Implement a PostgreSQL backend

5 files changed, 426 insertions, 0 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index feca199c1..ea1564eeb 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -189,6 +189,36 @@ if(ENABLE_CURSES)
 	endif()
 endif(ENABLE_CURSES)
 
+option(ENABLE_POSTGRESQL "Enable PostgreSQL backend" TRUE)
+set(USE_POSTGRESQL FALSE)
+
+if(ENABLE_POSTGRESQL)
+	find_program(POSTGRESQL_CONFIG_EXECUTABLE pg_config DOC "pg_config")
+	find_library(POSTGRESQL_LIBRARY pq)
+	if(POSTGRESQL_CONFIG_EXECUTABLE)
+		execute_process(COMMAND ${POSTGRESQL_CONFIG_EXECUTABLE} --includedir-server
+			OUTPUT_VARIABLE POSTGRESQL_SERVER_INCLUDE_DIRS
+			OUTPUT_STRIP_TRAILING_WHITESPACE)
+		execute_process(COMMAND ${POSTGRESQL_CONFIG_EXECUTABLE}
+			OUTPUT_VARIABLE POSTGRESQL_CLIENT_INCLUDE_DIRS
+			OUTPUT_STRIP_TRAILING_WHITESPACE)
+		# This variable is case sensitive for the cmake PostgreSQL module
+		set(PostgreSQL_ADDITIONAL_SEARCH_PATHS ${POSTGRESQL_SERVER_INCLUDE_DIRS} ${POSTGRESQL_CLIENT_INCLUDE_DIRS})
+	endif()
+
+	find_package("PostgreSQL")
+
+	if(POSTGRESQL_FOUND)
+		set(USE_POSTGRESQL TRUE)
+		message(STATUS "PostgreSQL backend enabled")
+		# This variable is case sensitive, don't try to change it to POSTGRESQL_INCLUDE_DIR
+		message(STATUS "PostgreSQL includes: ${PostgreSQL_INCLUDE_DIR}")
+		include_directories(${PostgreSQL_INCLUDE_DIR})
+	else()
+		message(STATUS "PostgreSQL not found!")
+	endif()
+endif(ENABLE_POSTGRESQL)
+
 option(ENABLE_LEVELDB "Enable LevelDB backend" TRUE)
 set(USE_LEVELDB FALSE)
 
@@ -361,6 +391,7 @@ set(common_SRCS
 	craftdef.cpp
 	database-dummy.cpp
 	database-leveldb.cpp
+	database-postgresql.cpp
 	database-redis.cpp
 	database-sqlite3.cpp
 	database.cpp
@@ -592,6 +623,9 @@ if(BUILD_CLIENT)
 	if (USE_CURSES)
 		target_link_libraries(${PROJECT_NAME} ${CURSES_LIBRARIES})
 	endif()
+	if (USE_POSTGRESQL)
+		target_link_libraries(${PROJECT_NAME} ${POSTGRESQL_LIBRARY})
+	endif()
 	if (USE_LEVELDB)
 		target_link_libraries(${PROJECT_NAME} ${LEVELDB_LIBRARY})
 	endif()
@@ -622,6 +656,9 @@ if(BUILD_SERVER)
 	if (USE_CURSES)
 		target_link_libraries(${PROJECT_NAME}server ${CURSES_LIBRARIES})
 	endif()
+	if (USE_POSTGRESQL)
+		target_link_libraries(${PROJECT_NAME}server ${POSTGRESQL_LIBRARY})
+	endif()
 	if (USE_LEVELDB)
 		target_link_libraries(${PROJECT_NAME}server ${LEVELDB_LIBRARY})
 	endif()
diff --git a/src/cmake_config.h.in b/src/cmake_config.h.in
index 018532d13..50f34a0b8 100644
--- a/src/cmake_config.h.in
+++ b/src/cmake_config.h.in
@@ -22,6 +22,7 @@
 #cmakedefine01 USE_CURSES
 #cmakedefine01 USE_LEVELDB
 #cmakedefine01 USE_LUAJIT
+#cmakedefine01 USE_POSTGRESQL
 #cmakedefine01 USE_SPATIAL
 #cmakedefine01 USE_SYSTEM_GMP
 #cmakedefine01 USE_REDIS
diff --git a/src/database-postgresql.cpp b/src/database-postgresql.cpp
new file mode 100644
index 000000000..3b6b42aea
--- /dev/null
+++ b/src/database-postgresql.cpp
@@ -0,0 +1,286 @@
+/*
+Copyright (C) 2016 Loic Blot <loic.blot@unix-experience.fr>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#include "config.h"
+
+#if USE_POSTGRESQL
+
+#include "database-postgresql.h"
+
+#ifdef _WIN32
+        #ifndef WIN32_LEAN_AND_MEAN
+                #define WIN32_LEAN_AND_MEAN
+        #endif
+        // Without this some of the network functions are not found on mingw
+        #ifndef _WIN32_WINNT
+                #define _WIN32_WINNT 0x0501
+        #endif
+        #include <windows.h>
+        #include <winsock2.h>
+#else
+#include <netinet/in.h>
+#endif
+
+#include "log.h"
+#include "exceptions.h"
+#include "settings.h"
+
+Database_PostgreSQL::Database_PostgreSQL(const Settings &conf) :
+	m_connect_string(""),
+	m_conn(NULL),
+	m_pgversion(0)
+{
+	if (!conf.getNoEx("pgsql_connection", m_connect_string)) {
+		throw SettingNotFoundException(
+			"Set pgsql_connection string in world.mt to "
+			"use the postgresql backend\n"
+			"Notes:\n"
+			"pgsql_connection has the following form: \n"
+			"\tpgsql_connection = host=127.0.0.1 port=5432 user=mt_user "
+			"password=mt_password dbname=minetest_world\n"
+			"mt_user should have CREATE TABLE, INSERT, SELECT, UPDATE and "
+			"DELETE rights on the database.\n"
+			"Don't create mt_user as a SUPERUSER!");
+	}
+
+	connectToDatabase();
+}
+
+Database_PostgreSQL::~Database_PostgreSQL()
+{
+	PQfinish(m_conn);
+}
+
+void Database_PostgreSQL::connectToDatabase()
+{
+	m_conn = PQconnectdb(m_connect_string.c_str());
+
+	if (PQstatus(m_conn) != CONNECTION_OK) {
+		throw DatabaseException(std::string(
+			"PostgreSQL database error: ") +
+			PQerrorMessage(m_conn));
+	}
+
+	m_pgversion = PQserverVersion(m_conn);
+
+	/*
+	* We are using UPSERT feature from PostgreSQL 9.5
+	* to have the better performance,
+	* set the minimum version to 90500
+	*/
+	if (m_pgversion < 90500) {
+		throw DatabaseException("PostgreSQL database error: "
+			"Server version 9.5 or greater required.");
+	}
+
+	infostream << "PostgreSQL Database: Version " << m_pgversion
+			<< " Connection made." << std::endl;
+
+	createDatabase();
+	initStatements();
+}
+
+void Database_PostgreSQL::verifyDatabase()
+{
+	if (PQstatus(m_conn) == CONNECTION_OK)
+		return;
+
+	PQreset(m_conn);
+	ping();
+}
+
+void Database_PostgreSQL::ping()
+{
+	if (PQping(m_connect_string.c_str()) != PQPING_OK) {
+		throw DatabaseException(std::string(
+			"PostgreSQL database error: ") +
+			PQerrorMessage(m_conn));
+	}
+}
+
+bool Database_PostgreSQL::initialized() const
+{
+	return (PQstatus(m_conn) == CONNECTION_OK);
+}
+
+void Database_PostgreSQL::initStatements()
+{
+	prepareStatement("read_block",
+			"SELECT data FROM blocks "
+			"WHERE posX = $1::int4 AND posY = $2::int4 AND "
+			"posZ = $3::int4");
+
+	prepareStatement("write_block",
+			"INSERT INTO blocks (posX, posY, posZ, data) VALUES "
+			"($1::int4, $2::int4, $3::int4, $4::bytea) "
+			"ON CONFLICT ON CONSTRAINT blocks_pkey DO "
+			"UPDATE SET data = $4::bytea");
+
+	prepareStatement("delete_block", "DELETE FROM blocks WHERE "
+			"posX = $1::int4 AND posY = $2::int4 AND posZ = $3::int4");
+
+	prepareStatement("list_all_loadable_blocks",
+			"SELECT posX, posY, posZ FROM blocks");
+}
+
+PGresult *Database_PostgreSQL::checkResults(PGresult *result, bool clear)
+{
+	ExecStatusType statusType = PQresultStatus(result);
+
+	switch (statusType) {
+	case PGRES_COMMAND_OK:
+	case PGRES_TUPLES_OK:
+		break;
+	case PGRES_FATAL_ERROR:
+	default:
+		throw DatabaseException(
+			std::string("PostgreSQL database error: ") +
+			PQresultErrorMessage(result));
+	}
+
+	if (clear)
+		PQclear(result);
+
+	return result;
+}
+
+void Database_PostgreSQL::createDatabase()
+{
+	PGresult *result = checkResults(PQexec(m_conn,
+		"SELECT relname FROM pg_class WHERE relname='blocks';"),
+		false);
+
+	// If table doesn't exist, create it
+	if (!PQntuples(result)) {
+		static const char* dbcreate_sql = "CREATE TABLE blocks ("
+			"posX INT NOT NULL,"
+			"posY INT NOT NULL,"
+			"posZ INT NOT NULL,"
+			"data BYTEA,"
+			"PRIMARY KEY (posX,posY,posZ)"
+		");";
+		checkResults(PQexec(m_conn, dbcreate_sql));
+	}
+
+	PQclear(result);
+
+	infostream << "PostgreSQL: Game Database was inited." << std::endl;
+}
+
+
+void Database_PostgreSQL::beginSave()
+{
+	verifyDatabase();
+	checkResults(PQexec(m_conn, "BEGIN;"));
+}
+
+void Database_PostgreSQL::endSave()
+{
+	checkResults(PQexec(m_conn, "COMMIT;"));
+}
+
+bool Database_PostgreSQL::saveBlock(const v3s16 &pos,
+		const std::string &data)
+{
+	// Verify if we don't overflow the platform integer with the mapblock size
+	if (data.size() > INT_MAX) {
+		errorstream << "Database_PostgreSQL::saveBlock: Data truncation! "
+				<< "data.size() over 0xFFFF (== " << data.size()
+				<< ")" << std::endl;
+		return false;
+	}
+
+	verifyDatabase();
+
+	s32 x, y, z;
+	x = htonl(pos.X);
+	y = htonl(pos.Y);
+	z = htonl(pos.Z);
+
+	const void *args[] = { &x, &y, &z, data.c_str() };
+	const int argLen[] = {
+		sizeof(x), sizeof(y), sizeof(z), (int)data.size()
+	};
+	const int argFmt[] = { 1, 1, 1, 1 };
+
+	execPrepared("write_block", ARRLEN(args), args, argLen, argFmt);
+	return true;
+}
+
+void Database_PostgreSQL::loadBlock(const v3s16 &pos,
+		std::string *block)
+{
+	verifyDatabase();
+
+	s32 x, y, z;
+	x = htonl(pos.X);
+	y = htonl(pos.Y);
+	z = htonl(pos.Z);
+
+	const void *args[] = { &x, &y, &z };
+	const int argLen[] = { sizeof(x), sizeof(y), sizeof(z) };
+	const int argFmt[] = { 1, 1, 1 };
+
+	PGresult *results = execPrepared("read_block", ARRLEN(args), args,
+			argLen, argFmt, false);
+
+	*block = "";
+
+	if (PQntuples(results)) {
+		*block = std::string(PQgetvalue(results, 0, 0),
+				PQgetlength(results, 0, 0));
+	}
+
+	PQclear(results);
+}
+
+bool Database_PostgreSQL::deleteBlock(const v3s16 &pos)
+{
+	verifyDatabase();
+
+	s32 x, y, z;
+	x = htonl(pos.X);
+	y = htonl(pos.Y);
+	z = htonl(pos.Z);
+
+	const void *args[] = { &x, &y, &z };
+	const int argLen[] = { sizeof(x), sizeof(y), sizeof(z) };
+	const int argFmt[] = { 1, 1, 1 };
+
+	execPrepared("read_block", ARRLEN(args), args, argLen, argFmt);
+
+	return true;
+}
+
+void Database_PostgreSQL::listAllLoadableBlocks(std::vector<v3s16> &dst)
+{
+	verifyDatabase();
+
+	PGresult *results = execPrepared("list_all_loadable_blocks", 0,
+			NULL, NULL, NULL, false, false);
+
+	int numrows = PQntuples(results);
+
+	for (int row = 0; row < numrows; ++row) {
+		dst.push_back(pg_to_v3s16(results, 0, 0));
+	}
+
+	PQclear(results);
+}
+
+#endif // USE_POSTGRESQL
diff --git a/src/database-postgresql.h b/src/database-postgresql.h
new file mode 100644
index 000000000..1cfa544e3
--- /dev/null
+++ b/src/database-postgresql.h
@@ -0,0 +1,95 @@
+/*
+Minetest
+Copyright (C) 2013 celeron55, Perttu Ahola <celeron55@gmail.com>
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU Lesser General Public License as published by
+the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
+
+You should have received a copy of the GNU Lesser General Public License along
+with this program; if not, write to the Free Software Foundation, Inc.,
+51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+
+#ifndef DATABASE_POSTGRESQL_HEADER
+#define DATABASE_POSTGRESQL_HEADER
+
+#include <string>
+#include <libpq-fe.h>
+#include "database.h"
+#include "util/basic_macros.h"
+
+class Settings;
+
+class Database_PostgreSQL : public Database
+{
+public:
+	Database_PostgreSQL(const Settings &conf);
+	~Database_PostgreSQL();
+
+	void beginSave();
+	void endSave();
+
+	bool saveBlock(const v3s16 &pos, const std::string &data);
+	void loadBlock(const v3s16 &pos, std::string *block);
+	bool deleteBlock(const v3s16 &pos);
+	void listAllLoadableBlocks(std::vector<v3s16> &dst);
+	bool initialized() const;
+
+private:
+	// Database initialization
+	void connectToDatabase();
+	void initStatements();
+	void createDatabase();
+
+	inline void prepareStatement(const std::string &name, const std::string &sql)
+	{
+		checkResults(PQprepare(m_conn, name.c_str(), sql.c_str(), 0, NULL));
+	}
+
+	// Database connectivity checks
+	void ping();
+	void verifyDatabase();
+
+	// Database usage
+	PGresult *checkResults(PGresult *res, bool clear = true);
+
+	inline PGresult *execPrepared(const char *stmtName, const int paramsNumber,
+			const void **params,
+			const int *paramsLengths = NULL, const int *paramsFormats = NULL,
+			bool clear = true, bool nobinary = true)
+	{
+		return checkResults(PQexecPrepared(m_conn, stmtName, paramsNumber,
+			(const char* const*) params, paramsLengths, paramsFormats,
+			nobinary ? 1 : 0), clear);
+	}
+
+	// Conversion helpers
+	inline int pg_to_int(PGresult *res, int row, int col)
+	{
+		return atoi(PQgetvalue(res, row, col));
+	}
+
+	inline v3s16 pg_to_v3s16(PGresult *res, int row, int col)
+	{
+		return v3s16(
+			pg_to_int(res, row, col),
+			pg_to_int(res, row, col + 1),
+			pg_to_int(res, row, col + 2)
+		);
+	}
+
+	// Attributes
+	std::string m_connect_string;
+	PGconn *m_conn;
+	int m_pgversion;
+};
+
+#endif
+
diff --git a/src/map.cpp b/src/map.cpp
index 848d2ef13..03daf4fa8 100644
--- a/src/map.cpp
+++ b/src/map.cpp
@@ -50,6 +50,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #if USE_REDIS
 #include "database-redis.h"
 #endif
+#if USE_POSTGRESQL
+#include "database-postgresql.h"
+#endif
 
 #define PP(x) "("<<(x).X<<","<<(x).Y<<","<<(x).Z<<")"
 
@@ -3240,6 +3243,10 @@ Database *ServerMap::createDatabase(
 	else if (name == "redis")
 		return new Database_Redis(conf);
 	#endif
+	#if USE_POSTGRESQL
+	else if (name == "postgresql")
+		return new Database_PostgreSQL(conf);
+	#endif
 	else
 		throw BaseException(std::string("Database backend ") + name + " not supported.");
 }