fix(logging): add logging namespace and create logging::init method (#2336)

src/logging.cpp

@@ -4,9 +4,11 @@
  */
 
 // standard includes
+#include <fstream>
 #include <iostream>
 
 // lib includes
+#include <boost/core/null_deleter.hpp>
 #include <boost/log/attributes/clock.hpp>
 #include <boost/log/common.hpp>
 #include <boost/log/expressions.hpp>
@@ -16,6 +18,10 @@
 // local includes
 #include "logging.h"
 
+extern "C" {
+#include <libavutil/log.h>
+}
+
 using namespace std::literals;
 
 namespace bl = boost::log;
@@ -29,45 +35,182 @@ bl::sources::severity_logger<int> warning(3);  // Strange events
 bl::sources::severity_logger<int> error(4);  // Recoverable errors
 bl::sources::severity_logger<int> fatal(5);  // Unrecoverable errors
 
-/**
- * @brief Flush the log.
- *
- * EXAMPLES:
- * ```cpp
- * log_flush();
- * ```
- */
-void
-log_flush() {
-  sink->flush();
-}
+BOOST_LOG_ATTRIBUTE_KEYWORD(severity, "Severity", int)
 
-/**
- * @brief Print help to stdout.
- * @param name The name of the program.
- *
- * EXAMPLES:
- * ```cpp
- * print_help("sunshine");
- * ```
- */
-void
-print_help(const char *name) {
-  std::cout
-    << "Usage: "sv << name << " [options] [/path/to/configuration_file] [--cmd]"sv << std::endl
-    << "    Any configurable option can be overwritten with: \"name=value\""sv << std::endl
-    << std::endl
-    << "    Note: The configuration will be created if it doesn't exist."sv << std::endl
-    << std::endl
-    << "    --help                    | print help"sv << std::endl
-    << "    --creds username password | set user credentials for the Web manager"sv << std::endl
-    << "    --version                 | print the version of sunshine"sv << std::endl
-    << std::endl
-    << "    flags"sv << std::endl
-    << "        -0 | Read PIN from stdin"sv << std::endl
-    << "        -1 | Do not load previously saved state and do retain any state after shutdown"sv << std::endl
-    << "           | Effectively starting as if for the first time without overwriting any pairings with your devices"sv << std::endl
-    << "        -2 | Force replacement of headers in video stream"sv << std::endl
-    << "        -p | Enable/Disable UPnP"sv << std::endl
-    << std::endl;
-}
+namespace logging {
+  /**
+   * @brief A destructor that restores the initial state.
+   */
+  deinit_t::~deinit_t() {
+    deinit();
+  }
+
+  /**
+   * @brief Deinitialize the logging system.
+   *
+   * EXAMPLES:
+   * ```cpp
+   * deinit();
+   * ```
+   */
+  void
+  deinit() {
+    log_flush();
+    bl::core::get()->remove_sink(sink);
+    sink.reset();
+  }
+
+  /**
+   * @brief Initialize the logging system.
+   * @param min_log_level The minimum log level to output.
+   * @param log_file The log file to write to.
+   * @returns A deinit_t object that will deinitialize the logging system when it goes out of scope.
+   *
+   * EXAMPLES:
+   * ```cpp
+   * log_init(2, "sunshine.log");
+   * ```
+   */
+  [[nodiscard]] std::unique_ptr<deinit_t>
+  init(int min_log_level, const std::string &log_file) {
+    if (sink) {
+      // Deinitialize the logging system before reinitializing it. This can probably only ever be hit in tests.
+      deinit();
+    }
+
+    setup_av_logging(min_log_level);
+
+    sink = boost::make_shared<text_sink>();
+
+    boost::shared_ptr<std::ostream> stream { &std::cout, boost::null_deleter() };
+    sink->locked_backend()->add_stream(stream);
+    sink->locked_backend()->add_stream(boost::make_shared<std::ofstream>(log_file));
+    sink->set_filter(severity >= min_log_level);
+
+    sink->set_formatter([](const bl::record_view &view, bl::formatting_ostream &os) {
+      constexpr const char *message = "Message";
+      constexpr const char *severity = "Severity";
+      constexpr int DATE_BUFFER_SIZE = 21 + 2 + 1;  // Full string plus ": \0"
+
+      auto log_level = view.attribute_values()[severity].extract<int>().get();
+
+      std::string_view log_type;
+      switch (log_level) {
+        case 0:
+          log_type = "Verbose: "sv;
+          break;
+        case 1:
+          log_type = "Debug: "sv;
+          break;
+        case 2:
+          log_type = "Info: "sv;
+          break;
+        case 3:
+          log_type = "Warning: "sv;
+          break;
+        case 4:
+          log_type = "Error: "sv;
+          break;
+        case 5:
+          log_type = "Fatal: "sv;
+          break;
+      };
+
+      char _date[DATE_BUFFER_SIZE];
+      std::time_t t = std::time(nullptr);
+      strftime(_date, DATE_BUFFER_SIZE, "[%Y:%m:%d:%H:%M:%S]: ", std::localtime(&t));
+
+      os << _date << log_type << view.attribute_values()[message].extract<std::string>();
+    });
+
+    // Flush after each log record to ensure log file contents on disk isn't stale.
+    // This is particularly important when running from a Windows service.
+    sink->locked_backend()->auto_flush(true);
+
+    bl::core::get()->add_sink(sink);
+    return std::make_unique<deinit_t>();
+  }
+
+  /**
+   * @brief Setup AV logging.
+   * @param min_log_level The log level.
+   */
+  void
+  setup_av_logging(int min_log_level) {
+    if (min_log_level >= 1) {
+      av_log_set_level(AV_LOG_QUIET);
+    }
+    else {
+      av_log_set_level(AV_LOG_DEBUG);
+    }
+    av_log_set_callback([](void *ptr, int level, const char *fmt, va_list vl) {
+      static int print_prefix = 1;
+      char buffer[1024];
+
+      av_log_format_line(ptr, level, fmt, vl, buffer, sizeof(buffer), &print_prefix);
+      if (level <= AV_LOG_ERROR) {
+        // We print AV_LOG_FATAL at the error level. FFmpeg prints things as fatal that
+        // are expected in some cases, such as lack of codec support or similar things.
+        BOOST_LOG(error) << buffer;
+      }
+      else if (level <= AV_LOG_WARNING) {
+        BOOST_LOG(warning) << buffer;
+      }
+      else if (level <= AV_LOG_INFO) {
+        BOOST_LOG(info) << buffer;
+      }
+      else if (level <= AV_LOG_VERBOSE) {
+        // AV_LOG_VERBOSE is less verbose than AV_LOG_DEBUG
+        BOOST_LOG(debug) << buffer;
+      }
+      else {
+        BOOST_LOG(verbose) << buffer;
+      }
+    });
+  }
+
+  /**
+   * @brief Flush the log.
+   *
+   * EXAMPLES:
+   * ```cpp
+   * log_flush();
+   * ```
+   */
+  void
+  log_flush() {
+    if (sink) {
+      sink->flush();
+    }
+  }
+
+  /**
+   * @brief Print help to stdout.
+   * @param name The name of the program.
+   *
+   * EXAMPLES:
+   * ```cpp
+   * print_help("sunshine");
+   * ```
+   */
+  void
+  print_help(const char *name) {
+    std::cout
+      << "Usage: "sv << name << " [options] [/path/to/configuration_file] [--cmd]"sv << std::endl
+      << "    Any configurable option can be overwritten with: \"name=value\""sv << std::endl
+      << std::endl
+      << "    Note: The configuration will be created if it doesn't exist."sv << std::endl
+      << std::endl
+      << "    --help                    | print help"sv << std::endl
+      << "    --creds username password | set user credentials for the Web manager"sv << std::endl
+      << "    --version                 | print the version of sunshine"sv << std::endl
+      << std::endl
+      << "    flags"sv << std::endl
+      << "        -0 | Read PIN from stdin"sv << std::endl
+      << "        -1 | Do not load previously saved state and do retain any state after shutdown"sv << std::endl
+      << "           | Effectively starting as if for the first time without overwriting any pairings with your devices"sv << std::endl
+      << "        -2 | Force replacement of headers in video stream"sv << std::endl
+      << "        -p | Enable/Disable UPnP"sv << std::endl
+      << std::endl;
+  }
+}  // namespace logging