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