Further harder rom loading, keep data in memory when actively emulati…

…ng and reload through it if needed. Data is deallocated on Esc, and the SHA1 is now calculated via the cached data instead of parsing the file a second time.

src/GuestClass/EmuCores/EmuCores.cpp

@@ -56,15 +56,11 @@ void Chip8_CoreInterface::instructionErrorML(const u32 HI, const u32 LO) {
 	setInterrupt(Interrupt::ERROR);
 }
 
-bool Chip8_CoreInterface::copyGameToMemory(u8* dest, const u32 offset) {
-	std::basic_ifstream<char> ifs(HDM.getFilePath(), std::ios::binary);
-	ifs.read(reinterpret_cast<char*>(dest + offset), HDM.getFileSize());
-	if (ifs.fail()) {
-		blog.newEntry(BLOG::ERROR, "Failed to copy rom data to memory, aborting.");
-		return false;
-	} else {
-		return true;
-	}
+void Chip8_CoreInterface::copyGameToMemory(u8* dest, const u32 offset) {
+	std::copy_n(
+		std::execution::unseq,
+		HDM.getFileData(), HDM.getFileSize(), dest + offset
+	);
 }
 
 void Chip8_CoreInterface::copyFontToMemory(u8* dest, const u32 offset, const u32 size) {

src/GuestClass/EmuCores/EmuCores.hpp

@@ -120,7 +120,7 @@ class Chip8_CoreInterface : public EmuInterface {
 	void instructionError(const u32 HI, const u32 LO);
 	void instructionErrorML(const u32 HI, const u32 LO);
 
-	bool copyGameToMemory(u8* dest, const u32 offset);
+	void copyGameToMemory(u8* dest, const u32 offset);
 	void copyFontToMemory(u8* dest, const u32 offset, const u32 size);
 
 public:

src/HostClass/HomeDirManager.cpp

@@ -5,6 +5,7 @@
 */
 
 #include <fstream>
+#include <iostream>
 
 #include "HomeDirManager.hpp"
 #include "../Assistants/BasicLogger.hpp"
@@ -29,14 +30,10 @@ HomeDirManager::HomeDirManager(const std::string_view homeDirName) try
 }
 
 void HomeDirManager::clearCachedFileData() noexcept {
-	//mFilePath.clear();
-	//mFileName.clear();
-	//mFileStem.clear();
-	//mFileExts.clear();
 	mFilePath.clear();
 	mFileSHA1.clear();
+	mFileData.resize(0);
 	mFileTime = {};
-	mFileSize = {};
 }
 
 void HomeDirManager::addDirectory() {
@@ -63,32 +60,29 @@ bool HomeDirManager::validateGameFile(const FilePath gamePath) noexcept {
 		blog.newEntry(BLOG::WARN, "Provided path is not to a file!");
 		return false;
 	}
-
-	const auto tempSize{ fs::file_size(gamePath, error) };
-	if (error) {
-		blog.newEntry(BLOG::ERROR, "Unable to read file!");
-		return false;
-	}
-	if (tempSize == 0) {
-		blog.newEntry(BLOG::WARN, "File must not be empty!");
-		return false;
-	}
 
 	const auto tempTime{ HDM::getFileTime(gamePath) };
-	const auto tempSHA1{ SHA1::from_file(gamePath.string()) };
+
+	std::ifstream ifs(gamePath, std::ios::binary);
+	mFileData.assign(std::istreambuf_iterator(ifs), {});
 
 	if (tempTime != HDM::getFileTime(gamePath)) {
 		blog.newEntry(BLOG::WARN, "File was modified while reading!");
 		return false;
 	}
 
-	const bool gameApproved{ checkGame(tempSize, gamePath.extension().string(), tempSHA1) };
+	if (!getFileSize()) {
+		blog.newEntry(BLOG::WARN, "File must not be empty!");
+		return false;
+	}
+
+	const auto tempSHA1{ SHA1::from_span(mFileData) };
+	const bool gameApproved{ checkGame(getFileSize(), gamePath.extension().string(), tempSHA1)};
 
 	if (gameApproved) {
 		mFilePath = gamePath;
 		mFileSHA1 = tempSHA1;
 		mFileTime = tempTime;
-		mFileSize = tempSize;
 	}
 
 	if (gameApproved) {

src/HostClass/HomeDirManager.hpp

@@ -8,6 +8,7 @@
 
 #include <cstdint>
 #include <string>
+#include <vector>
 #include <filesystem>
 #include <string_view>
 
@@ -17,15 +18,15 @@ class HomeDirManager final : public BasicHome {
 	using GameValidator = bool (*)(std::uint64_t, std::string_view, std::string_view);
 	using FileModTime   = std::filesystem::file_time_type;
 	using FilePath      = std::filesystem::path;
-	using FileSize      = std::uintmax_t;
 
 	FilePath    mFilePath{};
 	std::string mFileSHA1{};
 	FileModTime mFileTime{};
-	FileSize    mFileSize{};
 
 	GameValidator checkGame{};
 
+	std::vector<char> mFileData{};
+
 public:
 	HomeDirManager(const std::string_view);
 
@@ -37,9 +38,10 @@ class HomeDirManager final : public BasicHome {
 	auto getFileName() const noexcept { return mFilePath.filename().string(); }
 	auto getFileStem() const noexcept { return mFilePath.stem().string(); }
 	auto getFileExts() const noexcept { return mFilePath.extension().string(); }
+	auto getFileSize() const noexcept { return mFileData.size(); }
+	auto getFileData() const noexcept { return mFileData.data(); }
 	auto getFileSHA1() const noexcept { return mFileSHA1; }
 	auto getFileTime() const noexcept { return mFileTime; }
-	auto getFileSize() const noexcept { return mFileSize; }
 
 	void setValidator(GameValidator func) noexcept { checkGame = func; }
 

src/HostClass/HostFunctions.cpp

@@ -68,7 +68,7 @@ SDL_AppResult VM_Host::runFrame() {
 			return SDL_APP_CONTINUE;
 		}
 		if (kb.isPressed(KEY(BACKSPACE))) {
-			loadGameFile(HDM->getFullPath());
+			replaceGuest(false);
 			return SDL_APP_CONTINUE;
 		}
 		if (kb.isPressed(KEY(RSHIFT))) {