From c23d076a1bca43273a5cd4d0aac7607425fd2928 Mon Sep 17 00:00:00 2001
From: Mihai Stefanescu <mihai.t.gh.stefanescu@gmail.com>
Date: Thu, 14 Jun 2018 17:49:15 +0300
Subject: [PATCH] Upm logger

Signed-off-by: Mihai Stefanescu <mihai.t.gh.stefanescu@gmail.com>
---
 examples/c++/logger.cxx |  37 ++++++++++
 include/upm_logger.hpp  | 152 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 189 insertions(+)
 create mode 100644 examples/c++/logger.cxx
 create mode 100644 include/upm_logger.hpp

diff --git a/examples/c++/logger.cxx b/examples/c++/logger.cxx
new file mode 100644
index 00000000..4d798551
--- /dev/null
+++ b/examples/c++/logger.cxx
@@ -0,0 +1,37 @@
+#include <thread>
+#include <vector>
+
+#include "upm_logger.hpp"
+
+using namespace upm;
+
+void print()
+{
+  UPM_LOG(LOG_DEBUG) << "Thread " << std::this_thread::get_id() << ": running loop with 3 iterations";
+
+  for (int i = 0; i < 4; ++i) {
+    UPM_LOG(LOG_DEBUG) << std::this_thread::get_id() << ": i = " << i;
+  }
+}
+
+int main()
+{
+  std::vector<std::thread> threads;
+
+  UPM_LOGGER::LogLevel() = LOG_ERROR;
+
+  //UPM_LOGGER::outputFile() = "test.log";
+
+  UPM_LOG(LOG_WARNING) << "Testing the upm logger 1 " << "4";
+
+  // Launching 5 threads
+  for (int i = 0; i < 3; ++i) {
+    threads.push_back(std::thread(print));
+  }
+
+  for (auto& thread : threads) {
+    thread.join();
+  }
+
+  return 0;
+}
\ No newline at end of file
diff --git a/include/upm_logger.hpp b/include/upm_logger.hpp
new file mode 100644
index 00000000..2ac64214
--- /dev/null
+++ b/include/upm_logger.hpp
@@ -0,0 +1,152 @@
+/*
+ * Author: Mihai Stefanescu <mihai.stefanescu@rinftech.com>
+ * Copyright (c) 2018 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#pragma once
+
+#include <chrono>
+#include <fstream>
+#include <mutex>
+#include <sstream>
+#include <string>
+#include <thread>
+
+/* Helper macro for logger utility class. */
+#define UPM_LOG(log_level)                                                                     \
+    if (log_level < UPM_LOGGER::LogLevel())                                                    \
+        ;                                                                                      \
+    else                                                                                       \
+    UPM_LOGGER::getInstance().log(log_level) << LogHelper() << __FILE__ << " " << __FUNCTION__ \
+                                             << " " << __LINE__ << ": "
+
+#define DEFAULT_LOG_FILE "/dev/stdout"
+
+
+namespace upm
+{
+enum UpmLogLevel { LOG_ERROR, LOG_WARNING, LOG_INFO, LOG_DEBUG, NA };
+
+static const std::string logLevelNames[] = { "ERROR", "WARNING", "INFO", "DEBUG", "" };
+
+class UPM_LOGGER
+{
+    friend class LogHelper;
+
+  public:
+    static UPM_LOGGER&
+    getInstance()
+    {
+        static UPM_LOGGER instance;
+        return instance;
+    }
+
+    virtual ~UPM_LOGGER()
+    {
+    }
+
+    std::ofstream&
+    log(UpmLogLevel level = LOG_ERROR)
+    {
+        using namespace std::chrono;
+
+        std::lock_guard<std::mutex> lock(logMutex());
+
+        _logStream << "UPM - "
+                   << duration_cast<nanoseconds>(system_clock::now().time_since_epoch()).count();
+        _logStream << " [" << getLogLevelName(level) << "] ";
+
+        return _logStream;
+    }
+
+    static UpmLogLevel&
+    LogLevel()
+    {
+        static UpmLogLevel reportingLevel = LOG_DEBUG;
+
+        return reportingLevel;
+    }
+
+    static const std::string&
+    getLogLevelName(UpmLogLevel level)
+    {
+        if (level < LOG_ERROR || level >= NA) {
+            return NULL;
+        }
+
+        return logLevelNames[level];
+    }
+
+    static std::string&
+    outputFile()
+    {
+        static std::string file = DEFAULT_LOG_FILE;
+        return file;
+    }
+
+  private:
+    UPM_LOGGER()
+    {
+        _logStream.open(outputFile(), std::ios_base::app);
+    }
+
+    static std::mutex&
+    logMutex()
+    {
+        static std::mutex _mutex;
+        return _mutex;
+    }
+
+  public:
+    UPM_LOGGER(const UPM_LOGGER&) = delete;
+    UPM_LOGGER& operator=(const UPM_LOGGER&) = delete;
+
+  private:
+    std::ofstream _logStream;
+};
+
+class LogHelper
+{
+  public:
+    LogHelper()
+    {
+        _os = &UPM_LOGGER::getInstance()._logStream;
+        _mutex = &UPM_LOGGER::logMutex();
+    }
+
+    ~LogHelper()
+    {
+        std::lock_guard<std::mutex> lock(*_mutex);
+        *(_os) << std::endl;
+    }
+
+    friend std::ofstream&
+    operator<<(std::ofstream& os, const LogHelper& h)
+    {
+        return os;
+    }
+
+  private:
+    std::ofstream* _os;
+    std::mutex* _mutex;
+};
+}