Move db delete to the postgresql backend lib.

src/backends/postgresql/CMakeLists.txt

@@ -2,6 +2,7 @@ project(${bare_name}-backend-postgresql CXX)
 
 add_library(${PROJECT_NAME} STATIC
 	tag.cpp
+	delete.cpp
 )
 
 #target_include_directories(${PROJECT_NAME}
@@ -11,7 +12,7 @@ add_library(${PROJECT_NAME} STATIC
 
 target_link_libraries(${PROJECT_NAME}
 	PRIVATE ${bare_name}-if
-	PRIVATE pq
+	PRIVATE ${bare_name}-pq
 )
 
 install(TARGETS ${PROJECT_NAME}

src/backends/postgresql/delete.cpp

@@ -0,0 +1,75 @@
+/* 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/delete.hpp"
+#include "pq/connection.hpp"
+#include "dindexer-common/settings.hpp"
+#include "helpers/infix_iterator.hpp"
+#include <sstream>
+#include <utility>
+#include <iterator>
+#include <ciso646>
+#include <boost/range/adaptor/map.hpp>
+#include <boost/range/algorithm/copy.hpp>
+#include <boost/lexical_cast.hpp>
+
+namespace din {
+	namespace {
+		IDDescMap fetch_existing_ids (pq::Connection& parConn, const std::vector<uint32_t>& parIDs) {
+			using boost::lexical_cast;
+
+			IDDescMap retmap;
+			if (parIDs.empty()) {
+				return retmap;
+			}
+
+			std::ostringstream oss;
+			oss << "SELECT \"id\",\"desc\" FROM \"sets\" WHERE \"id\"=";
+			boost::copy(parIDs, infix_ostream_iterator<uint32_t>(oss, " OR \"id\"="));
+			oss << ';';
+
+			auto resultset = parConn.query(oss.str());
+			for (const auto& record : resultset) {
+				retmap[lexical_cast<IDDescMap::key_type>(record["id"])] = record["desc"];
+			}
+			return retmap;
+		}
+	} //unnamed namespace
+
+	void delete_group_from_db (const dinlib::SettingsDB& parDB, const std::vector<uint32_t>& parIDs, ConfirmDeleCallback parConf) {
+		pq::Connection conn(std::string(parDB.username), std::string(parDB.password), std::string(parDB.dbname), std::string(parDB.address), parDB.port);
+		conn.connect();
+		const auto dele_ids = fetch_existing_ids(conn, parIDs);
+		if (dele_ids.empty()) {
+			return;
+		}
+		if (not parConf(dele_ids)) {
+			return;
+		}
+
+		std::vector<std::string> ids;
+		ids.reserve(dele_ids.size());
+		std::ostringstream oss;
+		oss << "BEGIN;\nDELETE FROM \"files\" WHERE \"group_id\"=";
+		boost::copy(dele_ids | boost::adaptors::map_keys, infix_ostream_iterator<uint32_t>(oss, " OR \"group_id\"="));
+		oss << ";\nDELETE FROM \"sets\" WHERE \"id\"=";
+		boost::copy(dele_ids | boost::adaptors::map_keys, infix_ostream_iterator<uint32_t>(oss, " OR \"id\"="));
+		oss << ";\nCOMMIT;";
+
+		conn.query(oss.str());
+	}
+} //namespace din