Log: new logging library API

Makefile.am

@@ -129,6 +129,7 @@ src_mpd_SOURCES = \
 	src/FilterPlugin.cxx src/FilterPlugin.hxx \
 	src/FilterInternal.hxx \
 	src/FilterRegistry.cxx src/FilterRegistry.hxx \
+	src/UpdateDomain.cxx src/UpdateDomain.hxx \
 	src/UpdateGlue.cxx src/UpdateGlue.hxx \
 	src/UpdateQueue.cxx src/UpdateQueue.hxx \
 	src/UpdateIO.cxx src/UpdateIO.hxx \
@@ -154,7 +155,8 @@ src_mpd_SOURCES = \
 	src/ClientSubscribe.cxx src/ClientSubscribe.hxx \
 	src/ClientFile.cxx src/ClientFile.hxx \
 	src/Listen.cxx src/Listen.hxx \
-	src/Log.cxx src/Log.hxx \
+	src/LogInit.cxx src/LogInit.hxx \
+	src/Log.cxx src/Log.hxx src/LogV.hxx \
 	src/ls.cxx src/ls.hxx \
 	src/IOThread.cxx src/IOThread.hxx \
 	src/Main.cxx src/Main.hxx \
@@ -233,6 +235,7 @@ endif
 
 if ENABLE_INOTIFY
 src_mpd_SOURCES += \
+	src/InotifyDomain.cxx src/InotifyDomain.hxx \
 	src/InotifySource.cxx src/InotifySource.hxx \
 	src/InotifyQueue.cxx src/InotifyQueue.hxx \
 	src/InotifyUpdate.cxx src/InotifyUpdate.hxx
@@ -523,6 +526,7 @@ libdecoder_plugins_a_SOURCES += \
 	src/decoder/OggUtil.hxx \
 	src/decoder/OggSyncState.hxx \
 	src/decoder/OggFind.cxx src/decoder/OggFind.hxx \
+	src/decoder/OpusDomain.cxx src/decoder/OpusDomain.hxx \
 	src/decoder/OpusReader.hxx \
 	src/decoder/OpusHead.hxx \
 	src/decoder/OpusHead.cxx \
@@ -557,6 +561,7 @@ endif
 
 if ENABLE_VORBIS_DECODER
 libdecoder_plugins_a_SOURCES += \
+	src/decoder/VorbisDomain.cxx src/decoder/VorbisDomain.hxx \
 	src/decoder/VorbisComments.cxx src/decoder/VorbisComments.hxx \
 	src/decoder/VorbisDecoderPlugin.cxx src/decoder/VorbisDecoderPlugin.h
 endif
@@ -567,6 +572,7 @@ libdecoder_plugins_a_SOURCES += \
 	src/decoder/FlacIOHandle.cxx src/decoder/FlacIOHandle.hxx \
 	src/decoder/FlacMetadata.cxx src/decoder/FlacMetadata.hxx \
 	src/decoder/FlacPcm.cxx src/decoder/FlacPcm.hxx \
+	src/decoder/FlacDomain.cxx src/decoder/FlacDomain.hxx \
 	src/decoder/FlacCommon.cxx src/decoder/FlacCommon.hxx \
 	src/decoder/FlacDecoderPlugin.cxx \
 	src/decoder/FlacDecoderPlugin.h
@@ -1062,13 +1068,17 @@ test_read_conf_LDADD = \
 	libsystem.a \
 	libfs.a \
 	$(GLIB_LIBS)
-test_read_conf_SOURCES = test/read_conf.cxx
+test_read_conf_SOURCES = \
+	src/Log.cxx \
+	test/read_conf.cxx
 
 test_run_resolver_LDADD = \
 	libsystem.a \
 	libutil.a \
 	$(GLIB_LIBS)
-test_run_resolver_SOURCES = test/run_resolver.cxx
+test_run_resolver_SOURCES = \
+	src/Log.cxx \
+	test/run_resolver.cxx
 
 test_DumpDatabase_LDADD = \
 	$(DB_LIBS) \
@@ -1079,6 +1089,7 @@ test_DumpDatabase_LDADD = \
 	libfs.a \
 	$(GLIB_LIBS)
 test_DumpDatabase_SOURCES = test/DumpDatabase.cxx \
+	src/Log.cxx \
 	src/DatabaseError.cxx \
 	src/DatabaseRegistry.cxx \
 	src/DatabaseSelection.cxx \
@@ -1102,6 +1113,7 @@ test_run_input_LDADD = \
 	$(GLIB_LIBS)
 test_run_input_SOURCES = test/run_input.cxx \
 	test/stdbin.h \
+	src/Log.cxx \
 	src/IOThread.cxx \
 	src/TagSave.cxx
 
@@ -1118,6 +1130,7 @@ test_visit_archive_LDADD = \
 	libfs.a \
 	$(GLIB_LIBS)
 test_visit_archive_SOURCES = test/visit_archive.cxx \
+	src/Log.cxx \
 	src/IOThread.cxx \
 	src/InputStream.cxx
 
@@ -1139,6 +1152,7 @@ test_dump_text_file_LDADD = \
 	$(GLIB_LIBS)
 test_dump_text_file_SOURCES = test/dump_text_file.cxx \
 	test/stdbin.h \
+	src/Log.cxx \
 	src/IOThread.cxx \
 	src/TextInputStream.cxx
 
@@ -1158,6 +1172,7 @@ test_dump_playlist_LDADD = \
 	$(GLIB_LIBS)
 test_dump_playlist_SOURCES = test/dump_playlist.cxx \
 	$(DECODER_SRC) \
+	src/Log.cxx \
 	src/IOThread.cxx \
 	src/Song.cxx src/TagSave.cxx \
 	src/TagFile.cxx \
@@ -1185,6 +1200,7 @@ test_run_decoder_LDADD = \
 	$(GLIB_LIBS)
 test_run_decoder_SOURCES = test/run_decoder.cxx \
 	test/stdbin.h \
+	src/Log.cxx \
 	src/IOThread.cxx \
 	src/ReplayGainInfo.cxx \
 	src/AudioFormat.cxx src/CheckAudioFormat.cxx \
@@ -1206,6 +1222,7 @@ test_read_tags_LDADD = \
 	libutil.a \
 	$(GLIB_LIBS)
 test_read_tags_SOURCES = test/read_tags.cxx \
+	src/Log.cxx \
 	src/IOThread.cxx \
 	src/ReplayGainInfo.cxx \
 	src/CheckAudioFormat.cxx \
@@ -1216,7 +1233,9 @@ test_dump_rva2_LDADD = \
 	$(TAG_LIBS) \
 	libutil.a \
 	$(GLIB_LIBS)
-test_dump_rva2_SOURCES = test/dump_rva2.cxx
+test_dump_rva2_SOURCES = \
+	src/Log.cxx \
+	test/dump_rva2.cxx
 endif
 
 test_run_filter_LDADD = \
@@ -1229,6 +1248,7 @@ test_run_filter_LDADD = \
 test_run_filter_SOURCES = test/run_filter.cxx \
 	test/FakeReplayGainConfig.cxx \
 	test/stdbin.h \
+	src/Log.cxx \
 	src/FilterPlugin.cxx src/FilterRegistry.cxx \
 	src/CheckAudioFormat.cxx \
 	src/AudioFormat.cxx \
@@ -1248,6 +1268,7 @@ if ENABLE_ENCODER
 noinst_PROGRAMS += test/run_encoder
 test_run_encoder_SOURCES = test/run_encoder.cxx \
 	test/stdbin.h \
+	src/Log.cxx \
 	src/CheckAudioFormat.cxx \
 	src/AudioFormat.cxx \
 	src/AudioParser.cxx
@@ -1266,6 +1287,7 @@ if ENABLE_VORBIS_ENCODER
 noinst_PROGRAMS += test/test_vorbis_encoder
 test_test_vorbis_encoder_SOURCES = test/test_vorbis_encoder.cxx \
 	test/stdbin.h \
+	src/Log.cxx \
 	src/CheckAudioFormat.cxx \
 	src/AudioFormat.cxx \
 	src/AudioParser.cxx \
@@ -1302,6 +1324,7 @@ test_run_normalize_LDADD = \
 	$(GLIB_LIBS)
 
 test_run_convert_SOURCES = test/run_convert.cxx \
+	src/Log.cxx \
 	src/AudioFormat.cxx \
 	src/CheckAudioFormat.cxx \
 	src/AudioParser.cxx
@@ -1326,6 +1349,7 @@ test_run_output_LDADD = $(MPD_LIBS) \
 test_run_output_SOURCES = test/run_output.cxx \
 	test/FakeReplayGainConfig.cxx \
 	test/stdbin.h \
+	src/Log.cxx \
 	src/IOThread.cxx \
 	src/CheckAudioFormat.cxx \
 	src/AudioFormat.cxx \
@@ -1353,6 +1377,7 @@ test_read_mixer_LDADD = \
 	libfs.a \
 	$(GLIB_LIBS)
 test_read_mixer_SOURCES = test/read_mixer.cxx \
+	src/Log.cxx \
 	src/MixerControl.cxx \
 	src/FilterPlugin.cxx \
 	src/filter/VolumeFilterPlugin.cxx
@@ -1372,6 +1397,8 @@ endif
 if ENABLE_INOTIFY
 noinst_PROGRAMS += test/run_inotify
 test_run_inotify_SOURCES = test/run_inotify.cxx \
+	src/Log.cxx \
+	src/InotifyDomain.cxx \
 	src/InotifySource.cxx
 test_run_inotify_LDADD = \
 	libevent.a \

doc/developer.xml

@@ -61,7 +61,7 @@
 foo(const char *abc, int xyz)
 {
         if (abc == NULL) {
-                g_warning("Foo happened!\n");
+                LogWarning("Foo happened!");
                 return -1;
         }
 

src/ArchiveLookup.cxx

@@ -19,15 +19,17 @@
 
 #include "config.h" /* must be first for large file support */
 #include "ArchiveLookup.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
-#include <stdio.h>
+#include <glib.h>
 
 #include <string.h>
-#include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>
 #include <errno.h>
-#include <glib.h>
+
+static constexpr Domain archive_domain("archive");
 
 /**
  *
@@ -65,7 +67,8 @@ bool archive_lookup(char *pathname, char **archive, char **inpath, char **suffix
 		//try to stat if its real directory
 		if (stat(pathdupe, &st_info) == -1) {
 			if (errno != ENOTDIR) {
-				g_warning("stat %s failed (errno=%d)\n", pathdupe, errno);
+				FormatErrno(archive_domain,
+					    "Failed to stat %s", pathdupe);
 				break;
 			}
 		} else {
@@ -92,7 +95,9 @@ bool archive_lookup(char *pathname, char **archive, char **inpath, char **suffix
 				}
 				break;
 			} else {
-				g_warning("not a regular file %s\n", pathdupe);
+				FormatError(archive_domain,
+					    "Not a regular file: %s",
+					    pathdupe);
 				break;
 			}
 		}

src/Client.cxx

@@ -19,6 +19,9 @@
 
 #include "config.h"
 #include "ClientInternal.hxx"
+#include "util/Domain.hxx"
+
+const Domain client_domain("client");
 
 int client_get_uid(const Client *client)
 {

src/ClientEvent.cxx

@@ -20,13 +20,12 @@
 #include "config.h"
 #include "ClientInternal.hxx"
 #include "util/Error.hxx"
-
-#include <glib.h>
+#include "Log.hxx"
 
 void
 Client::OnSocketError(Error &&error)
 {
-	g_warning("error on client %d: %s", num, error.GetMessage());
+	FormatError(error, "error on client %d", num);
 
 	SetExpired();
 }

src/ClientExpire.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "ClientInternal.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -37,7 +38,7 @@ Client::OnTimeout()
 {
 	if (!IsExpired()) {
 		assert(!idle_waiting);
-		g_debug("[%u] timeout", num);
+		FormatDebug(client_domain, "[%u] timeout", num);
 	}
 
 	Close();

src/ClientInternal.hxx

@@ -32,9 +32,6 @@
 #include <string>
 #include <list>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "client"
-
 enum {
 	CLIENT_MAX_SUBSCRIPTIONS = 16,
 	CLIENT_MAX_MESSAGES = 64,
@@ -123,6 +120,8 @@ private:
 	virtual void OnTimeout() override;
 };
 
+extern const class Domain client_domain;
+
 extern int client_timeout;
 extern size_t client_max_command_list_size;
 extern size_t client_max_output_buffer_size;

src/ClientNew.cxx

@@ -26,6 +26,7 @@
 #include "system/Resolver.hxx"
 #include "Permission.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <assert.h>
 #include <sys/types.h>
@@ -40,9 +41,6 @@
 #include <tcpd.h>
 #endif
 
-
-#define LOG_LEVEL_SECURE G_LOG_LEVEL_INFO
-
 static const char GREETING[] = "OK MPD " PROTOCOL_VERSION "\n";
 
 Client::Client(EventLoop &_loop, Partition &_partition,
@@ -82,9 +80,9 @@ client_new(EventLoop &loop, Partition &partition,
 
 		if (!hosts_access(&req)) {
 			/* tcp wrappers says no */
-			g_log(G_LOG_DOMAIN, LOG_LEVEL_SECURE,
-			      "libwrap refused connection (libwrap=%s) from %s",
-			      progname, hostaddr);
+			FormatWarning(client_domain,
+				      "libwrap refused connection (libwrap=%s) from %s",
+				      progname, hostaddr);
 
 			g_free(hostaddr);
 			close_socket(fd);
@@ -97,7 +95,7 @@ client_new(EventLoop &loop, Partition &partition,
 
 	ClientList &client_list = *partition.instance.client_list;
 	if (client_list.IsFull()) {
-		g_warning("Max Connections Reached!");
+		LogWarning(client_domain, "Max connections reached");
 		close_socket(fd);
 		return;
 	}
@@ -110,8 +108,7 @@ client_new(EventLoop &loop, Partition &partition,
 	client_list.Add(*client);
 
 	remote = sockaddr_to_string(sa, sa_length, IgnoreError());
-	g_log(G_LOG_DOMAIN, LOG_LEVEL_SECURE,
-	      "[%u] opened from %s", client->num, remote);
+	FormatInfo(client_domain, "[%u] opened from %s", client->num, remote);
 	g_free(remote);
 }
 
@@ -122,6 +119,6 @@ Client::Close()
 
 	SetExpired();
 
-	g_log(G_LOG_DOMAIN, LOG_LEVEL_SECURE, "[%u] closed", num);
+	FormatInfo(client_domain, "[%u] closed", num);
 	delete this;
 }

src/ClientProcess.cxx

@@ -21,6 +21,7 @@
 #include "ClientInternal.hxx"
 #include "protocol/Result.hxx"
 #include "AllCommands.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -40,10 +41,9 @@ client_process_command_list(Client *client, bool list_ok,
 	for (auto &&i : list) {
 		char *cmd = &*i.begin();
 
-		g_debug("command_process_list: process command \"%s\"",
-			cmd);
+		FormatDebug(client_domain, "process command \"%s\"", cmd);
 		ret = command_process(client, num++, cmd);
-		g_debug("command_process_list: command returned %i", ret);
+		FormatDebug(client_domain, "command returned %i", ret);
 		if (ret != COMMAND_RETURN_OK || client->IsExpired())
 			break;
 		else if (list_ok)
@@ -73,23 +73,26 @@ client_process_line(Client *client, char *line)
 	} else if (client->idle_waiting) {
 		/* during idle mode, clients must not send anything
 		   except "noidle" */
-		g_warning("[%u] command \"%s\" during idle",
-			  client->num, line);
+		FormatWarning(client_domain,
+			      "[%u] command \"%s\" during idle",
+			      client->num, line);
 		return COMMAND_RETURN_CLOSE;
 	}
 
 	if (client->cmd_list.IsActive()) {
 		if (strcmp(line, CLIENT_LIST_MODE_END) == 0) {
-			g_debug("[%u] process command list",
-				client->num);
+			FormatDebug(client_domain,
+				    "[%u] process command list",
+				    client->num);
 
 			auto &&cmd_list = client->cmd_list.Commit();
 
 			ret = client_process_command_list(client,
 							  client->cmd_list.IsOKMode(),
 							  std::move(cmd_list));
-			g_debug("[%u] process command "
-				"list returned %i", client->num, ret);
+			FormatDebug(client_domain,
+				    "[%u] process command "
+				    "list returned %i", client->num, ret);
 
 			if (ret == COMMAND_RETURN_CLOSE ||
 			    client->IsExpired())
@@ -101,10 +104,11 @@ client_process_line(Client *client, char *line)
 			client->cmd_list.Reset();
 		} else {
 			if (!client->cmd_list.Add(line)) {
-				g_warning("[%u] command list size "
-					  "is larger than the max (%lu)",
-					  client->num,
-					  (unsigned long)client_max_command_list_size);
+				FormatWarning(client_domain,
+					      "[%u] command list size "
+					      "is larger than the max (%lu)",
+					      client->num,
+					      (unsigned long)client_max_command_list_size);
 				return COMMAND_RETURN_CLOSE;
 			}
 
@@ -118,11 +122,13 @@ client_process_line(Client *client, char *line)
 			client->cmd_list.Begin(true);
 			ret = COMMAND_RETURN_OK;
 		} else {
-			g_debug("[%u] process command \"%s\"",
-				client->num, line);
+			FormatDebug(client_domain,
+				    "[%u] process command \"%s\"",
+				    client->num, line);
 			ret = command_process(client, 0, line);
-			g_debug("[%u] command returned %i",
-				client->num, ret);
+			FormatDebug(client_domain,
+				    "[%u] command returned %i",
+				    client->num, ret);
 
 			if (ret == COMMAND_RETURN_CLOSE ||
 			    client->IsExpired())

src/CommandError.cxx

@@ -22,6 +22,7 @@
 #include "DatabaseError.hxx"
 #include "protocol/Result.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -93,7 +94,7 @@ print_error(Client *client, const Error &error)
 	assert(client != NULL);
 	assert(error.IsDefined());
 
-	g_warning("%s", error.GetMessage());
+	LogError(error);
 
 	if (error.IsDomain(playlist_domain)) {
 		return print_playlist_result(client,

src/CommandLine.cxx

@@ -20,6 +20,7 @@
 #include "config.h"
 #include "CommandLine.hxx"
 #include "ls.hxx"
+#include "LogInit.hxx"
 #include "Log.hxx"
 #include "ConfigGlobal.hxx"
 #include "DecoderList.hxx"
@@ -197,7 +198,8 @@ parse_cmdline(int argc, char **argv, struct options *options,
 	options->daemon = !option_no_daemon;
 
 	if (option_no_config) {
-		g_debug("Ignoring config, using daemon defaults\n");
+		LogDebug(cmdline_domain,
+			 "Ignoring config, using daemon defaults");
 		return true;
 	} else if (argc <= 1) {
 		/* default configuration file path */

src/ConfigFile.cxx

@@ -28,17 +28,13 @@
 #include "util/Domain.hxx"
 #include "fs/Path.hxx"
 #include "fs/FileSystem.hxx"
-
-#include <glib.h>
+#include "Log.hxx"
 
 #include <assert.h>
 #include <string.h>
 #include <stdio.h>
 #include <errno.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "config"
-
 #define MAX_STRING_SIZE	MPD_PATH_MAX+80
 
 #define CONF_COMMENT		'#'
@@ -261,7 +257,7 @@ ReadConfigFile(ConfigData &config_data, const Path &path, Error &error)
 	assert(!path.IsNull());
 	const std::string path_utf8 = path.ToUTF8();
 
-	g_debug("loading file %s", path_utf8.c_str());
+	FormatDebug(config_file_domain, "loading file %s", path_utf8.c_str());
 
 	FILE *fp = FOpen(path, FOpenMode::ReadText);
 	if (fp == nullptr) {

src/ConfigGlobal.cxx

@@ -23,18 +23,15 @@
 #include "ConfigData.hxx"
 #include "ConfigFile.hxx"
 #include "ConfigPath.hxx"
+#include "ConfigError.hxx"
 #include "fs/Path.hxx"
 #include "util/Error.hxx"
 #include "system/FatalError.hxx"
-
-#include <glib.h>
+#include "Log.hxx"
 
 #include <assert.h>
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "config"
-
 static ConfigData config_data;
 
 void config_global_finish(void)
@@ -64,8 +61,9 @@ Check(const config_param *param)
 
 	for (const auto &i : param->block_params) {
 		if (!i.used)
-			g_warning("option '%s' on line %i was not recognized",
-				  i.name.c_str(), i.line);
+			FormatWarning(config_domain,
+				      "option '%s' on line %i was not recognized",
+				      i.name.c_str(), i.line);
 	}
 }
 

src/CrossFade.cxx

@@ -21,23 +21,25 @@
 #include "CrossFade.hxx"
 #include "MusicChunk.hxx"
 #include "AudioFormat.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <cmath>
 
 #include <assert.h>
 #include <string.h>
 #include <stdlib.h>
-#include <glib.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "crossfade"
+static constexpr Domain cross_fade_domain("cross_fade");
+
+#ifdef WIN32
 
-#ifdef G_OS_WIN32
 static char *
 strtok_r(char *str, const char *delim, gcc_unused char **saveptr)
 {
 	return strtok(str, delim);
 }
+
 #endif
 
 static float mixramp_interpolate(char *ramp_list, float required_db)
@@ -123,14 +125,16 @@ unsigned cross_fade_calc(float duration, float total_time,
 		if (!std::isnan(mixramp_overlap) &&
 		    mixramp_delay <= mixramp_overlap) {
 			chunks = (chunks_f * (mixramp_overlap - mixramp_delay));
-			g_debug("will overlap %d chunks, %fs", chunks,
-				mixramp_overlap - mixramp_delay);
+			FormatDebug(cross_fade_domain,
+				    "will overlap %d chunks, %fs", chunks,
+				    mixramp_overlap - mixramp_delay);
 		}
 	}
 
 	if (chunks > max_chunks) {
 		chunks = max_chunks;
-		g_warning("audio_buffer_size too small for computed MixRamp overlap");
+		LogWarning(cross_fade_domain,
+			   "audio_buffer_size too small for computed MixRamp overlap");
 	}
 
 	return chunks;

src/Daemon.cxx

@@ -22,6 +22,8 @@
 #include "system/FatalError.hxx"
 #include "fs/Path.hxx"
 #include "fs/FileSystem.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -39,8 +41,7 @@
 #include <grp.h>
 #endif
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "daemon"
+static constexpr Domain daemon_domain("daemon");
 
 #ifndef WIN32
 
@@ -170,7 +171,7 @@ daemonize_detach(void)
 	FatalError("no support for daemonizing");
 #endif
 
-	g_debug("daemonized!");
+	LogDebug(daemon_domain, "daemonized");
 }
 
 void
@@ -181,7 +182,7 @@ daemonize(bool detach)
 	if (!pidfile.IsNull()) {
 		/* do this before daemon'izing so we can fail gracefully if we can't
 		 * write to the pid file */
-		g_debug("opening pid file");
+		LogDebug(daemon_domain, "opening pid file");
 		fp = FOpen(pidfile, "w+");
 		if (!fp) {
 			const std::string utf8 = pidfile.ToUTF8();
@@ -194,7 +195,7 @@ daemonize(bool detach)
 		daemonize_detach();
 
 	if (!pidfile.IsNull()) {
-		g_debug("writing pid file");
+		LogDebug(daemon_domain, "writing pid file");
 		fprintf(fp, "%lu\n", (unsigned long)getpid());
 		fclose(fp);
 	}

src/DatabaseGlue.cxx

@@ -43,9 +43,6 @@ extern "C" {
 #include <string.h>
 #include <errno.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "database"
-
 static Database *db;
 static bool db_is_open;
 static bool is_simple;

src/DatabaseSave.cxx

@@ -29,15 +29,13 @@
 #include "tag/TagSettings.h"
 #include "fs/Path.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
 #include <assert.h>
 #include <stdlib.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "database"
-
 #define DIRECTORY_INFO_BEGIN "info_begin"
 #define DIRECTORY_INFO_END "info_end"
 #define DB_FORMAT_PREFIX "format: "
@@ -155,7 +153,7 @@ db_load_internal(TextFile &file, Directory *music_root, Error &error)
 		}
 	}
 
-	g_debug("reading DB");
+	LogDebug(db_domain, "reading DB");
 
 	db_lock();
 	success = directory_load(file, music_root, error);

src/DecoderAPI.cxx

@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "DecoderAPI.hxx"
+#include "DecoderError.hxx"
 #include "AudioConfig.hxx"
 #include "replay_gain_config.h"
 #include "MusicChunk.hxx"
@@ -29,16 +30,12 @@
 #include "Song.hxx"
 #include "InputStream.hxx"
 #include "util/Error.hxx"
-
-#include <glib.h>
+#include "Log.hxx"
 
 #include <assert.h>
 #include <stdlib.h>
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "decoder"
-
 void
 decoder_initialized(struct decoder *decoder,
 		    const AudioFormat audio_format,
@@ -67,14 +64,14 @@ decoder_initialized(struct decoder *decoder,
 	dc->client_cond.signal();
 	dc->Unlock();
 
-	g_debug("audio_format=%s, seekable=%s",
-		audio_format_to_string(dc->in_audio_format, &af_string),
-		seekable ? "true" : "false");
+	FormatDebug(decoder_domain, "audio_format=%s, seekable=%s",
+		    audio_format_to_string(dc->in_audio_format, &af_string),
+		    seekable ? "true" : "false");
 
 	if (dc->in_audio_format != dc->out_audio_format)
-		g_debug("converting to %s",
-			audio_format_to_string(dc->out_audio_format,
-					       &af_string));
+		FormatDebug(decoder_domain, "converting to %s",
+			    audio_format_to_string(dc->out_audio_format,
+						   &af_string));
 }
 
 /**
@@ -288,7 +285,7 @@ size_t decoder_read(struct decoder *decoder,
 	assert(nbytes > 0 || error.IsDefined() || is->IsEOF());
 
 	if (gcc_unlikely(nbytes == 0 && error.IsDefined()))
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 
 	is->Unlock();
 
@@ -404,7 +401,7 @@ decoder_data(struct decoder *decoder,
 			/* the PCM conversion has failed - stop
 			   playback, since we have no better way to
 			   bail out */
-			g_warning("%s", error.GetMessage());
+			LogError(error);
 			return DecoderCommand::STOP;
 		}
 	}

src/DecoderControl.cxx

@@ -26,9 +26,6 @@
 
 #include <assert.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "decoder_control"
-
 decoder_control::decoder_control()
 	:thread(nullptr),
 	 state(DecoderState::STOP),

src/DecoderThread.cxx

@@ -33,15 +33,16 @@
 #include "DecoderList.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Error.hxx"
+#include "util/Domain.hxx"
 #include "tag/ApeReplayGain.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
 #include <unistd.h>
 #include <stdio.h> /* for SEEK_SET */
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "decoder_thread"
+static constexpr Domain decoder_thread_domain("decoder_thread");
 
 /**
  * Marks the current decoder command as "finished" and notifies the
@@ -78,7 +79,7 @@ decoder_input_stream_open(struct decoder_control *dc, const char *uri)
 	input_stream *is = input_stream::Open(uri, dc->mutex, dc->cond, error);
 	if (is == NULL) {
 		if (error.IsDefined())
-			g_warning("%s", error.GetMessage());
+			LogError(error);
 
 		return NULL;
 	}
@@ -99,7 +100,7 @@ decoder_input_stream_open(struct decoder_control *dc, const char *uri)
 	if (!is->Check(error)) {
 		dc->Unlock();
 
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return NULL;
 	}
 
@@ -122,7 +123,7 @@ decoder_stream_decode(const struct decoder_plugin *plugin,
 	assert(input_stream->ready);
 	assert(decoder->dc->state == DecoderState::START);
 
-	g_debug("probing plugin %s", plugin->name);
+	FormatDebug(decoder_thread_domain, "probing plugin %s", plugin->name);
 
 	if (decoder->dc->command == DecoderCommand::STOP)
 		return true;
@@ -155,7 +156,7 @@ decoder_file_decode(const struct decoder_plugin *plugin,
 	assert(g_path_is_absolute(path));
 	assert(decoder->dc->state == DecoderState::START);
 
-	g_debug("probing plugin %s", plugin->name);
+	FormatDebug(decoder_thread_domain, "probing plugin %s", plugin->name);
 
 	if (decoder->dc->command == DecoderCommand::STOP)
 		return true;

src/DespotifyUtils.cxx

@@ -21,13 +21,15 @@
 #include "tag/Tag.hxx"
 #include "ConfigGlobal.hxx"
 #include "ConfigOption.hxx"
-
-#include <glib.h>
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 extern "C" {
 #include <despotify.h>
 }
 
+const Domain despotify_domain("despotify");
+
 static struct despotify_session *g_session;
 static void (*registered_callbacks[8])(struct despotify_session *,
 		int, void *, void *);
@@ -121,24 +123,27 @@ struct despotify_session *mpd_despotify_get_session(void)
 	high_bitrate = config_get_bool(CONF_DESPOTIFY_HIGH_BITRATE, true);
 
 	if (user == NULL || passwd == NULL) {
-		g_debug("disabling despotify because account is not configured");
+		LogDebug(despotify_domain,
+			 "disabling despotify because account is not configured");
 		return nullptr;
 	}
 
 	if (!despotify_init()) {
-		g_debug("Can't initialize despotify\n");
+		LogWarning(despotify_domain, "Can't initialize despotify");
 		return nullptr;
 	}
 
 	g_session = despotify_init_client(callback, NULL,
 					  high_bitrate, true);
 	if (!g_session) {
-		g_debug("Can't initialize despotify client\n");
+		LogWarning(despotify_domain,
+			   "Can't initialize despotify client");
 		return nullptr;
 	}
 
 	if (!despotify_authenticate(g_session, user, passwd)) {
-		g_debug("Can't authenticate despotify session\n");
+		LogWarning(despotify_domain,
+			   "Can't authenticate despotify session");
 		despotify_exit(g_session);
 		return nullptr;
 	}

src/DespotifyUtils.hxx

@@ -24,6 +24,8 @@ struct Tag;
 struct despotify_session;
 struct ds_track;
 
+extern const class Domain despotify_domain;
+
 /**
  * Return the current despotify session.
  *

src/ExcludeList.cxx

+
 /*
  * Copyright (C) 2003-2011 The Music Player Daemon Project
  * http://www.musicpd.org
@@ -26,21 +27,26 @@
 #include "ExcludeList.hxx"
 #include "fs/Path.hxx"
 #include "fs/FileSystem.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <assert.h>
 #include <string.h>
 #include <errno.h>
 
+static constexpr Domain exclude_list_domain("exclude_list");
+
 bool
 ExcludeList::LoadFile(const Path &path_fs)
 {
 	FILE *file = FOpen(path_fs, FOpenMode::ReadText);
 	if (file == NULL) {
-		if (errno != ENOENT) {
-			const char *msg = g_strerror(errno);
+		const int e = errno;
+		if (e != ENOENT) {
 			const auto path_utf8 = path_fs.ToUTF8();
-			g_debug("Failed to open %s: %s",
-				path_utf8.c_str(), msg);
+			FormatErrno(exclude_list_domain,
+				    "Failed to open %s",
+				    path_utf8.c_str());
 		}
 
 		return false;

src/GlobalEvents.cxx

@@ -28,9 +28,6 @@
 #include <assert.h>
 #include <glib.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "global_events"
-
 namespace GlobalEvents {
 	class Monitor final : public DeferredMonitor {
 	public:

src/IcyMetaDataParser.cxx

@@ -20,14 +20,15 @@
 #include "config.h"
 #include "IcyMetaDataParser.hxx"
 #include "tag/Tag.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
 #include <assert.h>
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "icy_metadata"
+static constexpr Domain icy_metadata_domain("icy_metadata");
 
 void
 IcyMetaDataParser::Reset()
@@ -88,7 +89,8 @@ icy_parse_tag_item(Tag &tag, const char *item)
 		if (strcmp(p[0], "StreamTitle") == 0)
 			icy_add_item(tag, TAG_TITLE, p[1]);
 		else
-			g_debug("unknown icy-tag: '%s'", p[0]);
+			FormatDebug(icy_metadata_domain,
+				    "unknown icy-tag: '%s'", p[0]);
 	}
 
 	g_strfreev(p);

src/IcyMetaDataServer.cxx

@@ -27,9 +27,6 @@
 #include <assert.h>
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "icy_server"
-
 char*
 icy_server_metadata_header(const char *name,
 			   const char *genre, const char *url,

src/InotifyDomain.cxx

+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "InotifyDomain.hxx"
+#include "util/Domain.hxx"
+
+const Domain inotify_domain("inotify");

src/InotifyDomain.hxx

+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_INOTIFY_DOMAIN_HXX
+#define MPD_INOTIFY_DOMAIN_HXX
+
+extern const class Domain inotify_domain;
+
+#endif

src/InotifyQueue.cxx

@@ -19,16 +19,13 @@
 
 #include "config.h"
 #include "InotifyQueue.hxx"
+#include "InotifyDomain.hxx"
 #include "UpdateGlue.hxx"
 #include "event/Loop.hxx"
-
-#include <glib.h>
+#include "Log.hxx"
 
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "inotify"
-
 enum {
 	/**
 	 * Wait this long after the last change before calling
@@ -53,7 +50,8 @@ InotifyQueue::OnTimeout()
 			return;
 		}
 
-		g_debug("updating '%s' job=%u", uri_utf8, id);
+		FormatDebug(inotify_domain, "updating '%s' job=%u",
+			    uri_utf8, id);
 
 		queue.pop_front();
 	}

src/InotifySource.cxx

@@ -19,19 +19,17 @@
 
 #include "config.h"
 #include "InotifySource.hxx"
+#include "InotifyDomain.hxx"
 #include "util/fifo_buffer.h"
 #include "util/Error.hxx"
 #include "system/fd_util.h"
 #include "system/FatalError.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
 #include <sys/inotify.h>
 #include <unistd.h>
-#include <errno.h>
-
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "inotify"
 
 bool
 InotifySource::OnSocketReady(gcc_unused unsigned flags)
@@ -120,8 +118,7 @@ InotifySource::Remove(unsigned wd)
 {
 	int ret = inotify_rm_watch(Get(), wd);
 	if (ret < 0 && errno != EINVAL)
-		g_warning("inotify_rm_watch() has failed: %s",
-			  g_strerror(errno));
+		LogErrno(inotify_domain, "inotify_rm_watch() has failed");
 
 	/* EINVAL may happen here when the file has been deleted; the
 	   kernel seems to auto-unregister deleted files */

src/InotifyUpdate.cxx

@@ -21,10 +21,12 @@
 #include "InotifyUpdate.hxx"
 #include "InotifySource.hxx"
 #include "InotifyQueue.hxx"
+#include "InotifyDomain.hxx"
 #include "Mapper.hxx"
 #include "Main.hxx"
 #include "fs/Path.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -36,10 +38,6 @@
 #include <sys/stat.h>
 #include <string.h>
 #include <dirent.h>
-#include <errno.h>
-
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "inotify"
 
 enum {
 	IN_MASK = IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_DELETE_SELF
@@ -120,8 +118,9 @@ remove_watch_directory(WatchDirectory *directory)
 	assert(directory != NULL);
 
 	if (directory->parent == NULL) {
-		g_warning("music directory was removed - "
-			  "cannot continue to watch it");
+		LogWarning(inotify_domain,
+			   "music directory was removed - "
+			   "cannot continue to watch it");
 		return;
 	}
 
@@ -178,8 +177,8 @@ recursive_watch_subdirectories(WatchDirectory *directory,
 
 	dir = opendir(path_fs);
 	if (dir == NULL) {
-		g_warning("Failed to open directory %s: %s",
-			  path_fs, g_strerror(errno));
+		FormatErrno(inotify_domain,
+			    "Failed to open directory %s", path_fs);
 		return;
 	}
 
@@ -194,8 +193,9 @@ recursive_watch_subdirectories(WatchDirectory *directory,
 		child_path_fs = g_strconcat(path_fs, "/", ent->d_name, NULL);
 		ret = stat(child_path_fs, &st);
 		if (ret < 0) {
-			g_warning("Failed to stat %s: %s",
-				  child_path_fs, g_strerror(errno));
+			FormatErrno(inotify_domain,
+				    "Failed to stat %s",
+				    child_path_fs);
 			g_free(child_path_fs);
 			continue;
 		}
@@ -207,8 +207,8 @@ recursive_watch_subdirectories(WatchDirectory *directory,
 
 		ret = inotify_source->Add(child_path_fs, IN_MASK, error);
 		if (ret < 0) {
-			g_warning("Failed to register %s: %s",
-				  child_path_fs, error.GetMessage());
+			FormatError(error,
+				    "Failed to register %s", child_path_fs);
 			error.Clear();
 			g_free(child_path_fs);
 			continue;
@@ -253,7 +253,7 @@ mpd_inotify_callback(int wd, unsigned mask,
 	WatchDirectory *directory;
 	char *uri_fs;
 
-	/*g_debug("wd=%d mask=0x%x name='%s'", wd, mask, name);*/
+	/*FormatDebug(inotify_domain, "wd=%d mask=0x%x name='%s'", wd, mask, name);*/
 
 	directory = tree_find_watch_directory(wd);
 	if (directory == NULL)
@@ -309,11 +309,11 @@ mpd_inotify_callback(int wd, unsigned mask,
 void
 mpd_inotify_init(unsigned max_depth)
 {
-	g_debug("initializing inotify");
+	LogDebug(inotify_domain, "initializing inotify");
 
 	const Path &path = mapper_get_music_directory_fs();
 	if (path.IsNull()) {
-		g_debug("no music directory configured");
+		LogDebug(inotify_domain, "no music directory configured");
 		return;
 	}
 
@@ -322,7 +322,7 @@ mpd_inotify_init(unsigned max_depth)
 					       mpd_inotify_callback, nullptr,
 					       error);
 	if (inotify_source == NULL) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return;
 	}
 
@@ -330,7 +330,7 @@ mpd_inotify_init(unsigned max_depth)
 
 	int descriptor = inotify_source->Add(path.c_str(), IN_MASK, error);
 	if (descriptor < 0) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		delete inotify_source;
 		inotify_source = NULL;
 		return;
@@ -344,7 +344,7 @@ mpd_inotify_init(unsigned max_depth)
 
 	inotify_queue = new InotifyQueue(*main_loop);
 
-	g_debug("watching music directory");
+	LogDebug(inotify_domain, "watching music directory");
 }
 
 void

src/Listen.cxx

@@ -27,7 +27,9 @@
 #include "ConfigOption.hxx"
 #include "event/ServerSocket.hxx"
 #include "util/Error.hxx"
+#include "util/Domain.hxx"
 #include "fs/Path.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -38,8 +40,7 @@
 #include <systemd/sd-daemon.h>
 #endif
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "listen"
+static constexpr Domain listen_domain("listen");
 
 #define DEFAULT_PORT	6600
 
@@ -82,8 +83,8 @@ listen_systemd_activation(Error &error_r)
 	int n = sd_listen_fds(true);
 	if (n <= 0) {
 		if (n < 0)
-			g_warning("sd_listen_fds() failed: %s",
-				  g_strerror(-n));
+			FormatErrno(listen_domain, -n,
+				    "sd_listen_fds() failed");
 		return false;
 	}
 
@@ -155,7 +156,7 @@ listen_global_init(Error &error)
 
 void listen_global_finish(void)
 {
-	g_debug("listen_global_finish called");
+	LogDebug(listen_domain, "listen_global_finish called");
 
 	assert(listen_socket != NULL);
 

src/Log.cxx

@@ -18,7 +18,7 @@
  */
 
 #include "config.h"
-#include "Log.hxx"
+#include "LogV.hxx"
 #include "ConfigData.hxx"
 #include "ConfigGlobal.hxx"
 #include "ConfigOption.hxx"
@@ -30,322 +30,157 @@
 #include "util/Domain.hxx"
 #include "system/FatalError.hxx"
 
+#include <glib.h>
+
 #include <assert.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <string.h>
-#include <stdarg.h>
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <unistd.h>
 #include <errno.h>
-#include <glib.h>
-
-#ifdef HAVE_SYSLOG
-#include <syslog.h>
-#endif
-
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "log"
 
-#define LOG_LEVEL_SECURE G_LOG_LEVEL_INFO
-
-#define LOG_DATE_BUF_SIZE 16
-#define LOG_DATE_LEN (LOG_DATE_BUF_SIZE - 1)
-
-static constexpr Domain log_domain("log");
-
-static GLogLevelFlags log_threshold = G_LOG_LEVEL_MESSAGE;
+static GLogLevelFlags
+ToGLib(LogLevel level)
+{
+	switch (level) {
+	case LogLevel::DEBUG:
+		return G_LOG_LEVEL_DEBUG;
 
-static const char *log_charset;
+	case LogLevel::INFO:
+		return G_LOG_LEVEL_MESSAGE;
 
-static bool stdout_mode = true;
-static int out_fd;
-static Path out_path = Path::Null();
+	case LogLevel::WARNING:
+	case LogLevel::ERROR:
+		return G_LOG_LEVEL_WARNING;
+	}
 
-static void redirect_logs(int fd)
-{
-	assert(fd >= 0);
-	if (dup2(fd, STDOUT_FILENO) < 0)
-		FatalSystemError("Failed to dup2 stdout");
-	if (dup2(fd, STDERR_FILENO) < 0)
-		FatalSystemError("Failed to dup2 stderr");
+	assert(false);
+	gcc_unreachable();
 }
 
-static const char *log_date(void)
+void
+Log(const Domain &domain, LogLevel level, const char *msg)
 {
-	static char buf[LOG_DATE_BUF_SIZE];
-	time_t t = time(NULL);
-	strftime(buf, LOG_DATE_BUF_SIZE, "%b %d %H:%M : ", localtime(&t));
-	return buf;
+	g_log(domain.GetName(), ToGLib(level), "%s", msg);
 }
 
-/**
- * Determines the length of the string excluding trailing whitespace
- * characters.
- */
-static int
-chomp_length(const char *p)
+void
+LogFormatV(const Domain &domain, LogLevel level, const char *fmt, va_list ap)
 {
-	size_t length = strlen(p);
-
-	while (length > 0 && g_ascii_isspace(p[length - 1]))
-		--length;
-
-	return (int)length;
+	g_logv(domain.GetName(), ToGLib(level), fmt, ap);
 }
 
-static void
-file_log_func(const gchar *domain,
-	      GLogLevelFlags log_level,
-	      const gchar *message, gcc_unused gpointer user_data)
+void
+LogFormat(const Domain &domain, LogLevel level, const char *fmt, ...)
 {
-	char *converted;
-
-	if (log_level > log_threshold)
-		return;
-
-	if (log_charset != NULL) {
-		converted = g_convert_with_fallback(message, -1,
-						    log_charset, "utf-8",
-						    NULL, NULL, NULL, NULL);
-		if (converted != NULL)
-			message = converted;
-	} else
-		converted = NULL;
-
-	if (domain == nullptr)
-		domain = "";
-
-	fprintf(stderr, "%s%s%s%.*s\n",
-		stdout_mode ? "" : log_date(),
-		domain, *domain == 0 ? "" : ": ",
-		chomp_length(message), message);
-
-	g_free(converted);
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, level, fmt, ap);
+	va_end(ap);
 }
 
-static void
-log_init_stdout(void)
+void
+FormatDebug(const Domain &domain, const char *fmt, ...)
 {
-	g_log_set_default_handler(file_log_func, NULL);
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, LogLevel::DEBUG, fmt, ap);
+	va_end(ap);
 }
 
-static int
-open_log_file(void)
+void
+FormatInfo(const Domain &domain, const char *fmt, ...)
 {
-	assert(!out_path.IsNull());
-
-	return OpenFile(out_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, LogLevel::INFO, fmt, ap);
+	va_end(ap);
 }
 
-static bool
-log_init_file(unsigned line, Error &error)
+void
+FormatWarning(const Domain &domain, const char *fmt, ...)
 {
-	assert(!out_path.IsNull());
-
-	out_fd = open_log_file();
-	if (out_fd < 0) {
-		const std::string out_path_utf8 = out_path.ToUTF8();
-		error.FormatErrno("failed to open log file \"%s\" (config line %u)",
-				  out_path_utf8.c_str(), line);
-		return false;
-	}
-
-	g_log_set_default_handler(file_log_func, NULL);
-	return true;
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, LogLevel::WARNING, fmt, ap);
+	va_end(ap);
 }
 
-#ifdef HAVE_SYSLOG
-
-static int
-glib_to_syslog_level(GLogLevelFlags log_level)
+void
+FormatError(const Domain &domain, const char *fmt, ...)
 {
-	switch (log_level & G_LOG_LEVEL_MASK) {
-	case G_LOG_LEVEL_ERROR:
-	case G_LOG_LEVEL_CRITICAL:
-		return LOG_ERR;
-
-	case G_LOG_LEVEL_WARNING:
-		return LOG_WARNING;
-
-	case G_LOG_LEVEL_MESSAGE:
-		return LOG_NOTICE;
-
-	case G_LOG_LEVEL_INFO:
-		return LOG_INFO;
-
-	case G_LOG_LEVEL_DEBUG:
-		return LOG_DEBUG;
-
-	default:
-		return LOG_NOTICE;
-	}
+	va_list ap;
+	va_start(ap, fmt);
+	LogFormatV(domain, LogLevel::ERROR, fmt, ap);
+	va_end(ap);
 }
 
-static void
-syslog_log_func(const gchar *domain,
-		GLogLevelFlags log_level, const gchar *message,
-		gcc_unused gpointer user_data)
+void
+LogError(const Error &error)
 {
-	if (stdout_mode) {
-		/* fall back to the file log function during
-		   startup */
-		file_log_func(domain, log_level,
-			      message, user_data);
-		return;
-	}
-
-	if (log_level > log_threshold)
-		return;
-
-	if (domain == nullptr)
-		domain = "";
-
-	syslog(glib_to_syslog_level(log_level), "%s%s%.*s",
-	       domain, *domain == 0 ? "" : ": ",
-	       chomp_length(message), message);
+	Log(error.GetDomain(), LogLevel::ERROR, error.GetMessage());
 }
 
-static void
-log_init_syslog(void)
+void
+LogError(const Error &error, const char *msg)
 {
-	assert(out_path.IsNull());
-
-	openlog(PACKAGE, 0, LOG_DAEMON);
-	g_log_set_default_handler(syslog_log_func, NULL);
+	LogFormat(error.GetDomain(), LogLevel::ERROR, "%s: %s",
+		  msg, error.GetMessage());
 }
 
-#endif
-
-static inline GLogLevelFlags
-parse_log_level(const char *value, unsigned line)
+void
+FormatError(const Error &error, const char *fmt, ...)
 {
-	if (0 == strcmp(value, "default"))
-		return G_LOG_LEVEL_MESSAGE;
-	if (0 == strcmp(value, "secure"))
-		return LOG_LEVEL_SECURE;
-	else if (0 == strcmp(value, "verbose"))
-		return G_LOG_LEVEL_DEBUG;
-	else {
-		FormatFatalError("unknown log level \"%s\" at line %u",
-				 value, line);
-		return G_LOG_LEVEL_MESSAGE;
-	}
+	char msg[1024];
+	va_list ap;
+	va_start(ap, fmt);
+	vsnprintf(msg, sizeof(msg), fmt, ap);
+	va_end(ap);
+
+	LogError(error, msg);
 }
 
 void
-log_early_init(bool verbose)
+LogErrno(const Domain &domain, int e, const char *msg)
 {
-	if (verbose)
-		log_threshold = G_LOG_LEVEL_DEBUG;
-
-	log_init_stdout();
+	LogFormat(domain, LogLevel::ERROR, "%s: %s", msg, g_strerror(e));
 }
 
-bool
-log_init(bool verbose, bool use_stdout, Error &error)
+void
+LogErrno(const Domain &domain, const char *msg)
 {
-	const struct config_param *param;
-
-	g_get_charset(&log_charset);
-
-	if (verbose)
-		log_threshold = G_LOG_LEVEL_DEBUG;
-	else if ((param = config_get_param(CONF_LOG_LEVEL)) != NULL)
-		log_threshold = parse_log_level(param->value, param->line);
-
-	if (use_stdout) {
-		log_init_stdout();
-		return true;
-	} else {
-		param = config_get_param(CONF_LOG_FILE);
-		if (param == NULL) {
-#ifdef HAVE_SYSLOG
-			/* no configuration: default to syslog (if
-			   available) */
-			log_init_syslog();
-			return true;
-#else
-			error.Set(log_domain,
-				  "config parameter 'log_file' not found");
-			return false;
-#endif
-#ifdef HAVE_SYSLOG
-		} else if (strcmp(param->value, "syslog") == 0) {
-			log_init_syslog();
-			return true;
-#endif
-		} else {
-			out_path = config_get_path(CONF_LOG_FILE, error);
-			return !out_path.IsNull() &&
-				log_init_file(param->line, error);
-		}
-	}
+	LogErrno(domain, errno, msg);
 }
 
 static void
-close_log_files(void)
+FormatErrnoV(const Domain &domain, int e, const char *fmt, va_list ap)
 {
-	if (stdout_mode)
-		return;
+	char msg[1024];
+	vsnprintf(msg, sizeof(msg), fmt, ap);
 
-#ifdef HAVE_SYSLOG
-	if (out_path.IsNull())
-		closelog();
-#endif
+	LogErrno(domain, e, msg);
 }
 
 void
-log_deinit(void)
+FormatErrno(const Domain &domain, int e, const char *fmt, ...)
 {
-	close_log_files();
-	out_path = Path::Null();
+	va_list ap;
+	va_start(ap, fmt);
+	FormatErrnoV(domain, e, fmt, ap);
+	va_end(ap);
 }
 
-
-void setup_log_output(bool use_stdout)
-{
-	fflush(NULL);
-	if (!use_stdout) {
-#ifndef WIN32
-		if (out_path.IsNull())
-			out_fd = open("/dev/null", O_WRONLY);
-#endif
-
-		if (out_fd >= 0) {
-			redirect_logs(out_fd);
-			close(out_fd);
-		}
-
-		stdout_mode = false;
-		log_charset = NULL;
-	}
-}
-
-int cycle_log_files(void)
+void
+FormatErrno(const Domain &domain, const char *fmt, ...)
 {
-	int fd;
-
-	if (stdout_mode || out_path.IsNull())
-		return 0;
-
-	assert(!out_path.IsNull());
-
-	g_debug("Cycling log files...\n");
-	close_log_files();
-
-	fd = open_log_file();
-	if (fd < 0) {
-		const std::string out_path_utf8 = out_path.ToUTF8();
-		g_warning("error re-opening log file: %s",
-			  out_path_utf8.c_str());
-		return -1;
-	}
+	const int e = errno;
 
-	redirect_logs(fd);
-	g_debug("Done cycling log files\n");
-	return 0;
+	va_list ap;
+	va_start(ap, fmt);
+	FormatErrnoV(domain, e, fmt, ap);
+	va_end(ap);
 }

src/Log.hxx

@@ -20,27 +20,95 @@
 #ifndef MPD_LOG_HXX
 #define MPD_LOG_HXX
 
+#include "gcc.h"
+
+#ifdef WIN32
+#include <windows.h>
+/* damn you, windows.h! */
+#ifdef ERROR
+#undef ERROR
+#endif
+#endif
+
 class Error;
+class Domain;
+
+enum class LogLevel {
+	DEBUG,
+	INFO,
+	WARNING,
+	ERROR,
+};
+
+void
+Log(const Domain &domain, LogLevel level, const char *msg);
+
+gcc_fprintf_
+void
+LogFormat(const Domain &domain, LogLevel level, const char *fmt, ...);
+
+static inline void
+LogDebug(const Domain &domain, const char *msg)
+{
+	Log(domain, LogLevel::DEBUG, msg);
+}
+
+gcc_fprintf
+void
+FormatDebug(const Domain &domain, const char *fmt, ...);
+
+static inline void
+LogInfo(const Domain &domain, const char *msg)
+{
+	Log(domain, LogLevel::INFO, msg);
+}
+
+gcc_fprintf
+void
+FormatInfo(const Domain &domain, const char *fmt, ...);
+
+static inline void
+LogWarning(const Domain &domain, const char *msg)
+{
+	Log(domain, LogLevel::WARNING, msg);
+}
+
+gcc_fprintf
+void
+FormatWarning(const Domain &domain, const char *fmt, ...);
+
+static inline void
+LogError(const Domain &domain, const char *msg)
+{
+	Log(domain, LogLevel::ERROR, msg);
+}
+
+gcc_fprintf
+void
+FormatError(const Domain &domain, const char *fmt, ...);
 
-/**
- * Configure a logging destination for daemon startup, before the
- * configuration file is read.  This allows the daemon to use the
- * logging library (and the command line verbose level) before it's
- * daemonized.
- *
- * @param verbose true when the program is started with --verbose
- */
 void
-log_early_init(bool verbose);
+LogError(const Error &error);
 
-bool
-log_init(bool verbose, bool use_stdout, Error &error);
+void
+LogError(const Error &error, const char *msg);
+
+gcc_fprintf
+void
+FormatError(const Error &error, const char *fmt, ...);
 
 void
-log_deinit(void);
+LogErrno(const Domain &domain, int e, const char *msg);
 
-void setup_log_output(bool use_stdout);
+void
+LogErrno(const Domain &domain, const char *msg);
 
-int cycle_log_files(void);
+gcc_fprintf_
+void
+FormatErrno(const Domain &domain, int e, const char *fmt, ...);
+
+gcc_fprintf
+void
+FormatErrno(const Domain &domain, const char *fmt, ...);
 
 #endif /* LOG_H */

src/LogInit.cxx

+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "LogInit.hxx"
+#include "Log.hxx"
+#include "ConfigData.hxx"
+#include "ConfigGlobal.hxx"
+#include "ConfigOption.hxx"
+#include "system/fd_util.h"
+#include "system/FatalError.hxx"
+#include "fs/Path.hxx"
+#include "fs/FileSystem.hxx"
+#include "util/Error.hxx"
+#include "util/Domain.hxx"
+#include "system/FatalError.hxx"
+
+#include <assert.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <string.h>
+#include <stdarg.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <unistd.h>
+#include <errno.h>
+#include <glib.h>
+
+#ifdef HAVE_SYSLOG
+#include <syslog.h>
+#endif
+
+#define LOG_LEVEL_SECURE G_LOG_LEVEL_INFO
+
+#define LOG_DATE_BUF_SIZE 16
+#define LOG_DATE_LEN (LOG_DATE_BUF_SIZE - 1)
+
+static constexpr Domain log_domain("log");
+
+static GLogLevelFlags log_threshold = G_LOG_LEVEL_MESSAGE;
+
+static const char *log_charset;
+
+static bool stdout_mode = true;
+static int out_fd;
+static Path out_path = Path::Null();
+
+static void redirect_logs(int fd)
+{
+	assert(fd >= 0);
+	if (dup2(fd, STDOUT_FILENO) < 0)
+		FatalSystemError("Failed to dup2 stdout");
+	if (dup2(fd, STDERR_FILENO) < 0)
+		FatalSystemError("Failed to dup2 stderr");
+}
+
+static const char *log_date(void)
+{
+	static char buf[LOG_DATE_BUF_SIZE];
+	time_t t = time(NULL);
+	strftime(buf, LOG_DATE_BUF_SIZE, "%b %d %H:%M : ", localtime(&t));
+	return buf;
+}
+
+/**
+ * Determines the length of the string excluding trailing whitespace
+ * characters.
+ */
+static int
+chomp_length(const char *p)
+{
+	size_t length = strlen(p);
+
+	while (length > 0 && g_ascii_isspace(p[length - 1]))
+		--length;
+
+	return (int)length;
+}
+
+static void
+file_log_func(const gchar *domain,
+	      GLogLevelFlags log_level,
+	      const gchar *message, gcc_unused gpointer user_data)
+{
+	char *converted;
+
+	if (log_level > log_threshold)
+		return;
+
+	if (log_charset != NULL) {
+		converted = g_convert_with_fallback(message, -1,
+						    log_charset, "utf-8",
+						    NULL, NULL, NULL, NULL);
+		if (converted != NULL)
+			message = converted;
+	} else
+		converted = NULL;
+
+	if (domain == nullptr)
+		domain = "";
+
+	fprintf(stderr, "%s%s%s%.*s\n",
+		stdout_mode ? "" : log_date(),
+		domain, *domain == 0 ? "" : ": ",
+		chomp_length(message), message);
+
+	g_free(converted);
+}
+
+static void
+log_init_stdout(void)
+{
+	g_log_set_default_handler(file_log_func, NULL);
+}
+
+static int
+open_log_file(void)
+{
+	assert(!out_path.IsNull());
+
+	return OpenFile(out_path, O_CREAT | O_WRONLY | O_APPEND, 0666);
+}
+
+static bool
+log_init_file(unsigned line, Error &error)
+{
+	assert(!out_path.IsNull());
+
+	out_fd = open_log_file();
+	if (out_fd < 0) {
+		const std::string out_path_utf8 = out_path.ToUTF8();
+		error.FormatErrno("failed to open log file \"%s\" (config line %u)",
+				  out_path_utf8.c_str(), line);
+		return false;
+	}
+
+	g_log_set_default_handler(file_log_func, NULL);
+	return true;
+}
+
+#ifdef HAVE_SYSLOG
+
+static int
+glib_to_syslog_level(GLogLevelFlags log_level)
+{
+	switch (log_level & G_LOG_LEVEL_MASK) {
+	case G_LOG_LEVEL_ERROR:
+	case G_LOG_LEVEL_CRITICAL:
+		return LOG_ERR;
+
+	case G_LOG_LEVEL_WARNING:
+		return LOG_WARNING;
+
+	case G_LOG_LEVEL_MESSAGE:
+		return LOG_NOTICE;
+
+	case G_LOG_LEVEL_INFO:
+		return LOG_INFO;
+
+	case G_LOG_LEVEL_DEBUG:
+		return LOG_DEBUG;
+
+	default:
+		return LOG_NOTICE;
+	}
+}
+
+static void
+syslog_log_func(const gchar *domain,
+		GLogLevelFlags log_level, const gchar *message,
+		gcc_unused gpointer user_data)
+{
+	if (stdout_mode) {
+		/* fall back to the file log function during
+		   startup */
+		file_log_func(domain, log_level,
+			      message, user_data);
+		return;
+	}
+
+	if (log_level > log_threshold)
+		return;
+
+	if (domain == nullptr)
+		domain = "";
+
+	syslog(glib_to_syslog_level(log_level), "%s%s%.*s",
+	       domain, *domain == 0 ? "" : ": ",
+	       chomp_length(message), message);
+}
+
+static void
+log_init_syslog(void)
+{
+	assert(out_path.IsNull());
+
+	openlog(PACKAGE, 0, LOG_DAEMON);
+	g_log_set_default_handler(syslog_log_func, NULL);
+}
+
+#endif
+
+static inline GLogLevelFlags
+parse_log_level(const char *value, unsigned line)
+{
+	if (0 == strcmp(value, "default"))
+		return G_LOG_LEVEL_MESSAGE;
+	if (0 == strcmp(value, "secure"))
+		return LOG_LEVEL_SECURE;
+	else if (0 == strcmp(value, "verbose"))
+		return G_LOG_LEVEL_DEBUG;
+	else {
+		FormatFatalError("unknown log level \"%s\" at line %u",
+				 value, line);
+		return G_LOG_LEVEL_MESSAGE;
+	}
+}
+
+void
+log_early_init(bool verbose)
+{
+	if (verbose)
+		log_threshold = G_LOG_LEVEL_DEBUG;
+
+	log_init_stdout();
+}
+
+bool
+log_init(bool verbose, bool use_stdout, Error &error)
+{
+	const struct config_param *param;
+
+	g_get_charset(&log_charset);
+
+	if (verbose)
+		log_threshold = G_LOG_LEVEL_DEBUG;
+	else if ((param = config_get_param(CONF_LOG_LEVEL)) != NULL)
+		log_threshold = parse_log_level(param->value, param->line);
+
+	if (use_stdout) {
+		log_init_stdout();
+		return true;
+	} else {
+		param = config_get_param(CONF_LOG_FILE);
+		if (param == NULL) {
+#ifdef HAVE_SYSLOG
+			/* no configuration: default to syslog (if
+			   available) */
+			log_init_syslog();
+			return true;
+#else
+			error.Set(log_domain,
+				  "config parameter 'log_file' not found");
+			return false;
+#endif
+#ifdef HAVE_SYSLOG
+		} else if (strcmp(param->value, "syslog") == 0) {
+			log_init_syslog();
+			return true;
+#endif
+		} else {
+			out_path = config_get_path(CONF_LOG_FILE, error);
+			return !out_path.IsNull() &&
+				log_init_file(param->line, error);
+		}
+	}
+}
+
+static void
+close_log_files(void)
+{
+	if (stdout_mode)
+		return;
+
+#ifdef HAVE_SYSLOG
+	if (out_path.IsNull())
+		closelog();
+#endif
+}
+
+void
+log_deinit(void)
+{
+	close_log_files();
+	out_path = Path::Null();
+}
+
+
+void setup_log_output(bool use_stdout)
+{
+	fflush(NULL);
+	if (!use_stdout) {
+#ifndef WIN32
+		if (out_path.IsNull())
+			out_fd = open("/dev/null", O_WRONLY);
+#endif
+
+		if (out_fd >= 0) {
+			redirect_logs(out_fd);
+			close(out_fd);
+		}
+
+		stdout_mode = false;
+		log_charset = NULL;
+	}
+}
+
+int cycle_log_files(void)
+{
+	int fd;
+
+	if (stdout_mode || out_path.IsNull())
+		return 0;
+
+	assert(!out_path.IsNull());
+
+	FormatDebug(log_domain, "Cycling log files");
+	close_log_files();
+
+	fd = open_log_file();
+	if (fd < 0) {
+		const std::string out_path_utf8 = out_path.ToUTF8();
+		FormatError(log_domain,
+			    "error re-opening log file: %s",
+			    out_path_utf8.c_str());
+		return -1;
+	}
+
+	redirect_logs(fd);
+	FormatDebug(log_domain, "Done cycling log files");
+	return 0;
+}

src/LogInit.hxx

+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_LOG_INIT_HXX
+#define MPD_LOG_INIT_HXX
+
+class Error;
+
+/**
+ * Configure a logging destination for daemon startup, before the
+ * configuration file is read.  This allows the daemon to use the
+ * logging library (and the command line verbose level) before it's
+ * daemonized.
+ *
+ * @param verbose true when the program is started with --verbose
+ */
+void
+log_early_init(bool verbose);
+
+bool
+log_init(bool verbose, bool use_stdout, Error &error);
+
+void
+log_deinit(void);
+
+void setup_log_output(bool use_stdout);
+
+int cycle_log_files(void);
+
+#endif /* LOG_H */

src/LogV.hxx

+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_LOGV_HXX
+#define MPD_LOGV_HXX
+
+#include "Log.hxx"
+
+#include <stdarg.h>
+
+void
+LogFormatV(const Domain &domain, LogLevel level, const char *fmt, va_list ap);
+
+#endif /* LOG_H */

src/Main.cxx

@@ -43,6 +43,7 @@
 #include "Idle.hxx"
 #include "SignalHandlers.hxx"
 #include "Log.hxx"
+#include "LogInit.hxx"
 #include "GlobalEvents.hxx"
 #include "InputInit.hxx"
 #include "event/Loop.hxx"
@@ -56,6 +57,7 @@
 #include "Daemon.hxx"
 #include "system/FatalError.hxx"
 #include "util/Error.hxx"
+#include "util/Domain.hxx"
 #include "ConfigGlobal.hxx"
 #include "ConfigData.hxx"
 #include "ConfigDefaults.hxx"
@@ -98,6 +100,8 @@ enum {
 	DEFAULT_BUFFER_BEFORE_PLAY = 10,
 };
 
+static constexpr Domain main_domain("main");
+
 GThread *main_task;
 EventLoop *main_loop;
 
@@ -105,11 +109,6 @@ Instance *instance;
 
 static StateFile *state_file;
 
-static inline GQuark main_quark()
-{
-  return g_quark_from_static_string ("main");
-}
-
 static bool
 glue_daemonize_init(const struct options *options, Error &error)
 {
@@ -161,15 +160,18 @@ glue_db_init_and_load(void)
 	const struct config_param *path = config_get_param(CONF_DB_FILE);
 
 	if (param != nullptr && path != nullptr)
-		g_message("Found both 'database' and 'db_file' setting - ignoring the latter");
+		LogInfo(main_domain,
+			"Found both 'database' and 'db_file' setting - ignoring the latter");
 
 	if (!mapper_has_music_directory()) {
 		if (param != nullptr)
-			g_message("Found database setting without "
-				  "music_directory - disabling database");
+			LogInfo(main_domain,
+				"Found database setting without "
+				"music_directory - disabling database");
 		if (path != nullptr)
-			g_message("Found db_file setting without "
-				  "music_directory - disabling database");
+			LogInfo(main_domain,
+				"Found db_file setting without "
+				"music_directory - disabling database");
 		return true;
 	}
 
@@ -372,12 +374,12 @@ int mpd_main(int argc, char *argv[])
 
 	success = parse_cmdline(argc, argv, &options, error);
 	if (!success) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return EXIT_FAILURE;
 	}
 
 	if (!glue_daemonize_init(&options, error)) {
-		g_printerr("%s\n", error.GetMessage());
+		LogError(error);
 		return EXIT_FAILURE;
 	}
 
@@ -385,7 +387,7 @@ int mpd_main(int argc, char *argv[])
 	TagLoadConfig();
 
 	if (!log_init(options.verbose, options.log_stderr, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return EXIT_FAILURE;
 	}
 
@@ -399,7 +401,7 @@ int mpd_main(int argc, char *argv[])
 
 	success = listen_global_init(error);
 	if (!success) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return EXIT_FAILURE;
 	}
 
@@ -414,7 +416,7 @@ int mpd_main(int argc, char *argv[])
 	Path::GlobalInit();
 
 	if (!glue_mapper_init(error)) {
-		g_printerr("%s\n", error.GetMessage());
+		LogError(error);
 		return EXIT_FAILURE;
 	}
 
@@ -426,7 +428,7 @@ int mpd_main(int argc, char *argv[])
 #endif
 
 	if (!pcm_resample_global_init(error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return EXIT_FAILURE;
 	}
 
@@ -446,7 +448,7 @@ int mpd_main(int argc, char *argv[])
 	replay_gain_global_init();
 
 	if (!input_stream_global_init(error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return EXIT_FAILURE;
 	}
 
@@ -486,7 +488,8 @@ int mpd_main(int argc, char *argv[])
 						     G_MAXUINT));
 #else
 	if (success)
-		g_warning("inotify: auto_update was disabled. enable during compilation phase");
+		FormatWarning(main_domain,
+			      "inotify: auto_update was disabled. enable during compilation phase");
 #endif
 
 	config_global_check();
@@ -524,8 +527,9 @@ int mpd_main(int argc, char *argv[])
 
 	start = clock();
 	DatabaseGlobalDeinit();
-	g_debug("db_finish took %f seconds",
-		((float)(clock()-start))/CLOCKS_PER_SEC);
+	FormatDebug(main_domain,
+		    "db_finish took %f seconds",
+		    ((float)(clock()-start))/CLOCKS_PER_SEC);
 
 #ifdef ENABLE_SQLITE
 	sticker_global_finish();

src/Mapper.cxx

@@ -28,6 +28,8 @@
 #include "fs/Path.hxx"
 #include "fs/FileSystem.hxx"
 #include "fs/DirectoryReader.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -38,6 +40,8 @@
 #include <errno.h>
 #include <dirent.h>
 
+static constexpr Domain mapper_domain("mapper");
+
 /**
  * The absolute path of the music directory encoded in UTF-8.
  */
@@ -57,12 +61,6 @@ static size_t music_dir_fs_length;
  */
 static Path playlist_dir_fs = Path::Null();
 
-static inline GQuark
-mapper_quark()
-{
-  return g_quark_from_static_string ("mapper");
-}
-
 /**
  * Duplicate a string, chop all trailing slashes.
  */
@@ -82,26 +80,30 @@ check_directory(const char *path_utf8, const Path &path_fs)
 {
 	struct stat st;
 	if (!StatFile(path_fs, st)) {
-		g_warning("Failed to stat directory \"%s\": %s",
-			  path_utf8, g_strerror(errno));
+		FormatErrno(mapper_domain,
+			    "Failed to stat directory \"%s\"",
+			    path_utf8);
 		return;
 	}
 
 	if (!S_ISDIR(st.st_mode)) {
-		g_warning("Not a directory: %s", path_utf8);
+		FormatError(mapper_domain,
+			    "Not a directory: %s", path_utf8);
 		return;
 	}
 
 #ifndef WIN32
 	const Path x = Path::Build(path_fs, ".");
 	if (!StatFile(x, st) && errno == EACCES)
-		g_warning("No permission to traverse (\"execute\") directory: %s",
-			  path_utf8);
+		FormatError(mapper_domain,
+			    "No permission to traverse (\"execute\") directory: %s",
+			    path_utf8);
 #endif
 
 	const DirectoryReader reader(path_fs);
 	if (reader.HasFailed() && errno == EACCES)
-		g_warning("No permission to read directory: %s", path_utf8);
+		FormatError(mapper_domain,
+			    "No permission to read directory: %s", path_utf8);
 }
 
 static void

src/MixerAll.cxx

@@ -26,13 +26,12 @@
 #include "pcm/PcmVolume.hxx"
 #include "OutputInternal.hxx"
 #include "util/Error.hxx"
-
-#include <glib.h>
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <assert.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "mixer"
+static constexpr Domain mixer_domain("mixer");
 
 static int
 output_mixer_get_volume(unsigned i)
@@ -53,8 +52,9 @@ output_mixer_get_volume(unsigned i)
 	Error error;
 	volume = mixer_get_volume(mixer, error);
 	if (volume < 0 && error.IsDefined())
-		g_warning("Failed to read mixer for '%s': %s",
-			  output->name, error.GetMessage());
+		FormatError(error,
+			    "Failed to read mixer for '%s'",
+			    output->name);
 
 	return volume;
 }
@@ -99,8 +99,9 @@ output_mixer_set_volume(unsigned i, unsigned volume)
 	Error error;
 	success = mixer_set_volume(mixer, volume, error);
 	if (!success && error.IsDefined())
-		g_warning("Failed to set mixer for '%s': %s",
-			  output->name, error.GetMessage());
+		FormatError(error,
+			    "Failed to set mixer for '%s'",
+			    output->name);
 
 	return success;
 }

src/MixerControl.cxx

@@ -25,9 +25,6 @@
 #include <assert.h>
 #include <stddef.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "mixer"
-
 Mixer *
 mixer_new(const struct mixer_plugin *plugin, void *ao,
 	  const config_param &param,

src/OutputAll.cxx

@@ -36,9 +36,6 @@
 #include <assert.h>
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "output"
-
 static AudioFormat input_audio_format;
 
 static struct audio_output **audio_outputs;

src/OutputControl.cxx

@@ -22,12 +22,14 @@
 #include "OutputThread.hxx"
 #include "OutputInternal.hxx"
 #include "OutputPlugin.hxx"
+#include "OutputError.hxx"
 #include "MixerPlugin.hxx"
 #include "MixerControl.hxx"
 #include "notify.hxx"
 #include "filter/ReplayGainFilterPlugin.hxx"
 #include "FilterPlugin.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -191,8 +193,9 @@ audio_output_open(struct audio_output *ao,
 	if (open && ao->mixer != NULL) {
 		Error error;
 		if (!mixer_open(ao->mixer, error))
-			g_warning("Failed to open mixer for '%s': %s",
-				  ao->name, error.GetMessage());
+			FormatWarning(output_domain,
+				      "Failed to open mixer for '%s'",
+				      ao->name);
 	}
 
 	return open;

src/OutputInit.cxx

@@ -37,15 +37,11 @@
 #include "ConfigError.hxx"
 #include "ConfigGlobal.hxx"
 #include "util/Error.hxx"
-
-#include <glib.h>
+#include "Log.hxx"
 
 #include <assert.h>
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "output"
-
 #define AUDIO_OUTPUT_TYPE	"type"
 #define AUDIO_OUTPUT_NAME	"name"
 #define AUDIO_OUTPUT_FORMAT	"format"
@@ -54,14 +50,15 @@
 static const struct audio_output_plugin *
 audio_output_detect(Error &error)
 {
-	g_warning("Attempt to detect audio output device");
+	LogInfo(output_domain, "Attempt to detect audio output device");
 
 	audio_output_plugins_for_each(plugin) {
 		if (plugin->test_default_device == NULL)
 			continue;
 
-		g_warning("Attempting to detect a %s audio device",
-			  plugin->name);
+		FormatInfo(output_domain,
+			   "Attempting to detect a %s audio device",
+			   plugin->name);
 		if (ao_plugin_test_default_device(plugin))
 			return plugin;
 	}
@@ -201,8 +198,9 @@ ao_base_init(struct audio_output *ao,
 	// It's not really fatal - Part of the filter chain has been set up already
 	// and even an empty one will work (if only with unexpected behaviour)
 	if (filter_error.IsDefined())
-		g_warning("Failed to initialize filter chain for '%s': %s",
-			  ao->name, filter_error.GetMessage());
+		FormatError(filter_error,
+			    "Failed to initialize filter chain for '%s'",
+			    ao->name);
 
 	ao->thread = NULL;
 	ao->command = AO_COMMAND_NONE;
@@ -251,8 +249,9 @@ audio_output_setup(struct audio_output *ao, const config_param &param,
 					    ao->plugin->mixer_plugin,
 					    *ao->filter, mixer_error);
 	if (ao->mixer == NULL && mixer_error.IsDefined())
-		g_warning("Failed to initialize hardware mixer for '%s': %s",
-			  ao->name, mixer_error.GetMessage());
+		FormatError(mixer_error,
+			    "Failed to initialize hardware mixer for '%s'",
+			    ao->name);
 
 	/* use the hardware mixer for replay gain? */
 
@@ -261,7 +260,8 @@ audio_output_setup(struct audio_output *ao, const config_param &param,
 			replay_gain_filter_set_mixer(ao->replay_gain_filter,
 						     ao->mixer, 100);
 		else
-			g_warning("No such mixer for output '%s'", ao->name);
+			FormatError(output_domain,
+				    "No such mixer for output '%s'", ao->name);
 	} else if (strcmp(replay_gain_handler, "software") != 0 &&
 		   ao->replay_gain_filter != NULL) {
 		error.Set(config_domain,
@@ -304,14 +304,16 @@ audio_output_new(const config_param &param,
 			return nullptr;
 		}
 	} else {
-		g_warning("No 'audio_output' defined in config file\n");
+		LogWarning(output_domain,
+			   "No 'audio_output' defined in config file");
 
 		plugin = audio_output_detect(error);
 		if (plugin == NULL)
 			return nullptr;
 
-		g_message("Successfully detected a %s audio device",
-			  plugin->name);
+		FormatInfo(output_domain,
+			   "Successfully detected a %s audio device",
+			   plugin->name);
 	}
 
 	struct audio_output *ao = ao_plugin_init(plugin, param, error);

src/OutputState.cxx

@@ -26,6 +26,8 @@
 #include "OutputState.hxx"
 #include "OutputAll.hxx"
 #include "OutputInternal.hxx"
+#include "OutputError.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -76,7 +78,8 @@ audio_output_state_read(const char *line)
 	name = endptr + 1;
 	ao = audio_output_find(name);
 	if (ao == NULL) {
-		g_debug("Ignoring device state for '%s'", name);
+		FormatDebug(output_domain,
+			    "Ignoring device state for '%s'", name);
 		return true;
 	}
 

src/OutputThread.cxx

@@ -21,6 +21,7 @@
 #include "OutputThread.hxx"
 #include "OutputInternal.hxx"
 #include "OutputAPI.hxx"
+#include "OutputError.hxx"
 #include "pcm/PcmMix.hxx"
 #include "notify.hxx"
 #include "FilterInternal.hxx"
@@ -31,17 +32,13 @@
 #include "MusicChunk.hxx"
 #include "system/FatalError.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 #include "gcc.h"
 
 #include <glib.h>
 
 #include <assert.h>
-#include <stdlib.h>
 #include <string.h>
-#include <errno.h>
-
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "output"
 
 static void ao_command_finished(struct audio_output *ao)
 {
@@ -66,8 +63,9 @@ ao_enable(struct audio_output *ao)
 	success = ao_plugin_enable(ao, error);
 	ao->mutex.lock();
 	if (!success) {
-		g_warning("Failed to enable \"%s\" [%s]: %s\n",
-			  ao->name, ao->plugin->name, error.GetMessage());
+		FormatError(error,
+			    "Failed to enable \"%s\" [%s]",
+			    ao->name, ao->plugin->name);
 		return false;
 	}
 
@@ -159,8 +157,8 @@ ao_open(struct audio_output *ao)
 	const AudioFormat filter_audio_format =
 		ao_filter_open(ao, ao->in_audio_format, error);
 	if (!filter_audio_format.IsDefined()) {
-		g_warning("Failed to open filter for \"%s\" [%s]: %s",
-			  ao->name, ao->plugin->name, error.GetMessage());
+		FormatError(error, "Failed to open filter for \"%s\" [%s]",
+			    ao->name, ao->plugin->name);
 
 		ao->fail_timer = g_timer_new();
 		return;
@@ -178,8 +176,8 @@ ao_open(struct audio_output *ao)
 	assert(!ao->open);
 
 	if (!success) {
-		g_warning("Failed to open \"%s\" [%s]: %s",
-			  ao->name, ao->plugin->name, error.GetMessage());
+		FormatError(error, "Failed to open \"%s\" [%s]",
+			    ao->name, ao->plugin->name);
 
 		ao_filter_close(ao);
 		ao->fail_timer = g_timer_new();
@@ -190,15 +188,15 @@ ao_open(struct audio_output *ao)
 
 	ao->open = true;
 
-	g_debug("opened plugin=%s name=\"%s\" "
-		"audio_format=%s",
-		ao->plugin->name, ao->name,
-		audio_format_to_string(ao->out_audio_format, &af_string));
+	FormatDebug(output_domain,
+		    "opened plugin=%s name=\"%s\" audio_format=%s",
+		    ao->plugin->name, ao->name,
+		    audio_format_to_string(ao->out_audio_format, &af_string));
 
 	if (ao->in_audio_format != ao->out_audio_format)
-		g_debug("converting from %s",
-			audio_format_to_string(ao->in_audio_format,
-					       &af_string));
+		FormatDebug(output_domain, "converting from %s",
+			    audio_format_to_string(ao->in_audio_format,
+						   &af_string));
 }
 
 static void
@@ -223,7 +221,8 @@ ao_close(struct audio_output *ao, bool drain)
 
 	ao->mutex.lock();
 
-	g_debug("closed plugin=%s name=\"%s\"", ao->plugin->name, ao->name);
+	FormatDebug(output_domain, "closed plugin=%s name=\"%s\"",
+		    ao->plugin->name, ao->name);
 }
 
 static void
@@ -235,8 +234,9 @@ ao_reopen_filter(struct audio_output *ao)
 	const AudioFormat filter_audio_format =
 		ao_filter_open(ao, ao->in_audio_format, error);
 	if (!filter_audio_format.IsDefined()) {
-		g_warning("Failed to open filter for \"%s\" [%s]: %s",
-			  ao->name, ao->plugin->name, error.GetMessage());
+		FormatError(error,
+			    "Failed to open filter for \"%s\" [%s]",
+			    ao->name, ao->plugin->name);
 
 		/* this is a little code duplication fro ao_close(),
 		   but we cannot call this function because we must
@@ -334,8 +334,8 @@ ao_chunk_data(struct audio_output *ao, const struct music_chunk *chunk,
 		data = replay_gain_filter->FilterPCM(data, length,
 						     &length, error);
 		if (data == NULL) {
-			g_warning("\"%s\" [%s] failed to filter: %s",
-				  ao->name, ao->plugin->name, error.GetMessage());
+			FormatError(error, "\"%s\" [%s] failed to filter",
+				    ao->name, ao->plugin->name);
 			return NULL;
 		}
 	}
@@ -390,8 +390,9 @@ ao_filter_chunk(struct audio_output *ao, const struct music_chunk *chunk,
 		if (!pcm_mix(dest, data, length,
 			     ao->in_audio_format.format,
 			     1.0 - chunk->mix_ratio)) {
-			g_warning("Cannot cross-fade format %s",
-				  sample_format_to_string(ao->in_audio_format.format));
+			FormatError(output_domain,
+				    "Cannot cross-fade format %s",
+				    sample_format_to_string(ao->in_audio_format.format));
 			return NULL;
 		}
 
@@ -404,8 +405,8 @@ ao_filter_chunk(struct audio_output *ao, const struct music_chunk *chunk,
 	Error error;
 	data = ao->filter->FilterPCM(data, length, &length, error);
 	if (data == NULL) {
-		g_warning("\"%s\" [%s] failed to filter: %s",
-			  ao->name, ao->plugin->name, error.GetMessage());
+		FormatError(error, "\"%s\" [%s] failed to filter",
+			    ao->name, ao->plugin->name);
 		return NULL;
 	}
 
@@ -453,9 +454,8 @@ ao_play_chunk(struct audio_output *ao, const struct music_chunk *chunk)
 		ao->mutex.lock();
 		if (nbytes == 0) {
 			/* play()==0 means failure */
-			g_warning("\"%s\" [%s] failed to play: %s",
-				  ao->name, ao->plugin->name,
-				  error.GetMessage());
+			FormatError(error, "\"%s\" [%s] failed to play",
+				    ao->name, ao->plugin->name);
 
 			ao_close(ao, false);
 

src/PlayerThread.cxx

@@ -33,6 +33,8 @@
 #include "tag/Tag.hxx"
 #include "Idle.hxx"
 #include "GlobalEvents.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <cmath>
 
@@ -40,8 +42,7 @@
 
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "player_thread"
+static constexpr Domain player_domain("player");
 
 enum class CrossFadeState : int8_t {
 	DISABLED = -1,
@@ -402,7 +403,7 @@ Player::OpenOutput()
 
 		return true;
 	} else {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 
 		output_open = false;
 
@@ -461,8 +462,9 @@ Player::CheckDecoderStartup()
 
 		if (!paused && !OpenOutput()) {
 			char *uri = dc.song->GetURI();
-			g_warning("problems opening audio device "
-				  "while playing \"%s\"", uri);
+			FormatError(player_domain,
+				    "problems opening audio device "
+				    "while playing \"%s\"", uri);
 			g_free(uri);
 
 			return true;
@@ -487,7 +489,7 @@ Player::SendSilence()
 
 	struct music_chunk *chunk = buffer.Allocate();
 	if (chunk == nullptr) {
-		g_warning("Failed to allocate silence buffer");
+		LogError(player_domain, "Failed to allocate silence buffer");
 		return false;
 	}
 
@@ -506,7 +508,7 @@ Player::SendSilence()
 
 	Error error;
 	if (!audio_output_all_play(chunk, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		buffer.Return(chunk);
 		return false;
 	}
@@ -838,7 +840,7 @@ Player::PlayNextChunk()
 
 	Error error;
 	if (!play_chunk(pc, song, chunk, buffer, play_audio_format, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 
 		buffer.Return(chunk);
 
@@ -877,7 +879,7 @@ Player::SongBorder()
 	xfade_state = CrossFadeState::UNKNOWN;
 
 	char *uri = song->GetURI();
-	g_message("played \"%s\"", uri);
+	FormatInfo(player_domain, "played \"%s\"", uri);
 	g_free(uri);
 
 	ReplacePipe(dc.pipe);

src/Playlist.cxx

@@ -19,17 +19,16 @@
 
 #include "config.h"
 #include "Playlist.hxx"
+#include "PlaylistError.hxx"
 #include "PlayerControl.hxx"
 #include "Song.hxx"
 #include "Idle.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
 #include <assert.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "playlist"
-
 void
 playlist::FullIncrementVersions()
 {
@@ -65,7 +64,8 @@ playlist_queue_song_order(struct playlist *playlist, struct player_control *pc,
 	Song *song = playlist->queue.GetOrder(order)->DupDetached();
 
 	uri = song->GetURI();
-	g_debug("queue song %i:\"%s\"", playlist->queued, uri);
+	FormatDebug(playlist_domain, "queue song %i:\"%s\"",
+		    playlist->queued, uri);
 	g_free(uri);
 
 	pc->EnqueueSong(song);
@@ -156,7 +156,7 @@ playlist::PlayOrder(player_control &pc, int order)
 	Song *song = queue.GetOrder(order)->DupDetached();
 
 	char *uri = song->GetURI();
-	g_debug("play %i:\"%s\"", order, uri);
+	FormatDebug(playlist_domain, "play %i:\"%s\"", order, uri);
 	g_free(uri);
 
 	pc.Play(song);

src/PlaylistAny.cxx

@@ -21,9 +21,11 @@
 #include "PlaylistAny.hxx"
 #include "PlaylistMapper.hxx"
 #include "PlaylistRegistry.hxx"
+#include "PlaylistError.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Error.hxx"
 #include "InputStream.hxx"
+#include "Log.hxx"
 
 #include <assert.h>
 
@@ -43,8 +45,7 @@ playlist_open_remote(const char *uri, Mutex &mutex, Cond &cond,
 	input_stream *is = input_stream::Open(uri, mutex, cond, error);
 	if (is == nullptr) {
 		if (error.IsDefined())
-			g_warning("Failed to open %s: %s",
-				  uri, error.GetMessage());
+			FormatError(error, "Failed to open %s", uri);
 
 		return nullptr;
 	}

src/PlaylistControl.cxx

@@ -24,13 +24,10 @@
 
 #include "config.h"
 #include "Playlist.hxx"
+#include "PlaylistError.hxx"
 #include "PlayerControl.hxx"
 #include "Song.hxx"
-
-#include <glib.h>
-
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "playlist"
+#include "Log.hxx"
 
 void
 playlist::Stop(player_control &pc)
@@ -40,7 +37,7 @@ playlist::Stop(player_control &pc)
 
 	assert(current >= 0);
 
-	g_debug("stop");
+	FormatDebug(playlist_domain, "stop");
 	pc.Stop();
 	queued = -1;
 	playing = false;

src/PlaylistEdit.cxx

@@ -25,6 +25,7 @@
 
 #include "config.h"
 #include "Playlist.hxx"
+#include "PlaylistError.hxx"
 #include "PlayerControl.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Error.hxx"
@@ -32,6 +33,7 @@
 #include "Idle.hxx"
 #include "DatabaseGlue.hxx"
 #include "DatabasePlugin.hxx"
+#include "Log.hxx"
 
 #include <stdlib.h>
 
@@ -104,7 +106,7 @@ enum playlist_result
 playlist::AppendURI(struct player_control &pc,
 		    const char *uri, unsigned *added_id)
 {
-	g_debug("add to playlist: %s", uri);
+	FormatDebug(playlist_domain, "add to playlist: %s", uri);
 
 	const Database *db = nullptr;
 	Song *song;

src/PlaylistRegistry.cxx

@@ -37,6 +37,7 @@
 #include "ConfigGlobal.hxx"
 #include "ConfigData.hxx"
 #include "system/FatalError.hxx"
+#include "Log.hxx"
 
 #include <assert.h>
 #include <string.h>
@@ -321,7 +322,7 @@ playlist_list_open_path(const char *path_fs, Mutex &mutex, Cond &cond,
 	input_stream *is = input_stream::Open(path_fs, mutex, cond, error);
 	if (is == nullptr) {
 		if (error.IsDefined())
-			g_warning("%s", error.GetMessage());
+			LogError(error);
 
 		return nullptr;
 	}

src/PlaylistSave.cxx

@@ -20,6 +20,7 @@
 #include "config.h"
 #include "PlaylistSave.hxx"
 #include "PlaylistFile.hxx"
+#include "PlaylistError.hxx"
 #include "Playlist.hxx"
 #include "Song.hxx"
 #include "Mapper.hxx"
@@ -28,6 +29,7 @@
 #include "fs/FileSystem.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -123,7 +125,8 @@ playlist_load_spl(struct playlist *playlist, struct player_control *pc,
 			}
 
 			if (playlist->AppendURI(*pc, temp2) != PLAYLIST_RESULT_SUCCESS)
-				g_warning("can't add file \"%s\"", temp2);
+				FormatError(playlist_domain,
+					    "can't add file \"%s\"", temp2);
 
 			g_free(temp2);
 		}

src/PlaylistState.cxx

@@ -24,12 +24,14 @@
 
 #include "config.h"
 #include "PlaylistState.hxx"
+#include "PlaylistError.hxx"
 #include "Playlist.hxx"
 #include "QueueSave.hxx"
 #include "TextFile.hxx"
 #include "PlayerControl.hxx"
 #include "ConfigGlobal.hxx"
 #include "ConfigOption.hxx"
+#include "Log.hxx"
 
 #include <string.h>
 #include <stdlib.h>
@@ -102,7 +104,7 @@ playlist_state_load(TextFile &file, struct playlist *playlist)
 {
 	const char *line = file.ReadLine();
 	if (line == nullptr) {
-		g_warning("No playlist in state file");
+		LogWarning(playlist_domain, "No playlist in state file");
 		return;
 	}
 
@@ -111,8 +113,9 @@ playlist_state_load(TextFile &file, struct playlist *playlist)
 
 		line = file.ReadLine();
 		if (line == nullptr) {
-			g_warning("'" PLAYLIST_STATE_FILE_PLAYLIST_END
-				  "' not found in state file");
+			LogWarning(playlist_domain,
+				   "'" PLAYLIST_STATE_FILE_PLAYLIST_END
+				   "' not found in state file");
 			break;
 		}
 	}

src/QueueSave.cxx

@@ -19,7 +19,8 @@
 
 #include "config.h"
 #include "QueueSave.hxx"
-#include "Playlist.hxx"
+#include "Queue.hxx"
+#include "PlaylistError.hxx"
 #include "Song.hxx"
 #include "SongSave.hxx"
 #include "DatabasePlugin.hxx"
@@ -27,6 +28,7 @@
 #include "TextFile.hxx"
 #include "util/UriUtil.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -96,14 +98,15 @@ queue_load_song(TextFile &file, const char *line, queue *queue)
 		Error error;
 		song = song_load(file, NULL, uri, error);
 		if (song == NULL) {
-			g_warning("%s", error.GetMessage());
+			LogError(error);
 			return;
 		}
 	} else {
 		char *endptr;
 		long ret = strtol(line, &endptr, 10);
 		if (ret < 0 || *endptr != ':' || endptr[1] == 0) {
-			g_warning("Malformed playlist line in state file");
+			LogError(playlist_domain,
+				 "Malformed playlist line in state file");
 			return;
 		}
 

src/SignalHandlers.cxx

@@ -24,15 +24,17 @@
 #ifndef WIN32
 
 #include "Log.hxx"
+#include "LogInit.hxx"
 #include "Main.hxx"
 #include "event/Loop.hxx"
 #include "GlobalEvents.hxx"
 #include "system/FatalError.hxx"
-
-#include <glib.h>
+#include "util/Domain.hxx"
 
 #include <signal.h>
 
+static constexpr Domain signal_handlers_domain("signal_handlers");
+
 static EventLoop *shutdown_loop;
 
 static void
@@ -51,7 +53,7 @@ x_sigaction(int signum, const struct sigaction *act)
 static void
 handle_reload_event(void)
 {
-	g_debug("got SIGHUP, reopening log files");
+	LogDebug(signal_handlers_domain, "got SIGHUP, reopening log files");
 	cycle_log_files();
 }
 

src/SongSave.cxx

@@ -29,13 +29,8 @@
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
 
-#include <glib.h>
-
 #include <string.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "song"
-
 #define SONG_MTIME "mtime"
 #define SONG_END "song_end"
 

src/StateFile.cxx

@@ -26,14 +26,12 @@
 #include "Volume.hxx"
 #include "event/Loop.hxx"
 #include "fs/FileSystem.hxx"
-
-#include <glib.h>
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <string.h>
-#include <errno.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "state_file"
+static constexpr Domain state_file_domain("state_file");
 
 StateFile::StateFile(Path &&_path,
 		     Partition &_partition, EventLoop &_loop)
@@ -66,12 +64,13 @@ StateFile::IsModified() const
 void
 StateFile::Write()
 {
-	g_debug("Saving state file %s", path_utf8.c_str());
+	FormatDebug(state_file_domain,
+		    "Saving state file %s", path_utf8.c_str());
 
 	FILE *fp = FOpen(path, FOpenMode::WriteText);
-	if (G_UNLIKELY(!fp)) {
-		g_warning("failed to create %s: %s",
-			  path_utf8.c_str(), g_strerror(errno));
+	if (gcc_unlikely(!fp)) {
+		FormatErrno(state_file_domain, "failed to create %s",
+			    path_utf8.c_str());
 		return;
 	}
 
@@ -89,12 +88,12 @@ StateFile::Read()
 {
 	bool success;
 
-	g_debug("Loading state file %s", path_utf8.c_str());
+	FormatDebug(state_file_domain, "Loading state file %s", path_utf8.c_str());
 
 	TextFile file(path);
 	if (file.HasFailed()) {
-		g_warning("failed to open %s: %s",
-			  path_utf8.c_str(), g_strerror(errno));
+		FormatErrno(state_file_domain, "failed to open %s",
+			    path_utf8.c_str());
 		return;
 	}
 
@@ -105,7 +104,9 @@ StateFile::Read()
 			playlist_state_restore(line, file, &partition.playlist,
 					       &partition.pc);
 		if (!success)
-			g_warning("Unrecognized line in state file: %s", line);
+			FormatError(state_file_domain,
+				    "Unrecognized line in state file: %s",
+				    line);
 	}
 
 	RememberVersions();

src/Stats.cxx

@@ -30,6 +30,7 @@ extern "C" {
 #include "DatabasePlugin.hxx"
 #include "DatabaseSimple.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 struct stats stats;
 
@@ -56,7 +57,7 @@ void stats_update(void)
 		stats.artist_count = stats2.artist_count;
 		stats.album_count = stats2.album_count;
 	} else {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 
 		stats.song_count = 0;
 		stats.song_duration = 0;

src/StickerDatabase.cxx

@@ -23,6 +23,7 @@
 #include "Idle.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <string>
 #include <map>
@@ -31,9 +32,6 @@
 #include <sqlite3.h>
 #include <assert.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "sticker"
-
 #if SQLITE_VERSION_NUMBER < 3003009
 #define sqlite3_prepare_v2 sqlite3_prepare
 #endif
@@ -85,6 +83,12 @@ static sqlite3_stmt *sticker_stmt[G_N_ELEMENTS(sticker_sql)];
 
 static constexpr Domain sticker_domain("sticker");
 
+static void
+LogError(sqlite3 *db, const char *msg)
+{
+	FormatError(sticker_domain, "%s: %s", msg, sqlite3_errmsg(db));
+}
+
 static sqlite3_stmt *
 sticker_prepare(const char *sql, Error &error)
 {
@@ -186,22 +190,19 @@ sticker_load_value(const char *type, const char *uri, const char *name)
 
 	ret = sqlite3_bind_text(stmt, 1, type, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return NULL;
 	}
 
 	ret = sqlite3_bind_text(stmt, 2, uri, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return NULL;
 	}
 
 	ret = sqlite3_bind_text(stmt, 3, name, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return NULL;
 	}
 
@@ -217,8 +218,7 @@ sticker_load_value(const char *type, const char *uri, const char *name)
 		value = NULL;
 	} else {
 		/* error */
-		g_warning("sqlite3_step() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_step() failed");
 		return NULL;
 	}
 
@@ -243,15 +243,13 @@ sticker_list_values(std::map<std::string, std::string> &table,
 
 	ret = sqlite3_bind_text(stmt, 1, type, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 2, uri, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
@@ -272,8 +270,7 @@ sticker_list_values(std::map<std::string, std::string> &table,
 			/* no op */
 			break;
 		default:
-			g_warning("sqlite3_step() failed: %s",
-				  sqlite3_errmsg(sticker_db));
+			LogError(sticker_db, "sqlite3_step() failed");
 			return false;
 		}
 	} while (ret != SQLITE_DONE);
@@ -303,29 +300,25 @@ sticker_update_value(const char *type, const char *uri,
 
 	ret = sqlite3_bind_text(stmt, 1, value, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 2, type, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 3, uri, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 4, name, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
@@ -334,8 +327,7 @@ sticker_update_value(const char *type, const char *uri,
 	} while (ret == SQLITE_BUSY);
 
 	if (ret != SQLITE_DONE) {
-		g_warning("sqlite3_step() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_step() failed");
 		return false;
 	}
 
@@ -367,29 +359,25 @@ sticker_insert_value(const char *type, const char *uri,
 
 	ret = sqlite3_bind_text(stmt, 1, type, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 2, uri, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 3, name, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 4, value, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
@@ -398,8 +386,7 @@ sticker_insert_value(const char *type, const char *uri,
 	} while (ret == SQLITE_BUSY);
 
 	if (ret != SQLITE_DONE) {
-		g_warning("sqlite3_step() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_step() failed");
 		return false;
 	}
 
@@ -442,15 +429,13 @@ sticker_delete(const char *type, const char *uri)
 
 	ret = sqlite3_bind_text(stmt, 1, type, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 2, uri, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
@@ -459,8 +444,7 @@ sticker_delete(const char *type, const char *uri)
 	} while (ret == SQLITE_BUSY);
 
 	if (ret != SQLITE_DONE) {
-		g_warning("sqlite3_step() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_step() failed");
 		return false;
 	}
 
@@ -485,22 +469,19 @@ sticker_delete_value(const char *type, const char *uri, const char *name)
 
 	ret = sqlite3_bind_text(stmt, 1, type, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 2, uri, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 3, name, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
@@ -509,8 +490,7 @@ sticker_delete_value(const char *type, const char *uri, const char *name)
 	} while (ret == SQLITE_BUSY);
 
 	if (ret != SQLITE_DONE) {
-		g_warning("sqlite3_step() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_step() failed");
 		return false;
 	}
 
@@ -582,8 +562,7 @@ sticker_find(const char *type, const char *base_uri, const char *name,
 
 	ret = sqlite3_bind_text(stmt, 1, type, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
@@ -592,15 +571,13 @@ sticker_find(const char *type, const char *base_uri, const char *name,
 
 	ret = sqlite3_bind_text(stmt, 2, base_uri, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
 	ret = sqlite3_bind_text(stmt, 3, name, -1, NULL);
 	if (ret != SQLITE_OK) {
-		g_warning("sqlite3_bind_text() failed: %s",
-			  sqlite3_errmsg(sticker_db));
+		LogError(sticker_db, "sqlite3_bind_text() failed");
 		return false;
 	}
 
@@ -618,8 +595,7 @@ sticker_find(const char *type, const char *base_uri, const char *name,
 			/* no op */
 			break;
 		default:
-			g_warning("sqlite3_step() failed: %s",
-				  sqlite3_errmsg(sticker_db));
+			LogError(sticker_db, "sqlite3_step() failed");
 			return false;
 		}
 	} while (ret != SQLITE_DONE);

src/TextInputStream.cxx

@@ -22,6 +22,7 @@
 #include "InputStream.hxx"
 #include "util/fifo_buffer.h"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -58,7 +59,7 @@ bool TextInputStream::ReadLine(std::string &line)
 			if (nbytes > 0)
 				fifo_buffer_append(buffer, nbytes);
 			else if (error.IsDefined()) {
-				g_warning("%s", error.GetMessage());
+				LogError(error);
 				return false;
 			}
 		} else

src/UpdateArchive.cxx

@@ -20,6 +20,7 @@
 #include "config.h" /* must be first for large file support */
 #include "UpdateArchive.hxx"
 #include "UpdateInternal.hxx"
+#include "UpdateDomain.hxx"
 #include "DatabaseLock.hxx"
 #include "Directory.hxx"
 #include "Song.hxx"
@@ -30,6 +31,7 @@
 #include "ArchiveFile.hxx"
 #include "ArchiveVisitor.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -53,7 +55,8 @@ update_archive_tree(Directory *directory, const char *name)
 		update_archive_tree(subdir, tmp+1);
 	} else {
 		if (strlen(name) == 0) {
-			g_warning("archive returned directory only");
+			LogWarning(update_domain,
+				   "archive returned directory only");
 			return;
 		}
 
@@ -69,8 +72,8 @@ update_archive_tree(Directory *directory, const char *name)
 				db_unlock();
 
 				modified = true;
-				g_message("added %s/%s",
-					  directory->GetPath(), name);
+				FormatInfo(update_domain, "added %s/%s",
+					   directory->GetPath(), name);
 			}
 		}
 	}
@@ -105,14 +108,15 @@ update_archive_file2(Directory *parent, const char *name,
 	Error error;
 	ArchiveFile *file = archive_file_open(plugin, path_fs.c_str(), error);
 	if (file == NULL) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return;
 	}
 
-	g_debug("archive %s opened", path_fs.c_str());
+	FormatDebug(update_domain, "archive %s opened", path_fs.c_str());
 
 	if (directory == NULL) {
-		g_debug("creating archive directory: %s", name);
+		FormatDebug(update_domain,
+			    "creating archive directory: %s", name);
 		db_lock();
 		directory = parent->CreateChild(name);
 		/* mark this directory as archive (we use device for
@@ -131,7 +135,8 @@ update_archive_file2(Directory *parent, const char *name,
 			:directory(_directory) {}
 
 		virtual void VisitArchiveEntry(const char *path_utf8) override {
-			g_debug("adding archive file: %s", path_utf8);
+			FormatDebug(update_domain,
+				    "adding archive file: %s", path_utf8);
 			update_archive_tree(directory, path_utf8);
 		}
 	};

src/UpdateContainer.cxx

@@ -21,6 +21,7 @@
 #include "UpdateContainer.hxx"
 #include "UpdateInternal.hxx"
 #include "UpdateDatabase.hxx"
+#include "UpdateDomain.hxx"
 #include "DatabaseLock.hxx"
 #include "Directory.hxx"
 #include "Song.hxx"
@@ -29,6 +30,7 @@
 #include "fs/Path.hxx"
 #include "tag/TagHandler.hxx"
 #include "tag/TagBuilder.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -110,7 +112,8 @@ update_container_file(Directory *directory,
 
 		modified = true;
 
-		g_message("added %s/%s", directory->GetPath(), vtrack);
+		FormatInfo(update_domain, "added %s/%s",
+			   directory->GetPath(), vtrack);
 		g_free(vtrack);
 	}
 

src/UpdateDomain.cxx

+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "UpdateDomain.hxx"
+#include "util/Domain.hxx"
+
+const Domain update_domain("update");

src/UpdateDomain.hxx

+/*
+ * Copyright (C) 2003-2013 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_UPDATE_DOMAIN_HXX
+#define MPD_UPDATE_DOMAIN_HXX
+
+extern const class Domain update_domain;
+
+#endif

src/UpdateGlue.cxx

@@ -22,11 +22,13 @@
 #include "UpdateQueue.hxx"
 #include "UpdateWalk.hxx"
 #include "UpdateRemove.hxx"
+#include "UpdateDomain.hxx"
 #include "Mapper.hxx"
 #include "DatabaseSimple.hxx"
 #include "Idle.hxx"
 #include "GlobalEvents.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 extern "C" {
 #include "stats.h"
@@ -40,9 +42,6 @@ extern "C" {
 
 #include <assert.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "update"
-
 static enum update_progress {
 	UPDATE_PROGRESS_IDLE = 0,
 	UPDATE_PROGRESS_RUNNING = 1,
@@ -71,23 +70,22 @@ static void * update_task(void *_path)
 	const char *path = (const char *)_path;
 
 	if (path != NULL && *path != 0)
-		g_debug("starting: %s", path);
+		FormatDebug(update_domain, "starting: %s", path);
 	else
-		g_debug("starting");
+		LogDebug(update_domain, "starting");
 
 	modified = update_walk(path, discard);
 
 	if (modified || !db_exists()) {
 		Error error;
 		if (!db_save(error))
-			g_warning("Failed to save database: %s",
-				  error.GetMessage());
+			LogError(error, "Failed to save database");
 	}
 
 	if (path != NULL && *path != 0)
-		g_debug("finished: %s", path);
+		FormatDebug(update_domain, "finished: %s", path);
 	else
-		g_debug("finished");
+		LogDebug(update_domain, "finished");
 	g_free(_path);
 
 	progress = UPDATE_PROGRESS_DONE;
@@ -104,7 +102,7 @@ spawn_update_task(const char *path)
 	modified = false;
 
 #if GLIB_CHECK_VERSION(2,32,0)
-	update_thr = g_thread_new("updadte", update_task, g_strdup(path));
+	update_thr = g_thread_new("update", update_task, g_strdup(path));
 #else
 	GError *e = NULL;
 	update_thr = g_thread_create(update_task, g_strdup(path), TRUE, &e);
@@ -114,7 +112,8 @@ spawn_update_task(const char *path)
 
 	if (++update_task_id > update_task_id_max)
 		update_task_id = 1;
-	g_debug("spawned thread for update job id %i", update_task_id);
+	FormatDebug(update_domain,
+		    "spawned thread for update job id %i", update_task_id);
 }
 
 unsigned

src/UpdateIO.cxx

@@ -19,12 +19,12 @@
 
 #include "config.h" /* must be first for large file support */
 #include "UpdateIO.hxx"
+#include "src/UpdateDomain.hxx"
 #include "Directory.hxx"
 #include "Mapper.hxx"
 #include "fs/Path.hxx"
 #include "fs/FileSystem.hxx"
-
-#include <glib.h>
+#include "Log.hxx"
 
 #include <errno.h>
 #include <unistd.h>
@@ -39,8 +39,8 @@ stat_directory(const Directory *directory, struct stat *st)
 	if (!StatFile(path_fs, *st)) {
 		int error = errno;
 		const std::string path_utf8 = path_fs.ToUTF8();
-		g_warning("Failed to stat %s: %s",
-			  path_utf8.c_str(), g_strerror(error));
+		FormatErrno(update_domain, error,
+			    "Failed to stat %s", path_utf8.c_str());
 		return -1;
 	}
 
@@ -58,8 +58,8 @@ stat_directory_child(const Directory *parent, const char *name,
 	if (!StatFile(path_fs, *st)) {
 		int error = errno;
 		const std::string path_utf8 = path_fs.ToUTF8();
-		g_warning("Failed to stat %s: %s",
-			  path_utf8.c_str(), g_strerror(error));
+		FormatErrno(update_domain, error,
+			    "Failed to stat %s", path_utf8.c_str());
 		return -1;
 	}
 

src/UpdateRemove.cxx

@@ -19,14 +19,15 @@
 
 #include "config.h" /* must be first for large file support */
 #include "UpdateRemove.hxx"
+#include "UpdateDomain.hxx"
 #include "Playlist.hxx"
 #include "GlobalEvents.hxx"
 #include "thread/Mutex.hxx"
 #include "thread/Cond.hxx"
-
 #include "Song.hxx"
 #include "Main.hxx"
 #include "Instance.hxx"
+#include "Log.hxx"
 
 #ifdef ENABLE_SQLITE
 #include "StickerDatabase.hxx"
@@ -54,7 +55,7 @@ song_remove_event(void)
 	assert(removed_song != NULL);
 
 	uri = removed_song->GetURI();
-	g_message("removing %s", uri);
+	FormatInfo(update_domain, "removing %s", uri);
 	g_free(uri);
 
 #ifdef ENABLE_SQLITE

src/UpdateSong.cxx

@@ -23,13 +23,13 @@
 #include "UpdateIO.hxx"
 #include "UpdateDatabase.hxx"
 #include "UpdateContainer.hxx"
+#include "UpdateDomain.hxx"
 #include "DatabaseLock.hxx"
 #include "Directory.hxx"
 #include "Song.hxx"
 #include "DecoderPlugin.hxx"
 #include "DecoderList.hxx"
-
-#include <glib.h>
+#include "Log.hxx"
 
 #include <unistd.h>
 
@@ -43,8 +43,9 @@ update_song_file2(Directory *directory,
 	db_unlock();
 
 	if (!directory_child_access(directory, name, R_OK)) {
-		g_warning("no read permissions on %s/%s",
-			  directory->GetPath(), name);
+		FormatError(update_domain,
+			    "no read permissions on %s/%s",
+			    directory->GetPath(), name);
 		if (song != NULL) {
 			db_lock();
 			delete_song(directory, song);
@@ -67,11 +68,13 @@ update_song_file2(Directory *directory,
 	}
 
 	if (song == NULL) {
-		g_debug("reading %s/%s", directory->GetPath(), name);
+		FormatDebug(update_domain, "reading %s/%s",
+			    directory->GetPath(), name);
 		song = Song::LoadFile(name, directory);
 		if (song == NULL) {
-			g_debug("ignoring unrecognized file %s/%s",
-				directory->GetPath(), name);
+			FormatDebug(update_domain,
+				    "ignoring unrecognized file %s/%s",
+				    directory->GetPath(), name);
 			return;
 		}
 
@@ -80,14 +83,15 @@ update_song_file2(Directory *directory,
 		db_unlock();
 
 		modified = true;
-		g_message("added %s/%s",
-			  directory->GetPath(), name);
+		FormatInfo(update_domain, "added %s/%s",
+			   directory->GetPath(), name);
 	} else if (st->st_mtime != song->mtime || walk_discard) {
-		g_message("updating %s/%s",
-			  directory->GetPath(), name);
+		FormatInfo(update_domain, "updating %s/%s",
+			   directory->GetPath(), name);
 		if (!song->UpdateFile()) {
-			g_debug("deleting unrecognized file %s/%s",
-				directory->GetPath(), name);
+			FormatDebug(update_domain,
+				    "deleting unrecognized file %s/%s",
+				    directory->GetPath(), name);
 			db_lock();
 			delete_song(directory, song);
 			db_unlock();

src/UpdateWalk.cxx

@@ -23,6 +23,7 @@
 #include "UpdateDatabase.hxx"
 #include "UpdateSong.hxx"
 #include "UpdateArchive.hxx"
+#include "UpdateDomain.hxx"
 #include "DatabaseLock.hxx"
 #include "DatabaseSimple.hxx"
 #include "Directory.hxx"
@@ -37,6 +38,7 @@
 #include "fs/FileSystem.hxx"
 #include "fs/DirectoryReader.hxx"
 #include "util/UriUtil.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -49,9 +51,6 @@
 #include <stdlib.h>
 #include <errno.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "update"
-
 bool walk_discard;
 bool modified;
 
@@ -185,7 +184,7 @@ find_inode_ancestor(Directory *parent, ino_t inode, dev_t device)
 			return -1;
 
 		if (parent->inode == inode && parent->device == device) {
-			g_debug("recursive directory found");
+			LogDebug(update_domain, "recursive directory found");
 			return 1;
 		}
 
@@ -257,7 +256,8 @@ update_directory_child(Directory *directory,
 			db_unlock();
 		}
 	} else {
-		g_debug("update: %s is not a directory, archive or music", name);
+		FormatDebug(update_domain,
+			    "%s is not a directory, archive or music", name);
 	}
 }
 
@@ -352,8 +352,9 @@ update_directory(Directory *directory, const struct stat *st)
 	if (reader.HasFailed()) {
 		int error = errno;
 		const auto path_utf8 = path_fs.ToUTF8();
-		g_warning("Failed to open directory %s: %s",
-			  path_utf8.c_str(), g_strerror(error));
+		FormatErrno(update_domain, error,
+			    "Failed to open directory %s",
+			    path_utf8.c_str());
 		return false;
 	}
 

src/Volume.cxx

@@ -22,17 +22,18 @@
 #include "MixerAll.hxx"
 #include "Idle.hxx"
 #include "GlobalEvents.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
 #include <assert.h>
 #include <stdlib.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "volume"
-
 #define SW_VOLUME_STATE                         "sw_volume: "
 
+static constexpr Domain volume_domain("volume");
+
 static unsigned volume_software_set = 100;
 
 /** the cached hardware mixer value; invalid if negative */
@@ -122,7 +123,8 @@ read_sw_volume_state(const char *line)
 	if (*end == 0 && sv >= 0 && sv <= 100)
 		software_volume_change(sv);
 	else
-		g_warning("Can't parse software volume: %s\n", line);
+		FormatWarning(volume_domain,
+			      "Can't parse software volume: %s", line);
 	return true;
 }
 

src/ZeroconfAvahi.cxx

@@ -23,6 +23,8 @@
 #include "Listen.hxx"
 #include "event/Loop.hxx"
 #include "system/FatalError.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -36,8 +38,7 @@
 
 #include <avahi-glib/glib-watch.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "avahi"
+static constexpr Domain avahi_domain("avahi");
 
 static char *avahiName;
 static int avahiRunning;
@@ -58,13 +59,15 @@ static void avahiGroupCallback(AvahiEntryGroup * g,
 	char *n;
 	assert(g);
 
-	g_debug("Service group changed to state %d", state);
+	FormatDebug(avahi_domain,
+		    "Service group changed to state %d", state);
 
 	switch (state) {
 	case AVAHI_ENTRY_GROUP_ESTABLISHED:
 		/* The entry group has been established successfully */
-		g_message("Service '%s' successfully established.",
-			  avahiName);
+		FormatInfo(avahi_domain,
+			   "Service '%s' successfully established.",
+			   avahiName);
 		break;
 
 	case AVAHI_ENTRY_GROUP_COLLISION:
@@ -73,43 +76,48 @@ static void avahiGroupCallback(AvahiEntryGroup * g,
 		avahi_free(avahiName);
 		avahiName = n;
 
-		g_message("Service name collision, renaming service to '%s'",
-			  avahiName);
+		FormatInfo(avahi_domain,
+			   "Service name collision, renaming service to '%s'",
+			   avahiName);
 
 		/* And recreate the services */
 		avahiRegisterService(avahi_entry_group_get_client(g));
 		break;
 
 	case AVAHI_ENTRY_GROUP_FAILURE:
-		g_warning("Entry group failure: %s",
-			  avahi_strerror(avahi_client_errno
-					 (avahi_entry_group_get_client(g))));
+		FormatError(avahi_domain,
+			    "Entry group failure: %s",
+			    avahi_strerror(avahi_client_errno
+					   (avahi_entry_group_get_client(g))));
 		/* Some kind of failure happened while we were registering our services */
 		avahiRunning = 0;
 		break;
 
 	case AVAHI_ENTRY_GROUP_UNCOMMITED:
-		g_debug("Service group is UNCOMMITED");
+		LogDebug(avahi_domain, "Service group is UNCOMMITED");
 		break;
 	case AVAHI_ENTRY_GROUP_REGISTERING:
-		g_debug("Service group is REGISTERING");
+		LogDebug(avahi_domain, "Service group is REGISTERING");
 	}
 }
 
 /* Registers a new service with avahi */
 static void avahiRegisterService(AvahiClient * c)
 {
+	FormatDebug(avahi_domain, "Registering service %s/%s",
+		    SERVICE_TYPE, avahiName);
+
 	int ret;
 	assert(c);
-	g_debug("Registering service %s/%s", SERVICE_TYPE, avahiName);
 
 	/* If this is the first time we're called,
 	 * let's create a new entry group */
 	if (!avahiGroup) {
 		avahiGroup = avahi_entry_group_new(c, avahiGroupCallback, NULL);
 		if (!avahiGroup) {
-			g_warning("Failed to create avahi EntryGroup: %s",
-				  avahi_strerror(avahi_client_errno(c)));
+			FormatError(avahi_domain,
+				    "Failed to create avahi EntryGroup: %s",
+				    avahi_strerror(avahi_client_errno(c)));
 			goto fail;
 		}
 	}
@@ -124,16 +132,16 @@ static void avahiRegisterService(AvahiClient * c)
 					    avahiName, SERVICE_TYPE, NULL,
 					    NULL, listen_port, NULL);
 	if (ret < 0) {
-		g_warning("Failed to add service %s: %s", SERVICE_TYPE,
-			  avahi_strerror(ret));
+		FormatError(avahi_domain, "Failed to add service %s: %s",
+			    SERVICE_TYPE, avahi_strerror(ret));
 		goto fail;
 	}
 
 	/* Tell the server to register the service group */
 	ret = avahi_entry_group_commit(avahiGroup);
 	if (ret < 0) {
-		g_warning("Failed to commit service group: %s",
-			  avahi_strerror(ret));
+		FormatError(avahi_domain, "Failed to commit service group: %s",
+			    avahi_strerror(ret));
 		goto fail;
 	}
 	return;
@@ -150,11 +158,11 @@ static void avahiClientCallback(AvahiClient * c, AvahiClientState state,
 	assert(c);
 
 	/* Called whenever the client or server state changes */
-	g_debug("Client changed to state %d", state);
+	FormatDebug(avahi_domain, "Client changed to state %d", state);
 
 	switch (state) {
 	case AVAHI_CLIENT_S_RUNNING:
-		g_debug("Client is RUNNING");
+		LogDebug(avahi_domain, "Client is RUNNING");
 
 		/* The server has startup successfully and registered its host
 		 * name on the network, so it's time to create our services */
@@ -165,7 +173,8 @@ static void avahiClientCallback(AvahiClient * c, AvahiClientState state,
 	case AVAHI_CLIENT_FAILURE:
 		reason = avahi_client_errno(c);
 		if (reason == AVAHI_ERR_DISCONNECTED) {
-			g_message("Client Disconnected, will reconnect shortly");
+			LogInfo(avahi_domain,
+				"Client Disconnected, will reconnect shortly");
 			if (avahiGroup) {
 				avahi_entry_group_free(avahiGroup);
 				avahiGroup = NULL;
@@ -178,51 +187,57 @@ static void avahiClientCallback(AvahiClient * c, AvahiClientState state,
 					     avahiClientCallback, NULL,
 					     &reason);
 			if (!avahiClient) {
-				g_warning("Could not reconnect: %s",
-					  avahi_strerror(reason));
+				FormatWarning(avahi_domain,
+					      "Could not reconnect: %s",
+					      avahi_strerror(reason));
 				avahiRunning = 0;
 			}
 		} else {
-			g_warning("Client failure: %s (terminal)",
-				  avahi_strerror(reason));
+			FormatWarning(avahi_domain,
+				      "Client failure: %s (terminal)",
+				      avahi_strerror(reason));
 			avahiRunning = 0;
 		}
 		break;
 
 	case AVAHI_CLIENT_S_COLLISION:
-		g_debug("Client is COLLISION");
+		LogDebug(avahi_domain, "Client is COLLISION");
+
 		/* Let's drop our registered services. When the server is back
 		 * in AVAHI_SERVER_RUNNING state we will register them
 		 * again with the new host name. */
 		if (avahiGroup) {
-			g_debug("Resetting group");
+			LogDebug(avahi_domain, "Resetting group");
 			avahi_entry_group_reset(avahiGroup);
 		}
 
+		break;
+
 	case AVAHI_CLIENT_S_REGISTERING:
-		g_debug("Client is REGISTERING");
+		LogDebug(avahi_domain, "Client is REGISTERING");
+
 		/* The server records are now being established. This
 		 * might be caused by a host name change. We need to wait
 		 * for our own records to register until the host name is
 		 * properly esatblished. */
 
 		if (avahiGroup) {
-			g_debug("Resetting group");
+			LogDebug(avahi_domain, "Resetting group");
 			avahi_entry_group_reset(avahiGroup);
 		}
 
 		break;
 
 	case AVAHI_CLIENT_CONNECTING:
-		g_debug("Client is CONNECTING");
+		LogDebug(avahi_domain, "Client is CONNECTING");
+		break;
 	}
 }
 
 void
 AvahiInit(EventLoop &loop, const char *serviceName)
 {
-	int error;
-	g_debug("Initializing interface");
+	LogDebug(avahi_domain, "Initializing interface");
 
 	if (!avahi_is_valid_service_name(serviceName))
 		FormatFatalError("Invalid zeroconf_name \"%s\"", serviceName);
@@ -241,12 +256,13 @@ AvahiInit(EventLoop &loop, const char *serviceName)
 	avahi_poll = avahi_glib_poll_get(avahi_glib_poll);
 #endif
 
+	int error;
 	avahiClient = avahi_client_new(avahi_poll, AVAHI_CLIENT_NO_FAIL,
 				       avahiClientCallback, NULL, &error);
 
 	if (!avahiClient) {
-		g_warning("Failed to create client: %s",
-			  avahi_strerror(error));
+		FormatError(avahi_domain, "Failed to create client: %s",
+			    avahi_strerror(error));
 		AvahiDeinit();
 	}
 }
@@ -254,7 +270,7 @@ AvahiInit(EventLoop &loop, const char *serviceName)
 void
 AvahiDeinit(void)
 {
-	g_debug("Shutting down interface");
+	LogDebug(avahi_domain, "Shutting down interface");
 
 	if (avahiGroup) {
 		avahi_entry_group_free(avahiGroup);

src/ZeroconfBonjour.cxx

@@ -22,14 +22,15 @@
 #include "ZeroconfInternal.hxx"
 #include "Listen.hxx"
 #include "event/SocketMonitor.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 #include "gcc.h"
 
 #include <glib.h>
 
 #include <dns_sd.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "bonjour"
+static constexpr Domain bonjour_domain("bonjour");
 
 class BonjourMonitor final : public SocketMonitor {
 	DNSServiceRef service_ref;
@@ -64,11 +65,14 @@ dnsRegisterCallback(gcc_unused DNSServiceRef sdRef,
 		    gcc_unused void *context)
 {
 	if (errorCode != kDNSServiceErr_NoError) {
-		g_warning("Failed to register zeroconf service.");
+		LogError(bonjour_domain,
+			 "Failed to register zeroconf service");
 
 		bonjour_monitor->Cancel();
 	} else {
-		g_debug("Registered zeroconf service with name '%s'", name);
+		FormatDebug(bonjour_domain,
+			    "Registered zeroconf service with name '%s'",
+			    name);
 	}
 }
 
@@ -85,7 +89,8 @@ BonjourInit(EventLoop &loop, const char *service_name)
 						       NULL);
 
 	if (error != kDNSServiceErr_NoError) {
-		g_warning("Failed to register zeroconf service.");
+		LogError(bonjour_domain,
+			 "Failed to register zeroconf service");
 
 		if (dnsReference) {
 			DNSServiceRefDeallocate(dnsReference);

src/ZeroconfGlue.cxx

@@ -24,9 +24,11 @@
 #include "ConfigGlobal.hxx"
 #include "ConfigOption.hxx"
 #include "Listen.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 #include "gcc.h"
 
-#include <glib.h>
+static constexpr Domain zeroconf_domain("zeroconf");
 
 /* The default service name to publish
  * (overridden by 'zeroconf_name' config parameter)
@@ -48,7 +50,8 @@ ZeroconfInit(gcc_unused EventLoop &loop)
 		return;
 
 	if (listen_port <= 0) {
-		g_warning("No global port, disabling zeroconf");
+		LogInfo(zeroconf_domain,
+			"No global port, disabling zeroconf");
 		zeroconfEnabled = false;
 		return;
 	}

src/db/SimpleDatabasePlugin.cxx

@@ -31,6 +31,7 @@
 #include "fs/FileSystem.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -169,7 +170,7 @@ SimpleDatabase::Open(Error &error)
 	if (!Load(error)) {
 		root->Free();
 
-		g_warning("Failed to load database: %s", error.GetMessage());
+		LogError(error);
 		error.Clear();
 
 		if (!Check(error))
@@ -284,15 +285,15 @@ SimpleDatabase::Save(Error &error)
 {
 	db_lock();
 
-	g_debug("removing empty directories from DB");
+	LogDebug(simple_db_domain, "removing empty directories from DB");
 	root->PruneEmpty();
 
-	g_debug("sorting DB");
+	LogDebug(simple_db_domain, "sorting DB");
 	root->Sort();
 
 	db_unlock();
 
-	g_debug("writing DB");
+	LogDebug(simple_db_domain, "writing DB");
 
 	FILE *fp = FOpen(path, FOpenMode::WriteText);
 	if (!fp) {

src/decoder/AdPlugDecoderPlugin.cxx

@@ -23,6 +23,7 @@
 #include "DecoderAPI.hxx"
 #include "CheckAudioFormat.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <adplug/adplug.h>
 #include <adplug/emuopl.h>
@@ -31,9 +32,6 @@
 
 #include <assert.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "adplug"
-
 static unsigned sample_rate;
 
 static bool
@@ -43,7 +41,7 @@ adplug_init(const config_param &param)
 
 	sample_rate = param.GetBlockValue("sample_rate", 48000u);
 	if (!audio_check_sample_rate(sample_rate, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return false;
 	}
 

src/decoder/AudiofileDecoderPlugin.cxx

@@ -24,19 +24,19 @@
 #include "CheckAudioFormat.hxx"
 #include "tag/TagHandler.hxx"
 #include "util/Error.hxx"
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <audiofile.h>
 #include <af_vfs.h>
-#include <assert.h>
-#include <glib.h>
-#include <stdio.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "audiofile"
+#include <assert.h>
 
 /* pick 1020 since its devisible for 8,16,24, and 32-bit audio */
 #define CHUNK_SIZE		1020
 
+static constexpr Domain audiofile_domain("audiofile");
+
 static int audiofile_get_duration(const char *file)
 {
 	int total_time;
@@ -59,7 +59,7 @@ audiofile_file_read(AFvirtualfile *vfile, void *data, size_t length)
 	Error error;
 	size_t nbytes = is->LockRead(data, length, error);
 	if (nbytes == 0 && error.IsDefined()) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return -1;
 	}
 
@@ -143,8 +143,9 @@ audiofile_setup_sample_format(AFfilehandle af_fp)
 
 	afGetSampleFormat(af_fp, AF_DEFAULT_TRACK, &fs, &bits);
 	if (!audio_valid_sample_format(audiofile_bits_to_sample_format(bits))) {
-		g_debug("input file has %d bit samples, converting to 16",
-			bits);
+		FormatDebug(audiofile_domain,
+			    "input file has %d bit samples, converting to 16",
+			    bits);
 		bits = 16;
 	}
 
@@ -168,7 +169,7 @@ audiofile_stream_decode(struct decoder *decoder, struct input_stream *is)
 	char chunk[CHUNK_SIZE];
 
 	if (!is->IsSeekable()) {
-		g_warning("not seekable");
+		LogWarning(audiofile_domain, "not seekable");
 		return;
 	}
 
@@ -176,7 +177,7 @@ audiofile_stream_decode(struct decoder *decoder, struct input_stream *is)
 
 	af_fp = afOpenVirtualFile(vf, "r", nullptr);
 	if (af_fp == AF_NULL_FILEHANDLE) {
-		g_warning("failed to input stream\n");
+		LogWarning(audiofile_domain, "failed to input stream");
 		return;
 	}
 
@@ -186,7 +187,7 @@ audiofile_stream_decode(struct decoder *decoder, struct input_stream *is)
 				       audiofile_setup_sample_format(af_fp),
 				       afGetVirtualChannels(af_fp, AF_DEFAULT_TRACK),
 				       error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		afCloseFile(af_fp);
 		return;
 	}
@@ -232,8 +233,9 @@ audiofile_scan_file(const char *file,
 	int total_time = audiofile_get_duration(file);
 
 	if (total_time < 0) {
-		g_debug("Failed to get total song time from: %s\n",
-			file);
+		FormatWarning(audiofile_domain,
+			      "Failed to get total song time from: %s",
+			      file);
 		return false;
 	}
 

src/decoder/DsdiffDecoderPlugin.cxx

@@ -35,13 +35,11 @@
 #include "util/Error.hxx"
 #include "tag/TagHandler.hxx"
 #include "DsdLib.hxx"
+#include "Log.hxx"
 
 #include <unistd.h>
 #include <stdio.h> /* for SEEK_SET, SEEK_CUR */
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "dsdiff"
-
 struct DsdiffHeader {
 	struct dsdlib_id id;
 	uint32_t size_high, size_low;
@@ -437,7 +435,7 @@ dsdiff_stream_decode(struct decoder *decoder, struct input_stream *is)
 	if (!audio_format_init_checked(audio_format, metadata.sample_rate / 8,
 				       SampleFormat::DSD,
 				       metadata.channels, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return;
 	}
 

src/decoder/DsfDecoderPlugin.cxx

@@ -36,13 +36,11 @@
 #include "util/Error.hxx"
 #include "DsdLib.hxx"
 #include "tag/TagHandler.hxx"
+#include "Log.hxx"
 
 #include <unistd.h>
 #include <stdio.h> /* for SEEK_SET, SEEK_CUR */
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "dsf"
-
 struct DsfMetaData {
 	unsigned sample_rate, channels;
 	bool bitreverse;
@@ -290,7 +288,7 @@ dsf_stream_decode(struct decoder *decoder, struct input_stream *is)
 	if (!audio_format_init_checked(audio_format, metadata.sample_rate / 8,
 				       SampleFormat::DSD,
 				       metadata.channels, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		return;
 	}
 	/* Calculate song time from DSD chunk size and sample frequency */

src/decoder/FaadDecoderPlugin.cxx

@@ -26,18 +26,14 @@
 #include "tag/TagHandler.hxx"
 #include "util/Error.hxx"
 #include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <neaacdec.h>
 
-#include <glib.h>
-
 #include <assert.h>
 #include <string.h>
 #include <unistd.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "faad"
-
 #define AAC_MAX_CHANNELS	6
 
 static const unsigned adts_sample_rates[] =
@@ -395,7 +391,7 @@ faad_stream_decode(struct decoder *mpd_decoder, struct input_stream *is)
 	Error error;
 	ret = faad_decoder_init(decoder, buffer, audio_format, error);
 	if (!ret) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		NeAACDecClose(decoder);
 		return;
 	}
@@ -424,21 +420,24 @@ faad_stream_decode(struct decoder *mpd_decoder, struct input_stream *is)
 		decoded = faad_decoder_decode(decoder, buffer, &frame_info);
 
 		if (frame_info.error > 0) {
-			g_warning("error decoding AAC stream: %s\n",
-				  NeAACDecGetErrorMessage(frame_info.error));
+			FormatWarning(faad_decoder_domain,
+				      "error decoding AAC stream: %s",
+				      NeAACDecGetErrorMessage(frame_info.error));
 			break;
 		}
 
 		if (frame_info.channels != audio_format.channels) {
-			g_warning("channel count changed from %u to %u",
-				  audio_format.channels, frame_info.channels);
+			FormatInfo(faad_decoder_domain,
+				   "channel count changed from %u to %u",
+				   audio_format.channels, frame_info.channels);
 			break;
 		}
 
 		if (frame_info.samplerate != audio_format.sample_rate) {
-			g_warning("sample rate changed from %u to %lu",
-				  audio_format.sample_rate,
-				  (unsigned long)frame_info.samplerate);
+			FormatInfo(faad_decoder_domain,
+				   "sample rate changed from %u to %lu",
+				   audio_format.sample_rate,
+				   (unsigned long)frame_info.samplerate);
 			break;
 		}
 

src/decoder/FfmpegDecoderPlugin.cxx

@@ -28,6 +28,8 @@
 #include "InputStream.hxx"
 #include "CheckAudioFormat.hxx"
 #include "util/Error.hxx"
+#include "util/Domain.hxx"
+#include "LogV.hxx"
 
 #include <glib.h>
 
@@ -50,27 +52,26 @@ extern "C" {
 #include <libavutil/dict.h>
 }
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "ffmpeg"
+static constexpr Domain ffmpeg_domain("ffmpeg");
 
 /* suppress the ffmpeg compatibility macro */
 #ifdef SampleFormat
 #undef SampleFormat
 #endif
 
-static GLogLevelFlags
-level_ffmpeg_to_glib(int level)
+static LogLevel
+import_ffmpeg_level(int level)
 {
 	if (level <= AV_LOG_FATAL)
-		return G_LOG_LEVEL_CRITICAL;
+		return LogLevel::ERROR;
 
-	if (level <= AV_LOG_ERROR)
-		return G_LOG_LEVEL_WARNING;
+	if (level <= AV_LOG_WARNING)
+		return LogLevel::WARNING;
 
 	if (level <= AV_LOG_INFO)
-		return G_LOG_LEVEL_MESSAGE;
+		return LogLevel::INFO;
 
-	return G_LOG_LEVEL_DEBUG;
+	return LogLevel::DEBUG;
 }
 
 static void
@@ -83,8 +84,9 @@ mpd_ffmpeg_log_callback(gcc_unused void *ptr, int level,
 		cls = *(const AVClass *const*)ptr;
 
 	if (cls != NULL) {
-		char *domain = g_strconcat(G_LOG_DOMAIN, "/", cls->item_name(ptr), NULL);
-		g_logv(domain, level_ffmpeg_to_glib(level), fmt, vl);
+		char *domain = g_strconcat(ffmpeg_domain.GetName(), "/", cls->item_name(ptr), NULL);
+		const Domain d(domain);
+		LogFormatV(d, import_ffmpeg_level(level), fmt, vl);
 		g_free(domain);
 	}
 }
@@ -287,7 +289,8 @@ ffmpeg_send_packet(struct decoder *decoder, struct input_stream *is,
 
 		if (len < 0) {
 			/* if error, we skip the frame */
-			g_message("decoding failed, frame skipped\n");
+			LogInfo(ffmpeg_domain,
+				"decoding failed, frame skipped");
 			break;
 		}
 
@@ -328,11 +331,13 @@ ffmpeg_sample_format(enum AVSampleFormat sample_fmt)
 	const char *name = av_get_sample_fmt_string(buffer, sizeof(buffer),
 						    sample_fmt);
 	if (name != NULL)
-		g_warning("Unsupported libavcodec SampleFormat value: %s (%d)",
-			  name, sample_fmt);
+		FormatError(ffmpeg_domain,
+			    "Unsupported libavcodec SampleFormat value: %s (%d)",
+			    name, sample_fmt);
 	else
-		g_warning("Unsupported libavcodec SampleFormat value: %d",
-			  sample_fmt);
+		FormatError(ffmpeg_domain,
+			    "Unsupported libavcodec SampleFormat value: %d",
+			    sample_fmt);
 	return SampleFormat::UNDEFINED;
 }
 
@@ -377,12 +382,12 @@ ffmpeg_decode(struct decoder *decoder, struct input_stream *input)
 	if (input_format == NULL)
 		return;
 
-	g_debug("detected input format '%s' (%s)",
-		input_format->name, input_format->long_name);
+	FormatDebug(ffmpeg_domain, "detected input format '%s' (%s)",
+		    input_format->name, input_format->long_name);
 
 	AvioStream stream(decoder, input);
 	if (!stream.Open()) {
-		g_warning("Failed to open stream");
+		LogError(ffmpeg_domain, "Failed to open stream");
 		return;
 	}
 
@@ -391,21 +396,21 @@ ffmpeg_decode(struct decoder *decoder, struct input_stream *input)
 	if (mpd_ffmpeg_open_input(&format_context, stream.io,
 				  input->uri.c_str(),
 				  input_format) != 0) {
-		g_warning("Open failed\n");
+		LogError(ffmpeg_domain, "Open failed");
 		return;
 	}
 
 	const int find_result =
 		avformat_find_stream_info(format_context, NULL);
 	if (find_result < 0) {
-		g_warning("Couldn't find stream info\n");
+		LogError(ffmpeg_domain, "Couldn't find stream info");
 		avformat_close_input(&format_context);
 		return;
 	}
 
 	int audio_stream = ffmpeg_find_audio_stream(format_context);
 	if (audio_stream == -1) {
-		g_warning("No audio stream inside\n");
+		LogError(ffmpeg_domain, "No audio stream inside");
 		avformat_close_input(&format_context);
 		return;
 	}
@@ -414,12 +419,13 @@ ffmpeg_decode(struct decoder *decoder, struct input_stream *input)
 
 	AVCodecContext *codec_context = av_stream->codec;
 	if (codec_context->codec_name[0] != 0)
-		g_debug("codec '%s'", codec_context->codec_name);
+		FormatDebug(ffmpeg_domain, "codec '%s'",
+			    codec_context->codec_name);
 
 	AVCodec *codec = avcodec_find_decoder(codec_context->codec_id);
 
 	if (!codec) {
-		g_warning("Unsupported audio codec\n");
+		LogError(ffmpeg_domain, "Unsupported audio codec");
 		avformat_close_input(&format_context);
 		return;
 	}
@@ -435,7 +441,7 @@ ffmpeg_decode(struct decoder *decoder, struct input_stream *input)
 				       codec_context->sample_rate,
 				       sample_format,
 				       codec_context->channels, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		avformat_close_input(&format_context);
 		return;
 	}
@@ -447,7 +453,7 @@ ffmpeg_decode(struct decoder *decoder, struct input_stream *input)
 
 	const int open_result = avcodec_open2(codec_context, codec, NULL);
 	if (open_result < 0) {
-		g_warning("Could not open codec\n");
+		LogError(ffmpeg_domain, "Could not open codec");
 		avformat_close_input(&format_context);
 		return;
 	}
@@ -461,7 +467,7 @@ ffmpeg_decode(struct decoder *decoder, struct input_stream *input)
 
 	AVFrame *frame = avcodec_alloc_frame();
 	if (!frame) {
-		g_warning("Could not allocate frame\n");
+		LogError(ffmpeg_domain, "Could not allocate frame");
 		avformat_close_input(&format_context);
 		return;
 	}

src/decoder/FfmpegMetaData.cxx

@@ -25,9 +25,6 @@
 #include "tag/TagTable.hxx"
 #include "tag/TagHandler.hxx"
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "ffmpeg"
-
 static const struct tag_table ffmpeg_tags[] = {
 	{ "year", TAG_DATE },
 	{ "author-sort", TAG_ARTIST_SORT },

src/decoder/FlacCommon.cxx

@@ -27,8 +27,8 @@
 #include "FlacPcm.hxx"
 #include "CheckAudioFormat.hxx"
 #include "util/Error.hxx"
-
-#include <glib.h>
+#include "util/Domain.hxx"
+#include "Log.hxx"
 
 #include <assert.h>
 
@@ -74,7 +74,7 @@ flac_got_stream_info(struct flac_data *data,
 				       stream_info->sample_rate,
 				       flac_sample_format(stream_info->bits_per_sample),
 				       stream_info->channels, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		data->unsupported = true;
 		return;
 	}
@@ -136,7 +136,7 @@ flac_got_first_frame(struct flac_data *data, const FLAC__FrameHeader *header)
 				       header->sample_rate,
 				       flac_sample_format(header->bits_per_sample),
 				       header->channels, error)) {
-		g_warning("%s", error.GetMessage());
+		LogError(error);
 		data->unsupported = true;
 		return false;
 	}

src/decoder/FlacCommon.hxx

@@ -31,9 +31,6 @@
 #include <FLAC/stream_decoder.h>
 #include <FLAC/metadata.h>
 
-#undef G_LOG_DOMAIN
-#define G_LOG_DOMAIN "flac"
-
 struct flac_data : public FlacInput {
 	PcmBuffer buffer;
 

src/decoder/FlacDecoderPlugin.cxx

@@ -19,10 +19,12 @@
 
 #include "config.h" /* must be first for large file support */
 #include "FlacDecoderPlugin.h"
+#include "FlacDomain.hxx"
 #include "FlacCommon.hxx"
 #include "FlacMetadata.hxx"
 #include "OggCodec.hxx"
 #include "util/Error.hxx"
+#include "Log.hxx"
 
 #include <glib.h>
 
@@ -54,7 +56,7 @@ static void flacPrintErroredState(FLAC__StreamDecoderState state)
 		break;
 	}
 
-	g_warning("%s\n", FLAC__StreamDecoderStateString[state]);
+	LogError(flac_domain, FLAC__StreamDecoderStateString[state]);
 }
 
 static void flacMetadata(gcc_unused const FLAC__StreamDecoder * dec,
@@ -90,8 +92,9 @@ flac_scan_file(const char *file,
 {
 	FlacMetadataChain chain;
 	if (!chain.Read(file)) {
-		g_debug("Failed to read FLAC tags: %s",
-			chain.GetStatusString());
+		FormatDebug(flac_domain,
+			    "Failed to read FLAC tags: %s",
+			    chain.GetStatusString());
 		return false;
 	}
 
@@ -105,8 +108,9 @@ flac_scan_stream(struct input_stream *is,
 {
 	FlacMetadataChain chain;
 	if (!chain.Read(is)) {
-		g_debug("Failed to read FLAC tags: %s",
-			chain.GetStatusString());
+		FormatDebug(flac_domain,
+			    "Failed to read FLAC tags: %s",
+			    chain.GetStatusString());
 		return false;
 	}
 
@@ -122,12 +126,14 @@ flac_decoder_new(void)
 {
 	FLAC__StreamDecoder *sd = FLAC__stream_decoder_new();
 	if (sd == nullptr) {
-		g_warning("FLAC__stream_decoder_new() failed");
+		LogError(flac_domain,
+			 "FLAC__stream_decoder_new() failed");
 		return nullptr;
 	}
 
 	if(!FLAC__stream_decoder_set_metadata_respond(sd, FLAC__METADATA_TYPE_VORBIS_COMMENT))
-		g_debug("FLAC__stream_decoder_set_metadata_respond() has failed");
+		LogDebug(flac_domain,
+			 "FLAC__stream_decoder_set_metadata_respond() has failed");
 
 	return sd;
 }
@@ -139,7 +145,7 @@ flac_decoder_initialize(struct flac_data *data, FLAC__StreamDecoder *sd,
 	data->total_frames = duration;
 
 	if (!FLAC__stream_decoder_process_until_end_of_metadata(sd)) {
-		g_warning("problem reading metadata");
+		LogWarning(flac_domain, "problem reading metadata");
 		return false;
 	}
 
@@ -265,7 +271,8 @@ flac_decode_internal(struct decoder * decoder,
 		stream_init(flac_dec, &data, is_ogg);
 	if (status != FLAC__STREAM_DECODER_INIT_STATUS_OK) {
 		FLAC__stream_decoder_delete(flac_dec);
-		g_warning("%s", FLAC__StreamDecoderInitStatusString[status]);
+		LogWarning(flac_domain,
+			   FLAC__StreamDecoderInitStatusString[status]);
 		return;
 	}
 
@@ -299,8 +306,9 @@ oggflac_scan_file(const char *file,
 {
 	FlacMetadataChain chain;
 	if (!chain.ReadOgg(file)) {
-		g_debug("Failed to read OggFLAC tags: %s",
-			chain.GetStatusString());
+		FormatDebug(flac_domain,
+			    "Failed to read OggFLAC tags: %s",
+			    chain.GetStatusString());
 		return false;
 	}
 
@@ -314,8 +322,9 @@ oggflac_scan_stream(struct input_stream *is,
 {
 	FlacMetadataChain chain;
 	if (!chain.ReadOgg(is)) {
-		g_debug("Failed to read OggFLAC tags: %s",
-			chain.GetStatusString());
+		FormatDebug(flac_domain,
+			    "Failed to read OggFLAC tags: %s",
+			    chain.GetStatusString());
 		return false;
 	}
 

src/decoder/FlacDomain.cxx

+/*
+ * Copyright (C) 2003-2012 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#include "config.h"
+#include "FlacDomain.hxx"
+#include "util/Domain.hxx"
+
+const Domain flac_domain("flac");

src/decoder/FlacDomain.hxx

+/*
+ * Copyright (C) 2003-2012 The Music Player Daemon Project
+ * http://www.musicpd.org
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+#ifndef MPD_FLAC_DOMAIN_HXX
+#define MPD_FLAC_DOMAIN_HXX
+
+#include "check.h"
+
+extern const class Domain flac_domain;
+
+#endif