SongLoader: new class that merges duplicate code

There was quite a lot of duplicate code for loading DetachedSong
objects, with different semantics for "securely" loading local files.

1 files changed, 102 insertions, 0 deletions

diff --git a/src/SongLoader.cxx b/src/SongLoader.cxx
new file mode 100644
index 000000000..2ed34671c
--- /dev/null
+++ b/src/SongLoader.cxx
@@ -0,0 +1,102 @@
+/*
+ * 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 "SongLoader.hxx"
+#include "client/Client.hxx"
+#include "Mapper.hxx"
+#include "db/DatabaseSong.hxx"
+#include "ls.hxx"
+#include "fs/AllocatedPath.hxx"
+#include "fs/Traits.hxx"
+#include "util/UriUtil.hxx"
+#include "util/Error.hxx"
+#include "DetachedSong.hxx"
+#include "PlaylistError.hxx"
+
+#include <assert.h>
+#include <string.h>
+
+DetachedSong *
+SongLoader::LoadFile(const char *path_utf8, Error &error) const
+{
+#ifdef ENABLE_DATABASE
+	/* TODO fs_charset vs utf8? */
+	const char *suffix = map_to_relative_path(path_utf8);
+	assert(suffix != nullptr);
+
+	if (suffix != path_utf8)
+		/* this path was relative to the music directory -
+		   obtain it from the database */
+		return LoadSong(suffix, error);
+#endif
+
+	if (client != nullptr) {
+		const auto path_fs = AllocatedPath::FromUTF8(path_utf8, error);
+		if (path_fs.IsNull())
+			return nullptr;
+
+		if (!client->AllowFile(path_fs, error))
+			return nullptr;
+	}
+
+	DetachedSong *song = new DetachedSong(path_utf8);
+	if (!song->Update()) {
+		error.Set(playlist_domain, int(PlaylistResult::NO_SUCH_SONG),
+			  "No such file");
+		delete song;
+		return nullptr;
+	}
+
+	return song;
+}
+
+DetachedSong *
+SongLoader::LoadSong(const char *uri_utf8, Error &error) const
+{
+	assert(uri_utf8 != nullptr);
+
+	if (memcmp(uri_utf8, "file:///", 8) == 0)
+		/* absolute path */
+		return LoadFile(uri_utf8 + 7, error);
+	else if (PathTraitsUTF8::IsAbsolute(uri_utf8))
+		/* absolute path */
+		return LoadFile(uri_utf8, error);
+	else if (uri_has_scheme(uri_utf8)) {
+		/* remove URI */
+		if (!uri_supported_scheme(uri_utf8)) {
+			error.Set(playlist_domain,
+				  int(PlaylistResult::NO_SUCH_SONG),
+				  "Unsupported URI scheme");
+			return nullptr;
+		}
+
+		return new DetachedSong(uri_utf8);
+	} else {
+		/* URI relative to the music directory */
+
+#ifdef ENABLE_DATABASE
+		return DatabaseDetachSong(uri_utf8, error);
+#else
+		error.Set(playlist_domain, int(PlaylistResult::NO_SUCH_SONG),
+			  "No database");
+		return nullptr;
+#endif
+	}
+}