PKHeX/PKHeX.Core/Saves/Storage/SAV4Ranch.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

97 lines
4 KiB
C#

using System;
using System.Collections.Generic;
using System.Security.Cryptography;
using static System.Buffers.Binary.BinaryPrimitives;
namespace PKHeX.Core
{
/// <summary>
/// Generation 4 <see cref="SaveFile"/> object for My Pokémon Ranch saves.
/// </summary>
public sealed class SAV4Ranch : BulkStorage, ISaveFileRevision
{
protected override int SIZE_STORED => 0x88 + 0x1C;
protected override int SIZE_PARTY => SIZE_STORED;
public int SaveRevision => Version == GameVersion.DP ? 0 : 1;
public string SaveRevisionString => Version == GameVersion.DP ? "-DP" : "-Pt";
public override int BoxCount { get; }
public override int SlotCount { get; }
public override PersonalTable Personal => PersonalTable.Pt;
public override IReadOnlyList<ushort> HeldItems => Legal.HeldItems_Pt;
protected override SaveFile CloneInternal() => new SAV4Ranch((byte[])Data.Clone());
public override string PlayTimeString => Checksums.CRC16Invert(Data).ToString("X4");
protected internal override string ShortSummary => $"{OT} {PlayTimeString}";
public override string Extension => ".bin";
protected override PKM GetPKM(byte[] data) => new PK4(data);
protected override byte[] DecryptPKM(byte[] data) => PokeCrypto.DecryptArray45(data);
public override StorageSlotFlag GetSlotFlags(int index) => index >= SlotCount ? StorageSlotFlag.Locked : StorageSlotFlag.None;
protected override bool IsSlotSwapProtected(int box, int slot) => IsSlotOverwriteProtected(box, slot);
public SAV4Ranch(byte[] data) : base(data, typeof(PK4), 0)
{
Version = Data.Length == SaveUtil.SIZE_G4RANCH_PLAT ? GameVersion.Pt : GameVersion.DP;
OT = GetString(0x770, 0x12);
// 0x18 starts the header table
// Block 00, Offset = ???
// Block 01, Offset = Mii Data
// Block 02, Offset = Mii Link Data
// Block 03, Offset = Pokemon Data
// Block 04, Offset = ??
// Unpack the binary a little:
// size, count, Mii data[count]
// size, count, Mii Link data[count]
// size, count, Pokemon (PK4 + metadata)[count]
// size, count, ???
/* ====Metadata====
* uint8_t poke_type;// 01 trainer, 04 hayley, 05 traded
* uint8_t tradeable;// 02 is tradeable, normal 00
* uint16_t tid;
* uint16_t sid;
* uint32_t name1;
* uint32_t name2;
* uint32_t name3;
* uint32_t name4;
*/
var pkCountOffset = ReadInt32BigEndian(Data.AsSpan(0x34)) + 4;
SlotCount = ReadInt32BigEndian(Data.AsSpan(pkCountOffset));
BoxCount = (int)Math.Ceiling((decimal)SlotCount / SlotsPerBox);
Box = pkCountOffset + 4;
FinalCountOffset = ReadInt32BigEndian(Data.AsSpan(0x3C));
FinalCount = ReadInt32BigEndian(Data.AsSpan(FinalCountOffset));
}
private readonly int FinalCount;
private readonly int FinalCountOffset;
protected override void SetChecksums()
{
// ensure the final data is written if the user screws stuff up
WriteInt32BigEndian(Data.AsSpan(FinalCountOffset), FinalCount);
var goodlen = (FinalCountOffset + 4);
Array.Clear(Data, goodlen, Data.Length - goodlen);
// 20 byte SHA checksum at the top of the file, which covers all data that follows.
using var hash = SHA1.Create();
var result = hash.ComputeHash(Data, 20, Data.Length - 20);
SetData(result, 0);
}
public override string GetString(ReadOnlySpan<byte> data) => StringConverter4GC.GetStringUnicode(data);
public override int SetString(Span<byte> destBuffer, ReadOnlySpan<char> value, int maxLength, StringConverterOption option)
{
return StringConverter4GC.SetStringUnicode(value, destBuffer, maxLength, option);
}
}
}