prependtime: rename to prefix, add line number, make prefixes configu…

…rable

src/cpp/util/core/prefix.cpp

@@ -0,0 +1,121 @@
+#include <chrono>
+#include <iostream>
+#include <string>
+
+#include <cstdlib>
+
+#include <lyra/lyra.hpp>
+
+#include <xph/exec_info.hpp>
+#include <xph/units.hpp>
+
+#define DECLARE_FIELD(TYPE, NAME, DEFAULT)                   \
+public:                                                      \
+    static const constexpr TYPE km_default_##NAME = DEFAULT; \
+                                                             \
+private:                                                     \
+    TYPE m_##NAME = km_default_##NAME;                       \
+                                                             \
+public:                                                      \
+    [[nodiscard]] TYPE NAME() const noexcept                 \
+    {                                                        \
+        return m_##NAME;                                     \
+    }
+
+#define OPT(NAME) lyra::opt(m_##NAME)
+
+DEFINE_EXEC_INFO()
+
+class Options {
+    DECLARE_FIELD(bool, prefix_time, false);
+    DECLARE_FIELD(bool, prefix_delta, false);
+    DECLARE_FIELD(bool, prefix_line, false);
+
+public:
+    Options() = delete;
+
+    Options(int argc, char** argv)
+    {
+        bool help = false;
+        auto cli = lyra::cli() | lyra::help(help) |
+                   OPT(prefix_time)["-t"]["--time"]("prefix lines with current time") |
+                   OPT(prefix_delta)["-d"]["--delta"]("prefix lines with delta time") |
+                   OPT(prefix_line)["-l"]["--line"]("prefix lines with line number");
+        auto args = cli.parse({ argc, argv });
+
+        if (!args) {
+            std::cerr << args.message() << '\n';
+            std::cerr << "Try '" << xph::exec_path << " -h' for more information.\n";
+            std::exit(EXIT_FAILURE);
+        }
+
+        if (help) {
+            std::cout << cli << '\n';
+            std::exit(EXIT_SUCCESS);
+        }
+    }
+};
+
+int main(int argc, char* argv[])
+{
+    xph::gather_exec_info(argc, argv);
+
+    Options options(argc, argv);
+
+    std::chrono::steady_clock clock;
+
+    auto start_time = clock.now();
+    auto last_time = start_time;
+
+    for (std::string line; std::getline(std::cin, line);) {
+        auto current_time = clock.now();
+
+        bool prefixed = false;
+        if (options.prefix_line()) {
+            static int line_number = 0;
+
+            std::cout << "[#" << line_number++;
+
+            prefixed = true;
+        }
+
+        if (options.prefix_time()) {
+            auto elapsed_time = current_time - start_time;
+            auto elapsed_ticks = elapsed_time.count();
+            auto elapsed_human_ticks = xph::unit::tick_to_human(elapsed_ticks);
+
+            if (prefixed)
+                std::cout << " | ";
+            else
+                std::cout << '[';
+
+            std::cout << '@' << elapsed_human_ticks;
+
+            prefixed = true;
+        }
+
+        if (options.prefix_delta()) {
+            auto differential_time = current_time - last_time;
+            auto differential_ticks = differential_time.count();
+            auto differential_human_ticks = xph::unit::tick_to_human(differential_ticks);
+
+            if (prefixed)
+                std::cout << " | ";
+            else
+                std::cout << '[';
+
+            std::cout << '+' << differential_human_ticks;
+
+            prefixed = true;
+        }
+
+        if (prefixed)
+            std::cout << "]: ";
+
+        std::cout << line << '\n';
+
+        last_time = current_time;
+    }
+
+    return EXIT_SUCCESS;
+}