System: Rewrite save state I/O

No more ByteStream or virtual calls for every piece of data.

src/common/string_util.cpp

@@ -124,6 +124,12 @@ std::size_t StringUtil::Strlcpy(char* dst, const char* src, std::size_t size)
   return len;
 }
 
+std::size_t StringUtil::Strnlen(const char* str, std::size_t max_size)
+{
+  const char* loc = static_cast<const char*>(std::memchr(str, 0, max_size));
+  return loc ? static_cast<size_t>(loc - str) : max_size;
+}
+
 std::size_t StringUtil::Strlcpy(char* dst, const std::string_view src, std::size_t size)
 {
   std::size_t len = src.length();

src/common/string_util.h

@@ -35,6 +35,9 @@ std::size_t Strlcpy(char* dst, const char* src, std::size_t size);
 /// Strlcpy from string_view.
 std::size_t Strlcpy(char* dst, const std::string_view src, std::size_t size);
 
+/// Bounds checked version of strlen.
+std::size_t Strnlen(const char* str, std::size_t max_size);
+
 /// Platform-independent strcasecmp
 static inline int Strcasecmp(const char* s1, const char* s2)
 {

src/core/CMakeLists.txt

@@ -136,8 +136,8 @@ set(NEWREC_SOURCES
 target_precompile_headers(core PRIVATE "pch.h")
 target_include_directories(core PRIVATE "${CMAKE_CURRENT_SOURCE_DIR}/..")
 target_include_directories(core PUBLIC "${CMAKE_CURRENT_SOURCE_DIR}/..")
-target_link_libraries(core PUBLIC Threads::Threads common util ZLIB::ZLIB)
-target_link_libraries(core PRIVATE xxhash imgui rapidyaml rcheevos cpuinfo::cpuinfo)
+target_link_libraries(core PUBLIC Threads::Threads common util)
+target_link_libraries(core PRIVATE xxhash imgui rapidyaml rcheevos cpuinfo::cpuinfo ZLIB::ZLIB Zstd::Zstd)
 
 if(CPU_ARCH_X64)
   target_compile_definitions(core PUBLIC "ENABLE_RECOMPILER=1" "ENABLE_NEWREC=1" "ENABLE_MMAP_FASTMEM=1")

src/core/fullscreen_ui.cpp

@@ -5559,11 +5559,11 @@ bool FullscreenUI::InitializeSaveStateListEntryFromPath(SaveStateListEntry* li,
 void FullscreenUI::PopulateSaveStateScreenshot(SaveStateListEntry* li, const ExtendedSaveStateInfo* ssi)
 {
   li->preview_texture.reset();
-  if (ssi && !ssi->screenshot_data.empty())
+  if (ssi && ssi->screenshot.IsValid())
   {
-    li->preview_texture = g_gpu_device->FetchTexture(ssi->screenshot_width, ssi->screenshot_height, 1, 1, 1,
+    li->preview_texture = g_gpu_device->FetchTexture(ssi->screenshot.GetWidth(), ssi->screenshot.GetHeight(), 1, 1, 1,
                                                      GPUTexture::Type::Texture, GPUTexture::Format::RGBA8,
-                                                     ssi->screenshot_data.data(), sizeof(u32) * ssi->screenshot_width);
+                                                     ssi->screenshot.GetPixels(), ssi->screenshot.GetPitch());
   }
   else
   {
@@ -6112,7 +6112,7 @@ void FullscreenUI::DoLoadState(std::string path)
       else
       {
         Error error;
-        if (!System::LoadState(path.c_str(), &error))
+        if (!System::LoadState(path.c_str(), &error, true))
         {
           ShowToast(std::string(),
                     fmt::format(TRANSLATE_FS("System", "Failed to load state: {}"), error.GetDescription()));

src/core/hotkeys.cpp

@@ -84,7 +84,7 @@ static void HotkeyLoadStateSlot(bool global, s32 slot)
   }
 
   Error error;
-  if (!System::LoadState(path.c_str(), &error))
+  if (!System::LoadState(path.c_str(), &error, true))
   {
     Host::AddKeyedOSDMessage(
       "LoadState",

src/core/imgui_overlays.cpp

@@ -891,11 +891,11 @@ void SaveStateSelectorUI::InitializeListEntry(ListEntry* li, ExtendedSaveStateIn
   {
     g_gpu_device->RecycleTexture(std::move(li->preview_texture));
 
-    if (ssi && !ssi->screenshot_data.empty())
+    if (ssi->screenshot.IsValid())
     {
-      li->preview_texture = g_gpu_device->FetchTexture(
-        ssi->screenshot_width, ssi->screenshot_height, 1, 1, 1, GPUTexture::Type::Texture, GPUTexture::Format::RGBA8,
-        ssi->screenshot_data.data(), sizeof(u32) * ssi->screenshot_width);
+      li->preview_texture = g_gpu_device->FetchTexture(ssi->screenshot.GetWidth(), ssi->screenshot.GetHeight(), 1, 1, 1,
+                                                       GPUTexture::Type::Texture, GPUTexture::Format::RGBA8,
+                                                       ssi->screenshot.GetPixels(), ssi->screenshot.GetPitch());
       if (!li->preview_texture) [[unlikely]]
         ERROR_LOG("Failed to upload save state image to GPU");
     }
@@ -1084,7 +1084,7 @@ void SaveStateSelectorUI::LoadCurrentSlot()
     if (FileSystem::FileExists(path.c_str()))
     {
       Error error;
-      if (!System::LoadState(path.c_str(), &error))
+      if (!System::LoadState(path.c_str(), &error, true))
       {
         Host::AddKeyedOSDMessage("LoadState",
                                  fmt::format(TRANSLATE_FS("OSDMessage", "Failed to load state from slot {0}:\n{1}"),

src/core/pad.cpp

@@ -133,7 +133,7 @@ static bool s_receive_buffer_full = false;
 static bool s_transmit_buffer_full = false;
 
 static u32 s_last_memory_card_transfer_frame = 0;
-static std::unique_ptr<GrowableMemoryByteStream> s_memory_card_backup;
+static DynamicHeapArray<u8> s_memory_card_backup;
 static std::unique_ptr<MemoryCard> s_dummy_card;
 
 } // namespace Pad
@@ -145,7 +145,7 @@ void Pad::Initialize()
 
 void Pad::Shutdown()
 {
-  s_memory_card_backup.reset();
+  s_memory_card_backup.deallocate();
 
   s_transfer_event.Deactivate();
 
@@ -197,7 +197,7 @@ bool Pad::DoStateController(StateWrapper& sw, u32 i)
   if (controller_type != state_controller_type)
   {
     const Controller::ControllerInfo* state_cinfo = Controller::GetControllerInfo(state_controller_type);
-    Assert(sw.GetMode() == StateWrapper::Mode::Read);
+    Assert(sw.IsReading());
 
     // UI notification portion is separated from emulation portion (intentional condition check redundancy)
     if (g_settings.load_devices_from_save_states)
@@ -363,16 +363,10 @@ void Pad::BackupMemoryCardState()
 {
   DEV_LOG("Backing up memory card state.");
 
-  if (!s_memory_card_backup)
-  {
-    s_memory_card_backup =
-      std::make_unique<GrowableMemoryByteStream>(nullptr, MemoryCard::STATE_SIZE * NUM_CONTROLLER_AND_CARD_PORTS);
-  }
-
-  s_memory_card_backup->SeekAbsolute(0);
-
-  StateWrapper sw(s_memory_card_backup.get(), StateWrapper::Mode::Write, SAVE_STATE_VERSION);
+  if (s_memory_card_backup.empty())
+    s_memory_card_backup.resize(MemoryCard::STATE_SIZE * NUM_CONTROLLER_AND_CARD_PORTS);
 
+  StateWrapper sw(s_memory_card_backup.span(), StateWrapper::Mode::Write, SAVE_STATE_VERSION);
   for (u32 i = 0; i < NUM_CONTROLLER_AND_CARD_PORTS; i++)
   {
     if (s_memory_cards[i])
@@ -382,13 +376,11 @@ void Pad::BackupMemoryCardState()
 
 void Pad::RestoreMemoryCardState()
 {
-  DebugAssert(s_memory_card_backup);
+  DebugAssert(!s_memory_card_backup.empty());
 
   VERBOSE_LOG("Restoring backed up memory card state.");
 
-  s_memory_card_backup->SeekAbsolute(0);
-  StateWrapper sw(s_memory_card_backup.get(), StateWrapper::Mode::Read, SAVE_STATE_VERSION);
-
+  StateWrapper sw(s_memory_card_backup.cspan(), StateWrapper::Mode::Read, SAVE_STATE_VERSION);
   for (u32 i = 0; i < NUM_CONTROLLER_AND_CARD_PORTS; i++)
   {
     if (s_memory_cards[i])

src/core/pine_server.cpp

@@ -493,7 +493,7 @@ bool PINEServer::PINESocket::HandleCommand(IPCCommand command, BinarySpanReader
 
       Host::RunOnCPUThread([state_filename = std::move(state_filename)] {
         Error error;
-        if (!System::LoadState(state_filename.c_str(), &error))
+        if (!System::LoadState(state_filename.c_str(), &error, true))
           ERROR_LOG("PINE: Load state failed: {}", error.GetDescription());
       });
 

src/core/save_state_version.h

@@ -5,37 +5,42 @@
 #include "types.h"
 
 static constexpr u32 SAVE_STATE_MAGIC = 0x43435544;
-static constexpr u32 SAVE_STATE_VERSION = 68;
+static constexpr u32 SAVE_STATE_VERSION = 69;
 static constexpr u32 SAVE_STATE_MINIMUM_VERSION = 42;
 
 static_assert(SAVE_STATE_VERSION >= SAVE_STATE_MINIMUM_VERSION);
 
+enum class SaveStateCompression : u32
+{
+  None = 0,
+  ZLib = 1,
+  ZStd = 2,
+};
+
 #pragma pack(push, 4)
 struct SAVE_STATE_HEADER
 {
   enum : u32
   {
     MAX_TITLE_LENGTH = 128,
     MAX_SERIAL_LENGTH = 32,
-
-    COMPRESSION_TYPE_NONE = 0,
-    COMPRESSION_TYPE_ZLIB = 1,
-    COMPRESSION_TYPE_ZSTD = 2,
   };
 
   u32 magic;
   u32 version;
   char title[MAX_TITLE_LENGTH];
   char serial[MAX_SERIAL_LENGTH];
 
-  u32 media_filename_length;
-  u32 offset_to_media_filename;
+  u32 media_path_length;
+  u32 offset_to_media_path;
   u32 media_subimage_index;
-  u32 unused_offset_to_playlist_filename; // Unused as of version 51.
-
+
+  // Screenshot compression added in version 69.
+  // Uncompressed size not stored, it can be inferred from width/height.
+  u32 screenshot_compression_type;
   u32 screenshot_width;
   u32 screenshot_height;
-  u32 screenshot_size;
+  u32 screenshot_compressed_size;
   u32 offset_to_screenshot;
 
   u32 data_compression_type;