BizHawk/BizHawk.Emulation.Common/Interfaces/Services/ISaveRam.cs

namespace BizHawk.Emulation.Common
{
	/// <summary>
	/// This service provides the system by which a client can request SaveRAM data to be stored by the client
	/// SaveRam encompasses things like battery backed ram, memory cards, and data saved to disk drives
	/// If available, save files will be automatically loaded when loading a ROM,
	/// In addition the client will provide features like SRAM-anchored movies, and ways to clear SaveRam
	/// </summary>
	public interface ISaveRam : IEmulatorService
	{
		/// <summary>
		/// Returns a copy of the SaveRAM. Editing it won't do you any good unless you later call StoreSaveRam()
		/// TODO: Prescribe whether this is allowed to return null in case there is no SaveRAM
		/// </summary>
		byte[] CloneSaveRam();

		/// <summary>
		/// store new SaveRAM to the emu core. the data should be the same size as the return from ReadSaveRam()
		/// </summary>
		void StoreSaveRam(byte[] data);

		/// <summary>
		/// Gets a value indicating whether or not SaveRAM has been modified since the last save
		/// TODO: This is not the best interface. What defines a "save"? I suppose a Clone(), right? at least specify that here.
		/// Clone() should probably take an option that says whether to clear the dirty flag.
		/// And anyway, cores might not know if they can even track a functional dirty flag -- we should convey that fact somehow
		/// (reminder: do that with flags, so we don't have to change the interface 10000 times)
		/// Dirty SaveRAM can in principle be determined by the frontend in that case, but it could possibly be too slow for the file menu dropdown or other things
		/// </summary>
		bool SaveRamModified { get; }
	}
}