Add support for systemd sinks

Change-Id: I2cd3d0c480af9456d551f3f7642aa93764d62a06

Author: mattkdab

src/KDSpdSetup/details.cpp

@@ -216,4 +216,16 @@ auto genFromWinStr(toml::string &&typeStr) -> spdlog::sink_ptr
 }
 #endif
 
+#ifdef _KDSPDSETUP_SYSTEMD_
+auto genFromSystemdStr(toml::string &&typeStr, std::string &&ident, bool const enableFormatting) -> spdlog::sink_ptr
+{
+    if (typeStr == "systemd_sink_st") {
+        return createSystemdSinkStPtr(std::move(ident), enableFormatting);
+    }
+    if (typeStr == "systemd_sink_mt") {
+        return createSystemdSinkMtPtr(std::move(ident), enableFormatting);
+    }
+}
+#endif
+
 } // namespace KDSPDSetup::details

src/KDSpdSetup/details.h

@@ -28,6 +28,10 @@
 #elif _WIN32
 #include <spdlog/sinks/msvc_sink.h>
 #endif
+#if __has_include(<systemd/sd-journal.h>)
+#include <spdlog/sinks/systemd_sink.h>
+#define _KDSPDSETUP_SYSTEMD_
+#endif
 
 #include <toml.hpp>
 
@@ -93,6 +97,8 @@ static auto const linuxStrs{ std::vector<std::string>{ "syslog_sink_st", "syslog
  */
 static auto const winStrs{ std::vector<std::string>{ "msvc_sink_st", "msvc_sink_mt" } };
 
+static auto const systemdStrs{ std::vector<std::string>{ "systemd_sink_st", "systemd_sink_mt" } };
+
 /**
  * @brief A simple map associating strings of `spdlog::level::level_enum` names to the enums themselves.
  * Used to pass an enum to `spdlog::logger::set_level` given a string read from a TOML table.
@@ -312,6 +318,12 @@ class SPDMaps
 #define createMsvcSinkMtPtr createMsvcSinkPtr<std::mutex>
 #endif
 
+#ifdef _KDSPDSETUP_SYSTEMD_
+#define createSystemdSinkStPtr createSystemdSinkPtr<spdlog::details::null_mutex>
+
+#define createSystemdSinkMtPtr createSystemdSinkPtr<std::mutex>
+#endif
+
 /**
  * @brief Returns true if a string `typeStr` is present in a vector `strList`, and false if not.
  * Used to identify a group to which a sink's `type` belongs when reading from a configuration file.
@@ -574,6 +586,14 @@ auto createMsvcSinkPtr() -> std::shared_ptr<spdlog::sinks::msvc_sink<Mutex>>
 }
 #endif
 
+#ifdef _KDSPDSETUP_SYSTEMD_
+template<typename Mutex>
+auto createSystemdSinkPtr(std::string &&ident, bool const enableFormatting) -> std::shared_ptr<spdlog::sinks::systemd_sink<Mutex>>
+{
+    return std::make_shared<spdlog::sinks::systemd_sink<Mutex>>(ident, enableFormatting);
+}
+#endif
+
 /**
  * @brief Return the result of calling KDSPDSetup::details::createFileSinkPtr with the correct template argument
  * based on the value of `typeStr`. Uses macros `createFileSinkStPtr` and `createFileSinkMtPtr` for clarity.
@@ -651,4 +671,9 @@ auto genFromWinStr(toml::string &&typeStr) -> spdlog::sink_ptr;
 
 #endif
 
+#ifdef _KDSPDSETUP_SYSTEMD_
+auto genFromSystemdStr(toml::string &&typeStr, std::string &&ident, bool const enableFormatting) -> spdlog::sink_ptr;
+
+#endif
+
 } // namespace KDSPDSetup::details

src/KDSpdSetup/setup.cpp

@@ -83,6 +83,14 @@ void setupSink(toml::table &&sinkTable)
         sinkPtr = details::genFromWinStr(std::move(typeStr));
 #else
         return;
+#endif
+    } else if (details::inTypelist(typeStr, details::systemdStrs)) {
+#ifdef _KDSPDSETUP_SYSTEMD_
+        auto ident = (sinkTable.contains("ident")) ? sinkTable.at("ident").as_string().str : ""s;
+        auto const enableFormatting = (sinkTable.contains("enable_formatting")) ? sinkTable.at("enable_formatting").as_boolean() : false;
+        sinkPtr = details::genFromSystemdStr(std::move(typeStr), std::move(ident), enableFormatting);
+#else
+        return;
 #endif
     }