Merge pull request #5605 from Web-eWorks/lang-string-view

Use std::string_view for C++ Lang handling

src/Lang.cpp

@@ -104,23 +104,27 @@ namespace Lang {
 		return true;
 	}
 
-	const std::string &Resource::Get(const std::string &token) const
+	static const std::string _empty = "";
+	const std::string &Resource::Get(std::string_view token) const
 	{
 		std::map<std::string, std::string>::const_iterator i = m_strings.find(token);
 		if (i == m_strings.end()) {
-			static const std::string empty;
-			return empty;
+			return _empty;
 		}
 		return (*i).second;
 	}
 
-	std::vector<std::string> Resource::GetAvailableLanguages(const std::string &resourceName)
+	std::vector<std::string> Resource::GetAvailableLanguages(std::string_view resourceName)
 	{
 		std::vector<std::string> languages;
 
-		for (FileSystem::FileEnumerator files(FileSystem::gameDataFiles, "lang/" + resourceName); !files.Finished(); files.Next()) {
+		std::string searchPath = "lang/";
+		searchPath.append(resourceName);
+
+		for (FileSystem::FileEnumerator files(FileSystem::gameDataFiles, searchPath); !files.Finished(); files.Next()) {
 			assert(files.Current().IsFile());
 			const std::string &path = files.Current().GetPath();
+
 			if (ends_with_ci(path, ".json")) {
 				const std::string name = files.Current().GetName();
 				languages.push_back(name.substr(0, name.size() - 5));
@@ -175,21 +179,21 @@ namespace Lang {
 
 		for (token_map::iterator i = s_token_map.begin(); i != s_token_map.end(); ++i) {
 			const std::string &token = i->first;
-			std::string text = res.Get(token);
+			std::string_view text = res.Get(token);
 
 			if (text.empty()) {
-				Log::Info("{}/{}: token '{}' not found\n", res.GetName().c_str(), res.GetLangCode().c_str(), token.c_str());
+				Log::Info("{}/{}: token '{}' not found\n", res.GetName(), res.GetLangCode(), token);
 				text = token;
 			}
 
 			if (text.size() > size_t(STRING_RECORD_SIZE)) {
-				Log::Info("{}/{}: text for token '{}' is too long and will be truncated\n", res.GetName().c_str(), res.GetLangCode().c_str(), token.c_str());
-				text.resize(STRING_RECORD_SIZE);
+				Log::Info("{}/{}: text for token '{}' is too long and will be truncated\n", res.GetName(), res.GetLangCode(), token);
+				text = text.substr(0, STRING_RECORD_SIZE);
 			}
 
 			// const_cast so we can set the string, see above
 			char *record = const_cast<char *>(i->second);
-			copy_string(record, text.c_str(), text.size(), STRING_RECORD_SIZE);
+			copy_string(record, text.data(), text.size(), STRING_RECORD_SIZE);
 		}
 
 		s_coreResource = res;
@@ -202,9 +206,9 @@ namespace Lang {
 
 	static std::map<std::string, Resource> m_cachedResources;
 
-	Resource GetResource(const std::string &name, const std::string &langCode)
+	Resource &GetResource(std::string_view name, std::string_view langCode)
 	{
-		auto key = name + ":" + langCode;
+		std::string key = fmt::format("{}:{}", name, langCode);
 
 		auto i = m_cachedResources.find(key);
 		if (i != m_cachedResources.end())
@@ -214,19 +218,18 @@ namespace Lang {
 		bool loaded = res.Load();
 		if (!loaded) {
 			if (langCode != "en") {
-				Log::Warning("couldn't load language resource {}/{}, trying {}/en\n", name.c_str(), langCode.c_str(), name.c_str());
+				Log::Warning("couldn't load language resource {}/{}, trying {}/en\n", name, langCode, name);
 				res = Lang::Resource(name, "en");
 				loaded = res.Load();
-				key = name + ":" + "en";
+				key.replace(key.size() - langCode.size(), langCode.size(), "en");
 			}
 			if (!loaded)
-				Log::Warning("couldn't load language resource {}/en\n", name.c_str());
+				Log::Warning("couldn't load language resource {}/en\n", name);
 		}
 
-		if (loaded)
-			m_cachedResources.insert(std::make_pair(key, res));
+		m_cachedResources.insert(std::make_pair(key, std::move(res)));
 
-		return res;
+		return m_cachedResources.at(key);
 	}
 
 } // namespace Lang

src/Lang.h

@@ -8,38 +8,41 @@
 #include <SDL_stdinc.h>
 #include <map>
 #include <string>
+#include <string_view>
 #include <vector>
 
 namespace Lang {
 
 	class Resource {
 	public:
-		Resource(const std::string &name, const std::string &langCode) :
+		using StringMap = std::map<std::string, std::string, std::less<>>;
+
+		Resource(std::string_view name, std::string_view langCode) :
 			m_name(name),
 			m_langCode(langCode),
 			m_loaded(false) {}
 
-		const std::string &GetName() const { return m_name; }
-		const std::string &GetLangCode() const { return m_langCode; }
+		std::string_view GetName() const { return m_name; }
+		std::string_view GetLangCode() const { return m_langCode; }
 
 		bool Load();
 
 		Uint32 GetNumStrings() const { return static_cast<Uint32>(m_strings.size()); }
 
-		const std::string &Get(const std::string &token) const;
+		const std::string &Get(std::string_view token) const;
 
-		static std::vector<std::string> GetAvailableLanguages(const std::string &resourceName);
+		static std::vector<std::string> GetAvailableLanguages(std::string_view resourceName);
 
-		IterationProxy<std::map<std::string, std::string>> GetStrings() { return MakeIterationProxy(m_strings); }
-		const IterationProxy<const std::map<std::string, std::string>> GetStrings() const { return MakeIterationProxy(m_strings); }
+		IterationProxy<StringMap> GetStrings() { return MakeIterationProxy(m_strings); }
+		const IterationProxy<const StringMap> GetStrings() const { return MakeIterationProxy(m_strings); }
 
 	private:
 		std::string m_name;
 		std::string m_langCode;
 
 		bool m_loaded;
 
-		std::map<std::string, std::string> m_strings;
+		StringMap m_strings;
 	};
 
 // declare all strings
@@ -50,7 +53,7 @@ namespace Lang {
 	void MakeCore(Resource &res);
 	const Resource &GetCore();
 
-	Resource GetResource(const std::string &name, const std::string &langCode);
+	Resource &GetResource(std::string_view name, std::string_view langCode);
 
 } // namespace Lang
 

src/LangStrings.inc.h

@@ -1,6 +1,10 @@
 // Copyright © 2008-2023 Pioneer Developers. See AUTHORS.txt for details
 // Licensed under the terms of the GPL v3. See licenses/GPL-3.txt
 
+#ifndef DECLARE_STRING
+#define DECLARE_STRING(_)
+#endif
+
 DECLARE_STRING(LANG_NAME)
 DECLARE_STRING(SUGGESTED_RESPONSES)
 DECLARE_STRING(SHIP)

src/Pi.cpp

@@ -342,7 +342,7 @@ void Pi::App::Startup()
 
 	ModManager::Init();
 
-	Lang::Resource res(Lang::GetResource("core", config->String("Lang")));
+	Lang::Resource &res(Lang::GetResource("core", config->String("Lang")));
 	Lang::MakeCore(res);
 
 	// FIXME: move these out of the Pi namespace

src/lua/LuaLang.cpp

@@ -66,7 +66,7 @@ static int l_lang_get_resource(lua_State *l)
 	lua_pop(l, 1);
 
 	lua_newtable(l);
-	Lang::Resource res = Lang::GetResource(resourceName, langCode);
+	Lang::Resource &res = Lang::GetResource(resourceName, langCode);
 	if (res.Load()) {
 		for (auto i : res.GetStrings()) {
 			const std::string token(i.first);