Implement hashing task.

Also get rid of the ShorFileRecordData and put the new LeanBase
class to use.

src/machinery/scantask/hashing.cpp

@@ -0,0 +1,124 @@
+/* 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/scantask/hashing.hpp"
+#include "dindexer-machinery/recorddata.hpp"
+#include "dindexer-machinery/set_listing.hpp"
+#include "pathname.hpp"
+#include <cassert>
+#include <boost/range/empty.hpp>
+#include <boost/utility/string_ref.hpp>
+
+namespace mchlib {
+	namespace {
+
+		void append_to_vec (std::vector<char>& parDest, const TigerHash& parHash, boost::string_ref parString) {
+			const auto old_size = parDest.size();
+			parDest.resize(old_size + sizeof(TigerHash) + parString.size());
+			std::copy(parHash.byte_data, parHash.byte_data + sizeof(TigerHash), parDest.begin() + old_size);
+			std::copy(parString.begin(), parString.end(), parDest.begin() + old_size + sizeof(TigerHash));
+		}
+
+		void append_to_vec (std::vector<char>& parDest, boost::string_ref parString) {
+			const auto old_size = parDest.size();
+			parDest.resize(old_size + parString.size());
+			std::copy(parString.begin(), parString.end(), parDest.begin() + old_size);
+		}
+
+		void hash_dir (FileRecordData& parEntry, MutableSetListingView& parList, bool parIgnoreErrors) {
+			assert(parEntry.is_directory);
+
+			//Build a blob with the hashes and filenames of every directory that
+			//is a direct child of current entry
+			std::vector<char> dir_blob;
+#if defined(INDEXER_VERBOSE)
+			std::cout << "Making initial hash for " << parCurrDir << "...\n";
+#endif
+			for (auto it = parList.begin(); it != parList.end(); ++it) {
+				assert(PathName(parEntry.abs_path) == PathName(it->abs_path).pop_right());
+
+				if (it->is_directory) {
+					auto cd_list = MutableSetListingView(it);
+					assert(boost::empty(cd_list) or cd_list.begin()->abs_path != it->abs_path);
+
+					hash_dir(*it, cd_list, parIgnoreErrors);
+					append_to_vec(dir_blob, it->hash, it->path);
+				}
+				else {
+					append_to_vec(dir_blob, it->path);
+				}
+			}
+			tiger_data(dir_blob, parEntry.hash);
+
+#if defined(INDEXER_VERBOSE)
+			std::cout << "Got intermediate hash for dir " << parCurrDir <<
+				": " << tiger_to_string(parEntry.hash) <<
+				' ' << parEntry.mime_type << '\n';
+#endif
+
+			//Now with the initial hash ready, let's start hashing files, if any
+			for (auto it = first_file(parList); it != parList.end(); ++it) {
+				assert(not it->is_directory);
+#if defined(INDEXER_VERBOSE)
+				std::cout << "Hashing file " << it->abs_path << "...";
+#endif
+				//TODO: notify callback
+				try {
+					tiger_file(it->abs_path, it->hash, parEntry.hash, it->size);
+					it->hash_valid = true;
+				}
+				catch (const std::ios_base::failure& e) {
+					if (parIgnoreErrors) {
+						it->unreadable = true;
+						it->hash = TigerHash {};
+					}
+					else {
+						throw e;
+					}
+				}
+			}
+
+#if defined(INDEXER_VERBOSE)
+			std::cout << "Final hash for dir " << parCurrDir << " is " << tiger_to_string(parEntry.hash) << '\n';
+#endif
+			parEntry.hash_valid = true;
+		}
+	} //unnamed namespace
+
+	namespace scantask {
+		Hashing::Hashing (std::shared_ptr<FileTreeBase> parFileTree, bool parIgnoreErrors) :
+			m_file_tree_task(parFileTree),
+			m_ignore_errors(parIgnoreErrors)
+		{
+			assert(m_file_tree_task);
+		}
+
+		Hashing::~Hashing() noexcept {
+		}
+
+		std::vector<FileRecordData>& Hashing::on_data_get() {
+			return m_file_tree_task->get_or_create();
+		}
+
+		void Hashing::on_data_fill() {
+			std::vector<FileRecordData>& file_list = m_file_tree_task->get_or_create();
+
+			MutableSetListingView recordlist(file_list.begin(), file_list.end(), 0);
+			hash_dir(file_list.front(), recordlist, m_ignore_errors);
+		}
+	} //namespace scantask
+} //namespace mchlib