simplify logger

include/LightGBM/config.h

@@ -93,7 +93,7 @@ public:
   std::string output_result = "LightGBM_predict_result.txt";
   std::string input_model = "";
   std::string input_init_score = "";
-  int verbosity = 0;
+  int verbosity = 1;
   std::string log_file = "";
   int num_model_predict = -1;
   bool is_pre_partition = false;

include/LightGBM/utils/log.h

@@ -23,88 +23,13 @@ namespace LightGBM {
 
 // A enumeration type of log message levels. The values are ordered:
 // Debug < Info < Error < Fatal.
-enum class LogLevel : int {
-  Debug = 0,
+enum class LogLevel: int {
+  Fatal = -1,
+  Error = 0,
   Info = 1,
-  Error = 2,
-  Fatal = 3
+  Debug = 2,
 };
 
-/*!
-* \brief The Logger class is responsible for writing log messages into
-*        standard output or log file.
-*/
-class Logger {
-  // Enable the static Log class to call the private method.
-  friend class Log;
-
-public:
-  /*!
-  * \brief Creates an instance of Logger class. By default, the log
-  *        messages will be written to standard output with minimal
-  *        level of INFO. Users are able to further set the log file or
-  *        log level with corresponding methods.
-  * \param level Minimal log level, Info by default.
-  */
-  explicit Logger(LogLevel level = LogLevel::Info);
-  /*!
-  * \brief Creates an instance of Logger class by specifying log file
-  *        and log level. The log message will be written to both STDOUT
-  *        and file (if created successfully).
-  * \param filename Log file name
-  * \param level Minimal log level
-  */
-  explicit Logger(std::string filename, LogLevel level = LogLevel::Info);
-  ~Logger();
-
-  /*!
-  * \brief Resets the log file.
-  * \param filename The new log filename. If it is empty, the Logger
-  *        will close current log file (if it exists).
-  * \return Returns -1 if the filename is not empty but failed on
-  *         creating the log file, or 0 will be returned otherwise.
-  */
-  int ResetLogFile(std::string filename);
-  /*!
-  * \brief Resets the log level.
-  * \param level The new log level.
-  */
-  void ResetLogLevel(LogLevel level) { level_ = level; }
-  /*!
-  * \brief Resets the option of whether kill the process when fatal
-  *        error occurs. By defualt the option is false.
-  */
-  void ResetKillFatal(bool is_kill_fatal) { is_kill_fatal_ = is_kill_fatal; }
-
-  /*!
-  * \brief C style formatted method for writing log messages. A message
-  *        is with the following format: [LEVEL] [TIME] message
-  * \param level The log level of this message.
-  * \param format The C format string.
-  * \param ... Output items.
-  */
-  void Write(LogLevel level, const char *format, ...);
-  void Debug(const char *format, ...);
-  void Info(const char *format, ...);
-  void Error(const char *format, ...);
-  void Fatal(const char *format, ...);
-
-private:
-  void Write(LogLevel level, const char* format, va_list* val);
-  void CloseLogFile();
-  // Returns current system time as a string.
-  std::string GetSystemTime();
-  // Returns the string of a log level.
-  std::string GetLevelStr(LogLevel level);
-
-  std::FILE *file_;  // A file pointer to the log file.
-  LogLevel level_;   // Only the message not less than level_ will be outputed.
-  bool is_kill_fatal_;  // If kill the process when fatal error occurs.
-
-  // No copying allowed
-  Logger(const Logger&);
-  void operator=(const Logger&);
-};
 
 /*!
 * \brief The Log class is a static wrapper of a global Logger instance in
@@ -113,35 +38,61 @@ private:
 */
 class Log {
 public:
-  /*!
-  * \brief Resets the log file. The logger will write messages to the
-  *        log file if it exists in addition to the STDOUT by default.
-  * \param filename The log filename. If it is empty, the logger will
-  *        close the current log file (if it exists) and only output to
-  *        STDOUT.
-  * \return -1 if fail on creating the log file, or 0 otherwise.
-  */
-  static int ResetLogFile(std::string filename);
   /*!
   * \brief Resets the minimal log level. It is INFO by default.
   * \param level The new minimal log level.
   */
-  static void ResetLogLevel(LogLevel level);
-  /*!
-  * \brief Resets the option of whether kill the process when fatal
-  *        error occurs. By defualt the option is false.
-  */
-  static void ResetKillFatal(bool is_kill_fatal);
-
-  /*! \brief The C formatted methods of writing the messages. */
-  static void Write(LogLevel level, const char* format, ...);
-  static void Debug(const char *format, ...);
-  static void Info(const char *format, ...);
-  static void Error(const char *format, ...);
-  static void Fatal(const char *format, ...);
+  static void ResetLogLevel(LogLevel level) {
+    GetLevel() = level;
+  }
+
+  static void Debug(const char *format, ...) {
+    va_list val;
+    va_start(val, format);
+    Write(LogLevel::Debug, "Debug", format, val);
+    va_end(val);
+  }
+  static void Info(const char *format, ...) {
+    va_list val;
+    va_start(val, format);
+    Write(LogLevel::Info, "Info", format, val);
+    va_end(val);
+  }
+  static void Error(const char *format, ...) {
+    va_list val;
+    va_start(val, format);
+    Write(LogLevel::Error, "Error", format, val);
+    va_end(val);
+  }
+  static void Fatal(const char *format, ...) {
+    va_list val;
+    va_start(val, format);
+    Write(LogLevel::Fatal, "Fatal", format, val);
+    va_end(val);
+  }
 
 private:
-  static Logger logger_;
+
+  static void Write(LogLevel level, const char* level_str, const char *format, va_list val) {
+    if (level <= GetLevel()) {  // omit the message with low level
+      // write to STDOUT
+      printf("[LightGBM] [%s] ", level_str);
+      vprintf(format, val);
+      fflush(stdout);
+
+      if (level == LogLevel::Fatal) {
+        exit(1);
+      }
+    }
+  }
+
+  // a trick to use static variable in header file. 
+  // May be not good, but avoid to use an additional cpp file
+  static LogLevel& GetLevel() {
+    static LogLevel level;
+    return level;
+  };
+
 };
 
 }  // namespace LightGBM

src/CMakeLists.txt

@@ -11,9 +11,8 @@ AUX_SOURCE_DIRECTORY(./metric/ METRIC_SRC)
 AUX_SOURCE_DIRECTORY(./objective/ OBJECTIVE_SRC) 
 AUX_SOURCE_DIRECTORY(./network/ NETWORK_SRC) 
 AUX_SOURCE_DIRECTORY(./treelearner/ TREELEARNER_SRC) 
-AUX_SOURCE_DIRECTORY(./util/ UTIL_SRC) 
 
-add_executable(lightgbm main.cpp ${APPLICATION_SRC} ${BOOSTING_SRC} ${IO_SRC} ${METRIC_SRC} ${OBJECTIVE_SRC} ${NETWORK_SRC} ${TREELEARNER_SRC} ${UTIL_SRC})
+add_executable(lightgbm main.cpp ${APPLICATION_SRC} ${BOOSTING_SRC} ${IO_SRC} ${METRIC_SRC} ${OBJECTIVE_SRC} ${NETWORK_SRC} ${TREELEARNER_SRC})
 
 if(USE_MPI)
   TARGET_LINK_LIBRARIES(lightgbm ${MPI_CXX_LIBRARIES})

src/io/config.cpp

@@ -35,14 +35,18 @@ void OverallConfig::Set(const std::unordered_map<std::string, std::string>& para
   // check for conflicts
   CheckParamConflict();
 
-  if (io_config.verbosity == 1)
+  if (io_config.verbosity == 1) {
     LightGBM::Log::ResetLogLevel(LightGBM::LogLevel::Info);
-  else if (io_config.verbosity == 0)
+  }
+  else if (io_config.verbosity == 0) {
     LightGBM::Log::ResetLogLevel(LightGBM::LogLevel::Error);
-  else if (io_config.verbosity >= 2)
+  }
+  else if (io_config.verbosity >= 2) {
     LightGBM::Log::ResetLogLevel(LightGBM::LogLevel::Debug);
-  else 
+  }
+  else {
     LightGBM::Log::ResetLogLevel(LightGBM::LogLevel::Fatal);
+  }
 }
 
 void OverallConfig::GetBoostingType(const std::unordered_map<std::string, std::string>& params) {

src/util/log.cpp

-#include "LightGBM/utils/log.h"
-
-#include <time.h>
-#include <stdarg.h>
-
-#include <string>
-
-namespace LightGBM {
-    // Creates a Logger intance writing messages into STDOUT.
-    Logger::Logger(LogLevel level) {
-        level_ = level;
-        file_ = nullptr;
-        is_kill_fatal_ = true;
-    }
-
-    // Creates a Logger instance writing messages into both STDOUT and log file.
-    Logger::Logger(std::string filename, LogLevel level) {
-        level_ = level;
-        file_ = nullptr;
-        ResetLogFile(filename);
-    }
-
-    Logger::~Logger() {
-        CloseLogFile();
-    }
-
-    int Logger::ResetLogFile(std::string filename) {
-        CloseLogFile();
-        if (filename.size() > 0) {  // try to open the log file if it is specified
-#ifdef _MSC_VER
-            fopen_s(&file_, filename.c_str(), "w");
-#else
-            file_ = fopen(filename.c_str(), "w");
-#endif
-            if (file_ == nullptr) {
-                Error("Cannot create log file %s\n", filename.c_str());
-                return -1;
-            }
-        }
-        return 0;
-    }
-
-    void Logger::Write(LogLevel level, const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        Write(level, format, val);
-        va_end(val);
-    }
-
-    void Logger::Debug(const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        Write(LogLevel::Debug, format, val);
-        va_end(val);
-    }
-
-    void Logger::Info(const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        Write(LogLevel::Info, format, val);
-        va_end(val);
-    }
-
-    void Logger::Error(const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        Write(LogLevel::Error, format, val);
-        va_end(val);
-    }
-
-    void Logger::Fatal(const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        Write(LogLevel::Fatal, format, val);
-        va_end(val);
-    }
-
-    inline void Logger::Write(LogLevel level, const char *format, va_list* val) {
-        if (level >= level_) {  // omit the message with low level
-            std::string level_str = GetLevelStr(level);
-            std::string time_str = GetSystemTime();
-            va_list val_copy;
-            va_copy(val_copy, *val);
-            // write to STDOUT
-            printf("[%s] [%s] ", level_str.c_str(), time_str.c_str());
-            vprintf(format, *val);
-            fflush(stdout);
-            // write to log file
-            if (file_ != nullptr) {
-                fprintf(file_, "[%s] [%s] ", level_str.c_str(), time_str.c_str());
-                vfprintf(file_, format, val_copy);
-                fflush(file_);
-            }
-            va_end(val_copy);
-
-            if (is_kill_fatal_ && level == LogLevel::Fatal) {
-                CloseLogFile();
-                exit(1);
-            }
-        }
-    }
-
-    // Closes the log file if it it not null.
-    void Logger::CloseLogFile() {
-        if (file_ != nullptr) {
-            fclose(file_);
-            file_ = nullptr;
-        }
-    }
-
-    std::string Logger::GetSystemTime() {
-        time_t t = time(0);
-        char str[64];
-#ifdef _MSC_VER
-        tm time;
-        localtime_s(&time, &t);
-        strftime(str, sizeof(str), "%Y-%m-%d %H:%M:%S", &time);
-#else
-        strftime(str, sizeof(str), "%Y-%m-%d %H:%M:%S", localtime(&t));
-#endif
-        return str;
-    }
-
-    std::string Logger::GetLevelStr(LogLevel level) {
-        switch (level) {
-        case LogLevel::Debug: return "DEBUG";
-        case LogLevel::Info: return "INFO";
-        case LogLevel::Error: return "ERROR";
-        case LogLevel::Fatal: return "FATAL";
-        default: return "UNKNOW";
-        }
-    }
-    //-- End of Logger rountine ----------------------------------------------/
-
-    Logger Log::logger_;    // global (in process) static Logger instance
-
-    int Log::ResetLogFile(std::string filename) {
-        return logger_.ResetLogFile(filename);
-    }
-
-    void Log::ResetLogLevel(LogLevel level) {
-        logger_.ResetLogLevel(level);
-    }
-
-    void Log::ResetKillFatal(bool is_kill_fatal) {
-        logger_.ResetKillFatal(is_kill_fatal);
-    }
-
-    void Log::Write(LogLevel level, const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        logger_.Write(level, format, &val);
-        va_end(val);
-    }
-
-    void Log::Debug(const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        logger_.Write(LogLevel::Debug, format, &val);
-        va_end(val);
-    }
-
-    void Log::Info(const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        logger_.Write(LogLevel::Info, format, &val);
-        va_end(val);
-    }
-
-    void Log::Error(const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        logger_.Write(LogLevel::Error, format, &val);
-        va_end(val);
-    }
-
-    void Log::Fatal(const char *format, ...) {
-        va_list val;
-        va_start(val, format);
-        logger_.Write(LogLevel::Fatal, format, &val);
-        va_end(val);
-    }
-
-}  // namespace lightGBM

windows/LightGBM.vcxproj

@@ -218,7 +218,6 @@
     <ClCompile Include="..\src\treelearner\feature_parallel_tree_learner.cpp" />
     <ClCompile Include="..\src\treelearner\serial_tree_learner.cpp" />
     <ClCompile Include="..\src\treelearner\tree_learner.cpp" />
-    <ClCompile Include="..\src\util\log.cpp" />
   </ItemGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.targets" />
   <ImportGroup Label="ExtensionTargets">

windows/LightGBM.vcxproj.filters

@@ -221,8 +221,5 @@
     <ClCompile Include="..\src\main.cpp">
       <Filter>src</Filter>
     </ClCompile>
-    <ClCompile Include="..\src\util\log.cpp">
-      <Filter>include\LightGBM\utils</Filter>
-    </ClCompile>
   </ItemGroup>
 </Project>
\ No newline at end of file