db/Helpers: split library

Makefile.am

@@ -590,6 +590,7 @@ libdb_plugins_a_SOURCES = \
 	src/PlaylistDatabase.cxx src/PlaylistDatabase.hxx \
 	src/db/Registry.cxx src/db/Registry.hxx \
 	src/db/Helpers.cxx src/db/Helpers.hxx \
+	src/db/UniqueTags.cxx src/db/UniqueTags.hxx \
 	src/db/plugins/simple/DatabaseSave.cxx \
 	src/db/plugins/simple/DatabaseSave.hxx \
 	src/db/plugins/simple/DirectorySave.cxx \

src/db/Helpers.cxx

@@ -22,13 +22,9 @@
 #include "Interface.hxx"
 #include "LightSong.hxx"
 #include "tag/Tag.hxx"
-#include "tag/TagBuilder.hxx"
-#include "tag/Set.hxx"
 
-#include <functional>
 #include <set>
 
-#include <assert.h>
 #include <string.h>
 
 struct StringLess {
@@ -40,38 +36,6 @@ struct StringLess {
 
 typedef std::set<const char *, StringLess> StringSet;
 
-static bool
-CollectTags(TagSet &set, TagType tag_type, uint32_t group_mask,
-	    const LightSong &song)
-{
-	assert(song.tag != nullptr);
-	const Tag &tag = *song.tag;
-
-	set.InsertUnique(tag, tag_type, group_mask);
-	return true;
-}
-
-bool
-VisitUniqueTags(const Database &db, const DatabaseSelection &selection,
-		TagType tag_type, uint32_t group_mask,
-		VisitTag visit_tag,
-		Error &error)
-{
-	TagSet set;
-
-	using namespace std::placeholders;
-	const auto f = std::bind(CollectTags, std::ref(set),
-				 tag_type, group_mask, _1);
-	if (!db.Visit(selection, f, error))
-		return false;
-
-	for (const auto &value : set)
-		if (!visit_tag(value, error))
-			return false;
-
-	return true;
-}
-
 static void
 StatsVisitTag(DatabaseStats &stats, StringSet &artists, StringSet &albums,
 	      const Tag &tag)

src/db/Helpers.hxx

@@ -20,22 +20,11 @@
 #ifndef MPD_MEMORY_DATABASE_PLUGIN_HXX
 #define MPD_MEMORY_DATABASE_PLUGIN_HXX
 
-#include "Visitor.hxx"
-#include "tag/TagType.h"
-
-#include <stdint.h>
-
 class Error;
 class Database;
 struct DatabaseSelection;
 struct DatabaseStats;
 
-bool
-VisitUniqueTags(const Database &db, const DatabaseSelection &selection,
-		TagType tag_type, uint32_t group_mask,
-		VisitTag visit_tag,
-		Error &error);
-
 bool
 GetStats(const Database &db, const DatabaseSelection &selection,
 	 DatabaseStats &stats, Error &error);

src/db/UniqueTags.cxx

@@ -0,0 +1,59 @@
+/*
+ * 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 "UniqueTags.hxx"
+#include "Interface.hxx"
+#include "LightSong.hxx"
+#include "tag/Set.hxx"
+
+#include <functional>
+
+#include <assert.h>
+
+static bool
+CollectTags(TagSet &set, TagType tag_type, uint32_t group_mask,
+	    const LightSong &song)
+{
+	assert(song.tag != nullptr);
+	const Tag &tag = *song.tag;
+
+	set.InsertUnique(tag, tag_type, group_mask);
+	return true;
+}
+
+bool
+VisitUniqueTags(const Database &db, const DatabaseSelection &selection,
+		TagType tag_type, uint32_t group_mask,
+		VisitTag visit_tag,
+		Error &error)
+{
+	TagSet set;
+
+	using namespace std::placeholders;
+	const auto f = std::bind(CollectTags, std::ref(set),
+				 tag_type, group_mask, _1);
+	if (!db.Visit(selection, f, error))
+		return false;
+
+	for (const auto &value : set)
+		if (!visit_tag(value, error))
+			return false;
+
+	return true;
+}

src/db/UniqueTags.hxx

@@ -0,0 +1,38 @@
+/*
+ * 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.
+ */
+
+#ifndef MPD_DB_UNIQUE_TAGS_HXX
+#define MPD_DB_UNIQUE_TAGS_HXX
+
+#include "Visitor.hxx"
+#include "tag/TagType.h"
+
+#include <stdint.h>
+
+class Error;
+class Database;
+struct DatabaseSelection;
+
+bool
+VisitUniqueTags(const Database &db, const DatabaseSelection &selection,
+		TagType tag_type, uint32_t group_mask,
+		VisitTag visit_tag,
+		Error &error);
+
+#endif

src/db/plugins/simple/SimpleDatabasePlugin.cxx

@@ -23,6 +23,7 @@
 #include "db/DatabasePlugin.hxx"
 #include "db/Selection.hxx"
 #include "db/Helpers.hxx"
+#include "db/UniqueTags.hxx"
 #include "db/LightDirectory.hxx"
 #include "Directory.hxx"
 #include "Song.hxx"