1  using Microsoft.IO;
 2  using Ryujinx.Common.Memory;
 3  using Ryujinx.Memory;
 4  using System;
 5  using System.Runtime.CompilerServices;
 6  using System.Runtime.InteropServices;
 7  using System.Text;
 8  
 9  namespace Ryujinx.Cpu
10  {
11      public static class MemoryHelper
12      {
13          public static void FillWithZeros(IVirtualMemoryManager memory, ulong position, int size)
14          {
15              int size8 = size & ~(8 - 1);
16  
17              for (int offs = 0; offs < size8; offs += 8)
18              {
19                  memory.Write<long>(position + (ulong)offs, 0);
20              }
21  
22              for (int offs = size8; offs < (size - size8); offs++)
23              {
24                  memory.Write<byte>(position + (ulong)offs, 0);
25              }
26          }
27  
28          public static T Read<T>(IVirtualMemoryManager memory, ulong position) where T : unmanaged
29          {
30              return MemoryMarshal.Cast<byte, T>(memory.GetSpan(position, Unsafe.SizeOf<T>()))[0];
31          }
32  
33          public static ulong Write<T>(IVirtualMemoryManager memory, ulong position, T value) where T : unmanaged
34          {
35              ReadOnlySpan<byte> data = MemoryMarshal.Cast<T, byte>(MemoryMarshal.CreateReadOnlySpan(ref value, 1));
36  
37              memory.Write(position, data);
38  
39              return (ulong)data.Length;
40          }
41  
42          public static string ReadAsciiString(IVirtualMemoryManager memory, ulong position, long maxSize = -1)
43          {
44              using RecyclableMemoryStream ms = MemoryStreamManager.Shared.GetStream();
45  
46              for (long offs = 0; offs < maxSize || maxSize == -1; offs++)
47              {
48                  byte value = memory.Read<byte>(position + (ulong)offs);
49  
50                  if (value == 0)
51                  {
52                      break;
53                  }
54  
55                  ms.WriteByte(value);
56              }
57  
58              return Encoding.ASCII.GetString(ms.GetReadOnlySequence());
59          }
60      }
61  }