diff --git a/NEWS b/NEWS
index d356b271c..91e57d37d 100644
--- a/NEWS
+++ b/NEWS
@@ -6,7 +6,7 @@ ver 0.19 (not yet released)
- "playlistadd" supports file:///
- "idle" with unrecognized event name fails
- "list" on album artist falls back to the artist tag
- - "list" allows grouping
+ - "list" and "count" allow grouping
* database
- proxy: forward "idle" events
- proxy: copy "Last-Modified" from remote directories
diff --git a/doc/protocol.xml b/doc/protocol.xml
index e1fb08a84..e9c28995b 100644
--- a/doc/protocol.xml
+++ b/doc/protocol.xml
@@ -1493,12 +1493,15 @@ OK
<title>The music database</title>
<variablelist>
+
<varlistentry id="command_count">
<term>
<cmdsynopsis>
<command>count</command>
<arg choice="req"><replaceable>TAG</replaceable></arg>
<arg choice="req"><replaceable>NEEDLE</replaceable></arg>
+ <arg choice="opt">group</arg>
+ <arg choice="opt"><replaceable>GROUPTYPE</replaceable></arg>
</cmdsynopsis>
</term>
<listitem>
@@ -1506,8 +1509,15 @@ OK
Counts the number of songs and their total playtime in
the db matching <varname>TAG</varname> exactly.
</para>
+ <para>
+ The <parameter>group</parameter> keyword may be used to
+ group the results by a tag. The following prints
+ per-artist counts:
+ </para>
+ <programlisting>count group artist</programlisting>
</listitem>
</varlistentry>
+
<varlistentry id="command_find">
<term>
<cmdsynopsis>
diff --git a/src/command/DatabaseCommands.cxx b/src/command/DatabaseCommands.cxx
index 0f23dc959..f41c89c45 100644
--- a/src/command/DatabaseCommands.cxx
+++ b/src/command/DatabaseCommands.cxx
@@ -153,14 +153,28 @@ handle_count(Client &client, int argc, char *argv[])
{
ConstBuffer<const char *> args(argv + 1, argc - 1);
+ TagType group = TAG_NUM_OF_ITEM_TYPES;
+ if (args.size >= 2 && strcmp(args[args.size - 2], "group") == 0) {
+ const char *s = args[args.size - 1];
+ group = tag_name_parse_i(s);
+ if (group == TAG_NUM_OF_ITEM_TYPES) {
+ command_error(client, ACK_ERROR_ARG,
+ "Unknown tag type: %s", s);
+ return CommandResult::ERROR;
+ }
+
+ args.pop_back();
+ args.pop_back();
+ }
+
SongFilter filter;
- if (!filter.Parse(args, false)) {
+ if (!args.IsEmpty() && !filter.Parse(args, false)) {
command_error(client, ACK_ERROR_ARG, "incorrect arguments");
return CommandResult::ERROR;
}
Error error;
- return PrintSongCount(client, "", &filter, error)
+ return PrintSongCount(client, "", &filter, group, error)
? CommandResult::OK
: print_error(client, error);
}
diff --git a/src/db/Count.cxx b/src/db/Count.cxx
index 8c61e4c21..ec3eacd1f 100644
--- a/src/db/Count.cxx
+++ b/src/db/Count.cxx
@@ -23,8 +23,10 @@
#include "Interface.hxx"
#include "client/Client.hxx"
#include "LightSong.hxx"
+#include "tag/Set.hxx"
#include <functional>
+#include <map>
struct SearchStats {
unsigned n_songs;
@@ -34,6 +36,9 @@ struct SearchStats {
:n_songs(0), total_time_s(0) {}
};
+class TagCountMap : public std::map<std::string, SearchStats> {
+};
+
static void
PrintSearchStats(Client &client, const SearchStats &stats)
{
@@ -43,6 +48,18 @@ PrintSearchStats(Client &client, const SearchStats &stats)
stats.n_songs, stats.total_time_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)
{
@@ -52,9 +69,45 @@ stats_visitor_song(SearchStats &stats, const LightSong &song)
return true;
}
+static bool
+CollectGroupCounts(TagCountMap &map, TagType group, const Tag &tag)
+{
+ bool found = false;
+ for (unsigned i = 0; i < tag.num_items; ++i) {
+ const TagItem &item = *tag.items[i];
+
+ if (item.type == group) {
+ auto r = map.insert(std::make_pair(item.value,
+ SearchStats()));
+ SearchStats &s = r.first->second;
+ ++s.n_songs;
+ if (tag.time > 0)
+ s.total_time_s += tag.time;
+
+ 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);
@@ -63,14 +116,32 @@ PrintSongCount(Client &client, const char *name,
const DatabaseSelection selection(name, true, filter);
- SearchStats stats;
+ if (group == TAG_NUM_OF_ITEM_TYPES) {
+ /* no grouping */
- using namespace std::placeholders;
- const auto f = std::bind(stats_visitor_song, std::ref(stats),
- _1);
- if (!db->Visit(selection, f, error))
- return false;
+ 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);
+ }
- PrintSearchStats(client, stats);
return true;
}
diff --git a/src/db/Count.hxx b/src/db/Count.hxx
index 5c5fca1bd..d22a3210d 100644
--- a/src/db/Count.hxx
+++ b/src/db/Count.hxx
@@ -22,6 +22,9 @@
#include "Compiler.h"
+#include <stdint.h>
+
+enum TagType : uint8_t;
class Client;
class SongFilter;
class Error;
@@ -30,6 +33,7 @@ gcc_nonnull(2)
bool
PrintSongCount(Client &client, const char *name,
const SongFilter *filter,
+ TagType group,
Error &error);
#endif