Merge 43ecacfce73a049c5a667a100658522f6778bcbd into dc45cd78595c7c24c8a8574c63bb48b5bb99c5aa

examples/c++/logger.cxx

@@ -0,0 +1,35 @@
+#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_INFO;
+
+  UPM_LOG(LOG_WARNING) << "Testing the upm logger";
+
+  // Launching 5 threads
+  for (int i = 0; i < 5; ++i) {
+    threads.push_back(std::thread(print));
+  }
+
+  for (auto& thread : threads) {
+    thread.join();
+  }
+
+  return 0;
+}

include/upm_logger.hpp

@@ -0,0 +1,131 @@
+/*
+ * 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 <sstream>
+#include <fstream>
+#include <string>
+#include <chrono>
+#include <thread>
+#include <mutex>
+
+/* Helper macro for logger utility class. */
+#define UPM_LOG(log_level) \
+  if ( log_level < UPM_LOGGER::LogLevel() ) \
+    ; \
+  else \
+    UPM_LOGGER().log(log_level) << __FILE__ << " " \
+                                << __FUNCTION__ << " " \
+                                << __LINE__ << ": "
+
+#define LOG_FILE "/var/log/upm.log"
+
+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 {
+  public:
+    UPM_LOGGER() {}
+    virtual ~UPM_LOGGER();
+    std::ostringstream& log(UpmLogLevel level = LOG_ERROR);
+    static UpmLogLevel& LogLevel();
+  protected:
+    std::ostringstream os;
+  private:
+    UPM_LOGGER(const UPM_LOGGER&);
+    UPM_LOGGER& operator=(const UPM_LOGGER&);
+  private:
+    // Track logLevel for this particular instance of UPM_LOGGER
+    UpmLogLevel logLevel;
+    std::ofstream logStream;
+    static std::mutex logMutex;
+  public:
+    static const std::string& getLogLevelName(UpmLogLevel level);
+  private:
+    void write(std::ostringstream& os);
+  };
+
+  std::mutex UPM_LOGGER::logMutex;
+
+  void UPM_LOGGER::write(std::ostringstream& os)
+  {
+    std::lock_guard<std::mutex> lock(logMutex);
+
+    logStream.open(LOG_FILE, std::ios_base::app);
+    logStream << os.str();
+    logStream.flush();
+  }
+
+  const std::string& UPM_LOGGER::getLogLevelName(UpmLogLevel level)
+  {
+    if (level < LOG_ERROR || level >= NA) {
+      return NULL;
+    }
+
+    return logLevelNames[level];
+  }
+
+  UpmLogLevel& UPM_LOGGER::LogLevel()
+  {
+    static UpmLogLevel reportingLevel = LOG_DEBUG;
+
+    return reportingLevel;
+  }
+
+  std::ostringstream& UPM_LOGGER::log(UpmLogLevel level)
+  {
+    using namespace std::chrono;
+
+    os << "UPM - " << duration_cast<nanoseconds>
+      (system_clock::now().time_since_epoch()).count();
+    os << " " << getLogLevelName(level) << " ";
+
+    logLevel = level;
+
+    return os;
+  }
+
+  UPM_LOGGER::~UPM_LOGGER()
+  {
+    os << std::endl;
+
+    write(os);
+  }
+}