Top ports - introduce TopPorts class

Author: Zadamsa

src/plugins/input/parser/CMakeLists.txt

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+add_library(top-ports STATIC
+    topPorts.cpp
+    topPorts.hpp
+)
+
+target_include_directories(top-ports PUBLIC
+	${CMAKE_SOURCE_DIR}/include
+	${CMAKE_BINARY_DIR}/src
+)
+
+target_compile_options(top-ports PRIVATE -fPIC)

src/plugins/input/parser/topPorts.cpp

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+/**
+ * \file topPorts.cpp
+ * \brief TopPorts class implementation.
+ * \author Damir Zainullin <zaidamilda@gmail.com>
+ * \date 2024
+ */
+
+#include "topPorts.hpp"
+
+#include <functional>
+#include <algorithm>
+#include <array>
+#include <cstdint>
+#include <limits>
+#include <vector>
+#include <string>
+
+namespace ipxp {
+
+TopPorts::TopPorts(size_t top_ports_count) noexcept
+: m_top_ports_count(top_ports_count)
+{
+}
+
+std::string TopPorts::PortStats::to_string() const noexcept
+{
+    return std::to_string(port) + "[" +
+        (protocol == Protocol::TCP ? "TCP" : "UDP") + "] - " + std::to_string(frequency);
+}
+
+bool update_port_buffer(std::vector<TopPorts::PortStats>& port_buffer, TopPorts::PortStats port_stats) noexcept{
+        auto port_pos = std::lower_bound(port_buffer.begin(), port_buffer.end(), port_stats.frequency,
+        [](const TopPorts::PortStats& port_frequency, size_t count) {
+            return port_frequency.frequency >= count;
+        });
+
+        if (port_pos != port_buffer.end()) {
+            std::copy_backward(port_pos, std::prev(port_buffer.end()), port_buffer.end());
+            *port_pos = port_stats;
+            return true;
+            //ports_inserted = std::min<size_t>(m_top_ports_count, ports_inserted + 1);
+        }
+        return false;
+    };
+
+std::vector<TopPorts::PortStats> TopPorts::get_top_ports() const noexcept
+{
+    std::vector<PortStats> port_buffer(m_top_ports_count);
+    size_t ports_inserted = 0;
+
+    std::for_each(m_tcp_port_frequencies.begin(), m_tcp_port_frequencies.end(), [&, port = uint16_t{0}](size_t frequency) mutable {
+        ports_inserted += update_port_buffer(port_buffer, {port++, frequency, PortStats::Protocol::TCP});
+    });
+    std::for_each(m_udp_port_frequencies.begin(), m_udp_port_frequencies.end(), [&, port = uint16_t{0}](size_t frequency) mutable{
+        ports_inserted += update_port_buffer(port_buffer, {port++, frequency, PortStats::Protocol::UDP});
+    });
+
+    port_buffer.resize(std::min(m_top_ports_count, ports_inserted));
+    return port_buffer;
+}
+
+} // namespace ipxp

src/plugins/input/parser/topPorts.hpp

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+/**
+ * \file topPorts.hpp
+ * \brief TopPorts class declaration implementing the most popular ports.
+ * \author Damir Zainullin <zaidamilda@gmail.com>
+ * \date 2024
+ */
+#pragma once
+
+#include <array>
+#include <cstdint>
+#include <limits>
+#include <vector>
+#include <string>
+
+namespace ipxp {
+/**
+ * \brief Top ports counter.
+ */
+class TopPorts {
+public:
+
+    /**
+     * \brief Constructor.
+     * \param top_ports_count Number of the most popular ports to track.
+     */
+    TopPorts(size_t top_ports_count) noexcept;
+
+    /**
+     * \brief Increments number of times given tcp port has been seen.
+     * \param port Port to increment its frequency.
+     */
+    void increment_tcp_frequency(uint16_t port) noexcept
+    {
+        m_tcp_port_frequencies[port]++;
+    }
+
+    /**
+     * \brief Increments number of times given udp port has been seen.
+     * \param port Port to increment its frequency.
+     */
+    void increment_udp_frequency(uint16_t port) noexcept
+    {
+        m_udp_port_frequencies[port]++;
+    }
+
+    /**
+     * \brief Port frequency and protocol to which it belongs.
+     */
+    struct PortStats {
+        /**
+         * \brief Protocol type.
+         */
+        enum class Protocol {
+            TCP,
+            UDP
+        };
+
+        uint16_t port; /**< Port number. */
+        size_t frequency; /**< Number of times the port has been seen. */
+        Protocol protocol; /**< Protocol to which the port belongs. */
+
+        /**
+         * \brief Convert the port stats to string.
+         * \return String representation of the port stats.
+         */
+        std::string to_string() const noexcept;
+    };
+
+    /**
+     * \brief Get the top ports.
+     * \return Vector of the most popular ports.
+     */
+    std::vector<TopPorts::PortStats> get_top_ports() const noexcept;
+
+private:
+    std::array<std::size_t, std::numeric_limits<uint16_t>::max() + 1> m_tcp_port_frequencies {};
+    std::array<std::size_t, std::numeric_limits<uint16_t>::max() + 1> m_udp_port_frequencies {};
+    const size_t m_top_ports_count;
+};
+
+} // namespace ipxp