Particle Data Structure

Creating a general AoSoA data structure with general types.

packages/Core/src/Cabana_AoSoA.hpp

@@ -9,6 +9,23 @@
 
 namespace Cabana
 {
+//---------------------------------------------------------------------------//
+// Type traits.
+template<typename Device, std::size_t ArraySize, typename... Types>
+class AoSoA;
+
+template<typename >
+struct is_aosoa
+    : public std::false_type {};
+
+template<typename Device, std::size_t ArraySize, typename... Types>
+struct is_aosoa<AoSoA<Device,ArraySize,Types...> >
+    : public std::true_type {};
+
+template<typename Device, std::size_t ArraySize, typename... Types>
+struct is_aosoa<const AoSoA<Device,ArraySize,Types...> >
+    : public std::true_type {};
+
 //---------------------------------------------------------------------------//
 /*!
   \class AoSoA
@@ -83,7 +100,7 @@ class AoSoA
         inline std::size_t s() const
         { return _s; }
 
-        // Get the struct offset.
+        // Get the array offset in the struct.
         inline std::size_t i() const
         { return _i; }
 
@@ -122,9 +139,9 @@ class AoSoA
     AoSoA( const std::size_t size )
         : _size( size )
     {
-        _num_struct = std::floor(_size / soa_array_size);
-        if ( 0 < _size % soa_array_size ) ++_num_struct;
-        Device::allocate( _data, _num_struct );
+        _num_soa = std::floor(_size / soa_array_size);
+        if ( 0 < _size % soa_array_size ) ++_num_soa;
+        Device::allocate( _data, _num_soa );
     }
 
     // Destructor.
@@ -143,10 +160,10 @@ class AoSoA
     // elements). This may or not be equal to the total number of requested
     // elements in the AoSoA if the size of the struct arrays is not evenly
     // divisible by the requested size.
-    std::size_t allocatedSize() const { return _num_struct * soa_array_size; }
+    std::size_t allocatedSize() const { return _num_soa * soa_array_size; }
 
-    // Get the number of structs in the array.
-    std::size_t numStruct() const { return _num_struct; }
+    // Get the number of structs-of-arrays in the array.
+    std::size_t numSoA() const { return _num_soa; }
 
     // Access the data array at a given struct member index.
     template<std::size_t I>
@@ -161,19 +178,19 @@ class AoSoA
         return getStructMember<I>( _data[s] );
     }
 
-    // Get the index at the beginning of the array.
+    // Get the index at the beginning of the entire AoSoA.
     Index begin() const
     {
         return Index( 0, 0 );
     }
 
-    // Get the index at end of the array.
+    // Get the index at end of the entire AoSoA.
     Index end() const
     {
-        return Index( _num_struct - 1, _size % soa_array_size );
+        return Index( _num_soa - 1, _size % soa_array_size );
     }
 
-    // Access the data value at a given struct member index and offset index
+    // Access the data value at a given struct member index and array index
     // for Rank 0 data.
     template<std::size_t I>
     inline
@@ -193,7 +210,7 @@ class AoSoA
         return array<I>(idx.s())[idx.i()];
     }
 
-    // Access the data value at a given struct member index and offset index
+    // Access the data value at a given struct member index and array index
     // for Rank 1 data.
     template<std::size_t I>
     inline
@@ -215,7 +232,7 @@ class AoSoA
         return array<I>(idx.s())[idx.i()][d0];
     }
 
-    // Access the data value at a given struct member index and offset index
+    // Access the data value at a given struct member index and array index
     // for Rank 2 data.
     template<std::size_t I>
     inline
@@ -239,7 +256,7 @@ class AoSoA
         return array<I>(idx.s())[idx.i()][d0][d1];
     }
 
-    // Access the data value at a given struct member index and offset index
+    // Access the data value at a given struct member index and array index
     // for Rank 3 data.
     template<std::size_t I>
     inline
@@ -270,8 +287,8 @@ class AoSoA
     // Total size of the array.
     std::size_t _size;
 
-    // Number of structs in the array.
-    std::size_t _num_struct;
+    // Number of structs-of-arrays in the array.
+    std::size_t _num_soa;
 
     // Structs-of-Arrays.
     soa_type* _data;