LocateUri: new library to classify URIs in a standard way

src/LocateUri.hxx

@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2003-2015 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_LOCATE_URI_HXX
+#define MPD_LOCATE_URI_HXX
+
+#include "check.h"
+#include "Compiler.h"
+#include "fs/AllocatedPath.hxx"
+
+#ifdef WIN32
+#include <windows.h>
+/* damn you, windows.h! */
+#ifdef ABSOLUTE
+#undef ABSOLUTE
+#endif
+#ifdef RELATIVE
+#undef RELATIVE
+#endif
+#endif
+
+class Domain;
+class Error;
+class Client;
+
+#ifdef ENABLE_DATABASE
+class Storage;
+#endif
+
+struct LocatedUri {
+	enum class Type {
+		/**
+		 * Failed to parse the URI.
+		 */
+		UNKNOWN,
+
+		/**
+		 * An absolute URI with a supported scheme.
+		 */
+		ABSOLUTE,
+
+		/**
+		 * A relative URI path.
+		 */
+		RELATIVE,
+
+		/**
+		 * A local file.  The #path attribute is valid.
+		 */
+		PATH,
+	} type;
+
+	const char *canonical_uri;
+
+	/**
+	 * Contains the local file path if type==FILE.
+	 */
+	AllocatedPath path;
+
+	LocatedUri(Type _type, const char *_uri,
+		   AllocatedPath &&_path=AllocatedPath::Null())
+		:type(_type), canonical_uri(_uri), path(std::move(_path)) {}
+
+	gcc_const
+	static LocatedUri Unknown() {
+		return LocatedUri(Type::UNKNOWN, nullptr);
+	}
+
+	bool IsUnknown() const {
+		return type == Type::UNKNOWN;
+	}
+};
+
+extern const Domain locate_uri_domain;
+
+/**
+ * Classify a URI.
+ *
+ * @param client the #Client that is used to determine whether a local
+ * file is allowed; nullptr disables the check and allows all local
+ * files
+ * @param storage a #Storage instance which may be used to convert
+ * absolute URIs to relative ones, using Storage::MapToRelativeUTF8();
+ * that feature is disabled if this parameter is nullptr
+ */
+LocatedUri
+LocateUri(const char *uri, const Client *client,
+#ifdef ENABLE_DATABASE
+	  const Storage *storage,
+#endif
+	  Error &error);
+
+#endif