Moved some files around and added new Resource class

1 files changed, 129 insertions, 0 deletions

diff --git a/src/core/resource/ResourceLocator.hpp b/src/core/resource/ResourceLocator.hpp
new file mode 100644
index 0000000..39c7b30
--- /dev/null
+++ b/src/core/resource/ResourceLocator.hpp
@@ -0,0 +1,129 @@
+/*
+    Ousía
+    Copyright (C) 2014, 2015  Benjamin Paaßen, Andreas Stöckel
+
+    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 3 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, see <http://www.gnu.org/licenses/>.
+*/
+
+#ifndef _OUSIA_RESOURCE_LOCATOR_HPP_
+#define _OUSIA_RESOURCE_LOCATOR_HPP_
+
+#include <istream>
+#include <memory>
+
+namespace ousia {
+
+/**
+ * A ResourceLocator is a class able to locate resources in some way, usually
+ * on the hard drive.
+ *
+ * We specify this as an abstract superclass to have an interface layer between
+ * the program core and possible future extensions in terms of resource
+ * locations (e.g. online resources, .zip files, etc.).
+ */
+class ResourceLocator {
+public:
+	/**
+	 * This enum contains all possible types of includable resources in Ousía.
+	 */
+	enum class Type {
+		// A Domain description
+		DOMAIN_DESC,
+		// An ECMA/JavaScript
+		SCRIPT,
+		// A Type System
+		TYPESYS,
+		DOCUMENT,
+		ATTRIBUTES,
+		// TODO: Aren't documents and attribute descriptors missing?
+		// TODO: What is the purpose of these two?
+		GENERIC_MODULE,
+		GENERIC_INCLUDE
+	};
+
+	/**
+	 * A Location contains the location of a Resource, e.g. a file path
+	 * on a hard drive. Note that the 'found' flag might be set to false
+	 * indicating that a resource was not found.
+	 */
+	struct Location {
+		const bool found;
+		const ResourceLocator &locator;
+		const Type type;
+		/**
+		 * This is a fully qualified/canonical path to the resource found or
+		 * in an undefined state (possibly empty) if the 'found' flag is set
+		 * to 'false'.
+		 */
+		const std::string location;
+
+		Location(const bool found, const ResourceLocator &locator,
+		         const Type type, const std::string location)
+		    : found(found), locator(locator), type(type), location(location)
+		{
+		}
+
+		/**
+		 * This calls the 'stream' method of the underlying ResourceLocator that
+		 * found this location and returns a stream containing the data of the
+		 * Resource at this location.
+		 *
+		 * @return a stream containing the data of the Resource at this
+		 *         location. This has to be a unique_pointer because the current
+		 *         C++11 compiler does not yet support move semantics for
+		 *         streams.
+		 */
+		std::unique_ptr<std::istream> stream() const
+		{
+			return std::move(locator.stream(location));
+		}
+	};
+
+	/**
+	 * The locate function uses this ResourceLocator to search for a given
+	 * Resource name (path parameter). It returns a Location with the
+	 * 'found' flag set accordingly.
+	 *
+	 * @param path is the resource name.
+	 * @param relativeTo is an already resolved fully qualified name/canonical
+	 *                   path that is to be used as base directory for this
+	 *                   search.
+	 * @param type is the type of this resource.
+	 *
+	 * @return A Location containing either the found location of the
+	 *         Resource and the found flag set to 'true' or an empty location
+	 *         and the found flag set to 'false'.
+	 */
+	virtual Location locate(const std::string &path,
+	                        const std::string &relativeTo,
+	                        const Type type) const = 0;
+
+	/**
+	 * This method returns a strem containing the data of the resource at the
+	 * given location.
+	 *
+	 * @param location is a found location, most likely from a Location.
+	 *
+	 * @return a stream containing the data of the Resource at this
+	 *         location. This has to be a unique_pointer because the current
+	 *         C++11 compiler does not yet support move semantics for
+	 *         streams.
+	 */
+	virtual std::unique_ptr<std::istream> stream(
+	    const std::string &location) const = 0;
+};
+}
+
+#endif /* _RESOURCE_LOCATOR_HPP_ */
+