PKHeX/PKHeX.Core/PKM/Strings/StringConverter5.cs
Kurt 47071b41f3
Refactoring: Span-based value writes and method signatures (#3361)
Existing `get`/`set` logic is flawed in that it doesn't work on Big Endian operating systems, and it allocates heap objects when it doesn't need to.

`System.Buffers.Binary.BinaryPrimitives` in the `System.Memory` NuGet package provides both Little Endian and Big Endian methods to read and write data; all the `get`/`set` operations have been reworked to use this new API. This removes the need for PKHeX's manual `BigEndian` class, as all functions are already covered by the BinaryPrimitives API.

The `StringConverter` has now been rewritten to accept a Span to read from & write to, no longer requiring a temporary StringBuilder.

Other Fixes included:
- The Super Training UI for Gen6 has been reworked according to the latest block structure additions.
- Cloning a Stadium2 Save File now works correctly (opening from the Folder browser list).
- Checksum & Sanity properties removed from parent PKM class, and is now implemented via interface.
2022-01-02 21:35:59 -08:00

63 lines
2.1 KiB
C#

using System;
using static System.Buffers.Binary.BinaryPrimitives;
namespace PKHeX.Core;
public static class StringConverter5
{
private const char TerminatorFFFF = (char)0xFFFF;
/// <summary>Converts Generation 5 encoded data to decoded string.</summary>
/// <param name="data">Encoded data</param>
/// <returns>Decoded string.</returns>
public static string GetString(ReadOnlySpan<byte> data)
{
Span<char> result = stackalloc char[data.Length];
int length = LoadString(data, result);
return new string(result[..length].ToArray());
}
private static int LoadString(ReadOnlySpan<byte> data, Span<char> result)
{
int i = 0;
for (; i < data.Length; i += 2)
{
var value = ReadUInt16LittleEndian(data[i..]);
if (value == TerminatorFFFF)
break;
result[i/2] = StringConverter.SanitizeChar((char)value);
}
return i/2;
}
/// <summary>Gets the bytes for a Generation 5 string.</summary>
/// <param name="destBuffer"></param>
/// <param name="value">Decoded string.</param>
/// <param name="maxLength">Maximum length of the input <see cref="value"/></param>
/// <param name="option"></param>
/// <returns>Encoded data.</returns>
public static int SetString(Span<byte> destBuffer, ReadOnlySpan<char> value, int maxLength,
StringConverterOption option = StringConverterOption.ClearZero)
{
if (value.Length > maxLength)
value = value[..maxLength]; // Hard cap
if (option is StringConverterOption.ClearZero)
destBuffer.Clear();
else if (option is StringConverterOption.ClearFF)
destBuffer.Fill(0xFF);
for (int i = 0; i < value.Length; i++)
{
char c = value[i];
ushort val = StringConverter.UnSanitizeChar5(c);
WriteUInt16LittleEndian(destBuffer[(i * 2)..], val);
}
int count = value.Length * 2;
if (count == destBuffer.Length)
return count;
WriteUInt16LittleEndian(destBuffer[count..], TerminatorFFFF);
return count + 2;
}
}