Add ability to log 'per session', i.e. create a new file each time yo…

…u click play.

.gitignore

@@ -0,0 +1,2 @@
+Binaries/
+Intermediate/

Source/UniversalLogging/Private/LogStream.cpp

@@ -4,11 +4,13 @@
 
 #include "HAL/PlatformFilemanager.h"
 
-LogStreamImpl::LogStreamImpl(const FString filepath, const FString filename)
+LogStreamImpl::LogStreamImpl(const FString filepath, const FString filename, const bool per_session)
   : _filepath(filepath)
   , _filename(filename)
+  , _per_session(per_session)
   , _is_open(false)
   , _is_valid(false)
+  , _file_handle(nullptr)
 {
   Open();
   if (_is_open)
@@ -38,8 +40,12 @@ bool LogStreamImpl::GetIsValid()
 
 void LogStreamImpl::Open()
 {
-  FString file_path = FPaths::ConvertRelativePathToFull(FPaths::ProjectDir() + _filepath) + "/" + _filename;
   IPlatformFile& platform_file = FPlatformFileManager::Get().GetPlatformFile();
+  FString file_path = FPaths::ConvertRelativePathToFull(FPaths::ProjectDir() + _filepath);
+  if(_per_session)
+    file_path += "/" + UniLog.GetSessionIdentifier();
+  platform_file.CreateDirectoryTree(*file_path);
+  file_path += "/" + _filename;
   _file_handle = platform_file.OpenWrite(*file_path);
   if (!_file_handle)
   {
@@ -53,8 +59,8 @@ void LogStreamImpl::Open()
 
 void LogStreamImpl::Close()
 {
-  if (_file_handle)
-    delete _file_handle;
+  delete _file_handle;
+  _file_handle = nullptr;
   _is_open = false;
 }
 

Source/UniversalLogging/Private/LogStream.h

@@ -3,7 +3,7 @@
 class LogStreamImpl : public ILogStream
 {
 public:
-  LogStreamImpl(const FString filepath= "Saved/Logs", const FString filename = "UniversalLogging.log");
+  LogStreamImpl(const FString filepath= "Saved/Logs", const FString filename = "UniversalLogging.log", const bool per_session = false);
   virtual ~LogStreamImpl();
 
   FString GetFilepath() override;
@@ -19,6 +19,7 @@ class LogStreamImpl : public ILogStream
 private:
   const FString _filepath;
   const FString _filename;
+  bool _per_session;
 
   bool _is_open;
   bool _is_valid;

Source/UniversalLogging/Private/UniversalLogging.cpp

@@ -13,6 +13,8 @@ void UniversalLoggingImpl::StartupModule()
 
   on_pre_world_finish_destroy_delegate_.BindRaw(this, &UniversalLoggingImpl::OnSessionEnd);
   FWorldDelegates::OnPreWorldFinishDestroy.Add(on_pre_world_finish_destroy_delegate_);
+
+  _session_id = "";
 }
 
 void UniversalLoggingImpl::ShutdownModule()
@@ -21,14 +23,26 @@ void UniversalLoggingImpl::ShutdownModule()
 
 void UniversalLoggingImpl::OnSessionStart(UWorld* world, const UWorld::InitializationValues)
 {
-  if (world->IsGameWorld())
-    Log("OnSessionStart", "Test");
+  if (!world->IsGameWorld())
+    return;
+  if (world->IsPlayInEditor())
+    ResetSessionId("PlayInEditor");
+  else if (world->IsPlayInPreview())
+    ResetSessionId("PlayInPreview");
+  else
+    ResetSessionId("Play");
 }
 
 void UniversalLoggingImpl::OnSessionEnd(UWorld* world)
 {
-  if (world->IsGameWorld())
-    Log("OnSessionEnd", "Test");
+  if (!world->IsGameWorld())
+    return;
+  ResetSessionId("Stopped");
+
+  for (auto& elem : _streams)
+  {
+    elem.Value->Close();
+  }
 }
 
 ILogStream* UniversalLoggingImpl::NewLogStream(const FString streamname)
@@ -37,9 +51,9 @@ ILogStream* UniversalLoggingImpl::NewLogStream(const FString streamname)
   return _streams[streamname].Get();
 }
 
-ILogStream* UniversalLoggingImpl::NewLogStream(const FString streamname, const FString filepath, const FString filename)
+ILogStream* UniversalLoggingImpl::NewLogStream(const FString streamname, const FString filepath, const FString filename, bool per_session /* = false*/)
 {
-  _streams.Add(streamname, TUniquePtr<LogStreamImpl>(new LogStreamImpl(filepath, filename)));
+  _streams.Add(streamname, TUniquePtr<LogStreamImpl>(new LogStreamImpl(filepath, filename, per_session)));
   return _streams[streamname].Get();
 }
 
@@ -56,6 +70,11 @@ ILogStream * UniversalLoggingImpl::GetDefaultLogStream()
   return GetLogStream("");
 }
 
+FString UniversalLoggingImpl::GetSessionIdentifier()
+{
+  return _session_id;
+}
+
 void UniversalLoggingImpl::Log(const FString text, const FString stream /*= ""*/, bool omit_newline /*= false*/)
 {
   LogStreamImpl* stream_obj = nullptr;
@@ -68,4 +87,13 @@ void UniversalLoggingImpl::Log(const FString text, const FString stream /*= ""*/
   stream_obj->Write(full_text);
 }
 
+void UniversalLoggingImpl::ResetSessionId(FString prefix)
+{
+  FString timestamp = FGenericPlatformTime::StrTimestamp();
+  timestamp = timestamp.Replace(TEXT("/"), TEXT("-"));
+  timestamp = timestamp.Replace(TEXT(" "), TEXT("_"));
+  timestamp = timestamp.Replace(TEXT(":"), TEXT("-"));
+  _session_id = FString::Printf(TEXT("%s_%s"), *prefix, *timestamp);
+}
+
 IMPLEMENT_MODULE(UniversalLoggingImpl, UniversalLogging)

Source/UniversalLogging/Private/UniversalLogging.h

@@ -15,13 +15,17 @@ class UniversalLoggingImpl : public IUniversalLogging
   void OnSessionEnd(UWorld*);
 
   ILogStream* NewLogStream(const FString streamname) override;
-  ILogStream* NewLogStream(const FString streamname, const FString filepath, const FString filename) override;
+  ILogStream* NewLogStream(const FString streamname, const FString filepath, const FString filename, bool per_session = false) override;
   ILogStream* GetLogStream(const FString streamname) override;
   ILogStream* GetDefaultLogStream() override;
+  FString GetSessionIdentifier() override;
   void Log(const FString text, const FString stream = "", bool omit_newline = false) override;
 
+  void ResetSessionId(FString prefix);
+
 private:
   TMap<FString, TUniquePtr<LogStreamImpl>> _streams;
+  FString _session_id;
   TBaseDelegate<void, UWorld*, const UWorld::InitializationValues> on_post_world_initialization_delegate_;
   TBaseDelegate<void, UWorld*> on_pre_world_finish_destroy_delegate_;
 };

Source/UniversalLogging/Public/IUniversalLogging.h

@@ -10,8 +10,7 @@ class IUniversalLogging : public IModuleInterface
 {
 public:
   /**
-  * Singleton-like access to this module's interface.  This is just for convenience!
-  * Beware of calling this during the shutdown phase, though.  Your module might have been unloaded already.
+  * Singleton-like access to this module's interface. This should not be necessary as the intended use is through the UniLog macro
   *
   * @return Returns singleton instance, loading the module on demand if needed.
   */
@@ -42,7 +41,7 @@ class IUniversalLogging : public IModuleInterface
   *
   * @return the newly created log stream object.
   */
-  virtual ILogStream* NewLogStream(const FString streamname, const FString filepath, const FString filename) = 0;
+  virtual ILogStream* NewLogStream(const FString streamname, const FString filepath, const FString filename, bool per_session = false) = 0;
 
   /**
   * Getter for log streams.
@@ -58,6 +57,11 @@ class IUniversalLogging : public IModuleInterface
   */
   virtual ILogStream* GetDefaultLogStream() = 0;
 
+  /**
+  * Get the current session identifier. It uniquely identifies each time the application starts.
+  */
+  virtual FString GetSessionIdentifier() = 0;
+
   /**
   * Logs the given text to the given log stream. If no log stream is specified, the default is used.
   */