win/C#/interop/InteropUtilities.cs

   1 namespace HandBrake.Interop\r
   2 {\r
   3     using System;\r
   4     using System.Collections.Generic;\r
   5     using System.Linq;\r
   6     using System.Text;\r
   7     using System.Runtime.InteropServices;\r
   8 \r
   9     /// <summary>\r
  10     /// Helper utilities for native interop.\r
  11     /// </summary>\r
  12     public static class InteropUtilities\r
  13     {\r
  14         /// <summary>\r
  15         /// Reads the given native structure pointer.\r
  16         /// </summary>\r
  17         /// <typeparam name="T">The type to convert the structure to.</typeparam>\r
  18         /// <param name="structPtr">The pointer to the native structure.</param>\r
  19         /// <returns>The converted structure.</returns>\r
  20         public static T ReadStructure<T>(IntPtr structPtr)\r
  21         {\r
  22             return (T)Marshal.PtrToStructure(structPtr, typeof(T));\r
  23         }\r
  24 \r
  25         /// <summary>\r
  26         /// Converts the given native HandBrake list to a managed list.\r
  27         /// </summary>\r
  28         /// <typeparam name="T">The type of structure in the list.</typeparam>\r
  29         /// <param name="listPtr">The pointer to the native list.</param>\r
  30         /// <returns>The converted managed list.</returns>\r
  31         public static List<T> ConvertList<T>(IntPtr listPtr)\r
  32         {\r
  33             List<T> returnList = new List<T>();\r
  34             hb_list_s itemList = ReadStructure<hb_list_s>(listPtr);\r
  35 \r
  36             for (int i = 0; i < itemList.items_count; i++)\r
  37             {\r
  38                 IntPtr itemPtr = Marshal.ReadIntPtr(itemList.items, i * Marshal.SizeOf(typeof(IntPtr)));\r
  39                 returnList.Add(ReadStructure<T>(itemPtr));\r
  40             }\r
  41 \r
  42             return returnList;\r
  43         }\r
  44 \r
  45         /// <summary>\r
  46         /// Creates a native HandBrake list from the given managed list of pointers.\r
  47         /// </summary>\r
  48         /// <param name="list">The managed list to convert.</param>\r
  49         /// <returns>The converted native list.</returns>\r
  50         public static NativeList CreateIntPtrList(List<IntPtr> list)\r
  51         {\r
  52             NativeList returnList = new NativeList();\r
  53             int intSize = Marshal.SizeOf(typeof(IntPtr));\r
  54 \r
  55             IntPtr nativeListInternal = Marshal.AllocHGlobal(list.Count * intSize);\r
  56             returnList.AllocatedMemory.Add(nativeListInternal);\r
  57             for (int i = 0; i < list.Count; i++)\r
  58             {\r
  59                 Marshal.WriteIntPtr(nativeListInternal, i * intSize, list[i]);\r
  60             }\r
  61 \r
  62             hb_list_s nativeListStruct = new hb_list_s();\r
  63             nativeListStruct.items = nativeListInternal;\r
  64             nativeListStruct.items_alloc = list.Count;\r
  65             nativeListStruct.items_count = list.Count;\r
  66 \r
  67             IntPtr nativeListStructPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(hb_list_s)));\r
  68             Marshal.StructureToPtr(nativeListStruct, nativeListStructPtr, false);\r
  69 \r
  70             returnList.ListPtr = nativeListStructPtr;\r
  71             return returnList;\r
  72         }\r
  73 \r
  74         /// <summary>\r
  75         /// Creates a native HandBrake list from the given managed list of structures.\r
  76         /// </summary>\r
  77         /// <typeparam name="T">The type of structures in the list.</typeparam>\r
  78         /// <param name="list">The managed list to convert.</param>\r
  79         /// <returns>The converted native list.</returns>\r
  80         public static NativeList ConvertListBack<T>(List<T> list)\r
  81         {\r
  82             NativeList returnList = new NativeList();\r
  83             int intSize = Marshal.SizeOf(typeof(IntPtr));\r
  84 \r
  85             IntPtr nativeListInternal = Marshal.AllocHGlobal(list.Count * intSize);\r
  86             returnList.AllocatedMemory.Add(nativeListInternal);\r
  87             for (int i = 0; i < list.Count; i++)\r
  88             {\r
  89                 IntPtr itemPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(T)));\r
  90                 returnList.AllocatedMemory.Add(itemPtr);\r
  91                 Marshal.StructureToPtr(list[i], itemPtr, false);\r
  92 \r
  93                 Marshal.WriteIntPtr(nativeListInternal, i * intSize, itemPtr);\r
  94             }\r
  95 \r
  96             hb_list_s nativeListStruct = new hb_list_s();\r
  97             nativeListStruct.items = nativeListInternal;\r
  98             nativeListStruct.items_alloc = list.Count;\r
  99             nativeListStruct.items_count = list.Count;\r
 100 \r
 101             IntPtr nativeListStructPtr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(hb_list_s)));\r
 102             Marshal.StructureToPtr(nativeListStruct, nativeListStructPtr, false);\r
 103 \r
 104             returnList.ListPtr = nativeListStructPtr;\r
 105             return returnList;\r
 106         }\r
 107 \r
 108         /// <summary>\r
 109         /// Frees all the memory locations in the given list.\r
 110         /// </summary>\r
 111         /// <param name="memoryList">The list of memory locations to free.</param>\r
 112         public static void FreeMemory(List<IntPtr> memoryList)\r
 113         {\r
 114             foreach (IntPtr memoryLocation in memoryList)\r
 115             {\r
 116                 Marshal.FreeHGlobal(memoryLocation);\r
 117             }\r
 118         }\r
 119     }\r
 120 }\r