Ryujinx/Ryujinx.HLE/Loaders/Mods/MemPatch.cs
Ac_K 5d08e9b495
hos: Cleanup the project (#2634)
* hos: Cleanup the project

Since a lot of changes has been done on the HOS project, there are some leftover here and there, or class just used in one service, things at wrong places, and more.
This PR fixes that, additionnally to that, I've realigned some vars because I though it make the code more readable.

* Address gdkchan feedback

* addresses Thog feedback

* Revert ElfSymbol
2021-09-15 01:24:49 +02:00

96 lines
3.2 KiB
C#

using Ryujinx.Common.Logging;
using System;
using System.Collections.Generic;
using System.Linq;
namespace Ryujinx.HLE.Loaders.Mods
{
public class MemPatch
{
readonly Dictionary<uint, byte[]> _patches = new Dictionary<uint, byte[]>();
/// <summary>
/// Adds a patch to specified offset. Overwrites if already present.
/// </summary>
/// <param name="offset">Memory offset</param>
/// <param name="patch">The patch to add</param>
public void Add(uint offset, byte[] patch)
{
_patches[offset] = patch;
}
/// <summary>
/// Adds a patch in the form of an RLE (Fill mode).
/// </summary>
/// <param name="offset">Memory offset</param>
/// <param name="length"The fill length</param>
/// <param name="filler">The byte to fill</param>
public void AddFill(uint offset, int length, byte filler)
{
// TODO: Can be made space efficient by changing `_patches`
// Should suffice for now
byte[] patch = new byte[length];
patch.AsSpan().Fill(filler);
_patches[offset] = patch;
}
/// <summary>
/// Adds all patches from an existing MemPatch
/// </summary>
/// <param name="patches">The patches to add</param>
public void AddFrom(MemPatch patches)
{
if (patches == null)
{
return;
}
foreach (var (patchOffset, patch) in patches._patches)
{
_patches[patchOffset] = patch;
}
}
/// <summary>
/// Applies all the patches added to this instance.
/// </summary>
/// <remarks>
/// Patches are applied in ascending order of offsets to guarantee
/// overlapping patches always apply the same way.
/// </remarks>
/// <param name="memory">The span of bytes to patch</param>
/// <param name="maxSize">The maximum size of the slice of patchable memory</param>
/// <param name="protectedOffset">A secondary offset used in special cases (NSO header)</param>
/// <returns>Successful patches count</returns>
public int Patch(Span<byte> memory, int protectedOffset = 0)
{
int count = 0;
foreach (var (offset, patch) in _patches.OrderBy(item => item.Key))
{
int patchOffset = (int)offset;
int patchSize = patch.Length;
if (patchOffset < protectedOffset || patchOffset > memory.Length)
{
continue; // Add warning?
}
patchOffset -= protectedOffset;
if (patchOffset + patchSize > memory.Length)
{
patchSize = memory.Length - patchOffset; // Add warning?
}
Logger.Info?.Print(LogClass.ModLoader, $"Patching address offset {patchOffset:x} <= {BitConverter.ToString(patch).Replace('-', ' ')} len={patchSize}");
patch.AsSpan().Slice(0, patchSize).CopyTo(memory.Slice(patchOffset, patchSize));
count++;
}
return count;
}
}
}