win/C#/interop/InteropUtilities.cs

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