First implementation of set_listing.

Trying to move the depth-first iteration logic into
an iterator-like interface. Work in progress WiP

include/dindexer-machinery/set_listing.hpp

@@ -0,0 +1,108 @@
+/* Copyright 2015, 2016, Michele Santullo
+ * This file is part of "dindexer".
+ *
+ * "dindexer" 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.
+ *
+ * "dindexer" 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 "dindexer".  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "dindexer-machinery/recorddata.hpp"
+#include <vector>
+#include <boost/iterator/iterator_facade.hpp>
+#include <memory>
+
+#ifndef id040FEEC20F7B4F65A3EF67BA6460E737
+#define id040FEEC20F7B4F65A3EF67BA6460E737
+
+namespace mchlib {
+	class PathName;
+
+	namespace implem {
+		class DirIterator : public boost::iterator_facade<DirIterator, FileRecordData, boost::random_access_traversal_tag> {
+			friend class boost::iterator_core_access;
+			typedef boost::iterator_facade<DirIterator, FileRecordData, boost::random_access_traversal_tag> base_class;
+			typedef base_class::difference_type difference_type;
+			typedef base_class::reference reference;
+		public:
+			typedef std::vector<mchlib::FileRecordData>::const_iterator VecIterator;
+
+			DirIterator ( DirIterator&& parOther );
+			DirIterator ( VecIterator parBegin, VecIterator parEnd, std::unique_ptr<PathName>&& parBasePath );
+			~DirIterator ( void ) noexcept;
+
+		private:
+			void increment ( void );
+			void decrement ( void );
+			void advance ( std::size_t parAdvance );
+			difference_type distance_to ( const DirIterator& parOther ) const;
+			bool equal ( const DirIterator& parOther ) const;
+			reference dereference ( void ) const;
+			bool is_end ( void ) const;
+
+			//There are three iterators and an offset because the first item
+			//could very well be detached from the rest of its siblings. For
+			//example "a", "b", "a/c", "a/d": when iterating on that sequence the
+			//expected outcome is "a", "a/c", "a/d". So in order to be able to
+			//iterate back and forward we need a "first" iterator so we can
+			//always get back to it whene we are decrementing an iterator to
+			//"a/c" for example. current is just the current iterator, and the
+			//offset is needed so we can tell if at any moment we are at
+			//first+offset and skip back to first instead of decrementing
+			//current. end is just there so we know when to stop advancing.
+			VecIterator m_first;
+			VecIterator m_current;
+			VecIterator m_end;
+			std::unique_ptr<PathName> m_base_path;
+			std::vector<FileRecordData>::difference_type m_second_offs;
+		};
+	};
+
+	//class SetListingView {
+	//public:
+	//	typedef DirIterator const_iterator;
+
+	//	SetListingView ( SetListing::const_iterator parBeg, SetListing::const_iterator parVeryEnd );
+	//	~SetListingView ( void ) noexcept = default;
+
+	//	const_iterator begin ( void ) const;
+	//	const_iterator cbegin ( void ) const;
+	//	const_iterator end ( void ) const;
+	//	const_iterator cend ( void ) const;
+
+	//	SetListingView
+
+	//private:
+	//	const SetListing::const_iterator m_begin;
+	//	const SetListing::const_iterator m_end;
+	//};
+
+	class SetListing {
+		typedef std::vector<FileRecordData> ListType;
+	public:
+		typedef implem::DirIterator const_iterator;
+
+		explicit SetListing ( ListType&& parList, bool parSort=true );
+		~SetListing ( void ) noexcept;
+
+		const_iterator begin ( void ) const;
+		const_iterator cbegin ( void ) const;
+		const_iterator end ( void ) const;
+		const_iterator cend ( void ) const;
+
+		ListType descend_copy ( const const_iterator& parItem ) const;
+
+	private:
+		ListType m_list;
+	};
+} //namespace mchlib
+
+#endif