song: use C++ compiler

src/Song.cxx

@@ -0,0 +1,110 @@
+/*
+ * Copyright (C) 2003-2011 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 "song.h"
+#include "directory.h"
+
+extern "C" {
+#include "tag.h"
+}
+
+#include <glib.h>
+
+#include <assert.h>
+
+static struct song *
+song_alloc(const char *uri, struct directory *parent)
+{
+	size_t uri_length;
+
+	assert(uri);
+	uri_length = strlen(uri);
+	assert(uri_length);
+
+	struct song *song = (struct song *)
+		g_malloc(sizeof(*song) - sizeof(song->uri) + uri_length + 1);
+
+	song->tag = nullptr;
+	memcpy(song->uri, uri, uri_length + 1);
+	song->parent = parent;
+	song->mtime = 0;
+	song->start_ms = song->end_ms = 0;
+
+	return song;
+}
+
+struct song *
+song_remote_new(const char *uri)
+{
+	return song_alloc(uri, nullptr);
+}
+
+struct song *
+song_file_new(const char *path, struct directory *parent)
+{
+	assert((parent == nullptr) == (*path == '/'));
+
+	return song_alloc(path, parent);
+}
+
+struct song *
+song_replace_uri(struct song *old_song, const char *uri)
+{
+	struct song *new_song = song_alloc(uri, old_song->parent);
+	new_song->tag = old_song->tag;
+	new_song->mtime = old_song->mtime;
+	new_song->start_ms = old_song->start_ms;
+	new_song->end_ms = old_song->end_ms;
+	g_free(old_song);
+	return new_song;
+}
+
+void
+song_free(struct song *song)
+{
+	if (song->tag)
+		tag_free(song->tag);
+	g_free(song);
+}
+
+char *
+song_get_uri(const struct song *song)
+{
+	assert(song != nullptr);
+	assert(*song->uri);
+
+	if (!song_in_database(song) || directory_is_root(song->parent))
+		return g_strdup(song->uri);
+	else
+		return g_strconcat(directory_get_path(song->parent),
+				   "/", song->uri, nullptr);
+}
+
+double
+song_get_duration(const struct song *song)
+{
+	if (song->end_ms > 0)
+		return (song->end_ms - song->start_ms) / 1000.0;
+
+	if (song->tag == nullptr)
+		return 0;
+
+	return song->tag->time - song->start_ms / 1000.0;
+}