Move db scan functions to the postgresql backend lib.

src/backends/postgresql/scan.cpp

@@ -0,0 +1,147 @@
+/* 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 "backends/postgresql/scan.hpp"
+#include "pq/connection.hpp"
+#include "dindexer-common/settings.hpp"
+#include "dindexer-machinery/recorddata.hpp"
+#include <string>
+#include <sstream>
+#include <utility>
+#include <boost/lexical_cast.hpp>
+#include <exception>
+#include <memory>
+#include <boost/utility/string_ref.hpp>
+#include <chrono>
+
+namespace din {
+	namespace {
+	} //unnamed namespace
+
+	bool read_from_db (mchlib::FileRecordData& parItem, mchlib::SetRecordDataFull& parSet, const dinlib::SettingsDB& parDB, const mchlib::TigerHash& parHash) {
+		using boost::lexical_cast;
+
+		pq::Connection conn(std::string(parDB.username), std::string(parDB.password), std::string(parDB.dbname), std::string(parDB.address), parDB.port);
+		conn.connect();
+
+		uint32_t group_id;
+		{
+			auto resultset = conn.query(
+				"SELECT path,level,group_id,is_directory,is_symlink,size FROM files WHERE hash=$1 LIMIT 1;",
+				tiger_to_string(parHash, true)
+			);
+			if (resultset.empty()) {
+				return false;
+			}
+
+			auto row = resultset[0];
+			parItem.abs_path = row["path"];
+			parItem.hash = parHash;
+			parItem.level = lexical_cast<uint16_t>(row["level"]);
+			parItem.size = lexical_cast<uint64_t>(row["size"]);
+			parItem.is_directory = (row["is_directory"] == "t" ? true : false);
+			parItem.is_symlink = (row["is_symlink"] == "t" ? true : false);
+			group_id = lexical_cast<uint32_t>(row["group_id"]);
+
+			if (parItem.abs_path.size() != 1 or parItem.abs_path != "/") {
+				parItem.abs_path = std::string("/") + parItem.abs_path;
+			}
+			parItem.path_offset = 1;
+		}
+
+		{
+			auto resultset = conn.query(
+				"SELECT \"desc\",\"type\",\"disk_number\" FROM sets WHERE \"id\"=$1;",
+				group_id
+			);
+			if (resultset.empty()) {
+				std::ostringstream err_msg;
+				err_msg << "Missing set: found a record with group_id=" << group_id;
+				err_msg << " but there is no such id in table \"sets\"";
+				throw std::length_error(err_msg.str());
+			}
+			auto row = resultset[0];
+			parSet.type = lexical_cast<char>(row["type"]);
+			parSet.name = row["desc"];
+			parSet.disk_number = lexical_cast<uint32_t>(row["disk_number"]);
+		}
+		return true;
+	}
+
+	void write_to_db (const dinlib::SettingsDB& parDB, const std::vector<mchlib::FileRecordData>& parData, const mchlib::SetRecordData& parSetData, const std::string& parSignature) {
+		using std::chrono::system_clock;
+		using boost::lexical_cast;
+
+		if (parData.empty()) {
+			return;
+		}
+
+		pq::Connection conn(std::string(parDB.username), std::string(parDB.password), std::string(parDB.dbname), std::string(parDB.address), parDB.port);
+		conn.connect();
+
+		conn.query("BEGIN;");
+		uint32_t new_group_id;
+		{
+			auto id_res = conn.query("INSERT INTO \"sets\" "
+				"(\"desc\",\"type\",\"app_name\""
+				",\"content_type\") "
+				"VALUES ($1, $2, $3, $4) RETURNING \"id\";",
+				parSetData.name,
+				boost::string_ref(&parSetData.type, 1),
+				parSignature,
+				boost::string_ref(&parSetData.content_type, 1)
+			);
+			assert(id_res.size() == 1);
+			assert(id_res[0].size() == 1);
+			//TODO: make it possible to get the id directly as a string
+			new_group_id = lexical_cast<uint32_t>(id_res[0][0]);
+		}
+
+		//TODO: remove this empty_path part. This is a temporary fix needed to
+		//work around a bug in libpqtypes for which empty paths are inserted
+		//as null values in the db.
+		const char* const empty_path = "/";
+		const auto empty_path_string = boost::string_ref(empty_path);
+
+		for (std::size_t z = 0; z < parData.size(); ++z) {
+			const std::string query = "INSERT INTO \"files\" (path, hash, "
+				"level, group_id, is_directory, is_symlink, size, "
+				"access_time, modify_time, is_hash_valid, unreadable, "
+				"mimetype, charset) VALUES "
+				"($1, $2, $3, $4, $5, $6, $7, $8, $9, $10, $11, $12, $13);";
+
+			const auto& itm = parData[z];
+			assert(itm.path().data());
+			conn.query(query,
+				(itm.path().empty() ? empty_path_string : itm.path()),
+				tiger_to_string(itm.hash),
+				itm.level,
+				new_group_id,
+				itm.is_directory,
+				itm.is_symlink,
+				itm.size,
+				system_clock::from_time_t(itm.atime),
+				system_clock::from_time_t(itm.mtime),
+				itm.hash_valid,
+				itm.unreadable,
+				itm.mime_type(),
+				itm.mime_charset()
+			);
+		}
+		conn.query("COMMIT;");
+	}
+} //namespace din