DatabasePlugin: add method GetStats()

Optimize the ProxyDatabase by invoking "stats" on the peer, instead of
visiting all songs.

1 files changed, 18 insertions, 63 deletions

diff --git a/src/Stats.cxx b/src/Stats.cxx
index 07273bfd..35c162ef 100644
--- a/src/Stats.cxx
+++ b/src/Stats.cxx
@@ -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
@@ -22,11 +22,8 @@
 extern "C" {
 #include "stats.h"
 #include "database.h"
-#include "tag.h"
-#include "song.h"
 #include "client.h"
 #include "player_control.h"
-#include "strset.h"
 #include "client_internal.h"
 }
 
@@ -34,9 +31,6 @@ extern "C" {
 #include "DatabaseGlue.hxx"
 #include "DatabasePlugin.hxx"
 
-#include <functional>
-#include <set>
-
 struct stats stats;
 
 void stats_global_init(void)
@@ -49,66 +43,27 @@ void stats_global_finish(void)
 	g_timer_destroy(stats.timer);
 }
 
-struct StringLess {
-	gcc_pure
-	bool operator()(const char *a, const char *b) const {
-		return strcmp(a, b) < 0;
-	}
-};
-
-typedef std::set<const char *, StringLess> StringSet;
-
-static void
-visit_tag(StringSet &artists, StringSet &albums, const struct tag *tag)
-{
-	if (tag->time > 0)
-		stats.song_duration += tag->time;
-
-	for (unsigned i = 0; i < tag->num_items; ++i) {
-		const struct tag_item *item = tag->items[i];
-
-		switch (item->type) {
-		case TAG_ARTIST:
-			artists.insert(item->value);
-			break;
-
-		case TAG_ALBUM:
-			albums.insert(item->value);
-			break;
-
-		default:
-			break;
-		}
-	}
-}
-
-static bool
-collect_stats_song(StringSet &artists, StringSet &albums, song &song)
-{
-	++stats.song_count;
-
-	if (song.tag != NULL)
-		visit_tag(artists, albums, song.tag);
-
-	return true;
-}
-
 void stats_update(void)
 {
-	stats.song_count = 0;
-	stats.song_duration = 0;
-	stats.artist_count = 0;
-
-	const DatabaseSelection selection("", true);
+	GError *error = nullptr;
 
-	StringSet artists, albums;
-	using namespace std::placeholders;
-	const auto f = std::bind(collect_stats_song,
-				 std::ref(artists), std::ref(albums), _1);
-	GetDatabase()->Visit(selection, f, NULL);
+	DatabaseStats stats2;
 
-	stats.artist_count = artists.size();
-	stats.album_count = albums.size();
+	const DatabaseSelection selection("", true);
+	if (GetDatabase()->GetStats(selection, stats2, &error)) {
+		stats.song_count = stats2.song_count;
+		stats.song_duration = stats2.total_duration;
+		stats.artist_count = stats2.artist_count;
+		stats.album_count = stats2.album_count;
+	} else {
+		g_warning("%s", error->message);
+		g_error_free(error);
+
+		stats.song_count = 0;
+		stats.song_duration = 0;
+		stats.artist_count = 0;
+		stats.album_count = 0;
+	}
 }
 
 int stats_print(struct client *client)