Switched to header only spdlog for better portability

thirdparty/spdlog/sinks/systemd_sink.h

@@ -0,0 +1,103 @@
+// Copyright(c) 2019 ZVYAGIN.Alexander@gmail.com
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/sinks/base_sink.h>
+#include <spdlog/details/null_mutex.h>
+#include <spdlog/details/synchronous_factory.h>
+
+#include <array>
+#ifndef SD_JOURNAL_SUPPRESS_LOCATION
+#    define SD_JOURNAL_SUPPRESS_LOCATION
+#endif
+#include <systemd/sd-journal.h>
+
+namespace spdlog {
+namespace sinks {
+
+/**
+ * Sink that write to systemd journal using the `sd_journal_send()` library call.
+ *
+ * Locking is not needed, as `sd_journal_send()` itself is thread-safe.
+ */
+template<typename Mutex>
+class systemd_sink : public base_sink<Mutex>
+{
+public:
+    //
+    systemd_sink()
+        : syslog_levels_{{/* spdlog::level::trace      */ LOG_DEBUG,
+              /* spdlog::level::debug      */ LOG_DEBUG,
+              /* spdlog::level::info       */ LOG_INFO,
+              /* spdlog::level::warn       */ LOG_WARNING,
+              /* spdlog::level::err        */ LOG_ERR,
+              /* spdlog::level::critical   */ LOG_CRIT,
+              /* spdlog::level::off        */ LOG_INFO}}
+    {}
+
+    ~systemd_sink() override {}
+
+    systemd_sink(const systemd_sink &) = delete;
+    systemd_sink &operator=(const systemd_sink &) = delete;
+
+protected:
+    using levels_array = std::array<int, 7>;
+    levels_array syslog_levels_;
+
+    void sink_it_(const details::log_msg &msg) override
+    {
+        int err;
+
+        size_t length = msg.payload.size();
+        // limit to max int
+        if (length > static_cast<size_t>(std::numeric_limits<int>::max()))
+        {
+            length = static_cast<size_t>(std::numeric_limits<int>::max());
+        }
+
+        // Do not send source location if not available
+        if (msg.source.empty())
+        {
+            // Note: function call inside '()' to avoid macro expansion
+            err = (sd_journal_send)("MESSAGE=%.*s", static_cast<int>(length), msg.payload.data(), "PRIORITY=%d", syslog_level(msg.level),
+                "SYSLOG_IDENTIFIER=%.*s", static_cast<int>(msg.logger_name.size()), msg.logger_name.data(), nullptr);
+        }
+        else
+        {
+            err = (sd_journal_send)("MESSAGE=%.*s", static_cast<int>(length), msg.payload.data(), "PRIORITY=%d", syslog_level(msg.level),
+                "SYSLOG_IDENTIFIER=%.*s", static_cast<int>(msg.logger_name.size()), msg.logger_name.data(), "CODE_FILE=%s",
+                msg.source.filename, "CODE_LINE=%d", msg.source.line, "CODE_FUNC=%s", msg.source.funcname, nullptr);
+        }
+
+        if (err)
+        {
+            throw_spdlog_ex("Failed writing to systemd", errno);
+        }
+    }
+
+    int syslog_level(level::level_enum l)
+    {
+        return syslog_levels_.at(static_cast<levels_array::size_type>(l));
+    }
+
+    void flush_() override {}
+};
+
+using systemd_sink_mt = systemd_sink<std::mutex>;
+using systemd_sink_st = systemd_sink<details::null_mutex>;
+} // namespace sinks
+
+// Create and register a syslog logger
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> systemd_logger_mt(const std::string &logger_name)
+{
+    return Factory::template create<sinks::systemd_sink_mt>(logger_name);
+}
+
+template<typename Factory = spdlog::synchronous_factory>
+inline std::shared_ptr<logger> systemd_logger_st(const std::string &logger_name)
+{
+    return Factory::template create<sinks::systemd_sink_st>(logger_name);
+}
+} // namespace spdlog