法操作符
+        __host__ __device__
+        void advance(typename RowWiseIterator::difference_type n) {
+            offset_+=n;
+        }
+
+        // 实现减法操作符
+        __host__ __device__
+        typename RowWiseIterator::difference_type distance_to(const RowWiseIterator& other) const {
+            return (other.offset_ - offset_);
+        }
+
+        // 实现比较操作符
+        __host__ __device__
+        bool equal(const RowWiseIterator& other) const {
+            return (offset_ == other.offset_);
+        }
+
+        private:
+            ValueType* ptr_;
+            int row_elements_;
+            int col_elements_;
+            int offset_ = 0;
+    };
+
+};
+#endif // __AURORATHRUSTITERATOR_H__
\ No newline at end of file