1 files changed, 151 insertions, 0 deletions
diff --git a/src/db/Count.cxx b/src/db/Count.cxx
new file mode 100644
index 000000000..e5e244a6a
--- /dev/null
+++ b/src/db/Count.cxx
@@ -0,0 +1,151 @@
+/*
+ * Copyright (C) 2003-2014 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 "Count.hxx"
+#include "Selection.hxx"
+#include "Interface.hxx"
+#include "client/Client.hxx"
+#include "LightSong.hxx"
+#include "tag/Tag.hxx"
+
+#include <functional>
+#include <map>
+
+struct SearchStats {
+	unsigned n_songs;
+	std::chrono::duration<std::uint64_t, SongTime::period> total_duration;
+
+	constexpr SearchStats()
+		:n_songs(0), total_duration(0) {}
+};
+
+class TagCountMap : public std::map<std::string, SearchStats> {
+};
+
+static void
+PrintSearchStats(Client &client, const SearchStats &stats)
+{
+	unsigned total_duration_s =
+		std::chrono::duration_cast<std::chrono::seconds>(stats.total_duration).count();
+
+	client_printf(client,
+		      "songs: %u\n"
+		      "playtime: %u\n",
+		      stats.n_songs, total_duration_s);
+}
+
+static void
+Print(Client &client, TagType group, const TagCountMap &m)
+{
+	assert(unsigned(group) < TAG_NUM_OF_ITEM_TYPES);
+
+	for (const auto &i : m) {
+		client_printf(client, "%s: %s\n",
+			      tag_item_names[group], i.first.c_str());
+		PrintSearchStats(client, i.second);
+	}
+}
+
+static bool
+stats_visitor_song(SearchStats &stats, const LightSong &song)
+{
+	stats.n_songs++;
+
+	const auto duration = song.GetDuration();
+	if (!duration.IsNegative())
+		stats.total_duration += duration;
+
+	return true;
+}
+
+static bool
+CollectGroupCounts(TagCountMap &map, TagType group, const Tag &tag)
+{
+	bool found = false;
+	for (const auto &item : tag) {
+		if (item.type == group) {
+			auto r = map.insert(std::make_pair(item.value,
+							   SearchStats()));
+			SearchStats &s = r.first->second;
+			++s.n_songs;
+			if (!tag.duration.IsNegative())
+				s.total_duration += tag.duration;
+
+			found = true;
+		}
+	}
+
+	return found;
+}
+
+static bool
+GroupCountVisitor(TagCountMap &map, TagType group, const LightSong &song)
+{
+	assert(song.tag != nullptr);
+
+	const Tag &tag = *song.tag;
+	if (!CollectGroupCounts(map, group, tag) && group == TAG_ALBUM_ARTIST)
+		/* fall back to "Artist" if no "AlbumArtist" was found */
+		CollectGroupCounts(map, TAG_ARTIST, tag);
+
+	return true;
+}
+
+bool
+PrintSongCount(Client &client, const char *name,
+	       const SongFilter *filter,
+	       TagType group,
+	       Error &error)
+{
+	const Database *db = client.GetDatabase(error);
+	if (db == nullptr)
+		return false;
+
+	const DatabaseSelection selection(name, true, filter);
+
+	if (group == TAG_NUM_OF_ITEM_TYPES) {
+		/* no grouping */
+
+		SearchStats stats;
+
+		using namespace std::placeholders;
+		const auto f = std::bind(stats_visitor_song, std::ref(stats),
+					 _1);
+		if (!db->Visit(selection, f, error))
+			return false;
+
+		PrintSearchStats(client, stats);
+	} else {
+		/* group by the specified tag: store counts in a
+		   std::map */
+
+		TagCountMap map;
+
+		using namespace std::placeholders;
+		const auto f = std::bind(GroupCountVisitor, std::ref(map),
+					 group, _1);
+		if (!db->Visit(selection, f, error))
+			return false;
+
+		Print(client, group, map);
+	}
+
+	return true;
+}