Extract disc hashing from Octoshock, clean it up, and add to Nymashock

src/BizHawk.Client.EmuHawk/MainForm.Events.cs

@@ -1662,8 +1662,8 @@ namespace BizHawk.Client.EmuHawk
 
 		private void PsxHashDiscsMenuItem_Click(object sender, EventArgs e)
 		{
-			if (Emulator is not Octoshock psx) return;
+			if (Emulator is not IRedumpDiscChecksumInfo psx) return;
-			using PSXHashDiscs form = new(psx);
+			using PSXHashDiscs form = new() { _psx = psx };
 			this.ShowDialogWithTempMute(form);
 		}
 

src/BizHawk.Client.EmuHawk/config/PSX/PSXHashDiscs.Designer.cs

@@ -93,7 +93,6 @@
 			this.MaximizeBox = false;
 			this.MinimizeBox = false;
 			this.Name = "PSXHashDiscs";
-			this.Text = "PSX Disc Hasher";
 			this.ResumeLayout(false);
 			this.PerformLayout();
 

src/BizHawk.Client.EmuHawk/config/PSX/PSXHashDiscs.cs

@@ -1,18 +1,21 @@
 using System;
-using System.Windows.Forms;
 
-using BizHawk.Emulation.Cores.Sony.PSX;
+using BizHawk.Emulation.Common;
 
 namespace BizHawk.Client.EmuHawk
 {
-	public partial class PSXHashDiscs : Form
+	[SpecializedTool("Hash Discs")] // puts this in Nymashock's VSystem menu (the generic one), though when opened that way it's not modal
+	public partial class PSXHashDiscs : ToolFormBase
 	{
-		private readonly Octoshock _psx;
+		[RequiredService]
+		public IRedumpDiscChecksumInfo _psx { get; set; }
 
-		public PSXHashDiscs(Octoshock psx)
+		protected override string WindowTitleStatic { get; } = "PSX Disc Hasher";
+
+		public PSXHashDiscs()
 		{
-			_psx = psx;
 			InitializeComponent();
+			btnClose.Click += (_, _) => Close();
 		}
 
 		private void BtnHash_Click(object sender, EventArgs e)

src/BizHawk.Emulation.Common/Interfaces/Services/IRomInfo.cs

@@ -12,4 +12,9 @@
 		/// </summary>
 		string? RomDetails { get; }
 	}
+
+	public interface IRedumpDiscChecksumInfo : IRomInfo
+	{
+		string CalculateDiscHashes();
+	}
 }

src/BizHawk.Emulation.Cores/Consoles/Sony/PSX/DiscChecksumUtils.cs

@@ -0,0 +1,57 @@
+#nullable enable
+
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Runtime.CompilerServices;
+
+using BizHawk.Emulation.Common;
+using BizHawk.Emulation.DiscSystem;
+
+namespace BizHawk.Emulation.Cores.Sony.PSX
+{
+	internal static class DiscChecksumUtils
+	{
+		private static readonly ConditionalWeakTable<Disc, string> _redumpHashCache = new();
+
+		public static string CalculateDiscHashesImpl(IReadOnlyList<Disc> discs)
+			=> string.Join("\n", discs.Select(static disc =>
+			{
+				if (_redumpHashCache.TryGetValue(disc, out var hash)) return hash;
+				try
+				{
+					hash = $"{new DiscHasher(disc).Calculate_PSX_RedumpHash():X8} {disc.Name}";
+				}
+				catch
+				{
+					// ignored
+					return string.Empty;
+				}
+				_redumpHashCache.Add(disc, hash);
+				return hash;
+			}));
+
+		public static string GenQuickRomDetails(IReadOnlyList<IDiscAsset> discs)
+		{
+			static string DiscHashWarningText(string discHash)
+			{
+				var game = Database.CheckDatabase(discHash);
+				return game?.Status is null or RomStatus.BadDump or RomStatus.NotInDatabase or RomStatus.Overdump
+					? "Disc could not be identified as known-good. Look for a better rip."
+					: $@"Disc was identified (99.99% confidently) as known good with disc id hash CRC32:{discHash}
+Nonetheless it could be an unrecognized romhack or patched version.
+According to redump.org, the ideal hash for entire disc is: CRC32:{game.GetStringValue("dh")}
+The file you loaded hasn't been hashed entirely (it would take too long)
+Compare it with the full hash calculated by the PSX menu's Hash Discs tool";
+			}
+			return discs.Count is 0
+				? "PSX exe"
+				: string.Join("\n", discs.SelectMany(static disc => new[]
+				{
+					Path.GetFileName(disc.DiscName),
+					DiscHashWarningText(new DiscHasher(disc.DiscData).Calculate_PSX_BizIDHash()),
+					"-------------------------",
+				}));
+		}
+	}
+}

src/BizHawk.Emulation.Cores/Consoles/Sony/PSX/Nymashock.cs

@@ -5,12 +5,17 @@ using BizHawk.Common;
 using BizHawk.Common.StringExtensions;
 using BizHawk.Emulation.Common;
 using BizHawk.Emulation.Cores.Waterbox;
+using BizHawk.Emulation.DiscSystem;
 
 namespace BizHawk.Emulation.Cores.Sony.PSX
 {
 	[PortedCore(CoreNames.Nymashock, "Mednafen Team", "1.29.0", "https://mednafen.github.io/releases/")]
-	public class Nymashock : NymaCore, IRegionable, ICycleTiming
+	public class Nymashock : NymaCore, IRegionable, ICycleTiming, IRedumpDiscChecksumInfo
 	{
+		public string RomDetails { get; }
+
+		private readonly IReadOnlyList<Disc> _discs;
+
 		protected override void AddAxis(
 			ControllerDefinition ret,
 			string name,
@@ -68,8 +73,16 @@ namespace BizHawk.Emulation.Cores.Sony.PSX
 			DoInit<LibNymaCore>(lp, "shock.wbx", firmwares);
 
 			_cachedSettingsInfo ??= SettingsInfo.Clone();
+
+			List<Disc> discs = new();
+			foreach (var disc in lp.Discs) discs.Add(disc.DiscData);
+			_discs = discs;
+			RomDetails = DiscChecksumUtils.GenQuickRomDetails(lp.Discs);
 		}
 
+		public string CalculateDiscHashes()
+			=> DiscChecksumUtils.CalculateDiscHashesImpl(_discs);
+
 		protected override IDictionary<string, SettingOverride> SettingOverrides { get; } = new Dictionary<string, SettingOverride>
 		{
 			{ "psx.bios_jp", new() { Hide = true , Default = "$J" } }, // FIRMWARE:

src/BizHawk.Emulation.Cores/Consoles/Sony/PSX/Octoshock.cs

@@ -16,7 +16,6 @@ using System.Runtime.InteropServices;
 using System.IO;
 using System.Collections.Generic;
 using System.Linq;
-using System.Text;
 
 using Newtonsoft.Json;
 
@@ -30,7 +29,9 @@ using BizHawk.Emulation.DiscSystem;
 namespace BizHawk.Emulation.Cores.Sony.PSX
 {
 	[PortedCore(CoreNames.Octoshock, "Mednafen Team")]
-	public unsafe partial class Octoshock : IEmulator, IVideoProvider, ISoundProvider, ISaveRam, IStatable, IDriveLight, ISettable<Octoshock.Settings, Octoshock.SyncSettings>, IRegionable, IInputPollable, IRomInfo
+	public unsafe partial class Octoshock : IEmulator, IInputPollable, IRegionable, ISaveRam,
+		ISettable<Octoshock.Settings, Octoshock.SyncSettings>, ISoundProvider, IStatable, IVideoProvider,
+		IDriveLight, IRedumpDiscChecksumInfo
 	{
 		public Octoshock(CoreComm comm, PSF psf, Octoshock.Settings settings, Octoshock.SyncSettings syncSettings)
 		{
@@ -44,45 +45,15 @@ namespace BizHawk.Emulation.Cores.Sony.PSX
 		[CoreConstructor(VSystemID.Raw.PSX)]
 		public Octoshock(CoreLoadParameters<Octoshock.Settings, Octoshock.SyncSettings> lp)
 		{
-			string romDetails;
-			if (lp.Discs.Count > 0)
-			{
-				string DiscHashWarningText(GameInfo game, string discHash)
-				{
-					if (game == null || game.IsRomStatusBad() || game.Status == RomStatus.NotInDatabase)
-					{
-						return "Disc could not be identified as known-good. Look for a better rip.";
-					}
-					else
-					{
-						return $"Disc was identified (99.99% confidently) as known good with disc id hash CRC32:{discHash}\n"
-							+ "Nonetheless it could be an unrecognized romhack or patched version.\n"
-							+ $"According to redump.org, the ideal hash for entire disc is: CRC32:{game.GetStringValue("dh")}\n"
-							+ "The file you loaded hasn't been hashed entirely (it would take too long)\n"
-							+ "Compare it with the full hash calculated by the PSX menu's Hash Discs tool";
-					}
-				}
-
-				var sw = new StringWriter();
-				foreach (var d in lp.Discs)
-				{
-					var discHash = new DiscHasher(d.DiscData).Calculate_PSX_BizIDHash();
-					sw.WriteLine(Path.GetFileName(d.DiscName));
-					sw.WriteLine(DiscHashWarningText(Database.CheckDatabase(discHash), discHash));
-					sw.WriteLine("-------------------------");
-				}
-				romDetails = sw.ToString();
-			}
-			else
-			{
-				romDetails = "PSX exe";
-			}
-
 			Load(
 				lp.Comm,
 				lp.Discs.Select(d => d.DiscData).ToList(),
 				lp.Discs.Select(d => d.DiscName).ToList(),
-				lp.Roms.FirstOrDefault()?.RomData, lp.Settings, lp.SyncSettings, null, romDetails);
+				lp.Roms.FirstOrDefault()?.RomData,
+				lp.Settings,
+				lp.SyncSettings,
+				null,
+				DiscChecksumUtils.GenQuickRomDetails(lp.Discs));
 			OctoshockDll.shock_PowerOn(psx);
 		}
 
@@ -498,21 +469,7 @@ namespace BizHawk.Emulation.Cores.Sony.PSX
 		}
 
 		public string CalculateDiscHashes()
-		{
+			=> DiscChecksumUtils.CalculateDiscHashesImpl(Discs);
-			var sb = new StringBuilder();
-			try
-			{
-				foreach (var disc in Discs)
-				{
-					sb.Append($"{new DiscHasher(disc).Calculate_PSX_RedumpHash():X8} {disc.Name}\r\n");
-				}
-			}
-			catch
-			{
-				// ignored
-			}
-			return sb.ToString();
-		}
 
 		public void ResetCounters()
 		{