Host: Add message translation functions

pcsx2-gsrunner/Main.cpp

@@ -658,6 +658,18 @@ void Host::VSyncOnCPUThread()
 	GSRunner::PumpPlatformMessages();
 }
 
+s32 Host::Internal::GetTranslatedStringImpl(
+	const std::string_view& context, const std::string_view& msg, char* tbuf, size_t tbuf_space)
+{
+	if (msg.size() > tbuf_space)
+		return -1;
+	else if (msg.empty())
+		return 0;
+
+	std::memcpy(tbuf, msg.data(), msg.size());
+	return static_cast<s32>(msg.size());
+}
+
 //////////////////////////////////////////////////////////////////////////
 // Platform specific code
 //////////////////////////////////////////////////////////////////////////

pcsx2-qt/QtHost.cpp

@@ -1179,6 +1179,23 @@ void Host::SetFullscreen(bool enabled)
 	g_emu_thread->setFullscreen(enabled, true);
 }
 
+s32 Host::Internal::GetTranslatedStringImpl(
+	const std::string_view& context, const std::string_view& msg, char* tbuf, size_t tbuf_space)
+{
+	// This is really awful. Thankfully we're caching the results...
+	const std::string temp_context(context);
+	const std::string temp_msg(msg);
+	const QString translated_msg = qApp->translate(temp_context.c_str(), temp_msg.c_str());
+	const QByteArray translated_utf8 = translated_msg.toUtf8();
+	const size_t translated_size = translated_utf8.size();
+	if (translated_size > tbuf_space)
+		return -1;
+	else if (translated_size > 0)
+		std::memcpy(tbuf, translated_utf8.constData(), translated_size);
+
+	return static_cast<s32>(translated_size);
+}
+
 alignas(16) static SysMtgsThread s_mtgs_thread;
 
 SysMtgsThread& GetMTGS()

pcsx2/Host.cpp

@@ -26,13 +26,122 @@
 #include "common/Assertions.h"
 #include "common/CrashHandler.h"
 #include "common/FileSystem.h"
+#include "common/HeterogeneousContainers.h"
 #include "common/Path.h"
 #include "common/StringUtil.h"
 
 #include <cstdarg>
+#include <shared_mutex>
 
-static std::mutex s_settings_mutex;
-static LayeredSettingsInterface s_layered_settings_interface;
+namespace Host
+{
+	static std::pair<const char*, u32> LookupTranslationString(
+		const std::string_view& context, const std::string_view& msg);
+
+	static std::mutex s_settings_mutex;
+	static LayeredSettingsInterface s_layered_settings_interface;
+
+	static constexpr u32 TRANSLATION_STRING_CACHE_SIZE = 4 * 1024 * 1024;
+	using TranslationStringMap = UnorderedStringMap<std::pair<u32, u32>>;
+	using TranslationStringContextMap = UnorderedStringMap<TranslationStringMap>;
+	static std::shared_mutex s_translation_string_mutex;
+	static TranslationStringContextMap s_translation_string_map;
+	static std::vector<char> s_translation_string_cache;
+	static u32 s_translation_string_cache_pos;
+} // namespace Host
+
+std::pair<const char*, u32> Host::LookupTranslationString(const std::string_view& context, const std::string_view& msg)
+{
+	// TODO: TranslatableString, compile-time hashing.
+
+	TranslationStringContextMap::iterator ctx_it;
+	TranslationStringMap::iterator msg_it;
+	std::pair<const char*, u32> ret;
+	s32 len;
+
+	// Shouldn't happen, but just in case someone tries to translate an empty string.
+	if (unlikely(msg.empty()))
+	{
+		ret.first = &s_translation_string_cache[0];
+		ret.second = 0;
+		return ret;
+	}
+
+	s_translation_string_mutex.lock_shared();
+	ctx_it = UnorderedStringMapFind(s_translation_string_map, context);
+
+	if (unlikely(ctx_it == s_translation_string_map.end()))
+		goto add_string;
+
+	msg_it = UnorderedStringMapFind(ctx_it->second, msg);
+	if (unlikely(msg_it == ctx_it->second.end()))
+		goto add_string;
+
+	ret.first = &s_translation_string_cache[msg_it->second.first];
+	ret.second = msg_it->second.second;
+	s_translation_string_mutex.unlock_shared();
+	return ret;
+
+add_string:
+	s_translation_string_mutex.unlock_shared();
+	s_translation_string_mutex.lock();
+
+	if (unlikely(s_translation_string_cache.empty()))
+	{
+		// First element is always an empty string.
+		s_translation_string_cache.resize(TRANSLATION_STRING_CACHE_SIZE);
+		s_translation_string_cache[0] = '\0';
+		s_translation_string_cache_pos = 0;
+	}
+
+	if ((len = Internal::GetTranslatedStringImpl(context, msg,
+			 &s_translation_string_cache[s_translation_string_cache_pos],
+			 TRANSLATION_STRING_CACHE_SIZE - 1 - s_translation_string_cache_pos)) < 0)
+	{
+		Console.Error("WARNING: Clearing translation string cache, it might need to be larger.");
+		s_translation_string_cache_pos = 0;
+		if ((len = Internal::GetTranslatedStringImpl(context, msg,
+				 &s_translation_string_cache[s_translation_string_cache_pos],
+				 TRANSLATION_STRING_CACHE_SIZE - 1 - s_translation_string_cache_pos)) < 0)
+		{
+			pxFailRel("Failed to get translated string after clearing cache.");
+			len = 0;
+		}
+	}
+
+	// New context?
+	if (ctx_it == s_translation_string_map.end())
+		ctx_it = s_translation_string_map.emplace(context, TranslationStringMap()).first;
+
+	// Impl doesn't null terminate, we need that for C strings.
+	// TODO: do we want to consider aligning the buffer?
+	const u32 insert_pos = s_translation_string_cache_pos;
+	s_translation_string_cache[insert_pos + static_cast<u32>(len)] = 0;
+
+	ctx_it->second.emplace(msg, std::pair<u32, u32>(insert_pos, static_cast<u32>(len)));
+	s_translation_string_cache_pos = insert_pos + static_cast<u32>(len) + 1;
+
+	ret.first = &s_translation_string_cache[insert_pos];
+	ret.second = static_cast<u32>(len);
+	s_translation_string_mutex.unlock();
+	return ret;
+}
+
+const char* Host::TranslateToCString(const std::string_view& context, const std::string_view& msg)
+{
+	return LookupTranslationString(context, msg).first;
+}
+
+std::string_view Host::TranslateToStringView(const std::string_view& context, const std::string_view& msg)
+{
+	const auto mp = LookupTranslationString(context, msg);
+	return std::string_view(mp.first, mp.second);
+}
+
+std::string Host::TranslateToString(const std::string_view& context, const std::string_view& msg)
+{
+	return std::string(TranslateToStringView(context, msg));
+}
 
 void Host::ReportFormattedErrorAsync(const std::string_view& title, const char* format, ...)
 {

pcsx2/Host.h

@@ -17,6 +17,8 @@
 
 #include "common/Pcsx2Defs.h"
 
+#include "fmt/format.h"
+
 #include <ctime>
 #include <functional>
 #include <mutex>
@@ -48,6 +50,24 @@ namespace Host
 	/// Returns the modified time of a resource.
 	std::optional<std::time_t> GetResourceFileTimestamp(const char* filename);
 
+	/// Returns a localized version of the specified string within the specified context.
+	/// The pointer is guaranteed to be valid until the next language change.
+	const char* TranslateToCString(const std::string_view& context, const std::string_view& msg);
+
+	/// Returns a localized version of the specified string within the specified context.
+	/// The view is guaranteed to be valid until the next language change.
+	/// NOTE: When passing this to fmt, positional arguments should be used in the base string, as
+	/// not all locales follow the same word ordering.
+	std::string_view TranslateToStringView(const std::string_view& context, const std::string_view& msg);
+
+	/// Returns a localized version of the specified string within the specified context.
+	std::string TranslateToString(const std::string_view& context, const std::string_view& msg);
+
+	/// Returns a localized version of the specified string, after formatting.
+
+	template<typename... T>
+	std::string TranslateAndFmt(const std::string_view& context, const std::string_view& format, T&&... args);
+
 	/// Adds OSD messages, duration is in seconds.
 	void AddOSDMessage(std::string message, float duration = 2.0f);
 	void AddKeyedOSDMessage(std::string key, std::string message, float duration = 2.0f);
@@ -155,5 +175,16 @@ namespace Host
 
 		/// Sets the input profile settings layer. Called by VMManager when the game changes.
 		void SetInputSettingsLayer(SettingsInterface* sif);
+
+		/// Implementation to retrieve a translated string.
+		s32 GetTranslatedStringImpl(const std::string_view& context, const std::string_view& msg, char* tbuf, size_t tbuf_space);
 	} // namespace Internal
 } // namespace Host
+
+// Helper macros for retrieving translated strings.
+#define TRANSLATE(context, msg) Host::TranslateToCString(context, msg)
+#define TRANSLATE_SV(context, msg) Host::TranslateToStringView(context, msg)
+#define TRANSLATE_STR(context, msg) Host::TranslateToString(context, msg)
+
+// Does not translate the string at runtime, but allows the UI to in its own way.
+#define TRANSLATE_NOOP(context, msg) msg