tag/handler: use CamelCase

src/SongUpdate.cxx

@@ -78,7 +78,7 @@ Song::LoadFile(Storage &storage, const char *path_utf8, Directory &parent)
  */
 static bool
 tag_scan_fallback(Path path,
-		  const struct tag_handler *handler, void *handler_ctx)
+		  const TagHandler *handler, void *handler_ctx)
 {
 	return tag_ape_scan2(path, handler, handler_ctx) ||
 		tag_id3_scan(path, handler, handler_ctx);

src/TagArchive.cxx

@@ -29,7 +29,7 @@
 #include <assert.h>
 
 bool
-tag_archive_scan(Path path, const tag_handler &handler, void *handler_ctx)
+tag_archive_scan(Path path, const TagHandler &handler, void *handler_ctx)
 {
 	assert(!path.IsNull());
 

src/TagArchive.hxx

@@ -23,7 +23,7 @@
 #include "check.h"
 
 class Path;
-struct tag_handler;
+struct TagHandler;
 
 /**
  * Scan the tags of a song file inside an archive.  Invokes matching
@@ -34,6 +34,6 @@ struct tag_handler;
  * found)
  */
 bool
-tag_archive_scan(Path path, const tag_handler &handler, void *handler_ctx);
+tag_archive_scan(Path path, const TagHandler &handler, void *handler_ctx);
 
 #endif

src/TagFile.cxx

@@ -34,7 +34,7 @@ class TagFileScan {
 	const Path path_fs;
 	const char *const suffix;
 
-	const tag_handler &handler;
+	const TagHandler &handler;
 	void *handler_ctx;
 
 	Mutex mutex;
@@ -43,7 +43,7 @@ class TagFileScan {
 
 public:
 	TagFileScan(Path _path_fs, const char *_suffix,
-		    const tag_handler &_handler, void *_handler_ctx)
+		    const TagHandler &_handler, void *_handler_ctx)
 		:path_fs(_path_fs), suffix(_suffix),
 		 handler(_handler), handler_ctx(_handler_ctx) ,
 		 is(nullptr) {}
@@ -77,7 +77,7 @@ public:
 };
 
 bool
-tag_file_scan(Path path_fs, const tag_handler &handler, void *handler_ctx)
+tag_file_scan(Path path_fs, const TagHandler &handler, void *handler_ctx)
 {
 	assert(!path_fs.IsNull());
 

src/TagFile.hxx

@@ -23,7 +23,7 @@
 #include "check.h"
 
 class Path;
-struct tag_handler;
+struct TagHandler;
 
 /**
  * Scan the tags of a song file.  Invokes matching decoder plugins,
@@ -33,6 +33,6 @@ struct tag_handler;
  * found)
  */
 bool
-tag_file_scan(Path path, const tag_handler &handler, void *handler_ctx);
+tag_file_scan(Path path, const TagHandler &handler, void *handler_ctx);
 
 #endif

src/TagStream.cxx

@@ -42,7 +42,7 @@ CheckDecoderPlugin(const DecoderPlugin &plugin,
 }
 
 bool
-tag_stream_scan(InputStream &is, const tag_handler &handler, void *ctx)
+tag_stream_scan(InputStream &is, const TagHandler &handler, void *ctx)
 {
 	assert(is.IsReady());
 
@@ -63,7 +63,7 @@ tag_stream_scan(InputStream &is, const tag_handler &handler, void *ctx)
 }
 
 bool
-tag_stream_scan(const char *uri, const tag_handler &handler, void *ctx)
+tag_stream_scan(const char *uri, const TagHandler &handler, void *ctx)
 {
 	Mutex mutex;
 	Cond cond;

src/TagStream.hxx

@@ -23,7 +23,7 @@
 #include "check.h"
 
 class InputStream;
-struct tag_handler;
+struct TagHandler;
 
 /**
  * Scan the tags of an #InputStream.  Invokes matching decoder
@@ -33,9 +33,9 @@ struct tag_handler;
  * found)
  */
 bool
-tag_stream_scan(InputStream &is, const tag_handler &handler, void *ctx);
+tag_stream_scan(InputStream &is, const TagHandler &handler, void *ctx);
 
 bool
-tag_stream_scan(const char *uri, const tag_handler &handler, void *ctx);
+tag_stream_scan(const char *uri, const TagHandler &handler, void *ctx);
 
 #endif

src/command/FileCommands.cxx

@@ -148,7 +148,7 @@ print_pair(const char *key, const char *value, void *ctx)
 		r.Format("%s: %s\n", key, value);
 }
 
-static constexpr tag_handler print_comment_handler = {
+static constexpr TagHandler print_comment_handler = {
 	nullptr,
 	nullptr,
 	print_pair,

src/command/OtherCommands.cxx

@@ -168,7 +168,7 @@ handle_listfiles(Client &client, Request args, Response &r)
 	gcc_unreachable();
 }
 
-static constexpr tag_handler print_tag_handler = {
+static constexpr TagHandler print_tag_handler = {
 	nullptr,
 	print_tag,
 	nullptr,

src/decoder/DecoderPlugin.hxx

@@ -24,7 +24,7 @@
 
 struct ConfigBlock;
 class InputStream;
-struct tag_handler;
+struct TagHandler;
 class Path;
 
 /**
@@ -74,7 +74,7 @@ struct DecoderPlugin {
 	 * @return false if the operation has failed
 	 */
 	bool (*scan_file)(Path path_fs,
-			  const struct tag_handler *handler,
+			  const TagHandler *handler,
 			  void *handler_ctx);
 
 	/**
@@ -83,7 +83,7 @@ struct DecoderPlugin {
 	 * @return false if the operation has failed
 	 */
 	bool (*scan_stream)(InputStream &is,
-			    const struct tag_handler *handler,
+			    const TagHandler *handler,
 			    void *handler_ctx);
 
 	/**
@@ -145,7 +145,7 @@ struct DecoderPlugin {
 	 */
 	template<typename P>
 	bool ScanFile(P path_fs,
-		      const tag_handler &handler, void *handler_ctx) const {
+		      const TagHandler &handler, void *handler_ctx) const {
 		return scan_file != nullptr
 			? scan_file(path_fs, &handler, handler_ctx)
 			: false;
@@ -155,7 +155,7 @@ struct DecoderPlugin {
 	 * Read the tag of a stream.
 	 */
 	bool ScanStream(InputStream &is,
-			const tag_handler &handler, void *handler_ctx) const {
+			const TagHandler &handler, void *handler_ctx) const {
 		return scan_stream != nullptr
 			? scan_stream(is, &handler, handler_ctx)
 			: false;

src/decoder/plugins/AdPlugDecoderPlugin.cxx

@@ -89,7 +89,7 @@ adplug_file_decode(Decoder &decoder, Path path_fs)
 
 static void
 adplug_scan_tag(TagType type, const std::string &value,
-		const struct tag_handler *handler, void *handler_ctx)
+		const TagHandler *handler, void *handler_ctx)
 {
 	if (!value.empty())
 		tag_handler_invoke_tag(handler, handler_ctx,
@@ -98,7 +98,7 @@ adplug_scan_tag(TagType type, const std::string &value,
 
 static bool
 adplug_scan_file(Path path_fs,
-		 const struct tag_handler *handler, void *handler_ctx)
+		 const TagHandler *handler, void *handler_ctx)
 {
 	CEmuopl opl(sample_rate, true, true);
 	opl.init();

src/decoder/plugins/AudiofileDecoderPlugin.cxx

@@ -263,7 +263,7 @@ audiofile_get_duration(InputStream &is)
 
 static bool
 audiofile_scan_stream(InputStream &is,
-		      const struct tag_handler *handler, void *handler_ctx)
+		      const TagHandler *handler, void *handler_ctx)
 {
 	const auto duration = audiofile_get_duration(is);
 	if (duration.IsNegative())

src/decoder/plugins/DsdLib.cxx

@@ -106,7 +106,7 @@ dsdlib_valid_freq(uint32_t samplefreq)
 #ifdef ENABLE_ID3TAG
 void
 dsdlib_tag_id3(InputStream &is,
-	       const struct tag_handler *handler,
+	       const TagHandler *handler,
 	       void *handler_ctx, offset_type tagoffset)
 {
 	if (tagoffset == 0 || !is.KnownSize())

src/decoder/plugins/DsdLib.hxx

@@ -28,6 +28,7 @@
 #include <stdint.h>
 
 struct Decoder;
+struct TagHandler;
 class InputStream;
 
 struct DsdId {
@@ -80,7 +81,7 @@ dsdlib_valid_freq(uint32_t samplefreq);
  */
 void
 dsdlib_tag_id3(InputStream &is,
-	       const struct tag_handler *handler,
+	       const TagHandler *handler,
 	       void *handler_ctx, offset_type tagoffset);
 
 #endif

src/decoder/plugins/DsdiffDecoderPlugin.cxx

@@ -187,7 +187,7 @@ dsdiff_read_prop(Decoder *decoder, InputStream &is,
 
 static void
 dsdiff_handle_native_tag(InputStream &is,
-			 const struct tag_handler *handler,
+			 const TagHandler *handler,
 			 void *handler_ctx, offset_type tagoffset,
 			 TagType type)
 {
@@ -229,7 +229,7 @@ static bool
 dsdiff_read_metadata_extra(Decoder *decoder, InputStream &is,
 			   DsdiffMetaData *metadata,
 			   DsdiffChunkHeader *chunk_header,
-			   const struct tag_handler *handler,
+			   const TagHandler *handler,
 			   void *handler_ctx)
 {
 
@@ -456,7 +456,7 @@ dsdiff_stream_decode(Decoder &decoder, InputStream &is)
 
 static bool
 dsdiff_scan_stream(InputStream &is,
-		   gcc_unused const struct tag_handler *handler,
+		   gcc_unused const TagHandler *handler,
 		   gcc_unused void *handler_ctx)
 {
 	DsdiffMetaData metadata;

src/decoder/plugins/DsfDecoderPlugin.cxx

@@ -331,7 +331,7 @@ dsf_stream_decode(Decoder &decoder, InputStream &is)
 
 static bool
 dsf_scan_stream(InputStream &is,
-		gcc_unused const struct tag_handler *handler,
+		gcc_unused const TagHandler *handler,
 		gcc_unused void *handler_ctx)
 {
 	/* check DSF metadata */

src/decoder/plugins/FaadDecoderPlugin.cxx

@@ -419,7 +419,7 @@ faad_stream_decode(Decoder &mpd_decoder, InputStream &is)
 
 static bool
 faad_scan_stream(InputStream &is,
-		 const struct tag_handler *handler, void *handler_ctx)
+		 const TagHandler *handler, void *handler_ctx)
 {
 	auto result = faad_get_file_time(is);
 	if (!result.first)

src/decoder/plugins/FfmpegDecoderPlugin.cxx

@@ -390,14 +390,14 @@ FfmpegParseMetaData(Decoder &decoder,
 
 static void
 FfmpegScanMetadata(const AVStream &stream,
-		   const tag_handler &handler, void *handler_ctx)
+		   const TagHandler &handler, void *handler_ctx)
 {
 	FfmpegScanDictionary(stream.metadata, &handler, handler_ctx);
 }
 
 static void
 FfmpegScanMetadata(const AVFormatContext &format_context, int audio_stream,
-		   const tag_handler &handler, void *handler_ctx)
+		   const TagHandler &handler, void *handler_ctx)
 {
 	assert(audio_stream >= 0);
 
@@ -614,7 +614,7 @@ ffmpeg_decode(Decoder &decoder, InputStream &input)
 
 static bool
 FfmpegScanStream(AVFormatContext &format_context,
-		 const struct tag_handler &handler, void *handler_ctx)
+		 const TagHandler &handler, void *handler_ctx)
 {
 	const int find_result =
 		avformat_find_stream_info(&format_context, nullptr);
@@ -638,7 +638,7 @@ FfmpegScanStream(AVFormatContext &format_context,
 
 static bool
 ffmpeg_scan_stream(InputStream &is,
-		   const struct tag_handler *handler, void *handler_ctx)
+		   const TagHandler *handler, void *handler_ctx)
 {
 	AVInputFormat *input_format = ffmpeg_probe(nullptr, is);
 	if (input_format == nullptr)

src/decoder/plugins/FfmpegMetaData.cxx

@@ -42,7 +42,7 @@ static constexpr struct tag_table ffmpeg_tags[] = {
 static void
 FfmpegScanTag(TagType type,
 	      AVDictionary *m, const char *name,
-	      const struct tag_handler *handler, void *handler_ctx)
+	      const TagHandler *handler, void *handler_ctx)
 {
 	AVDictionaryEntry *mt = nullptr;
 
@@ -53,7 +53,7 @@ FfmpegScanTag(TagType type,
 
 static void
 FfmpegScanPairs(AVDictionary *dict,
-		const struct tag_handler *handler, void *handler_ctx)
+		const TagHandler *handler, void *handler_ctx)
 {
 	AVDictionaryEntry *i = nullptr;
 
@@ -64,7 +64,7 @@ FfmpegScanPairs(AVDictionary *dict,
 
 void
 FfmpegScanDictionary(AVDictionary *dict,
-		     const struct tag_handler *handler, void *handler_ctx)
+		     const TagHandler *handler, void *handler_ctx)
 {
 	if (handler->tag != nullptr) {
 		for (unsigned i = 0; i < TAG_NUM_OF_ITEM_TYPES; ++i)

src/decoder/plugins/FfmpegMetaData.hxx

@@ -21,10 +21,10 @@
 #define MPD_FFMPEG_METADATA_HXX
 
 struct AVDictionary;
-struct tag_handler;
+struct TagHandler;
 
 void
 FfmpegScanDictionary(AVDictionary *dict,
-		     const tag_handler *handler, void *handler_ctx);
+		     const TagHandler *handler, void *handler_ctx);
 
 #endif

src/decoder/plugins/FlacDecoderPlugin.cxx

@@ -82,7 +82,7 @@ flac_write_cb(const FLAC__StreamDecoder *dec, const FLAC__Frame *frame,
 
 static bool
 flac_scan_file(Path path_fs,
-	       const struct tag_handler *handler, void *handler_ctx)
+	       const TagHandler *handler, void *handler_ctx)
 {
 	FlacMetadataChain chain;
 	if (!chain.Read(NarrowPath(path_fs))) {
@@ -98,7 +98,7 @@ flac_scan_file(Path path_fs,
 
 static bool
 flac_scan_stream(InputStream &is,
-		 const struct tag_handler *handler, void *handler_ctx)
+		 const TagHandler *handler, void *handler_ctx)
 {
 	FlacMetadataChain chain;
 	if (!chain.Read(is)) {
@@ -299,7 +299,7 @@ oggflac_init(gcc_unused const ConfigBlock &block)
 
 static bool
 oggflac_scan_file(Path path_fs,
-		  const struct tag_handler *handler, void *handler_ctx)
+		  const TagHandler *handler, void *handler_ctx)
 {
 	FlacMetadataChain chain;
 	if (!chain.ReadOgg(NarrowPath(path_fs))) {
@@ -315,7 +315,7 @@ oggflac_scan_file(Path path_fs,
 
 static bool
 oggflac_scan_stream(InputStream &is,
-		    const struct tag_handler *handler, void *handler_ctx)
+		    const TagHandler *handler, void *handler_ctx)
 {
 	FlacMetadataChain chain;
 	if (!chain.ReadOgg(is)) {

src/decoder/plugins/FlacMetadata.cxx

@@ -80,7 +80,7 @@ flac_comment_value(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
 static bool
 flac_copy_comment(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
 		  const char *name, TagType tag_type,
-		  const struct tag_handler *handler, void *handler_ctx)
+		  const TagHandler *handler, void *handler_ctx)
 {
 	const char *value = flac_comment_value(entry, name);
 	if (value != nullptr) {
@@ -93,7 +93,7 @@ flac_copy_comment(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
 
 static void
 flac_scan_comment(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
-		  const struct tag_handler *handler, void *handler_ctx)
+		  const TagHandler *handler, void *handler_ctx)
 {
 	if (handler->pair != nullptr) {
 		const char *comment = (const char *)entry->entry;
@@ -118,7 +118,7 @@ flac_scan_comment(const FLAC__StreamMetadata_VorbisComment_Entry *entry,
 
 static void
 flac_scan_comments(const FLAC__StreamMetadata_VorbisComment *comment,
-		   const struct tag_handler *handler, void *handler_ctx)
+		   const TagHandler *handler, void *handler_ctx)
 {
 	for (unsigned i = 0; i < comment->num_comments; ++i)
 		flac_scan_comment(&comment->comments[i],
@@ -137,7 +137,7 @@ flac_duration(const FLAC__StreamMetadata_StreamInfo *stream_info)
 
 void
 flac_scan_metadata(const FLAC__StreamMetadata *block,
-		   const struct tag_handler *handler, void *handler_ctx)
+		   const TagHandler *handler, void *handler_ctx)
 {
 	switch (block->type) {
 	case FLAC__METADATA_TYPE_VORBIS_COMMENT:
@@ -165,7 +165,7 @@ flac_vorbis_comments_to_tag(const FLAC__StreamMetadata_VorbisComment *comment)
 }
 
 void
-FlacMetadataChain::Scan(const struct tag_handler *handler, void *handler_ctx)
+FlacMetadataChain::Scan(const TagHandler *handler, void *handler_ctx)
 {
 	FLACMetadataIterator iterator(*this);
 

src/decoder/plugins/FlacMetadata.hxx

@@ -27,7 +27,7 @@
 
 #include <assert.h>
 
-struct tag_handler;
+struct TagHandler;
 class MixRampInfo;
 
 class FlacMetadataChain {
@@ -82,7 +82,7 @@ public:
 		return FLAC__Metadata_ChainStatusString[GetStatus()];
 	}
 
-	void Scan(const tag_handler *handler, void *handler_ctx);
+	void Scan(const TagHandler *handler, void *handler_ctx);
 };
 
 class FLACMetadataIterator {
@@ -126,6 +126,6 @@ flac_vorbis_comments_to_tag(const FLAC__StreamMetadata_VorbisComment *comment);
 
 void
 flac_scan_metadata(const FLAC__StreamMetadata *block,
-		   const tag_handler *handler, void *handler_ctx);
+		   const TagHandler *handler, void *handler_ctx);
 
 #endif

src/decoder/plugins/FluidsynthDecoderPlugin.cxx

@@ -201,7 +201,7 @@ fluidsynth_file_decode(Decoder &decoder, Path path_fs)
 
 static bool
 fluidsynth_scan_file(Path path_fs,
-		     gcc_unused const struct tag_handler *handler,
+		     gcc_unused const TagHandler *handler,
 		     gcc_unused void *handler_ctx)
 {
 	return fluid_is_midifile(path_fs.c_str());

src/decoder/plugins/GmeDecoderPlugin.cxx

@@ -215,7 +215,7 @@ gme_file_decode(Decoder &decoder, Path path_fs)
 
 static void
 ScanGmeInfo(const gme_info_t &info, unsigned song_num, int track_count,
-	    const struct tag_handler *handler, void *handler_ctx)
+	    const TagHandler *handler, void *handler_ctx)
 {
 	if (info.play_length > 0)
 		tag_handler_invoke_duration(handler, handler_ctx,
@@ -255,7 +255,7 @@ ScanGmeInfo(const gme_info_t &info, unsigned song_num, int track_count,
 
 static bool
 ScanMusicEmu(Music_Emu *emu, unsigned song_num,
-	     const struct tag_handler *handler, void *handler_ctx)
+	     const TagHandler *handler, void *handler_ctx)
 {
 	gme_info_t *ti;
 	const char *gme_err = gme_track_info(emu, &ti, song_num);
@@ -275,7 +275,7 @@ ScanMusicEmu(Music_Emu *emu, unsigned song_num,
 
 static bool
 gme_scan_file(Path path_fs,
-	      const struct tag_handler *handler, void *handler_ctx)
+	      const TagHandler *handler, void *handler_ctx)
 {
 	const auto container = ParseContainerPath(path_fs);
 

src/decoder/plugins/MadDecoderPlugin.cxx

@@ -1083,7 +1083,7 @@ mp3_decode(Decoder &decoder, InputStream &input_stream)
 
 static bool
 mad_decoder_scan_stream(InputStream &is,
-			const struct tag_handler *handler, void *handler_ctx)
+			const TagHandler *handler, void *handler_ctx)
 {
 	const auto result = mad_decoder_total_file_time(is);
 	if (!result.first)

src/decoder/plugins/MikmodDecoderPlugin.cxx

@@ -187,7 +187,7 @@ mikmod_decoder_file_decode(Decoder &decoder, Path path_fs)
 
 static bool
 mikmod_decoder_scan_file(Path path_fs,
-			 const struct tag_handler *handler, void *handler_ctx)
+			 const TagHandler *handler, void *handler_ctx)
 {
 	/* deconstify the path because libmikmod wants a non-const
 	   string pointer */

src/decoder/plugins/ModplugDecoderPlugin.cxx

@@ -177,7 +177,7 @@ mod_decode(Decoder &decoder, InputStream &is)
 
 static bool
 modplug_scan_stream(InputStream &is,
-		    const struct tag_handler *handler, void *handler_ctx)
+		    const TagHandler *handler, void *handler_ctx)
 {
 	ModPlugFile *f = LoadModPlugFile(nullptr, is);
 	if (f == nullptr)

src/decoder/plugins/MpcdecDecoderPlugin.cxx

@@ -249,7 +249,7 @@ mpcdec_get_file_duration(InputStream &is)
 
 static bool
 mpcdec_scan_stream(InputStream &is,
-		   const struct tag_handler *handler, void *handler_ctx)
+		   const TagHandler *handler, void *handler_ctx)
 {
 	const auto duration = mpcdec_get_file_duration(is);
 	if (duration.IsNegative())

src/decoder/plugins/Mpg123DecoderPlugin.cxx

@@ -287,7 +287,7 @@ mpd_mpg123_file_decode(Decoder &decoder, Path path_fs)
 
 static bool
 mpd_mpg123_scan_file(Path path_fs,
-		     const struct tag_handler *handler, void *handler_ctx)
+		     const TagHandler *handler, void *handler_ctx)
 {
 	int error;
 	mpg123_handle *const handle = mpg123_new(nullptr, &error);

src/decoder/plugins/OpusDecoderPlugin.cxx

@@ -433,7 +433,7 @@ mpd_opus_stream_decode(Decoder &decoder,
 
 static bool
 mpd_opus_scan_stream(InputStream &is,
-		     const struct tag_handler *handler, void *handler_ctx)
+		     const TagHandler *handler, void *handler_ctx)
 {
 	OggSyncState oy(is);
 

src/decoder/plugins/OpusTags.cxx

@@ -43,7 +43,7 @@ ParseOpusTagName(const char *name)
 static void
 ScanOneOpusTag(const char *name, const char *value,
 	       ReplayGainInfo *rgi,
-	       const struct tag_handler *handler, void *ctx)
+	       const TagHandler *handler, void *ctx)
 {
 	if (rgi != nullptr && strcmp(name, "R128_TRACK_GAIN") == 0) {
 		/* R128_TRACK_GAIN is a Q7.8 fixed point number in
@@ -67,7 +67,7 @@ ScanOneOpusTag(const char *name, const char *value,
 bool
 ScanOpusTags(const void *data, size_t size,
 	     ReplayGainInfo *rgi,
-	     const struct tag_handler *handler, void *ctx)
+	     const TagHandler *handler, void *ctx)
 {
 	OpusReader r(data, size);
 	if (!r.Expect("OpusTags", 8))

src/decoder/plugins/OpusTags.hxx

@@ -25,10 +25,11 @@
 #include <stddef.h>
 
 struct ReplayGainInfo;
+struct TagHandler;
 
 bool
 ScanOpusTags(const void *data, size_t size,
 	     ReplayGainInfo *rgi,
-	     const struct tag_handler *handler, void *ctx);
+	     const TagHandler *handler, void *ctx);
 
 #endif

src/decoder/plugins/SidplayDecoderPlugin.cxx

@@ -286,7 +286,7 @@ sidplay_file_decode(Decoder &decoder, Path path_fs)
 
 static bool
 sidplay_scan_file(Path path_fs,
-		  const struct tag_handler *handler, void *handler_ctx)
+		  const TagHandler *handler, void *handler_ctx)
 {
 	const auto container = ParseContainerPath(path_fs);
 	const unsigned song_num = container.track;

src/decoder/plugins/SndfileDecoderPlugin.cxx

@@ -244,7 +244,7 @@ sndfile_stream_decode(Decoder &decoder, InputStream &is)
 
 static void
 sndfile_handle_tag(SNDFILE *sf, int str, TagType tag,
-		   const struct tag_handler *handler, void *handler_ctx)
+		   const TagHandler *handler, void *handler_ctx)
 {
 	const char *value = sf_get_string(sf, str);
 	if (value != nullptr)
@@ -266,7 +266,7 @@ static constexpr struct {
 
 static bool
 sndfile_scan_stream(InputStream &is,
-		    const struct tag_handler *handler, void *handler_ctx)
+		    const TagHandler *handler, void *handler_ctx)
 {
 	SF_INFO info;
 

src/decoder/plugins/VorbisComments.cxx

@@ -56,7 +56,7 @@ vorbis_comments_to_replay_gain(ReplayGainInfo &rgi, char **comments)
 static bool
 vorbis_copy_comment(const char *comment,
 		    const char *name, TagType tag_type,
-		    const struct tag_handler *handler, void *handler_ctx)
+		    const TagHandler *handler, void *handler_ctx)
 {
 	const char *value;
 
@@ -71,7 +71,7 @@ vorbis_copy_comment(const char *comment,
 
 static void
 vorbis_scan_comment(const char *comment,
-		    const struct tag_handler *handler, void *handler_ctx)
+		    const TagHandler *handler, void *handler_ctx)
 {
 	if (handler->pair != nullptr) {
 		const DivideString split(comment, '=');
@@ -95,7 +95,7 @@ vorbis_scan_comment(const char *comment,
 
 void
 vorbis_comments_scan(char **comments,
-		     const struct tag_handler *handler, void *handler_ctx)
+		     const TagHandler *handler, void *handler_ctx)
 {
 	while (*comments)
 		vorbis_scan_comment(*comments++,

src/decoder/plugins/VorbisComments.hxx

@@ -23,7 +23,7 @@
 #include "check.h"
 
 struct ReplayGainInfo;
-struct tag_handler;
+struct TagHandler;
 struct Tag;
 
 bool
@@ -31,7 +31,7 @@ vorbis_comments_to_replay_gain(ReplayGainInfo &rgi, char **comments);
 
 void
 vorbis_comments_scan(char **comments,
-		     const tag_handler *handler, void *handler_ctx);
+		     const TagHandler *handler, void *handler_ctx);
 
 Tag *
 vorbis_comments_to_tag(char **comments);

src/decoder/plugins/VorbisDecoderPlugin.cxx

@@ -335,7 +335,7 @@ vorbis_stream_decode(Decoder &decoder,
 
 static bool
 vorbis_scan_stream(InputStream &is,
-		   const struct tag_handler *handler, void *handler_ctx)
+		   const TagHandler *handler, void *handler_ctx)
 {
 	VorbisInputStream vis(nullptr, is);
 	OggVorbis_File vf;

src/decoder/plugins/WavpackDecoderPlugin.cxx

@@ -243,7 +243,7 @@ wavpack_replaygain(ReplayGainInfo &rgi,
 static void
 wavpack_scan_tag_item(WavpackContext *wpc, const char *name,
 		      TagType type,
-		      const struct tag_handler *handler, void *handler_ctx)
+		      const TagHandler *handler, void *handler_ctx)
 {
 	char buffer[1024];
 	int len = WavpackGetTagItem(wpc, name, buffer, sizeof(buffer));
@@ -256,7 +256,7 @@ wavpack_scan_tag_item(WavpackContext *wpc, const char *name,
 
 static void
 wavpack_scan_pair(WavpackContext *wpc, const char *name,
-		  const struct tag_handler *handler, void *handler_ctx)
+		  const TagHandler *handler, void *handler_ctx)
 {
 	char buffer[8192];
 	int len = WavpackGetTagItem(wpc, name, buffer, sizeof(buffer));
@@ -271,7 +271,7 @@ wavpack_scan_pair(WavpackContext *wpc, const char *name,
  */
 static bool
 wavpack_scan_file(Path path_fs,
-		  const struct tag_handler *handler, void *handler_ctx)
+		  const TagHandler *handler, void *handler_ctx)
 {
 	char error[ERRORLEN];
 	WavpackContext *wpc = WavpackOpenFileInput(path_fs.c_str(), error,

src/decoder/plugins/WildmidiDecoderPlugin.cxx

@@ -123,7 +123,7 @@ wildmidi_file_decode(Decoder &decoder, Path path_fs)
 
 static bool
 wildmidi_scan_file(Path path_fs,
-		   const struct tag_handler *handler, void *handler_ctx)
+		   const TagHandler *handler, void *handler_ctx)
 {
 	midi *wm = WildMidi_Open(path_fs.c_str());
 	if (wm == nullptr)

src/playlist/plugins/EmbeddedCuePlaylistPlugin.cxx

@@ -82,7 +82,7 @@ embcue_tag_pair(const char *name, const char *value, void *ctx)
 		playlist->cuesheet = value;
 }
 
-static const struct tag_handler embcue_tag_handler = {
+static constexpr TagHandler embcue_tag_handler = {
 	nullptr,
 	nullptr,
 	embcue_tag_pair,

src/tag/ApeTag.cxx

@@ -77,7 +77,7 @@ ForEachValue(const char *value, const char *end, C &&callback)
 static bool
 tag_ape_import_item(unsigned long flags,
 		    const char *key, StringView value,
-		    const struct tag_handler *handler, void *handler_ctx)
+		    const TagHandler *handler, void *handler_ctx)
 {
 	/* we only care about utf-8 text tags */
 	if ((flags & (0x3 << 1)) != 0)
@@ -107,7 +107,7 @@ tag_ape_import_item(unsigned long flags,
 
 bool
 tag_ape_scan2(InputStream &is,
-	      const struct tag_handler *handler, void *handler_ctx)
+	      const TagHandler *handler, void *handler_ctx)
 {
 	bool recognized = false;
 
@@ -124,7 +124,7 @@ tag_ape_scan2(InputStream &is,
 
 bool
 tag_ape_scan2(Path path_fs,
-	      const struct tag_handler *handler, void *handler_ctx)
+	      const TagHandler *handler, void *handler_ctx)
 {
 	bool recognized = false;
 

src/tag/ApeTag.hxx

@@ -24,7 +24,7 @@
 
 class Path;
 class InputStream;
-struct tag_handler;
+struct TagHandler;
 
 extern const struct tag_table ape_tags[];
 
@@ -35,7 +35,7 @@ extern const struct tag_table ape_tags[];
  */
 bool
 tag_ape_scan2(InputStream &is,
-	      const tag_handler *handler, void *handler_ctx);
+	      const TagHandler *handler, void *handler_ctx);
 
 /**
  * Scan the APE tags of a file.
@@ -44,6 +44,6 @@ tag_ape_scan2(InputStream &is,
  */
 bool
 tag_ape_scan2(Path path_fs,
-	      const tag_handler *handler, void *handler_ctx);
+	      const TagHandler *handler, void *handler_ctx);
 
 #endif

src/tag/TagHandler.cxx

@@ -51,7 +51,7 @@ add_tag_tag(TagType type, const char *value, void *ctx)
 		tag.AddItem(type, value);
 }
 
-const struct tag_handler add_tag_handler = {
+const TagHandler add_tag_handler = {
 	add_tag_duration,
 	add_tag_tag,
 	nullptr,
@@ -66,7 +66,7 @@ full_tag_pair(const char *name, gcc_unused const char *value, void *ctx)
 		tag.SetHasPlaylist(true);
 }
 
-const struct tag_handler full_tag_handler = {
+const TagHandler full_tag_handler = {
 	add_tag_duration,
 	add_tag_tag,
 	full_tag_pair,

src/tag/TagHandler.hxx

@@ -29,7 +29,7 @@
 /**
  * A callback table for receiving metadata of a song.
  */
-struct tag_handler {
+struct TagHandler {
 	/**
 	 * Declare the duration of a song.  Do not call
 	 * this when the duration could not be determined, because
@@ -53,7 +53,7 @@ struct tag_handler {
 };
 
 static inline void
-tag_handler_invoke_duration(const struct tag_handler *handler, void *ctx,
+tag_handler_invoke_duration(const TagHandler *handler, void *ctx,
 			    SongTime duration)
 {
 	assert(handler != nullptr);
@@ -63,7 +63,7 @@ tag_handler_invoke_duration(const struct tag_handler *handler, void *ctx,
 }
 
 static inline void
-tag_handler_invoke_tag(const struct tag_handler *handler, void *ctx,
+tag_handler_invoke_tag(const TagHandler *handler, void *ctx,
 		       TagType type, const char *value)
 {
 	assert(handler != nullptr);
@@ -75,7 +75,7 @@ tag_handler_invoke_tag(const struct tag_handler *handler, void *ctx,
 }
 
 static inline void
-tag_handler_invoke_pair(const struct tag_handler *handler, void *ctx,
+tag_handler_invoke_pair(const TagHandler *handler, void *ctx,
 			const char *name, const char *value)
 {
 	assert(handler != nullptr);
@@ -87,16 +87,16 @@ tag_handler_invoke_pair(const struct tag_handler *handler, void *ctx,
 }
 
 /**
- * This #tag_handler implementation adds tag values to a #TagBuilder object
+ * This #TagHandler implementation adds tag values to a #TagBuilder object
  * (casted from the context pointer).
  */
-extern const struct tag_handler add_tag_handler;
+extern const TagHandler add_tag_handler;
 
 /**
- * This #tag_handler implementation adds tag values to a #TagBuilder object
+ * This #TagHandler implementation adds tag values to a #TagBuilder object
  * (casted from the context pointer), and supports the has_playlist
  * attribute.
  */
-extern const struct tag_handler full_tag_handler;
+extern const TagHandler full_tag_handler;
 
 #endif

src/tag/TagId3.cxx

@@ -97,7 +97,7 @@ import_id3_string(const id3_ucs4_t *ucs4)
 static void
 tag_id3_import_text_frame(const struct id3_frame *frame,
 			  TagType type,
-			  const struct tag_handler *handler, void *handler_ctx)
+			  const TagHandler *handler, void *handler_ctx)
 {
 	if (frame->nfields != 2)
 		return;
@@ -140,7 +140,7 @@ tag_id3_import_text_frame(const struct id3_frame *frame,
  */
 static void
 tag_id3_import_text(struct id3_tag *tag, const char *id, TagType type,
-		    const struct tag_handler *handler, void *handler_ctx)
+		    const TagHandler *handler, void *handler_ctx)
 {
 	const struct id3_frame *frame;
 	for (unsigned i = 0;
@@ -160,7 +160,7 @@ tag_id3_import_text(struct id3_tag *tag, const char *id, TagType type,
  */
 static void
 tag_id3_import_comment_frame(const struct id3_frame *frame, TagType type,
-			     const struct tag_handler *handler,
+			     const TagHandler *handler,
 			     void *handler_ctx)
 {
 	if (frame->nfields != 4)
@@ -189,7 +189,7 @@ tag_id3_import_comment_frame(const struct id3_frame *frame, TagType type,
  */
 static void
 tag_id3_import_comment(struct id3_tag *tag, const char *id, TagType type,
-		       const struct tag_handler *handler, void *handler_ctx)
+		       const TagHandler *handler, void *handler_ctx)
 {
 	const struct id3_frame *frame;
 	for (unsigned i = 0;
@@ -226,7 +226,7 @@ tag_id3_parse_txxx_name(const char *name)
  */
 static void
 tag_id3_import_musicbrainz(struct id3_tag *id3_tag,
-			   const struct tag_handler *handler,
+			   const TagHandler *handler,
 			   void *handler_ctx)
 {
 	for (unsigned i = 0;; ++i) {
@@ -262,7 +262,7 @@ tag_id3_import_musicbrainz(struct id3_tag *id3_tag,
  */
 static void
 tag_id3_import_ufid(struct id3_tag *id3_tag,
-		    const struct tag_handler *handler, void *handler_ctx)
+		    const TagHandler *handler, void *handler_ctx)
 {
 	for (unsigned i = 0;; ++i) {
 		const id3_frame *frame = id3_tag_findframe(id3_tag, "UFID", i);
@@ -296,7 +296,7 @@ tag_id3_import_ufid(struct id3_tag *id3_tag,
 
 void
 scan_id3_tag(struct id3_tag *tag,
-	     const struct tag_handler *handler, void *handler_ctx)
+	     const TagHandler *handler, void *handler_ctx)
 {
 	tag_id3_import_text(tag, ID3_FRAME_ARTIST, TAG_ARTIST,
 			    handler, handler_ctx);
@@ -345,7 +345,7 @@ tag_id3_import(struct id3_tag *tag)
 
 bool
 tag_id3_scan(Path path_fs,
-	     const struct tag_handler *handler, void *handler_ctx)
+	     const TagHandler *handler, void *handler_ctx)
 {
 	UniqueId3Tag tag;
 

src/tag/TagId3.hxx

@@ -24,7 +24,7 @@
 #include "Compiler.h"
 
 class Path;
-struct tag_handler;
+struct TagHandler;
 struct Tag;
 struct id3_tag;
 
@@ -32,7 +32,7 @@ struct id3_tag;
 
 bool
 tag_id3_scan(Path path_fs,
-	     const tag_handler *handler, void *handler_ctx);
+	     const TagHandler *handler, void *handler_ctx);
 
 Tag *
 tag_id3_import(id3_tag *);
@@ -43,7 +43,7 @@ tag_id3_import(id3_tag *);
  */
 void
 scan_id3_tag(id3_tag *tag,
-	     const tag_handler *handler, void *handler_ctx);
+	     const TagHandler *handler, void *handler_ctx);
 
 #else
 
@@ -51,7 +51,7 @@ scan_id3_tag(id3_tag *tag,
 
 static inline bool
 tag_id3_scan(gcc_unused Path path_fs,
-	     gcc_unused const tag_handler *handler,
+	     gcc_unused const TagHandler *handler,
 	     gcc_unused void *handler_ctx)
 {
 	return false;

test/read_tags.cxx

@@ -62,7 +62,7 @@ print_pair(const char *name, const char *value, gcc_unused void *ctx)
 	printf("\"%s\"=%s\n", name, value);
 }
 
-static const struct tag_handler print_handler = {
+static constexpr TagHandler print_handler = {
 	print_duration,
 	print_tag,
 	print_pair,