fdsdump: add logger component

Author: sedmicha

src/tools/fdsdump/src/common/CMakeLists.txt

@@ -7,6 +7,7 @@ set(COMMON_SRC
     flowProvider.cpp
     ipaddr.cpp
     ieMgr.cpp
+    logger.cpp
 )
 
 add_library(common_obj OBJECT ${COMMON_SRC})

src/tools/fdsdump/src/common/logger.cpp

@@ -0,0 +1,62 @@
+/**
+ * @file
+ * @author Michal Sedlak <[email protected]>
+ * @brief Logger component
+ *
+ * Copyright: (C) 2024 CESNET, z.s.p.o.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <common/logger.hpp>
+
+namespace fdsdump {
+
+static constexpr const char *loglevel_str[] = {
+    "",
+    "ERROR",
+    "WARNING",
+    "INFO",
+    "DEBUG",
+    "TRACE"
+};
+
+Logger &Logger::get_instance()
+{
+    static Logger logger;
+    return logger;
+}
+
+LogLevel operator++(LogLevel &level, int)
+{
+    LogLevel old = level;
+    if (level != LogLevel::trace) {
+        level = static_cast<LogLevel>(static_cast<uint8_t>(level) + 1);
+    }
+    return old;
+}
+
+LogLevel operator--(LogLevel &level, int)
+{
+    LogLevel old = level;
+    if (level != LogLevel::none) {
+        level = static_cast<LogLevel>(static_cast<uint8_t>(level) - 1);
+    }
+    return old;
+}
+
+Logger::Line::Line(LogLevel verbosity_level, LogLevel message_level)
+    : m_ignored(message_level > verbosity_level)
+{
+    if (!m_ignored) {
+        std::cerr << loglevel_str[static_cast<uint8_t>(message_level)] << ": ";
+    }
+}
+
+Logger::Line::~Line()
+{
+    if (!m_ignored) {
+        std::cerr << "\n";
+    }
+}
+
+} // fdsdump

src/tools/fdsdump/src/common/logger.hpp

@@ -0,0 +1,120 @@
+/**
+ * @file
+ * @author Michal Sedlak <[email protected]>
+ * @brief Logger component
+ *
+ * Copyright: (C) 2024 CESNET, z.s.p.o.
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#pragma once
+
+#include <common/common.hpp>
+
+#include <iostream>
+
+namespace fdsdump {
+
+/**
+ * The logging level
+ */
+enum class LogLevel : uint8_t {
+    none,
+    error,
+    warning,
+    info,
+    debug,
+    trace
+};
+
+/**
+ * @brief Increase the log level
+ */
+LogLevel operator++(LogLevel &level, int);
+
+/**
+ * @brief Decrease the log level
+ */
+LogLevel operator--(LogLevel &level, int);
+
+/**
+ * @brief A logger component
+ */
+class Logger {
+public:
+    /**
+     * @brief A single log line
+     */
+    class Line {
+        DISABLE_COPY_AND_MOVE(Line)
+
+    public:
+        /**
+         * @brief Finish the log line
+         */
+        ~Line();
+
+        /**
+         * @brief Write value onto the log line
+         *
+         * @param value  The value to write
+         *
+         * @return reference to self
+         */
+        template <typename T>
+        Line &operator<<(const T& value)
+        {
+            if (!m_ignored) {
+                std::cerr << value;
+            }
+            return *this;
+        }
+
+    private:
+        friend class Logger;
+
+        bool m_ignored;
+        Line(LogLevel verbosity_level, LogLevel message_level);
+    };
+
+
+    /**
+     * @brief Get the instance of the logger
+     */
+    static Logger &get_instance();
+
+    /**
+     * @brief Set the maximum level of messages to show
+     *
+     * @param level  The level
+     */
+    void set_log_level(LogLevel level)
+    {
+        m_log_level = level;
+    }
+
+    /**
+     * @brief Log a line on a specified logging level
+     *
+     * @param level  The log level
+     *
+     * @return The line object
+     */
+    Line log(LogLevel level)
+    {
+        return {m_log_level, level};
+    }
+
+private:
+    LogLevel m_log_level = LogLevel::trace;
+
+    Logger() = default;
+};
+
+#define LOG_TRACE (Logger::get_instance().log(LogLevel::trace))
+#define LOG_DEBUG (Logger::get_instance().log(LogLevel::debug))
+#define LOG_INFO (Logger::get_instance().log(LogLevel::info))
+#define LOG_WARNING (Logger::get_instance().log(LogLevel::warning))
+#define LOG_ERROR (Logger::get_instance().log(LogLevel::error))
+
+} // fdsdump