/// <summary>
/// Studies and patches a file.
/// </summary>
/// <param name="patch">The patch file to study.</param>
/// <param name="study">The study struct to use for patching.</param>
/// <param name="source">The unpatched source file.</param>
/// <param name="target">The target file to copy the source file to, but with the patch applied.</param>
public void PatchStudy(string patch, Studier.IpsStudy study, string source, string target)
{
using (FileStream patchStream = File.OpenRead(patch), sourceStream = File.OpenRead(source), targetStream = File.Open(target, FileMode.Create))
{
PatchStudy(patchStream, study, sourceStream, targetStream);
}
}
/// <summary>
/// Patches a stream.
/// </summary>
/// <param name="patch">The patch stream.</param>
/// <param name="source">The unpatched source stream.</param>
/// <param name="target">The target stream to write the source stream to, but with the patch applied.</param>
public void Patch(Stream patch, Stream source, Stream target)
{
Studier studier = new Studier();
Studier.IpsStudy study = studier.Study(patch);
PatchStudy(patch, study, source, target);
}
/// <summary>
/// Studies and patches a stream.
/// </summary>
/// <param name="patch">The patch stream to study.</param>
/// <param name="study">The study struct to use for patching.</param>
/// <param name="source">The unpatched source stream.</param>
/// <param name="target">The target stream to copy the source stream to, but with the patch applied.</param>
public void PatchStudy(Stream patch, Studier.IpsStudy study, Stream source, Stream target)
{
source.CopyTo(target);
long sourceLength = source.Length;
if (study.Error == Studier.IpsError.IpsInvalid)
{
throw new Exceptions.IpsInvalidException();
}
int outlen = (int)Clamp(target.Length, study.OutlenMin, study.OutlenMax);
// Set target file length to new size.
target.SetLength(outlen);
// Skip PATCH text.
patch.Seek(5, SeekOrigin.Begin);
int offset = Reader.Read24(patch);
while (offset != EndOfFile)
{
int size = Reader.Read16(patch);
target.Seek(offset, SeekOrigin.Begin);
// If RLE patch.
if (size == 0)
{
int runLength = Reader.Read16(patch);
byte value = Reader.Read8(patch);
target.Write(Enumerable.Repeat(value, runLength).ToArray(), 0, runLength);
}
// If normal patch.
else
{
byte[] data = new byte[size];
patch.Read(data, 0, size);
target.Write(data, 0, size);
}
offset = Reader.Read24(patch);
}
if (study.OutlenMax != 0xFFFFFFFF && sourceLength <= study.OutlenMax)
{
throw new Exceptions.IpsNotThisException(); // Truncate data without this being needed is a poor idea.
}
}
