Make plugin loading errors non fatal (#364)

make plugin loading errors non fatal

3 files changed, 46 insertions, 29 deletions

diff --git a/src/zenhttp/httpserver.cpp b/src/zenhttp/httpserver.cpp
index d12f89a92..764f2a2a7 100644
--- a/src/zenhttp/httpserver.cpp
+++ b/src/zenhttp/httpserver.cpp
@@ -831,7 +831,6 @@ CreateHttpServerPlugin(const HttpServerPluginConfig& PluginConfig)
 	const std::string& PluginName = PluginConfig.PluginName;
 
 	ZEN_INFO("using '{}' plugin HTTP server implementation", PluginName)
-	Ref<HttpPluginServer> Server{CreateHttpPluginServer()};
 
 	if (PluginName.starts_with("builtin:"sv))
 	{
@@ -845,28 +844,41 @@ CreateHttpServerPlugin(const HttpServerPluginConfig& PluginConfig)
 		{
 			Plugin = CreateAsioTransportPlugin();
 		}
+		else
+		{
+			ZEN_WARN("Unknown builtin plugin '{}'", PluginName)
+			return {};
+		}
+
+		ZEN_ASSERT(!Plugin.IsNull());
 
-		if (!Plugin.IsNull())
+		for (const std::pair<std::string, std::string>& Option : PluginConfig.PluginOptions)
 		{
-			for (const std::pair<std::string, std::string>& Option : PluginConfig.PluginOptions)
-			{
-				Plugin->Configure(Option.first.c_str(), Option.second.c_str());
-			}
-			Server->AddPlugin(Plugin);
+			Plugin->Configure(Option.first.c_str(), Option.second.c_str());
 		}
+
+		Ref<HttpPluginServer> Server{CreateHttpPluginServer()};
+		Server->AddPlugin(Plugin);
+		return Server;
+#	else
+		ZEN_WARN("Builtin plugin '{}' is not supported", PluginName)
+		return {};
 #	endif
 	}
-	else
+
+	Ref<DllTransportPlugin> DllPlugin{CreateDllTransportPlugin()};
+	if (!DllPlugin->LoadDll(PluginName))
 	{
-		Ref<DllTransportPlugin> DllPlugin{CreateDllTransportPlugin()};
-		DllPlugin->LoadDll(PluginName);
-		for (const std::pair<std::string, std::string>& Option : PluginConfig.PluginOptions)
-		{
-			DllPlugin->ConfigureDll(PluginName, Option.first.c_str(), Option.second.c_str());
-		}
-		Server->AddPlugin(DllPlugin);
+		return {};
+	}
+
+	for (const std::pair<std::string, std::string>& Option : PluginConfig.PluginOptions)
+	{
+		DllPlugin->ConfigureDll(PluginName, Option.first.c_str(), Option.second.c_str());
 	}
 
+	Ref<HttpPluginServer> Server{CreateHttpPluginServer()};
+	Server->AddPlugin(DllPlugin);
 	return Server;
 }
 #endif
@@ -888,7 +900,11 @@ CreateHttpServer(const HttpServerConfig& Config)
 
 		for (const HttpServerPluginConfig& PluginConfig : Config.PluginConfigs)
 		{
-			Server->AddServer(CreateHttpServerPlugin(PluginConfig));
+			Ref<HttpServer> PluginServer = CreateHttpServerPlugin(PluginConfig);
+			if (!PluginServer.IsNull())
+			{
+				Server->AddServer(PluginServer);
+			}
 		}
 
 		return Server;
diff --git a/src/zenhttp/transports/dlltransport.cpp b/src/zenhttp/transports/dlltransport.cpp
index dd05f6f0c..fb3dd23b5 100644
--- a/src/zenhttp/transports/dlltransport.cpp
+++ b/src/zenhttp/transports/dlltransport.cpp
@@ -55,7 +55,7 @@ public:
 	virtual const char* GetDebugName() override;
 	virtual bool		IsAvailable() override;
 
-	virtual void LoadDll(std::string_view Name) override;
+	virtual bool LoadDll(std::string_view Name) override;
 	virtual void ConfigureDll(std::string_view Name, const char* OptionTag, const char* OptionValue) override;
 
 private:
@@ -172,7 +172,7 @@ DllTransportPluginImpl::ConfigureDll(std::string_view Name, const char* OptionTa
 	}
 }
 
-void
+bool
 DllTransportPluginImpl::LoadDll(std::string_view Name)
 {
 	RwLock::ExclusiveLockScope _(m_Lock);
@@ -190,9 +190,8 @@ DllTransportPluginImpl::LoadDll(std::string_view Name)
 
 	if (!DllHandle)
 	{
-		std::error_code Ec = MakeErrorCodeFromLastError();
-
-		throw std::system_error(Ec, fmt::format("failed to load transport DLL from '{}'", DllPath));
+		ZEN_WARN("Failed to load transport DLL from '{}' due to '{}'", DllPath, GetLastErrorAsString())
+		return false;
 	}
 
 	PfnGetTransportPluginVersion GetVersion	  = (PfnGetTransportPluginVersion)GetProcAddress(DllHandle, "GetTransportPluginVersion");
@@ -216,17 +215,18 @@ DllTransportPluginImpl::LoadDll(std::string_view Name)
 
 		if (GetVersion && !bValidApiVersion)
 		{
-			throw std::system_error(
-				Ec,
-				fmt::format("invalid API version '{}' detected in transport DLL loaded from '{}', supported API version '{}'",
-							APIVersion,
-							DllPath,
-							kTransportApiVersion));
+			ZEN_WARN("Failed to load transport DLL from '{}' due to invalid API version {}, supported API version is {}",
+					 DllPath,
+					 APIVersion,
+					 kTransportApiVersion)
 		}
 		else
 		{
-			throw std::system_error(Ec, fmt::format("API mismatch detected in transport DLL loaded from '{}'", DllPath));
+			ZEN_WARN("Failed to load transport DLL from '{}' due to not finding GetTransportPluginVersion or CreateTransportPlugin",
+					 DllPath)
 		}
+
+		return false;
 	}
 
 	LoadedDll NewDll;
@@ -238,6 +238,7 @@ DllTransportPluginImpl::LoadDll(std::string_view Name)
 	NewDll.Plugin = CreatePlugin(NewDll.Logger);
 
 	m_Transports.emplace_back(std::move(NewDll));
+	return true;
 }
 
 DllTransportPlugin*
diff --git a/src/zenhttp/transports/dlltransport.h b/src/zenhttp/transports/dlltransport.h
index 9346a10ce..c49f888da 100644
--- a/src/zenhttp/transports/dlltransport.h
+++ b/src/zenhttp/transports/dlltransport.h
@@ -15,7 +15,7 @@ namespace zen {
 class DllTransportPlugin : public TransportPlugin
 {
 public:
-	virtual void LoadDll(std::string_view Name)														 = 0;
+	virtual bool LoadDll(std::string_view Name)														 = 0;
 	virtual void ConfigureDll(std::string_view Name, const char* OptionTag, const char* OptionValue) = 0;
 };