SongFilter: convert to a C++ class

20 files changed, 210 insertions, 241 deletions

diff --git a/Makefile.am b/Makefile.am
index 2f015ed80..97747bcd2 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -177,7 +177,6 @@ mpd_headers = \
 	src/riff.h \
 	src/aiff.h \
 	src/queue.h \
-	src/queue_print.h \
 	src/queue_save.h \
 	src/refcount.h \
 	src/replay_gain_config.h \
@@ -333,7 +332,7 @@ src_mpd_SOURCES = \
 	src/playlist_vector.c \
 	src/playlist_database.c \
 	src/queue.c \
-	src/QueuePrint.cxx \
+	src/QueuePrint.cxx src/QueuePrint.hxx \
 	src/queue_save.c \
 	src/replay_gain_config.c \
 	src/replay_gain_info.c \
diff --git a/src/DatabaseCommands.cxx b/src/DatabaseCommands.cxx
index 047d3a550..14e83e96a 100644
--- a/src/DatabaseCommands.cxx
+++ b/src/DatabaseCommands.cxx
@@ -59,25 +59,18 @@ handle_lsinfo2(struct client *client, int argc, char *argv[])
 static enum command_return
 handle_match(struct client *client, int argc, char *argv[], bool fold_case)
 {
-	struct locate_item_list *list =
-		locate_item_list_parse(argv + 1, argc - 1, fold_case);
-
-	if (list == NULL) {
+	SongFilter filter;
+	if (!filter.Parse(argc - 1, argv + 1, fold_case)) {
 		command_error(client, ACK_ERROR_ARG, "incorrect arguments");
 		return COMMAND_RETURN_ERROR;
 	}
 
-	const DatabaseSelection selection("", true, list);
+	const DatabaseSelection selection("", true, &filter);
 
 	GError *error = NULL;
-	enum command_return ret =
-		db_selection_print(client, selection, true, &error)
+	return db_selection_print(client, selection, true, &error)
 		? COMMAND_RETURN_OK
 		: print_error(client, error);
-
-	locate_item_list_free(list);
-
-	return ret;
 }
 
 enum command_return
@@ -95,22 +88,16 @@ handle_search(struct client *client, int argc, char *argv[])
 static enum command_return
 handle_match_add(struct client *client, int argc, char *argv[], bool fold_case)
 {
-	struct locate_item_list *list =
-		locate_item_list_parse(argv + 1, argc - 1, fold_case);
-	if (list == NULL) {
+	SongFilter filter;
+	if (!filter.Parse(argc - 1, argv + 1, fold_case)) {
 		command_error(client, ACK_ERROR_ARG, "incorrect arguments");
 		return COMMAND_RETURN_ERROR;
 	}
 
 	GError *error = NULL;
-	enum command_return ret =
-		findAddIn(client->player_control, "", list, &error)
+	return findAddIn(client->player_control, "", &filter, &error)
 		? COMMAND_RETURN_OK
 		: print_error(client, error);
-
-	locate_item_list_free(list);
-
-	return ret;
 }
 
 enum command_return
@@ -130,45 +117,31 @@ handle_searchaddpl(struct client *client, int argc, char *argv[])
 {
 	const char *playlist = argv[1];
 
-	struct locate_item_list *list =
-		locate_item_list_parse(argv + 2, argc - 2, true);
-
-	if (list == NULL) {
+	SongFilter filter;
+	if (!filter.Parse(argc - 2, argv + 2, true)) {
 		command_error(client, ACK_ERROR_ARG, "incorrect arguments");
 		return COMMAND_RETURN_ERROR;
 	}
 
 	GError *error = NULL;
-	enum command_return ret =
-		search_add_to_playlist("", playlist, list, &error)
+	return search_add_to_playlist("", playlist, &filter, &error)
 		? COMMAND_RETURN_OK
 		: print_error(client, error);
-
-	locate_item_list_free(list);
-
-	return ret;
 }
 
 enum command_return
 handle_count(struct client *client, int argc, char *argv[])
 {
-	struct locate_item_list *list =
-		locate_item_list_parse(argv + 1, argc - 1, false);
-
-	if (list == NULL) {
+	SongFilter filter;
+	if (!filter.Parse(argc - 1, argv + 1, false)) {
 		command_error(client, ACK_ERROR_ARG, "incorrect arguments");
 		return COMMAND_RETURN_ERROR;
 	}
 
 	GError *error = NULL;
-	enum command_return ret =
-		searchStatsForSongsIn(client, "", list, &error)
+	return  searchStatsForSongsIn(client, "", &filter, &error)
 		? COMMAND_RETURN_OK
 		: print_error(client, error);
-
-	locate_item_list_free(list);
-
-	return ret;
 }
 
 enum command_return
@@ -188,7 +161,6 @@ handle_listall(struct client *client, G_GNUC_UNUSED int argc, char *argv[])
 enum command_return
 handle_list(struct client *client, int argc, char *argv[])
 {
-	struct locate_item_list *conditionals;
 	unsigned tagType = locate_parse_type(argv[1]);
 
 	if (tagType == TAG_NUM_OF_ITEM_TYPES) {
@@ -203,6 +175,7 @@ handle_list(struct client *client, int argc, char *argv[])
 	}
 
 	/* for compatibility with < 0.12.0 */
+	SongFilter *filter;
 	if (argc == 3) {
 		if (tagType != TAG_ALBUM) {
 			command_error(client, ACK_ERROR_ARG,
@@ -211,28 +184,25 @@ handle_list(struct client *client, int argc, char *argv[])
 			return COMMAND_RETURN_ERROR;
 		}
 
-		conditionals =
-			locate_item_list_new_single((unsigned)TAG_ARTIST,
-						    argv[2]);
+		filter = new SongFilter((unsigned)TAG_ARTIST, argv[2]);
 	} else if (argc > 2) {
-		conditionals =
-			locate_item_list_parse(argv + 2, argc - 2, false);
-		if (conditionals == NULL) {
+		filter = new SongFilter();
+		if (!filter->Parse(argc - 2, argv + 2, false)) {
+			delete filter;
 			command_error(client, ACK_ERROR_ARG,
 				      "not able to parse args");
 			return COMMAND_RETURN_ERROR;
 		}
 	} else
-		conditionals = nullptr;
+		filter = nullptr;
 
 	GError *error = NULL;
 	enum command_return ret =
-		listAllUniqueTags(client, tagType, conditionals, &error)
+		listAllUniqueTags(client, tagType, filter, &error)
 		? COMMAND_RETURN_OK
 		: print_error(client, error);
 
-	if (conditionals != nullptr)
-		locate_item_list_free(conditionals);
+	delete filter;
 
 	return ret;
 }
diff --git a/src/DatabasePlaylist.cxx b/src/DatabasePlaylist.cxx
index 1faf79dad..f9934bab2 100644
--- a/src/DatabasePlaylist.cxx
+++ b/src/DatabasePlaylist.cxx
@@ -39,14 +39,14 @@ AddSong(const char *playlist_path_utf8,
 
 bool
 search_add_to_playlist(const char *uri, const char *playlist_path_utf8,
-		       const struct locate_item_list *criteria,
+		       const SongFilter *filter,
 		       GError **error_r)
 {
 	const Database *db = GetDatabase(error_r);
 	if (db == nullptr)
 		return false;
 
-	const DatabaseSelection selection(uri, true, criteria);
+	const DatabaseSelection selection(uri, true, filter);
 
 	using namespace std::placeholders;
 	const auto f = std::bind(AddSong, playlist_path_utf8, _1, _2);
diff --git a/src/DatabasePlaylist.hxx b/src/DatabasePlaylist.hxx
index 269585c32..7c6952ffa 100644
--- a/src/DatabasePlaylist.hxx
+++ b/src/DatabasePlaylist.hxx
@@ -23,12 +23,12 @@
 #include "gcc.h"
 #include "gerror.h"
 
-struct locate_item_list;
+class SongFilter;
 
 gcc_nonnull(1,2)
 bool
 search_add_to_playlist(const char *uri, const char *path_utf8,
-		       const struct locate_item_list *criteria,
+		       const SongFilter *filter,
 		       GError **error_r);
 
 #endif
diff --git a/src/DatabasePrint.cxx b/src/DatabasePrint.cxx
index 9ff833ffd..97ff9c12c 100644
--- a/src/DatabasePrint.cxx
+++ b/src/DatabasePrint.cxx
@@ -120,12 +120,12 @@ db_selection_print(struct client *client, const DatabaseSelection &selection,
 		return false;
 
 	using namespace std::placeholders;
-	const auto d = selection.match == nullptr
+	const auto d = selection.filter == nullptr
 		? std::bind(PrintDirectory, client, _1)
 		: VisitDirectory();
 	const auto s = std::bind(full ? PrintSongFull : PrintSongBrief,
 				 client, _1);
-	const auto p = selection.match == nullptr
+	const auto p = selection.filter == nullptr
 		? std::bind(full ? PrintPlaylistFull : PrintPlaylistBrief,
 			    client, _1, _2)
 		: VisitPlaylist();
@@ -155,14 +155,14 @@ stats_visitor_song(SearchStats &stats, song &song)
 
 bool
 searchStatsForSongsIn(struct client *client, const char *name,
-		      const struct locate_item_list *criteria,
+		      const SongFilter *filter,
 		      GError **error_r)
 {
 	const Database *db = GetDatabase(error_r);
 	if (db == nullptr)
 		return false;
 
-	const DatabaseSelection selection(name, true, criteria);
+	const DatabaseSelection selection(name, true, filter);
 
 	SearchStats stats;
 	stats.numberOfSongs = 0;
@@ -211,14 +211,14 @@ PrintUniqueTag(struct client *client, enum tag_type tag_type,
 
 bool
 listAllUniqueTags(struct client *client, int type,
-		  const struct locate_item_list *criteria,
+		  const SongFilter *filter,
 		  GError **error_r)
 {
 	const Database *db = GetDatabase(error_r);
 	if (db == nullptr)
 		return false;
 
-	const DatabaseSelection selection("", true, criteria);
+	const DatabaseSelection selection("", true, filter);
 
 	if (type == LOCATE_TAG_FILE_TYPE) {
 		using namespace std::placeholders;
diff --git a/src/DatabasePrint.hxx b/src/DatabasePrint.hxx
index e9a19cd52..4aacd9363 100644
--- a/src/DatabasePrint.hxx
+++ b/src/DatabasePrint.hxx
@@ -26,7 +26,7 @@
 #include <stdbool.h>
 
 struct client;
-struct locate_item_list;
+class SongFilter;
 struct DatabaseSelection;
 struct db_visitor;
 
@@ -47,13 +47,13 @@ printInfoForAllIn(struct client *client, const char *uri_utf8,
 gcc_nonnull(1,2)
 bool
 searchStatsForSongsIn(struct client *client, const char *name,
-		      const struct locate_item_list *criteria,
+		      const SongFilter *filter,
 		      GError **error_r);
 
 gcc_nonnull(1)
 bool
 listAllUniqueTags(struct client *client, int type,
-		  const struct locate_item_list *criteria,
+		  const SongFilter *filter,
 		  GError **error_r);
 
 #endif
diff --git a/src/DatabaseQueue.cxx b/src/DatabaseQueue.cxx
index 527539401..325748d02 100644
--- a/src/DatabaseQueue.cxx
+++ b/src/DatabaseQueue.cxx
@@ -46,13 +46,13 @@ AddToQueue(struct player_control *pc, song &song, GError **error_r)
 
 bool
 findAddIn(struct player_control *pc, const char *uri,
-	  const struct locate_item_list *criteria, GError **error_r)
+	  const SongFilter *filter, GError **error_r)
 {
 	const Database *db = GetDatabase(error_r);
 	if (db == nullptr)
 		return false;
 
-	const DatabaseSelection selection(uri, true, criteria);
+	const DatabaseSelection selection(uri, true, filter);
 
 	using namespace std::placeholders;
 	const auto f = std::bind(AddToQueue, pc, _1, _2);
diff --git a/src/DatabaseQueue.hxx b/src/DatabaseQueue.hxx
index cf8c3ba5d..21ffe0fb0 100644
--- a/src/DatabaseQueue.hxx
+++ b/src/DatabaseQueue.hxx
@@ -23,12 +23,12 @@
 #include "gcc.h"
 #include "gerror.h"
 
-struct locate_item_list;
+class SongFilter;
 struct player_control;
 
 gcc_nonnull(1,2)
 bool
 findAddIn(struct player_control *pc, const char *name,
-	  const struct locate_item_list *criteria, GError **error_r);
+	  const SongFilter *filter, GError **error_r);
 
 #endif
diff --git a/src/DatabaseSelection.cxx b/src/DatabaseSelection.cxx
index 72c3f9196..bd756f5f9 100644
--- a/src/DatabaseSelection.cxx
+++ b/src/DatabaseSelection.cxx
@@ -23,5 +23,5 @@
 bool
 DatabaseSelection::Match(const song &song) const
 {
-	return match == nullptr || locate_list_song_match(&song, match);
+	return filter == nullptr || filter->Match(song);
 }
diff --git a/src/DatabaseSelection.hxx b/src/DatabaseSelection.hxx
index c5ee5cf0d..3a81c01ec 100644
--- a/src/DatabaseSelection.hxx
+++ b/src/DatabaseSelection.hxx
@@ -25,7 +25,7 @@
 #include <assert.h>
 #include <stddef.h>
 
-struct locate_item_list;
+class SongFilter;
 struct song;
 
 struct DatabaseSelection {
@@ -41,11 +41,11 @@ struct DatabaseSelection {
 	 */
 	bool recursive;
 
-	const locate_item_list *match;
+	const SongFilter *filter;
 
 	DatabaseSelection(const char *_uri, bool _recursive,
-			  const locate_item_list *_match=nullptr)
-		:uri(_uri), recursive(_recursive), match(_match) {
+			  const SongFilter *_filter=nullptr)
+		:uri(_uri), recursive(_recursive), filter(_filter) {
 		assert(uri != NULL);
 	}
 
diff --git a/src/Directory.cxx b/src/Directory.cxx
index d4564d69e..eeba903d1 100644
--- a/src/Directory.cxx
+++ b/src/Directory.cxx
@@ -291,7 +291,7 @@ directory_sort(struct directory *directory)
 }
 
 bool
-directory::Walk(bool recursive, const locate_item_list *match,
+directory::Walk(bool recursive, const SongFilter *filter,
 		VisitDirectory visit_directory, VisitSong visit_song,
 		VisitPlaylist visit_playlist,
 		GError **error_r) const
@@ -301,8 +301,7 @@ directory::Walk(bool recursive, const locate_item_list *match,
 	if (visit_song) {
 		struct song *song;
 		directory_for_each_song(song, this)
-			if ((match == NULL ||
-			     locate_list_song_match(song, match)) &&
+			if ((filter == nullptr || filter->Match(*song)) &&
 			    !visit_song(*song, error_r))
 				return false;
 	}
@@ -321,7 +320,7 @@ directory::Walk(bool recursive, const locate_item_list *match,
 			return false;
 
 		if (recursive &&
-		    !child->Walk(recursive, match,
+		    !child->Walk(recursive, filter,
 				 visit_directory, visit_song, visit_playlist,
 				 error_r))
 			return false;
diff --git a/src/PlaylistPrint.cxx b/src/PlaylistPrint.cxx
index 9ff7f270e..345506d5e 100644
--- a/src/PlaylistPrint.cxx
+++ b/src/PlaylistPrint.cxx
@@ -19,6 +19,7 @@
 
 #include "config.h"
 #include "PlaylistPrint.hxx"
+#include "QueuePrint.hxx"
 
 extern "C" {
 #include "playlist_list.h"
@@ -26,7 +27,6 @@ extern "C" {
 #include "playlist_any.h"
 #include "playlist_song.h"
 #include "playlist.h"
-#include "queue_print.h"
 #include "stored_playlist.h"
 #include "song_print.h"
 #include "song.h"
@@ -91,9 +91,9 @@ playlist_print_current(struct client *client, const struct playlist *playlist)
 
 void
 playlist_print_find(struct client *client, const struct playlist *playlist,
-		    const struct locate_item_list *list)
+		    const SongFilter &filter)
 {
-	queue_find(client, &playlist->queue, list);
+	queue_find(client, &playlist->queue, filter);
 }
 
 void
diff --git a/src/PlaylistPrint.hxx b/src/PlaylistPrint.hxx
index c6be5a93f..ac0712f01 100644
--- a/src/PlaylistPrint.hxx
+++ b/src/PlaylistPrint.hxx
@@ -26,7 +26,7 @@
 
 struct client;
 struct playlist;
-struct locate_item_list;
+class SongFilter;
 
 /**
  * Sends the whole playlist to the client, song URIs only.
@@ -66,7 +66,7 @@ playlist_print_current(struct client *client, const struct playlist *playlist);
  */
 void
 playlist_print_find(struct client *client, const struct playlist *playlist,
-		    const struct locate_item_list *list);
+		    const SongFilter &filter);
 
 /**
  * Print detailed changes since the specified playlist version.
diff --git a/src/QueueCommands.cxx b/src/QueueCommands.cxx
index c47454e08..5dac6a8a0 100644
--- a/src/QueueCommands.cxx
+++ b/src/QueueCommands.cxx
@@ -246,18 +246,13 @@ static enum command_return
 handle_playlist_match(struct client *client, int argc, char *argv[],
 		      bool fold_case)
 {
-	struct locate_item_list *list =
-		locate_item_list_parse(argv + 1, argc - 1, fold_case);
-
-	if (list == NULL) {
+	SongFilter filter;
+	if (!filter.Parse(argc - 1, argv + 1, fold_case)) {
 		command_error(client, ACK_ERROR_ARG, "incorrect arguments");
 		return COMMAND_RETURN_ERROR;
 	}
 
-	playlist_print_find(client, &g_playlist, list);
-
-	locate_item_list_free(list);
-
+	playlist_print_find(client, &g_playlist, filter);
 	return COMMAND_RETURN_OK;
 }
 
diff --git a/src/QueuePrint.cxx b/src/QueuePrint.cxx
index 0a61cc5dd..edac7c7ad 100644
--- a/src/QueuePrint.cxx
+++ b/src/QueuePrint.cxx
@@ -18,10 +18,10 @@
  */
 
 #include "config.h"
+#include "QueuePrint.hxx"
 #include "SongFilter.hxx"
 
 extern "C" {
-#include "queue_print.h"
 #include "queue.h"
 #include "song.h"
 #include "song_print.h"
@@ -96,12 +96,12 @@ queue_print_changes_position(struct client *client, const struct queue *queue,
 
 void
 queue_find(struct client *client, const struct queue *queue,
-	   const struct locate_item_list *criteria)
+	   const SongFilter &filter)
 {
 	for (unsigned i = 0; i < queue_length(queue); i++) {
 		const struct song *song = queue_get(queue, i);
 
-		if (locate_list_song_match(song, criteria))
+		if (filter.Match(*song))
 			queue_print_song_info(client, queue, i);
 	}
 }
diff --git a/src/queue_print.h b/src/QueuePrint.hxx
index 28620c41f..808b8dec1 100644
--- a/src/queue_print.h
+++ b/src/QueuePrint.hxx
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2003-2011 The Music Player Daemon Project
+ * 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
@@ -22,14 +22,14 @@
  * client.
  */
 
-#ifndef QUEUE_PRINT_H
-#define QUEUE_PRINT_H
+#ifndef MPD_QUEUE_PRINT_HXX
+#define MPD_QUEUE_PRINT_HXX
 
 #include <stdint.h>
 
 struct client;
 struct queue;
-struct locate_item_list;
+class SongFilter;
 
 void
 queue_print_info(struct client *client, const struct queue *queue,
@@ -49,6 +49,6 @@ queue_print_changes_position(struct client *client, const struct queue *queue,
 
 void
 queue_find(struct client *client, const struct queue *queue,
-	   const struct locate_item_list *criteria);
+	   const SongFilter &filter);
 
 #endif
diff --git a/src/SongFilter.cxx b/src/SongFilter.cxx
index c99776e18..6803b453e 100644
--- a/src/SongFilter.cxx
+++ b/src/SongFilter.cxx
@@ -35,27 +35,6 @@ extern "C" {
 #define LOCATE_TAG_FILE_KEY_OLD "filename"
 #define LOCATE_TAG_ANY_KEY      "any"
 
-/* struct used for search, find, list queries */
-struct locate_item {
-	uint8_t tag;
-
-	bool fold_case;
-
-	/* what we are looking for */
-	char *needle;
-};
-
-/**
- * An array of struct locate_item objects.
- */
-struct locate_item_list {
-	/** number of items */
-	unsigned length;
-
-	/** this is a variable length array */
-	struct locate_item items[1];
-};
-
 unsigned
 locate_parse_type(const char *str)
 {
@@ -69,107 +48,52 @@ locate_parse_type(const char *str)
 	return tag_name_parse_i(str);
 }
 
-static bool
-locate_item_init(struct locate_item *item,
-		 const char *type_string, const char *needle,
-		 bool fold_case)
-{
-	item->tag = locate_parse_type(type_string);
-
-	if (item->tag == TAG_NUM_OF_ITEM_TYPES)
-		return false;
-
-	item->fold_case = fold_case;
-	item->needle = fold_case
-		? g_utf8_casefold(needle, -1)
-		: g_strdup(needle);
-
-	return true;
-}
-
-void
-locate_item_list_free(struct locate_item_list *list)
+SongFilter::Item::Item(unsigned _tag, const char *_value, bool _fold_case)
+	:tag(_tag), fold_case(_fold_case),
+	 value(fold_case
+	       ? g_utf8_casefold(_value, -1)
+	       : g_strdup(_value))
 {
-	for (unsigned i = 0; i < list->length; ++i)
-		g_free(list->items[i].needle);
-
-	g_free(list);
-}
-
-static struct locate_item_list *
-locate_item_list_new(unsigned length)
-{
-	struct locate_item_list *list = (struct locate_item_list *)
-		g_malloc(sizeof(*list) - sizeof(list->items[0]) +
-			 length * sizeof(list->items[0]));
-	list->length = length;
-
-	return list;
-}
-
-struct locate_item_list *
-locate_item_list_new_single(unsigned tag, const char *needle)
-{
-	struct locate_item_list *list = locate_item_list_new(1);
-	list->items[0].tag = tag;
-	list->items[0].fold_case = false;
-	list->items[0].needle = g_strdup(needle);
-	return list;
 }
 
-struct locate_item_list *
-locate_item_list_parse(char *argv[], unsigned argc, bool fold_case)
+SongFilter::Item::~Item()
 {
-	if (argc == 0 || argc % 2 != 0)
-		return NULL;
-
-	struct locate_item_list *list = locate_item_list_new(argc / 2);
-
-	for (unsigned i = 0; i < list->length; ++i) {
-		if (!locate_item_init(&list->items[i], argv[i * 2],
-				      argv[i * 2 + 1], fold_case)) {
-			locate_item_list_free(list);
-			return NULL;
-		}
-	}
-
-	return list;
+	g_free(value);
 }
 
-gcc_pure
-static bool
-locate_string_match(const struct locate_item *item, const char *value)
+bool
+SongFilter::Item::StringMatch(const char *s) const
 {
-	assert(item != NULL);
-	assert(value != NULL);
+	assert(value != nullptr);
+	assert(s != nullptr);
 
-	if (item->fold_case) {
-		char *p = g_utf8_casefold(value, -1);
-		const bool result = strstr(p, item->needle) != NULL;
+	if (fold_case) {
+		char *p = g_utf8_casefold(s, -1);
+		const bool result = strstr(p, value) != NULL;
 		g_free(p);
 		return result;
 	} else {
-		return strcmp(value, item->needle) == 0;
+		return strcmp(s, value) == 0;
 	}
 }
 
-gcc_pure
-static bool
-locate_tag_match(const struct locate_item *item, const struct tag *tag)
+bool
+SongFilter::Item::Match(const tag_item &item) const
 {
-	assert(item != NULL);
-	assert(tag != NULL);
+	return (tag == LOCATE_TAG_ANY_TYPE || (unsigned)item.type == tag) &&
+		StringMatch(item.value);
+}
 
+bool
+SongFilter::Item::Match(const struct tag &_tag) const
+{
 	bool visited_types[TAG_NUM_OF_ITEM_TYPES];
-	memset(visited_types, 0, sizeof(visited_types));
+	std::fill(visited_types, visited_types + TAG_NUM_OF_ITEM_TYPES, false);
 
-	for (unsigned i = 0; i < tag->num_items; i++) {
-		visited_types[tag->items[i]->type] = true;
-		if (item->tag != LOCATE_TAG_ANY_TYPE &&
-		    tag->items[i]->type != item->tag)
-			continue;
+	for (unsigned i = 0; i < _tag.num_items; i++) {
+		visited_types[_tag.items[i]->type] = true;
 
-		if (locate_string_match(item, tag->items[i]->value))
+		if (Match(*_tag.items[i]))
 			return true;
 	}
 
@@ -179,36 +103,67 @@ locate_tag_match(const struct locate_item *item, const struct tag *tag)
 	 *  empty (first char is a \0), then it's a match as well and
 	 *  we should return true.
 	 */
-	if (*item->needle == 0 && item->tag != LOCATE_TAG_ANY_TYPE &&
-	    !visited_types[item->tag])
+	if (*value == 0 && tag < TAG_NUM_OF_ITEM_TYPES &&
+	    !visited_types[tag])
 		return true;
 
 	return false;
 }
 
-gcc_pure
-static bool
-locate_song_match(const struct locate_item *item, const struct song *song)
+bool
+SongFilter::Item::Match(const song &song) const
 {
-	if (item->tag == LOCATE_TAG_FILE_TYPE ||
-	    item->tag == LOCATE_TAG_ANY_TYPE) {
-		char *uri = song_get_uri(song);
-		const bool result = locate_string_match(item, uri);
+	if (tag == LOCATE_TAG_FILE_TYPE || tag == LOCATE_TAG_ANY_TYPE) {
+		char *uri = song_get_uri(&song);
+		const bool result = StringMatch(uri);
 		g_free(uri);
 
-		if (result || item->tag == LOCATE_TAG_FILE_TYPE)
+		if (result || tag == LOCATE_TAG_FILE_TYPE)
 			return result;
 	}
 
-	return song->tag != NULL && locate_tag_match(item, song->tag);
+	return song.tag != NULL && Match(*song.tag);
+}
+
+SongFilter::SongFilter(unsigned tag, const char *value, bool fold_case)
+{
+	items.push_back(Item(tag, value, fold_case));
+}
+
+SongFilter::~SongFilter()
+{
+	/* this destructor exists here just so it won't get inlined */
+}
+
+bool
+SongFilter::Parse(const char *tag_string, const char *value, bool fold_case)
+{
+	unsigned tag = locate_parse_type(tag_string);
+	if (tag == TAG_NUM_OF_ITEM_TYPES)
+		return false;
+
+	items.push_back(Item(tag, value, fold_case));
+	return true;
+}
+
+bool
+SongFilter::Parse(unsigned argc, char *argv[], bool fold_case)
+{
+	if (argc == 0 || argc % 2 != 0)
+		return false;
+
+	for (unsigned i = 0; i < argc; i += 2)
+		if (!Parse(argv[i], argv[i + 1], fold_case))
+			return false;
+
+	return true;
 }
 
 bool
-locate_list_song_match(const struct song *song,
-		       const struct locate_item_list *criteria)
+SongFilter::Match(const song &song) const
 {
-	for (unsigned i = 0; i < criteria->length; i++)
-		if (!locate_song_match(&criteria->items[i], song))
+	for (const auto &i : items)
+		if (!i.Match(song))
 			return false;
 
 	return true;
diff --git a/src/SongFilter.hxx b/src/SongFilter.hxx
index 38c1dae67..a3068a970 100644
--- a/src/SongFilter.hxx
+++ b/src/SongFilter.hxx
@@ -22,15 +22,82 @@
 
 #include "gcc.h"
 
+#include <list>
+
 #include <stdint.h>
 #include <stdbool.h>
 
 #define LOCATE_TAG_FILE_TYPE	TAG_NUM_OF_ITEM_TYPES+10
 #define LOCATE_TAG_ANY_TYPE     TAG_NUM_OF_ITEM_TYPES+20
 
-struct locate_item_list;
+struct tag;
+struct tag_item;
 struct song;
 
+class SongFilter {
+	class Item {
+		uint8_t tag;
+
+		bool fold_case;
+
+		char *value;
+
+	public:
+		gcc_nonnull(3)
+		Item(unsigned tag, const char *value, bool fold_case=false);
+
+		Item(const Item &other) = delete;
+
+		Item(Item &&other)
+			:tag(other.tag), fold_case(other.fold_case),
+			 value(other.value) {
+			other.value = nullptr;
+		}
+
+		~Item();
+
+		Item &operator=(const Item &other) = delete;
+
+		unsigned GetTag() const {
+			return tag;
+		}
+
+		gcc_pure gcc_nonnull(2)
+		bool StringMatch(const char *s) const;
+
+		gcc_pure
+		bool Match(const tag_item &tag_item) const;
+
+		gcc_pure
+		bool Match(const struct tag &tag) const;
+
+		gcc_pure
+		bool Match(const song &song) const;
+	};
+
+	std::list<Item> items;
+
+public:
+	SongFilter() = default;
+
+	gcc_nonnull(3)
+	SongFilter(unsigned tag, const char *value, bool fold_case=false);
+
+	~SongFilter();
+
+	gcc_nonnull(2,3)
+	bool Parse(const char *tag, const char *value, bool fold_case=false);
+
+	gcc_nonnull(3)
+	bool Parse(unsigned argc, char *argv[], bool fold_case=false);
+
+	gcc_pure
+	bool Match(const tag &tag) const;
+
+	gcc_pure
+	bool Match(const song &song) const;
+};
+
 /**
  * @return #TAG_NUM_OF_ITEM_TYPES on error
  */
@@ -38,23 +105,4 @@ gcc_pure
 unsigned
 locate_parse_type(const char *str);
 
-gcc_malloc
-struct locate_item_list *
-locate_item_list_new_single(unsigned tag, const char *needle);
-
-/* return number of items or -1 on error */
-gcc_nonnull(1)
-struct locate_item_list *
-locate_item_list_parse(char *argv[], unsigned argc, bool fold_case);
-
-gcc_nonnull(1)
-void
-locate_item_list_free(struct locate_item_list *list);
-
-gcc_pure
-gcc_nonnull(1,2)
-bool
-locate_list_song_match(const struct song *song,
-		       const struct locate_item_list *criteria);
-
 #endif
diff --git a/src/db/SimpleDatabasePlugin.cxx b/src/db/SimpleDatabasePlugin.cxx
index 1a16c336f..54441f4cd 100644
--- a/src/db/SimpleDatabasePlugin.cxx
+++ b/src/db/SimpleDatabasePlugin.cxx
@@ -282,7 +282,7 @@ SimpleDatabase::Visit(const DatabaseSelection &selection,
 		return false;
 
 	db_lock();
-	bool ret = directory->Walk(selection.recursive, selection.match,
+	bool ret = directory->Walk(selection.recursive, selection.filter,
 				   visit_directory, visit_song, visit_playlist,
 				   error_r);
 	db_unlock();
diff --git a/src/directory.h b/src/directory.h
index d569fee9e..607e812cd 100644
--- a/src/directory.h
+++ b/src/directory.h
@@ -55,7 +55,10 @@
 
 struct song;
 struct db_visitor;
-struct locate_item_list;
+
+#ifdef __cplusplus
+class SongFilter;
+#endif
 
 struct directory {
 	/**
@@ -97,7 +100,7 @@ struct directory {
 	/**
 	 * Caller must lock #db_mutex.
 	 */
-	bool Walk(bool recursive, const locate_item_list *match,
+	bool Walk(bool recursive, const SongFilter *match,
 		  VisitDirectory visit_directory, VisitSong visit_song,
 		  VisitPlaylist visit_playlist,
 		  GError **error_r) const;