1 files changed, 84 insertions, 0 deletions
diff --git a/src/tracer.h b/src/tracer.h
new file mode 100644
index 0000000..e42c29e
--- /dev/null
+++ b/src/tracer.h
@@ -0,0 +1,84 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/***************************************************************************
+ *            tracer.h
+ *
+ *  Sun Dec 29 18:04:28 CET 2019
+ *  Copyright 2019 Daniel Pastor
+ *  marlborometal@gmail.com
+ ****************************************************************************/
+
+/*
+ *  This file is part of DrumGizmo.
+ *
+ *  DrumGizmo is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU Lesser General Public License as published by
+ *  the Free Software Foundation; either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  DrumGizmo is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public License
+ *  along with DrumGizmo; if not, write to the Free Software
+ *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA.
+ */
+#pragma once
+
+#include <fstream>
+#include <memory>
+#include <stdexcept>
+
+//! This file contains the trace tool for developmnent purposes. The trace tool
+//! just prints messages to a given file.
+namespace tracer 
+{
+
+//! This class takes care of the output stream where trace messages will be
+//! printed. Its methods are not supposed to be called by anyone else than the
+//! "trace" functions.
+class tracer_manager 
+{
+	public:
+
+	//! Returns a reference to the file stream.
+	static std::ofstream& get()
+	{
+		if(nullptr==outfile.get()) 
+		{
+//TODO: This should not be fixed, but either depend on the OS or be able to
+//specified somehow.
+			outfile.reset(new std::ofstream("/tmp/drumgizmo.trace", 
+								std::ios::app));
+		}
+
+		if(nullptr==outfile.get())
+		{
+			throw std::runtime_error("the tracer file could not be initialized");
+		}
+
+		return *(outfile.get());
+	}
+
+	private:
+
+	//! Single output file. Will be initialized to nullptr when the program
+	//! starts and freed when the program ends.
+	static std::unique_ptr<std::ofstream> outfile;	
+};
+
+//! Trace function without parameters, used on the last call to the variadic
+//! templace "trace".
+void trace();
+
+//! Variadic trace function. Obtains a reference to the file stream and prints
+//! its arguments there.
+template<typename T, typename... Args> 
+void trace(T val, Args... args)
+{
+	tracer_manager::get()<<val;
+	trace(args...);
+}
+
+}//End of tracer namespace.
+\ No newline at end of file