Player data to Database (#5475)

* Player data to Database Add player data into databases (SQLite3 & PG only) PostgreSQL & SQLite: better POO Design for databases Add --migrate-players argument to server + deprecation warning * Remove players directory if empty
2017-04-23 14:35:08 +02:00 · 2017-04-23 14:35:08 +02:00 · 29ab20c272
parent dda171d292
commit 29ab20c272
31 changed files with 1555 additions and 378 deletions
--- a/build/android/jni/Android.mk
+++ b/build/android/jni/Android.mk
@ -134,6 +134,7 @@ LOCAL_SRC_FILES := \
 		jni/src/convert_json.cpp                  \
 		jni/src/craftdef.cpp                      \
 		jni/src/database-dummy.cpp                \
+		jni/src/database-files.cpp                \
 		jni/src/database-sqlite3.cpp              \
 		jni/src/database.cpp                      \
 		jni/src/debug.cpp                         \
--- a/builtin/game/chatcommands.lua
+++ b/builtin/game/chatcommands.lua
@ -279,6 +279,31 @@ core.register_chatcommand("auth_reload", {
 	end,
 })

+core.register_chatcommand("remove_player", {
+	params = "<name>",
+	description = "Remove player data",
+	privs = {server=true},
+	func = function(name, param)
+		local toname = param
+		if toname == "" then
+			return false, "Name field required"
+		end
+
+		local rc = core.remove_player(toname)
+
+		if rc == 0 then
+			core.log("action", name .. " removed player data of " .. toname .. ".")
+			return true, "Player \"" .. toname .. "\" removed."
+		elseif rc == 1 then
+			return true, "No such player \"" .. toname .. "\" to remove."
+		elseif rc == 2 then
+			return true, "Player \"" .. toname .. "\" is connected, cannot remove."
+		end
+
+		return false, "Unhandled remove_player return code " .. rc .. ""
+	end,
+})
+
 core.register_chatcommand("teleport", {
 	params = "<X>,<Y>,<Z> | <to_name> | <name> <X>,<Y>,<Z> | <name> <to_name>",
 	description = "Teleport to player or position",
--- a/doc/lua_api.txt
+++ b/doc/lua_api.txt
@ -2599,6 +2599,8 @@ These functions return the leftover itemstack.
 * `minetest.cancel_shutdown_requests()`: cancel current delayed shutdown
 * `minetest.get_server_status()`: returns server status string
 * `minetest.get_server_uptime()`: returns the server uptime in seconds
+* `minetest.remove_player(name)`: remove player from database (if he is not connected).
+    * Returns a code (0: successful, 1: no such player, 2: player is connected)

 ### Bans
 * `minetest.get_ban_list()`: returns the ban list (same as `minetest.get_ban_description("")`)
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@ -377,6 +377,7 @@ set(common_SRCS
 	convert_json.cpp
 	craftdef.cpp
 	database-dummy.cpp
+	database-files.cpp
 	database-leveldb.cpp
 	database-postgresql.cpp
 	database-redis.cpp
--- a/src/client.cpp
+++ b/src/client.cpp
@ -770,7 +770,7 @@ void Client::initLocalMapSaving(const Address &address,

 	fs::CreateAllDirs(world_path);

-	m_localdb = new Database_SQLite3(world_path);
+	m_localdb = new MapDatabaseSQLite3(world_path);
 	m_localdb->beginSave();
 	actionstream << "Local map saving started, map will be saved at '" << world_path << "'" << std::endl;
 }
--- a/src/client.h
+++ b/src/client.h
@ -49,7 +49,7 @@ class ClientMediaDownloader;
 struct MapDrawControl;
 class MtEventManager;
 struct PointedThing;
-class Database;
+class MapDatabase;
 class Minimap;
 struct MinimapMapblock;
 class Camera;
@ -645,7 +645,7 @@ private:
 	LocalClientState m_state;

 	// Used for saving server map to disk client-side
-	Database *m_localdb;
+	MapDatabase *m_localdb;
 	IntervalLimiter m_localdb_save_interval;
 	u16 m_cache_save_interval;

--- a/src/content_sao.cpp
+++ b/src/content_sao.cpp
@ -764,9 +764,10 @@ bool LuaEntitySAO::collideWithObjects() const

 // No prototype, PlayerSAO does not need to be deserialized

-PlayerSAO::PlayerSAO(ServerEnvironment *env_, u16 peer_id_, bool is_singleplayer):
+PlayerSAO::PlayerSAO(ServerEnvironment *env_, RemotePlayer *player_, u16 peer_id_,
+		bool is_singleplayer):
 	UnitSAO(env_, v3f(0,0,0)),
-	m_player(NULL),
+	m_player(player_),
 	m_peer_id(peer_id_),
 	m_inventory(NULL),
 	m_damage(0),
@ -819,7 +820,7 @@ PlayerSAO::~PlayerSAO()
 		delete m_inventory;
 }

-void PlayerSAO::initialize(RemotePlayer *player, const std::set<std::string> &privs)
+void PlayerSAO::finalize(RemotePlayer *player, const std::set<std::string> &privs)
 {
 	assert(player);
 	m_player = player;
--- a/src/content_sao.h
+++ b/src/content_sao.h
@ -194,7 +194,7 @@ class RemotePlayer;
 class PlayerSAO : public UnitSAO
 {
 public:
-	PlayerSAO(ServerEnvironment *env_, u16 peer_id_, bool is_singleplayer);
+	PlayerSAO(ServerEnvironment *env_, RemotePlayer *player_, u16 peer_id_, bool is_singleplayer);
 	~PlayerSAO();
 	ActiveObjectType getType() const
 	{ return ACTIVEOBJECT_TYPE_PLAYER; }
@ -349,7 +349,7 @@ public:
 	bool getCollisionBox(aabb3f *toset) const;
 	bool collideWithObjects() const { return true; }

-	void initialize(RemotePlayer *player, const std::set<std::string> &privs);
+	void finalize(RemotePlayer *player, const std::set<std::string> &privs);

 	v3f getEyePosition() const { return m_base_position + getEyeOffset(); }
 	v3f getEyeOffset() const;
--- a/src/database-dummy.h
+++ b/src/database-dummy.h
@ -25,7 +25,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "database.h"
 #include "irrlichttypes.h"

-class Database_Dummy : public Database
+class Database_Dummy : public MapDatabase, public PlayerDatabase
 {
 public:
 	bool saveBlock(const v3s16 &pos, const std::string &data);
@ -33,6 +33,13 @@ public:
 	bool deleteBlock(const v3s16 &pos);
 	void listAllLoadableBlocks(std::vector<v3s16> &dst);

+	void savePlayer(RemotePlayer *player) {}
+	bool loadPlayer(RemotePlayer *player, PlayerSAO *sao) { return true; }
+	bool removePlayer(const std::string &name) { return true; }
+	void listPlayers(std::vector<std::string> &) {}
+
+	void beginSave() {}
+	void endSave() {}
 private:
 	std::map<s64, std::string> m_database;
 };
--- a/src/database-files.cpp
+++ b/src/database-files.cpp
@ -0,0 +1,179 @@
+/*
+Minetest
+Copyright (C) 2017 nerzhul, 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 <cassert>
+#include <json/json.h>
+#include "database-files.h"
+#include "content_sao.h"
+#include "remoteplayer.h"
+#include "settings.h"
+#include "porting.h"
+#include "filesys.h"
+
+// !!! WARNING !!!
+// This backend is intended to be used on Minetest 0.4.16 only for the transition backend for
+// player files
+
+void PlayerDatabaseFiles::serialize(std::ostringstream &os, RemotePlayer *player)
+{
+	// Utilize a Settings object for storing values
+	Settings args;
+	args.setS32("version", 1);
+	args.set("name", player->getName());
+
+	sanity_check(player->getPlayerSAO());
+	args.setS32("hp", player->getPlayerSAO()->getHP());
+	args.setV3F("position", player->getPlayerSAO()->getBasePosition());
+	args.setFloat("pitch", player->getPlayerSAO()->getPitch());
+	args.setFloat("yaw", player->getPlayerSAO()->getYaw());
+	args.setS32("breath", player->getPlayerSAO()->getBreath());
+
+	std::string extended_attrs = "";
+	player->serializeExtraAttributes(extended_attrs);
+	args.set("extended_attributes", extended_attrs);
+
+	args.writeLines(os);
+
+	os << "PlayerArgsEnd\n";
+
+	player->inventory.serialize(os);
+}
+
+void PlayerDatabaseFiles::savePlayer(RemotePlayer *player)
+{
+	std::string savedir = m_savedir + DIR_DELIM;
+	std::string path = savedir + player->getName();
+	bool path_found = false;
+	RemotePlayer testplayer("", NULL);
+
+	for (u32 i = 0; i < PLAYER_FILE_ALTERNATE_TRIES && !path_found; i++) {
+		if (!fs::PathExists(path)) {
+			path_found = true;
+			continue;
+		}
+
+		// Open and deserialize file to check player name
+		std::ifstream is(path.c_str(), std::ios_base::binary);
+		if (!is.good()) {
+			errorstream << "Failed to open " << path << std::endl;
+			return;
+		}
+
+		testplayer.deSerialize(is, path, NULL);
+		is.close();
+		if (strcmp(testplayer.getName(), player->getName()) == 0) {
+			path_found = true;
+			continue;
+		}
+
+		path = savedir + player->getName() + itos(i);
+	}
+
+	if (!path_found) {
+		errorstream << "Didn't find free file for player " << player->getName()
+				<< std::endl;
+		return;
+	}
+
+	// Open and serialize file
+	std::ostringstream ss(std::ios_base::binary);
+	serialize(ss, player);
+	if (!fs::safeWriteToFile(path, ss.str())) {
+		infostream << "Failed to write " << path << std::endl;
+	}
+	player->setModified(false);
+}
+
+bool PlayerDatabaseFiles::removePlayer(const std::string &name)
+{
+	std::string players_path = m_savedir + DIR_DELIM;
+	std::string path = players_path + name;
+
+	RemotePlayer temp_player("", NULL);
+	for (u32 i = 0; i < PLAYER_FILE_ALTERNATE_TRIES; i++) {
+		// Open file and deserialize
+		std::ifstream is(path.c_str(), std::ios_base::binary);
+		if (!is.good())
+			continue;
+
+		temp_player.deSerialize(is, path, NULL);
+		is.close();
+
+		if (temp_player.getName() == name) {
+			fs::DeleteSingleFileOrEmptyDirectory(path);
+			return true;
+		}
+
+		path = players_path + name + itos(i);
+	}
+
+	return false;
+}
+
+bool PlayerDatabaseFiles::loadPlayer(RemotePlayer *player, PlayerSAO *sao)
+{
+	std::string players_path = m_savedir + DIR_DELIM;
+	std::string path = players_path + player->getName();
+
+	const std::string player_to_load = player->getName();
+	for (u32 i = 0; i < PLAYER_FILE_ALTERNATE_TRIES; i++) {
+		// Open file and deserialize
+		std::ifstream is(path.c_str(), std::ios_base::binary);
+		if (!is.good())
+			continue;
+
+		player->deSerialize(is, path, sao);
+		is.close();
+
+		if (player->getName() == player_to_load)
+			return true;
+
+		path = players_path + player_to_load + itos(i);
+	}
+
+	infostream << "Player file for player " << player_to_load << " not found" << std::endl;
+	return false;
+}
+
+void PlayerDatabaseFiles::listPlayers(std::vector<std::string> &res)
+{
+	std::vector<fs::DirListNode> files = fs::GetDirListing(m_savedir);
+	// list files into players directory
+	for (std::vector<fs::DirListNode>::const_iterator it = files.begin(); it !=
+		files.end(); ++it) {
+		// Ignore directories
+		if (it->dir)
+			continue;
+
+		const std::string &filename = it->name;
+		std::string full_path = m_savedir + DIR_DELIM + filename;
+		std::ifstream is(full_path.c_str(), std::ios_base::binary);
+		if (!is.good())
+			continue;
+
+		RemotePlayer player(filename.c_str(), NULL);
+		// Null env & dummy peer_id
+		PlayerSAO playerSAO(NULL, &player, 15789, false);
+
+		player.deSerialize(is, "", &playerSAO);
+		is.close();
+
+		res.push_back(player.getName());
+	}
+}
--- a/src/database-files.h
+++ b/src/database-files.h
@ -0,0 +1,46 @@
+/*
+Minetest
+Copyright (C) 2017 nerzhul, 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.
+*/
+
+#ifndef DATABASE_FILES_HEADER
+#define DATABASE_FILES_HEADER
+
+// !!! WARNING !!!
+// This backend is intended to be used on Minetest 0.4.16 only for the transition backend for
+// player files
+
+#include "database.h"
+
+class PlayerDatabaseFiles : public PlayerDatabase
+{
+public:
+	PlayerDatabaseFiles(const std::string &savedir) : m_savedir(savedir) {}
+	virtual ~PlayerDatabaseFiles() {}
+
+	void savePlayer(RemotePlayer *player);
+	bool loadPlayer(RemotePlayer *player, PlayerSAO *sao);
+	bool removePlayer(const std::string &name);
+	void listPlayers(std::vector<std::string> &res);
+
+private:
+	void serialize(std::ostringstream &os, RemotePlayer *player);
+
+	std::string m_savedir;
+};
+
+#endif
--- a/src/database-leveldb.h
+++ b/src/database-leveldb.h
@ -28,7 +28,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "database.h"
 #include "leveldb/db.h"

-class Database_LevelDB : public Database
+class Database_LevelDB : public MapDatabase
 {
 public:
 	Database_LevelDB(const std::string &savedir);
@ -39,6 +39,8 @@ public:
 	bool deleteBlock(const v3s16 &pos);
 	void listAllLoadableBlocks(std::vector<v3s16> &dst);

+	void beginSave() {}
+	void endSave() {}
 private:
 	leveldb::DB *m_database;
 };
--- a/src/database-postgresql.cpp
+++ b/src/database-postgresql.cpp
@ -39,13 +39,15 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "log.h"
 #include "exceptions.h"
 #include "settings.h"
+#include "content_sao.h"
+#include "remoteplayer.h"

-Database_PostgreSQL::Database_PostgreSQL(const Settings &conf) :
-	m_connect_string(""),
+Database_PostgreSQL::Database_PostgreSQL(const std::string &connect_string) :
+	m_connect_string(connect_string),
 	m_conn(NULL),
 	m_pgversion(0)
 {
-	if (!conf.getNoEx("pgsql_connection", m_connect_string)) {
+	if (m_connect_string.empty()) {
 		throw SettingNotFoundException(
 			"Set pgsql_connection string in world.mt to "
 			"use the postgresql backend\n"
@ -57,8 +59,6 @@ Database_PostgreSQL::Database_PostgreSQL(const Settings &conf) :
 			"DELETE rights on the database.\n"
 			"Don't create mt_user as a SUPERUSER!");
 	}
-
-	connectToDatabase();
 }

 Database_PostgreSQL::~Database_PostgreSQL()
@ -118,40 +118,6 @@ 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");
-
-	if (m_pgversion < 90500) {
-		prepareStatement("write_block_insert",
-			"INSERT INTO blocks (posX, posY, posZ, data) SELECT "
-			"$1::int4, $2::int4, $3::int4, $4::bytea "
-			"WHERE NOT EXISTS (SELECT true FROM blocks "
-			"WHERE posX = $1::int4 AND posY = $2::int4 AND "
-			"posZ = $3::int4)");
-
-		prepareStatement("write_block_update",
-			"UPDATE blocks SET data = $4::bytea "
-			"WHERE posX = $1::int4 AND posY = $2::int4 AND "
-			"posZ = $3::int4");
-	} else {
-		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);
@ -173,30 +139,21 @@ PGresult *Database_PostgreSQL::checkResults(PGresult *result, bool clear)
 	return result;
 }

-void Database_PostgreSQL::createDatabase()
+void Database_PostgreSQL::createTableIfNotExists(const std::string &table_name,
+		const std::string &definition)
 {
-	PGresult *result = checkResults(PQexec(m_conn,
-		"SELECT relname FROM pg_class WHERE relname='blocks';"),
-		false);
+	std::string sql_check_table = "SELECT relname FROM pg_class WHERE relname='" +
+		table_name + "';";
+	PGresult *result = checkResults(PQexec(m_conn, sql_check_table.c_str()), 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));
+		checkResults(PQexec(m_conn, definition.c_str()));
 	}

 	PQclear(result);
-
-	infostream << "PostgreSQL: Game Database was inited." << std::endl;
 }

-
 void Database_PostgreSQL::beginSave()
 {
 	verifyDatabase();
@ -208,14 +165,70 @@ void Database_PostgreSQL::endSave()
 	checkResults(PQexec(m_conn, "COMMIT;"));
 }

-bool Database_PostgreSQL::saveBlock(const v3s16 &pos,
-		const std::string &data)
+MapDatabasePostgreSQL::MapDatabasePostgreSQL(const std::string &connect_string):
+	Database_PostgreSQL(connect_string),
+	MapDatabase()
+{
+	connectToDatabase();
+}
+
+
+void MapDatabasePostgreSQL::createDatabase()
+{
+	createTableIfNotExists("blocks",
+		"CREATE TABLE blocks ("
+			"posX INT NOT NULL,"
+			"posY INT NOT NULL,"
+			"posZ INT NOT NULL,"
+			"data BYTEA,"
+			"PRIMARY KEY (posX,posY,posZ)"
+			");"
+	);
+
+	infostream << "PostgreSQL: Map Database was initialized." << std::endl;
+}
+
+void MapDatabasePostgreSQL::initStatements()
+{
+	prepareStatement("read_block",
+		"SELECT data FROM blocks "
+			"WHERE posX = $1::int4 AND posY = $2::int4 AND "
+			"posZ = $3::int4");
+
+	if (getPGVersion() < 90500) {
+		prepareStatement("write_block_insert",
+			"INSERT INTO blocks (posX, posY, posZ, data) SELECT "
+				"$1::int4, $2::int4, $3::int4, $4::bytea "
+				"WHERE NOT EXISTS (SELECT true FROM blocks "
+				"WHERE posX = $1::int4 AND posY = $2::int4 AND "
+				"posZ = $3::int4)");
+
+		prepareStatement("write_block_update",
+			"UPDATE blocks SET data = $4::bytea "
+				"WHERE posX = $1::int4 AND posY = $2::int4 AND "
+				"posZ = $3::int4");
+	} else {
+		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");
+}
+
+bool MapDatabasePostgreSQL::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;
+			<< "data.size() over 0xFFFFFFFF (== " << data.size()
+			<< ")" << std::endl;
 		return false;
 	}

@ -232,7 +245,7 @@ bool Database_PostgreSQL::saveBlock(const v3s16 &pos,
 	};
 	const int argFmt[] = { 1, 1, 1, 1 };

-	if (m_pgversion < 90500) {
+	if (getPGVersion() < 90500) {
 		execPrepared("write_block_update", ARRLEN(args), args, argLen, argFmt);
 		execPrepared("write_block_insert", ARRLEN(args), args, argLen, argFmt);
 	} else {
@ -241,8 +254,7 @@ bool Database_PostgreSQL::saveBlock(const v3s16 &pos,
 	return true;
 }

-void Database_PostgreSQL::loadBlock(const v3s16 &pos,
-		std::string *block)
+void MapDatabasePostgreSQL::loadBlock(const v3s16 &pos, std::string *block)
 {
 	verifyDatabase();

@ -256,19 +268,17 @@ void Database_PostgreSQL::loadBlock(const v3s16 &pos,
 	const int argFmt[] = { 1, 1, 1 };

 	PGresult *results = execPrepared("read_block", ARRLEN(args), args,
-			argLen, argFmt, false);
+		argLen, argFmt, false);

 	*block = "";

-	if (PQntuples(results)) {
-		*block = std::string(PQgetvalue(results, 0, 0),
-				PQgetlength(results, 0, 0));
-	}
+	if (PQntuples(results))
+		*block = std::string(PQgetvalue(results, 0, 0), PQgetlength(results, 0, 0));

 	PQclear(results);
 }

-bool Database_PostgreSQL::deleteBlock(const v3s16 &pos)
+bool MapDatabasePostgreSQL::deleteBlock(const v3s16 &pos)
 {
 	verifyDatabase();

@ -286,19 +296,339 @@ bool Database_PostgreSQL::deleteBlock(const v3s16 &pos)
 	return true;
 }

-void Database_PostgreSQL::listAllLoadableBlocks(std::vector<v3s16> &dst)
+void MapDatabasePostgreSQL::listAllLoadableBlocks(std::vector<v3s16> &dst)
 {
 	verifyDatabase();

 	PGresult *results = execPrepared("list_all_loadable_blocks", 0,
-			NULL, NULL, NULL, false, false);
+		NULL, NULL, NULL, false, false);

 	int numrows = PQntuples(results);

-	for (int row = 0; row < numrows; ++row) {
+	for (int row = 0; row < numrows; ++row)
 		dst.push_back(pg_to_v3s16(results, 0, 0));
+
+	PQclear(results);
+}
+
+/*
+ * Player Database
+ */
+PlayerDatabasePostgreSQL::PlayerDatabasePostgreSQL(const std::string &connect_string):
+	Database_PostgreSQL(connect_string),
+	PlayerDatabase()
+{
+	connectToDatabase();
+}
+
+
+void PlayerDatabasePostgreSQL::createDatabase()
+{
+	createTableIfNotExists("player",
+		"CREATE TABLE player ("
+			"name VARCHAR(60) NOT NULL,"
+			"pitch NUMERIC(15, 7) NOT NULL,"
+			"yaw NUMERIC(15, 7) NOT NULL,"
+			"posX NUMERIC(15, 7) NOT NULL,"
+			"posY NUMERIC(15, 7) NOT NULL,"
+			"posZ NUMERIC(15, 7) NOT NULL,"
+			"hp INT NOT NULL,"
+			"breath INT NOT NULL,"
+			"creation_date TIMESTAMP WITHOUT TIME ZONE NOT NULL DEFAULT NOW(),"
+			"modification_date TIMESTAMP WITHOUT TIME ZONE NOT NULL DEFAULT NOW(),"
+			"PRIMARY KEY (name)"
+			");"
+	);
+
+	createTableIfNotExists("player_inventories",
+		"CREATE TABLE player_inventories ("
+			"player VARCHAR(60) NOT NULL,"
+			"inv_id INT NOT NULL,"
+			"inv_width INT NOT NULL,"
+			"inv_name TEXT NOT NULL DEFAULT '',"
+			"inv_size INT NOT NULL,"
+			"PRIMARY KEY(player, inv_id),"
+			"CONSTRAINT player_inventories_fkey FOREIGN KEY (player) REFERENCES "
+			"player (name) ON DELETE CASCADE"
+			");"
+	);
+
+	createTableIfNotExists("player_inventory_items",
+		"CREATE TABLE player_inventory_items ("
+			"player VARCHAR(60) NOT NULL,"
+			"inv_id INT NOT NULL,"
+			"slot_id INT NOT NULL,"
+			"item TEXT NOT NULL DEFAULT '',"
+			"PRIMARY KEY(player, inv_id, slot_id),"
+			"CONSTRAINT player_inventory_items_fkey FOREIGN KEY (player) REFERENCES "
+			"player (name) ON DELETE CASCADE"
+			");"
+	);
+
+	createTableIfNotExists("player_metadata",
+		"CREATE TABLE player_metadata ("
+			"player VARCHAR(60) NOT NULL,"
+			"attr VARCHAR(256) NOT NULL,"
+			"value TEXT,"
+			"PRIMARY KEY(player, attr),"
+			"CONSTRAINT player_metadata_fkey FOREIGN KEY (player) REFERENCES "
+			"player (name) ON DELETE CASCADE"
+			");"
+	);
+
+	infostream << "PostgreSQL: Player Database was inited." << std::endl;
+}
+
+void PlayerDatabasePostgreSQL::initStatements()
+{
+	if (getPGVersion() < 90500) {
+		prepareStatement("create_player",
+			"INSERT INTO player(name, pitch, yaw, posX, posY, posZ, hp, breath) VALUES "
+				"($1, $2, $3, $4, $5, $6, $7::int, $8::int)");
+
+		prepareStatement("update_player",
+			"UPDATE SET pitch = $2, yaw = $3, posX = $4, posY = $5, posZ = $6, hp = $7::int, "
+				"breath = $8::int, modification_date = NOW() WHERE name = $1");
+	} else {
+		prepareStatement("save_player",
+			"INSERT INTO player(name, pitch, yaw, posX, posY, posZ, hp, breath) VALUES "
+				"($1, $2, $3, $4, $5, $6, $7::int, $8::int)"
+				"ON CONFLICT ON CONSTRAINT player_pkey DO UPDATE SET pitch = $2, yaw = $3, "
+				"posX = $4, posY = $5, posZ = $6, hp = $7::int, breath = $8::int, "
+				"modification_date = NOW()");
 	}

+	prepareStatement("remove_player", "DELETE FROM player WHERE name = $1");
+
+	prepareStatement("load_player_list", "SELECT name FROM player");
+
+	prepareStatement("remove_player_inventories",
+		"DELETE FROM player_inventories WHERE player = $1");
+
+	prepareStatement("remove_player_inventory_items",
+		"DELETE FROM player_inventory_items WHERE player = $1");
+
+	prepareStatement("add_player_inventory",
+		"INSERT INTO player_inventories (player, inv_id, inv_width, inv_name, inv_size) VALUES "
+			"($1, $2::int, $3::int, $4, $5::int)");
+
+	prepareStatement("add_player_inventory_item",
+		"INSERT INTO player_inventory_items (player, inv_id, slot_id, item) VALUES "
+			"($1, $2::int, $3::int, $4)");
+
+	prepareStatement("load_player_inventories",
+		"SELECT inv_id, inv_width, inv_name, inv_size FROM player_inventories "
+			"WHERE player = $1 ORDER BY inv_id");
+
+	prepareStatement("load_player_inventory_items",
+		"SELECT slot_id, item FROM player_inventory_items WHERE "
+			"player = $1 AND inv_id = $2::int");
+
+	prepareStatement("load_player",
+		"SELECT pitch, yaw, posX, posY, posZ, hp, breath FROM player WHERE name = $1");
+
+	prepareStatement("remove_player_metadata",
+		"DELETE FROM player_metadata WHERE player = $1");
+
+	prepareStatement("save_player_metadata",
+		"INSERT INTO player_metadata (player, attr, value) VALUES ($1, $2, $3)");
+
+	prepareStatement("load_player_metadata",
+		"SELECT attr, value FROM player_metadata WHERE player = $1");
+
+}
+
+bool PlayerDatabasePostgreSQL::playerDataExists(const std::string &playername)
+{
+	verifyDatabase();
+
+	const char *values[] = { playername.c_str() };
+	PGresult *results = execPrepared("load_player", 1, values, false);
+
+	bool res = (PQntuples(results) > 0);
+	PQclear(results);
+	return res;
+}
+
+void PlayerDatabasePostgreSQL::savePlayer(RemotePlayer *player)
+{
+	PlayerSAO* sao = player->getPlayerSAO();
+	if (!sao)
+		return;
+
+	verifyDatabase();
+
+	v3f pos = sao->getBasePosition();
+	std::string pitch = ftos(sao->getPitch());
+	std::string yaw = ftos(sao->getYaw());
+	std::string posx = ftos(pos.X);
+	std::string posy = ftos(pos.Y);
+	std::string posz = ftos(pos.Z);
+	std::string hp = itos(sao->getHP());
+	std::string breath = itos(sao->getBreath());
+	const char *values[] = {
+		player->getName(),
+		pitch.c_str(),
+		yaw.c_str(),
+		posx.c_str(), posy.c_str(), posz.c_str(),
+		hp.c_str(),
+		breath.c_str()
+	};
+
+	const char* rmvalues[] = { player->getName() };
+	beginSave();
+
+	if (getPGVersion() < 90500) {
+		if (!playerDataExists(player->getName()))
+			execPrepared("create_player", 8, values, true, false);
+		else
+			execPrepared("update_player", 8, values, true, false);
+	}
+	else
+		execPrepared("save_player", 8, values, true, false);
+
+	// Write player inventories
+	execPrepared("remove_player_inventories", 1, rmvalues);
+	execPrepared("remove_player_inventory_items", 1, rmvalues);
+
+	std::vector<const InventoryList*> inventory_lists = sao->getInventory()->getLists();
+	for (u16 i = 0; i < inventory_lists.size(); i++) {
+		const InventoryList* list = inventory_lists[i];
+		std::string name = list->getName(), width = itos(list->getWidth()),
+			inv_id = itos(i), lsize = itos(list->getSize());
+
+		const char* inv_values[] = {
+			player->getName(),
+			inv_id.c_str(),
+			width.c_str(),
+			name.c_str(),
+			lsize.c_str()
+		};
+		execPrepared("add_player_inventory", 5, inv_values);
+
+		for (u32 j = 0; j < list->getSize(); j++) {
+			std::ostringstream os;
+			list->getItem(j).serialize(os);
+			std::string itemStr = os.str(), slotId = itos(j);
+
+			const char* invitem_values[] = {
+				player->getName(),
+				inv_id.c_str(),
+				slotId.c_str(),
+				itemStr.c_str()
+			};
+			execPrepared("add_player_inventory_item", 4, invitem_values);
+		}
+	}
+
+	execPrepared("remove_player_metadata", 1, rmvalues);
+	const PlayerAttributes &attrs = sao->getExtendedAttributes();
+	for (PlayerAttributes::const_iterator it = attrs.begin(); it != attrs.end(); ++it) {
+		const char *meta_values[] = {
+			player->getName(),
+			it->first.c_str(),
+			it->second.c_str()
+		};
+		execPrepared("save_player_metadata", 3, meta_values);
+	}
+	endSave();
+}
+
+bool PlayerDatabasePostgreSQL::loadPlayer(RemotePlayer *player, PlayerSAO *sao)
+{
+	sanity_check(sao);
+	verifyDatabase();
+
+	const char *values[] = { player->getName() };
+	PGresult *results = execPrepared("load_player", 1, values, false, false);
+
+	// Player not found, return not found
+	if (!PQntuples(results)) {
+		PQclear(results);
+		return false;
+	}
+
+	sao->setPitch(pg_to_float(results, 0, 0));
+	sao->setYaw(pg_to_float(results, 0, 1));
+	sao->setBasePosition(v3f(
+		pg_to_float(results, 0, 2),
+		pg_to_float(results, 0, 3),
+		pg_to_float(results, 0, 4))
+	);
+	sao->setHPRaw((s16) pg_to_int(results, 0, 5));
+	sao->setBreath((u16) pg_to_int(results, 0, 6), false);
+
+	PQclear(results);
+
+	// Load inventory
+	results = execPrepared("load_player_inventories", 1, values, false, false);
+
+	int resultCount = PQntuples(results);
+
+	for (int row = 0; row < resultCount; ++row) {
+		InventoryList* invList = player->inventory.
+			addList(PQgetvalue(results, row, 2), pg_to_uint(results, row, 3));
+		invList->setWidth(pg_to_uint(results, row, 1));
+
+		u32 invId = pg_to_uint(results, row, 0);
+		std::string invIdStr = itos(invId);
+
+		const char* values2[] = {
+			player->getName(),
+			invIdStr.c_str()
+		};
+		PGresult *results2 = execPrepared("load_player_inventory_items", 2,
+			values2, false, false);
+
+		int resultCount2 = PQntuples(results2);
+		for (int row2 = 0; row2 < resultCount2; row2++) {
+			const std::string itemStr = PQgetvalue(results2, row2, 1);
+			if (itemStr.length() > 0) {
+				ItemStack stack;
+				stack.deSerialize(itemStr);
+				invList->addItem(pg_to_uint(results2, row2, 0), stack);
+			}
+		}
+		PQclear(results2);
+	}
+
+	PQclear(results);
+
+	results = execPrepared("load_player_metadata", 1, values, false);
+
+	int numrows = PQntuples(results);
+	for (int row = 0; row < numrows; row++) {
+		sao->setExtendedAttribute(PQgetvalue(results, row, 0),PQgetvalue(results, row, 1));
+	}
+
+	PQclear(results);
+
+	return true;
+}
+
+bool PlayerDatabasePostgreSQL::removePlayer(const std::string &name)
+{
+	if (!playerDataExists(name))
+		return false;
+
+	verifyDatabase();
+
+	const char *values[] = { name.c_str() };
+	execPrepared("remove_player", 1, values);
+
+	return true;
+}
+
+void PlayerDatabasePostgreSQL::listPlayers(std::vector<std::string> &res)
+{
+	verifyDatabase();
+
+	PGresult *results = execPrepared("load_player_list", 0, NULL, false);
+
+	int numrows = PQntuples(results);
+	for (int row = 0; row < numrows; row++)
+		res.push_back(PQgetvalue(results, row, 0));
+
 	PQclear(results);
 }

--- a/src/database-postgresql.h
+++ b/src/database-postgresql.h
@ -27,55 +27,35 @@ with this program; if not, write to the Free Software Foundation, Inc.,

 class Settings;

-class Database_PostgreSQL : public Database
+class Database_PostgreSQL: public Database
 {
 public:
-	Database_PostgreSQL(const Settings &conf);
+	Database_PostgreSQL(const std::string &connect_string);
 	~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);
-	}

+protected:
 	// Conversion helpers
 	inline int pg_to_int(PGresult *res, int row, int col)
 	{
 		return atoi(PQgetvalue(res, row, col));
 	}

+	inline u32 pg_to_uint(PGresult *res, int row, int col)
+	{
+		return (u32) atoi(PQgetvalue(res, row, col));
+	}
+
+	inline float pg_to_float(PGresult *res, int row, int col)
+	{
+		return (float) atof(PQgetvalue(res, row, col));
+	}
+
 	inline v3s16 pg_to_v3s16(PGresult *res, int row, int col)
 	{
 		return v3s16(
@ -85,11 +65,86 @@ private:
 		);
 	}

+	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);
+	}
+
+	inline PGresult *execPrepared(const char *stmtName, const int paramsNumber,
+		const char **params, bool clear = true, bool nobinary = true)
+	{
+		return execPrepared(stmtName, paramsNumber,
+			(const void **)params, NULL, NULL, clear, nobinary);
+	}
+
+	void createTableIfNotExists(const std::string &table_name, const std::string &definition);
+	void verifyDatabase();
+
+	// Database initialization
+	void connectToDatabase();
+	virtual void createDatabase() = 0;
+	virtual void initStatements() = 0;
+	inline void prepareStatement(const std::string &name, const std::string &sql)
+	{
+		checkResults(PQprepare(m_conn, name.c_str(), sql.c_str(), 0, NULL));
+	}
+
+	const int getPGVersion() const { return m_pgversion; }
+private:
+	// Database connectivity checks
+	void ping();
+
+	// Database usage
+	PGresult *checkResults(PGresult *res, bool clear = true);
+
 	// Attributes
 	std::string m_connect_string;
 	PGconn *m_conn;
 	int m_pgversion;
 };

+class MapDatabasePostgreSQL : private Database_PostgreSQL, public MapDatabase
+{
+public:
+	MapDatabasePostgreSQL(const std::string &connect_string);
+	virtual ~MapDatabasePostgreSQL() {}
+
+	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);
+
+	void beginSave() { Database_PostgreSQL::beginSave(); }
+	void endSave() { Database_PostgreSQL::endSave(); }
+
+protected:
+	virtual void createDatabase();
+	virtual void initStatements();
+};
+
+class PlayerDatabasePostgreSQL : private Database_PostgreSQL, public PlayerDatabase
+{
+public:
+	PlayerDatabasePostgreSQL(const std::string &connect_string);
+	virtual ~PlayerDatabasePostgreSQL() {}
+
+	void savePlayer(RemotePlayer *player);
+	bool loadPlayer(RemotePlayer *player, PlayerSAO *sao);
+	bool removePlayer(const std::string &name);
+	void listPlayers(std::vector<std::string> &res);
+
+protected:
+	virtual void createDatabase();
+	virtual void initStatements();
+
+private:
+	bool playerDataExists(const std::string &playername);
+};
+
 #endif

--- a/src/database-redis.h
+++ b/src/database-redis.h
@ -30,7 +30,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,

 class Settings;

-class Database_Redis : public Database
+class Database_Redis : public MapDatabase
 {
 public:
 	Database_Redis(Settings &conf);
--- a/src/database-sqlite3.cpp
+++ b/src/database-sqlite3.cpp
@ -33,6 +33,8 @@ SQLite format specification:
 #include "settings.h"
 #include "porting.h"
 #include "util/string.h"
+#include "content_sao.h"
+#include "remoteplayer.h"

 #include <cassert>

@ -111,27 +113,26 @@ int Database_SQLite3::busyHandler(void *data, int count)
 }


-Database_SQLite3::Database_SQLite3(const std::string &savedir) :
+Database_SQLite3::Database_SQLite3(const std::string &savedir, const std::string &dbname) :
+	m_database(NULL),
 	m_initialized(false),
 	m_savedir(savedir),
-	m_database(NULL),
-	m_stmt_read(NULL),
-	m_stmt_write(NULL),
-	m_stmt_list(NULL),
-	m_stmt_delete(NULL),
+	m_dbname(dbname),
 	m_stmt_begin(NULL),
 	m_stmt_end(NULL)
 {
 }

-void Database_SQLite3::beginSave() {
+void Database_SQLite3::beginSave()
+{
 	verifyDatabase();
 	SQLRES(sqlite3_step(m_stmt_begin), SQLITE_DONE,
 		"Failed to start SQLite3 transaction");
 	sqlite3_reset(m_stmt_begin);
 }

-void Database_SQLite3::endSave() {
+void Database_SQLite3::endSave()
+{
 	verifyDatabase();
 	SQLRES(sqlite3_step(m_stmt_end), SQLITE_DONE,
 		"Failed to commit SQLite3 transaction");
@ -142,7 +143,7 @@ void Database_SQLite3::openDatabase()
 {
 	if (m_database) return;

-	std::string dbp = m_savedir + DIR_DELIM + "map.sqlite";
+	std::string dbp = m_savedir + DIR_DELIM + m_dbname + ".sqlite";

 	// Open the database connection

@ -170,6 +171,8 @@ void Database_SQLite3::openDatabase()
 			 + itos(g_settings->getU16("sqlite_synchronous"));
 	SQLOK(sqlite3_exec(m_database, query_str.c_str(), NULL, NULL, NULL),
 		"Failed to modify sqlite3 synchronous mode");
+	SQLOK(sqlite3_exec(m_database, "PRAGMA foreign_keys = ON", NULL, NULL, NULL),
+		"Failed to enable sqlite3 foreign key support");
 }

 void Database_SQLite3::verifyDatabase()
@ -178,8 +181,61 @@ void Database_SQLite3::verifyDatabase()

 	openDatabase();

-	PREPARE_STATEMENT(begin, "BEGIN");
-	PREPARE_STATEMENT(end, "COMMIT");
+	PREPARE_STATEMENT(begin, "BEGIN;");
+	PREPARE_STATEMENT(end, "COMMIT;");
+
+	initStatements();
+
+	m_initialized = true;
+}
+
+Database_SQLite3::~Database_SQLite3()
+{
+	FINALIZE_STATEMENT(m_stmt_begin)
+	FINALIZE_STATEMENT(m_stmt_end)
+
+	SQLOK_ERRSTREAM(sqlite3_close(m_database), "Failed to close database");
+}
+
+/*
+ * Map database
+ */
+
+MapDatabaseSQLite3::MapDatabaseSQLite3(const std::string &savedir):
+	Database_SQLite3(savedir, "map"),
+	MapDatabase(),
+	m_stmt_read(NULL),
+	m_stmt_write(NULL),
+	m_stmt_list(NULL),
+	m_stmt_delete(NULL)
+{
+
+}
+
+MapDatabaseSQLite3::~MapDatabaseSQLite3()
+{
+	FINALIZE_STATEMENT(m_stmt_read)
+	FINALIZE_STATEMENT(m_stmt_write)
+	FINALIZE_STATEMENT(m_stmt_list)
+	FINALIZE_STATEMENT(m_stmt_delete)
+}
+
+
+void MapDatabaseSQLite3::createDatabase()
+{
+	assert(m_database); // Pre-condition
+
+	SQLOK(sqlite3_exec(m_database,
+		"CREATE TABLE IF NOT EXISTS `blocks` (\n"
+			"	`pos` INT PRIMARY KEY,\n"
+			"	`data` BLOB\n"
+			");\n",
+		NULL, NULL, NULL),
+		"Failed to create database table");
+}
+
+void MapDatabaseSQLite3::initStatements()
+{
 	PREPARE_STATEMENT(read, "SELECT `data` FROM `blocks` WHERE `pos` = ? LIMIT 1");
 #ifdef __ANDROID__
 	PREPARE_STATEMENT(write,  "INSERT INTO `blocks` (`pos`, `data`) VALUES (?, ?)");
@ -189,18 +245,16 @@ void Database_SQLite3::verifyDatabase()
 	PREPARE_STATEMENT(delete, "DELETE FROM `blocks` WHERE `pos` = ?");
 	PREPARE_STATEMENT(list, "SELECT `pos` FROM `blocks`");

-	m_initialized = true;
-
 	verbosestream << "ServerMap: SQLite3 database opened." << std::endl;
 }

-inline void Database_SQLite3::bindPos(sqlite3_stmt *stmt, const v3s16 &pos, int index)
+inline void MapDatabaseSQLite3::bindPos(sqlite3_stmt *stmt, const v3s16 &pos, int index)
 {
 	SQLOK(sqlite3_bind_int64(stmt, index, getBlockAsInteger(pos)),
 		"Internal error: failed to bind query at " __FILE__ ":" TOSTRING(__LINE__));
 }

-bool Database_SQLite3::deleteBlock(const v3s16 &pos)
+bool MapDatabaseSQLite3::deleteBlock(const v3s16 &pos)
 {
 	verifyDatabase();

@ -216,7 +270,7 @@ bool Database_SQLite3::deleteBlock(const v3s16 &pos)
 	return good;
 }

-bool Database_SQLite3::saveBlock(const v3s16 &pos, const std::string &data)
+bool MapDatabaseSQLite3::saveBlock(const v3s16 &pos, const std::string &data)
 {
 	verifyDatabase();

@ -243,7 +297,7 @@ bool Database_SQLite3::saveBlock(const v3s16 &pos, const std::string &data)
 	return true;
 }

-void Database_SQLite3::loadBlock(const v3s16 &pos, std::string *block)
+void MapDatabaseSQLite3::loadBlock(const v3s16 &pos, std::string *block)
 {
 	verifyDatabase();

@ -264,37 +318,312 @@ void Database_SQLite3::loadBlock(const v3s16 &pos, std::string *block)
 	sqlite3_reset(m_stmt_read);
 }

-void Database_SQLite3::createDatabase()
-{
-	assert(m_database); // Pre-condition
-	SQLOK(sqlite3_exec(m_database,
-		"CREATE TABLE IF NOT EXISTS `blocks` (\n"
-		"	`pos` INT PRIMARY KEY,\n"
-		"	`data` BLOB\n"
-		");\n",
-		NULL, NULL, NULL),
-		"Failed to create database table");
-}
-
-void Database_SQLite3::listAllLoadableBlocks(std::vector<v3s16> &dst)
+void MapDatabaseSQLite3::listAllLoadableBlocks(std::vector<v3s16> &dst)
 {
 	verifyDatabase();

-	while (sqlite3_step(m_stmt_list) == SQLITE_ROW) {
+	while (sqlite3_step(m_stmt_list) == SQLITE_ROW)
 		dst.push_back(getIntegerAsBlock(sqlite3_column_int64(m_stmt_list, 0)));
-	}
+
 	sqlite3_reset(m_stmt_list);
 }

-Database_SQLite3::~Database_SQLite3()
-{
-	FINALIZE_STATEMENT(m_stmt_read)
-	FINALIZE_STATEMENT(m_stmt_write)
-	FINALIZE_STATEMENT(m_stmt_list)
-	FINALIZE_STATEMENT(m_stmt_begin)
-	FINALIZE_STATEMENT(m_stmt_end)
-	FINALIZE_STATEMENT(m_stmt_delete)
+/*
+ * Player Database
+ */

-	SQLOK_ERRSTREAM(sqlite3_close(m_database), "Failed to close database");
+PlayerDatabaseSQLite3::PlayerDatabaseSQLite3(const std::string &savedir):
+	Database_SQLite3(savedir, "players"),
+	PlayerDatabase(),
+	m_stmt_player_load(NULL),
+	m_stmt_player_add(NULL),
+	m_stmt_player_update(NULL),
+	m_stmt_player_remove(NULL),
+	m_stmt_player_list(NULL),
+	m_stmt_player_load_inventory(NULL),
+	m_stmt_player_load_inventory_items(NULL),
+	m_stmt_player_add_inventory(NULL),
+	m_stmt_player_add_inventory_items(NULL),
+	m_stmt_player_remove_inventory(NULL),
+	m_stmt_player_remove_inventory_items(NULL),
+	m_stmt_player_metadata_load(NULL),
+	m_stmt_player_metadata_remove(NULL),
+	m_stmt_player_metadata_add(NULL)
+{
+
+}
+PlayerDatabaseSQLite3::~PlayerDatabaseSQLite3()
+{
+	FINALIZE_STATEMENT(m_stmt_player_load)
+	FINALIZE_STATEMENT(m_stmt_player_add)
+	FINALIZE_STATEMENT(m_stmt_player_update)
+	FINALIZE_STATEMENT(m_stmt_player_remove)
+	FINALIZE_STATEMENT(m_stmt_player_list)
+	FINALIZE_STATEMENT(m_stmt_player_add_inventory)
+	FINALIZE_STATEMENT(m_stmt_player_add_inventory_items)
+	FINALIZE_STATEMENT(m_stmt_player_remove_inventory)
+	FINALIZE_STATEMENT(m_stmt_player_remove_inventory_items)
+	FINALIZE_STATEMENT(m_stmt_player_load_inventory)
+	FINALIZE_STATEMENT(m_stmt_player_load_inventory_items)
+	FINALIZE_STATEMENT(m_stmt_player_metadata_load)
+	FINALIZE_STATEMENT(m_stmt_player_metadata_add)
+	FINALIZE_STATEMENT(m_stmt_player_metadata_remove)
+};
+
+
+void PlayerDatabaseSQLite3::createDatabase()
+{
+	assert(m_database); // Pre-condition
+
+	SQLOK(sqlite3_exec(m_database,
+		"CREATE TABLE IF NOT EXISTS `player` ("
+			"`name` VARCHAR(50) NOT NULL,"
+			"`pitch` NUMERIC(11, 4) NOT NULL,"
+			"`yaw` NUMERIC(11, 4) NOT NULL,"
+			"`posX` NUMERIC(11, 4) NOT NULL,"
+			"`posY` NUMERIC(11, 4) NOT NULL,"
+			"`posZ` NUMERIC(11, 4) NOT NULL,"
+			"`hp` INT NOT NULL,"
+			"`breath` INT NOT NULL,"
+			"`creation_date` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,"
+			"`modification_date` DATETIME NOT NULL DEFAULT CURRENT_TIMESTAMP,"
+			"PRIMARY KEY (`name`));",
+		NULL, NULL, NULL),
+		"Failed to create player table");
+
+	SQLOK(sqlite3_exec(m_database,
+		"CREATE TABLE IF NOT EXISTS `player_metadata` ("
+			"    `player` VARCHAR(50) NOT NULL,"
+			"    `metadata` VARCHAR(256) NOT NULL,"
+			"    `value` TEXT,"
+			"    PRIMARY KEY(`player`, `metadata`),"
+			"    FOREIGN KEY (`player`) REFERENCES player (`name`) ON DELETE CASCADE );",
+		NULL, NULL, NULL),
+		"Failed to create player metadata table");
+
+	SQLOK(sqlite3_exec(m_database,
+		"CREATE TABLE IF NOT EXISTS `player_inventories` ("
+			"   `player` VARCHAR(50) NOT NULL,"
+			"	`inv_id` INT NOT NULL,"
+			"	`inv_width` INT NOT NULL,"
+			"	`inv_name` TEXT NOT NULL DEFAULT '',"
+			"	`inv_size` INT NOT NULL,"
+			"	PRIMARY KEY(player, inv_id),"
+			"   FOREIGN KEY (`player`) REFERENCES player (`name`) ON DELETE CASCADE );",
+		NULL, NULL, NULL),
+		"Failed to create player inventory table");
+
+	SQLOK(sqlite3_exec(m_database,
+		"CREATE TABLE `player_inventory_items` ("
+			"   `player` VARCHAR(50) NOT NULL,"
+			"	`inv_id` INT NOT NULL,"
+			"	`slot_id` INT NOT NULL,"
+			"	`item` TEXT NOT NULL DEFAULT '',"
+			"	PRIMARY KEY(player, inv_id, slot_id),"
+			"   FOREIGN KEY (`player`) REFERENCES player (`name`) ON DELETE CASCADE );",
+		NULL, NULL, NULL),
+		"Failed to create player inventory items table");
 }

+void PlayerDatabaseSQLite3::initStatements()
+{
+	PREPARE_STATEMENT(player_load, "SELECT `pitch`, `yaw`, `posX`, `posY`, `posZ`, `hp`, "
+		"`breath`"
+		"FROM `player` WHERE `name` = ?")
+	PREPARE_STATEMENT(player_add, "INSERT INTO `player` (`name`, `pitch`, `yaw`, `posX`, "
+		"`posY`, `posZ`, `hp`, `breath`) VALUES (?, ?, ?, ?, ?, ?, ?, ?)")
+	PREPARE_STATEMENT(player_update, "UPDATE `player` SET `pitch` = ?, `yaw` = ?, "
+			"`posX` = ?, `posY` = ?, `posZ` = ?, `hp` = ?, `breath` = ?, "
+			"`modification_date` = CURRENT_TIMESTAMP WHERE `name` = ?")
+	PREPARE_STATEMENT(player_remove, "DELETE FROM `player` WHERE `name` = ?")
+	PREPARE_STATEMENT(player_list, "SELECT `name` FROM `player`")
+
+	PREPARE_STATEMENT(player_add_inventory, "INSERT INTO `player_inventories` "
+		"(`player`, `inv_id`, `inv_width`, `inv_name`, `inv_size`) VALUES (?, ?, ?, ?, ?)")
+	PREPARE_STATEMENT(player_add_inventory_items, "INSERT INTO `player_inventory_items` "
+		"(`player`, `inv_id`, `slot_id`, `item`) VALUES (?, ?, ?, ?)")
+	PREPARE_STATEMENT(player_remove_inventory, "DELETE FROM `player_inventories` "
+		"WHERE `player` = ?")
+	PREPARE_STATEMENT(player_remove_inventory_items, "DELETE FROM `player_inventory_items` "
+		"WHERE `player` = ?")
+	PREPARE_STATEMENT(player_load_inventory, "SELECT `inv_id`, `inv_width`, `inv_name`, "
+		"`inv_size` FROM `player_inventories` WHERE `player` = ? ORDER BY inv_id")
+	PREPARE_STATEMENT(player_load_inventory_items, "SELECT `slot_id`, `item` "
+		"FROM `player_inventory_items` WHERE `player` = ? AND `inv_id` = ?")
+
+	PREPARE_STATEMENT(player_metadata_load, "SELECT `metadata`, `value` FROM "
+		"`player_metadata` WHERE `player` = ?")
+	PREPARE_STATEMENT(player_metadata_add, "INSERT INTO `player_metadata` "
+		"(`player`, `metadata`, `value`) VALUES (?, ?, ?)")
+	PREPARE_STATEMENT(player_metadata_remove, "DELETE FROM `player_metadata` "
+		"WHERE `player` = ?")
+	verbosestream << "ServerEnvironment: SQLite3 database opened (players)." << std::endl;
+}
+
+bool PlayerDatabaseSQLite3::playerDataExists(const std::string &name)
+{
+	verifyDatabase();
+	str_to_sqlite(m_stmt_player_load, 1, name);
+	bool res = (sqlite3_step(m_stmt_player_load) == SQLITE_ROW);
+	sqlite3_reset(m_stmt_player_load);
+	return res;
+}
+
+void PlayerDatabaseSQLite3::savePlayer(RemotePlayer *player)
+{
+	PlayerSAO* sao = player->getPlayerSAO();
+	sanity_check(sao);
+
+	const v3f &pos = sao->getBasePosition();
+	// Begin save in brace is mandatory
+	if (!playerDataExists(player->getName())) {
+		beginSave();
+		str_to_sqlite(m_stmt_player_add, 1, player->getName());
+		double_to_sqlite(m_stmt_player_add, 2, sao->getPitch());
+		double_to_sqlite(m_stmt_player_add, 3, sao->getYaw());
+		double_to_sqlite(m_stmt_player_add, 4, pos.X);
+		double_to_sqlite(m_stmt_player_add, 5, pos.Y);
+		double_to_sqlite(m_stmt_player_add, 6, pos.Z);
+		int64_to_sqlite(m_stmt_player_add, 7, sao->getHP());
+		int64_to_sqlite(m_stmt_player_add, 8, sao->getBreath());
+
+		sqlite3_vrfy(sqlite3_step(m_stmt_player_add), SQLITE_DONE);
+		sqlite3_reset(m_stmt_player_add);
+	} else {
+		beginSave();
+		double_to_sqlite(m_stmt_player_update, 1, sao->getPitch());
+		double_to_sqlite(m_stmt_player_update, 2, sao->getYaw());
+		double_to_sqlite(m_stmt_player_update, 3, pos.X);
+		double_to_sqlite(m_stmt_player_update, 4, pos.Y);
+		double_to_sqlite(m_stmt_player_update, 5, pos.Z);
+		int64_to_sqlite(m_stmt_player_update, 6, sao->getHP());
+		int64_to_sqlite(m_stmt_player_update, 7, sao->getBreath());
+		str_to_sqlite(m_stmt_player_update, 8, player->getName());
+
+		sqlite3_vrfy(sqlite3_step(m_stmt_player_update), SQLITE_DONE);
+		sqlite3_reset(m_stmt_player_update);
+	}
+
+	// Write player inventories
+	str_to_sqlite(m_stmt_player_remove_inventory, 1, player->getName());
+	sqlite3_vrfy(sqlite3_step(m_stmt_player_remove_inventory), SQLITE_DONE);
+	sqlite3_reset(m_stmt_player_remove_inventory);
+
+	str_to_sqlite(m_stmt_player_remove_inventory_items, 1, player->getName());
+	sqlite3_vrfy(sqlite3_step(m_stmt_player_remove_inventory_items), SQLITE_DONE);
+	sqlite3_reset(m_stmt_player_remove_inventory_items);
+
+	std::vector<const InventoryList*> inventory_lists = sao->getInventory()->getLists();
+	for (u16 i = 0; i < inventory_lists.size(); i++) {
+		const InventoryList* list = inventory_lists[i];
+
+		str_to_sqlite(m_stmt_player_add_inventory, 1, player->getName());
+		int_to_sqlite(m_stmt_player_add_inventory, 2, i);
+		int_to_sqlite(m_stmt_player_add_inventory, 3, list->getWidth());
+		str_to_sqlite(m_stmt_player_add_inventory, 4, list->getName());
+		int_to_sqlite(m_stmt_player_add_inventory, 5, list->getSize());
+		sqlite3_vrfy(sqlite3_step(m_stmt_player_add_inventory), SQLITE_DONE);
+		sqlite3_reset(m_stmt_player_add_inventory);
+
+		for (u32 j = 0; j < list->getSize(); j++) {
+			std::ostringstream os;
+			list->getItem(j).serialize(os);
+			std::string itemStr = os.str();
+
+			str_to_sqlite(m_stmt_player_add_inventory_items, 1, player->getName());
+			int_to_sqlite(m_stmt_player_add_inventory_items, 2, i);
+			int_to_sqlite(m_stmt_player_add_inventory_items, 3, j);
+			str_to_sqlite(m_stmt_player_add_inventory_items, 4, itemStr);
+			sqlite3_vrfy(sqlite3_step(m_stmt_player_add_inventory_items), SQLITE_DONE);
+			sqlite3_reset(m_stmt_player_add_inventory_items);
+		}
+	}
+
+	str_to_sqlite(m_stmt_player_metadata_remove, 1, player->getName());
+	sqlite3_vrfy(sqlite3_step(m_stmt_player_metadata_remove), SQLITE_DONE);
+	sqlite3_reset(m_stmt_player_metadata_remove);
+
+	const PlayerAttributes &attrs = sao->getExtendedAttributes();
+	for (PlayerAttributes::const_iterator it = attrs.begin(); it != attrs.end(); ++it) {
+		str_to_sqlite(m_stmt_player_metadata_add, 1, player->getName());
+		str_to_sqlite(m_stmt_player_metadata_add, 2, it->first);
+		str_to_sqlite(m_stmt_player_metadata_add, 3, it->second);
+		sqlite3_vrfy(sqlite3_step(m_stmt_player_metadata_add), SQLITE_DONE);
+		sqlite3_reset(m_stmt_player_metadata_add);
+	}
+
+	endSave();
+}
+
+bool PlayerDatabaseSQLite3::loadPlayer(RemotePlayer *player, PlayerSAO *sao)
+{
+	verifyDatabase();
+
+	str_to_sqlite(m_stmt_player_load, 1, player->getName());
+	if (sqlite3_step(m_stmt_player_load) != SQLITE_ROW) {
+		sqlite3_reset(m_stmt_player_load);
+		return false;
+	}
+	sao->setPitch(sqlite_to_float(m_stmt_player_load, 0));
+	sao->setYaw(sqlite_to_float(m_stmt_player_load, 1));
+	sao->setBasePosition(sqlite_to_v3f(m_stmt_player_load, 2));
+	sao->setHPRaw((s16) MYMIN(sqlite_to_int(m_stmt_player_load, 5), S16_MAX));
+	sao->setBreath((u16) MYMIN(sqlite_to_int(m_stmt_player_load, 6), U16_MAX), false);
+	sqlite3_reset(m_stmt_player_load);
+
+	// Load inventory
+	str_to_sqlite(m_stmt_player_load_inventory, 1, player->getName());
+	while (sqlite3_step(m_stmt_player_load_inventory) == SQLITE_ROW) {
+		InventoryList *invList = player->inventory.addList(
+			sqlite_to_string(m_stmt_player_load_inventory, 2),
+			sqlite_to_uint(m_stmt_player_load_inventory, 3));
+		invList->setWidth(sqlite_to_uint(m_stmt_player_load_inventory, 1));
+
+		u32 invId = sqlite_to_uint(m_stmt_player_load_inventory, 0);
+
+		str_to_sqlite(m_stmt_player_load_inventory_items, 1, player->getName());
+		int_to_sqlite(m_stmt_player_load_inventory_items, 2, invId);
+		while (sqlite3_step(m_stmt_player_load_inventory_items) == SQLITE_ROW) {
+			const std::string itemStr = sqlite_to_string(m_stmt_player_load_inventory_items, 1);
+			if (itemStr.length() > 0) {
+				ItemStack stack;
+				stack.deSerialize(itemStr);
+				invList->addItem(sqlite_to_uint(m_stmt_player_load_inventory_items, 0), stack);
+			}
+		}
+		sqlite3_reset(m_stmt_player_load_inventory_items);
+	}
+
+	sqlite3_reset(m_stmt_player_load_inventory);
+
+	str_to_sqlite(m_stmt_player_metadata_load, 1, sao->getPlayer()->getName());
+	while (sqlite3_step(m_stmt_player_metadata_load) == SQLITE_ROW) {
+		std::string attr = sqlite_to_string(m_stmt_player_metadata_load, 0);
+		std::string value = sqlite_to_string(m_stmt_player_metadata_load, 1);
+
+		sao->setExtendedAttribute(attr, value);
+	}
+	sqlite3_reset(m_stmt_player_metadata_load);
+	return true;
+}
+
+bool PlayerDatabaseSQLite3::removePlayer(const std::string &name)
+{
+	if (!playerDataExists(name))
+		return false;
+
+	str_to_sqlite(m_stmt_player_remove, 1, name);
+	sqlite3_vrfy(sqlite3_step(m_stmt_player_remove), SQLITE_DONE);
+	sqlite3_reset(m_stmt_player_remove);
+	return true;
+}
+
+void PlayerDatabaseSQLite3::listPlayers(std::vector<std::string> &res)
+{
+	verifyDatabase();
+
+	while (sqlite3_step(m_stmt_player_list) == SQLITE_ROW)
+		res.push_back(sqlite_to_string(m_stmt_player_list, 0));
+
+	sqlite3_reset(m_stmt_player_list);
+}
--- a/src/database-sqlite3.h
+++ b/src/database-sqlite3.h
@ -20,8 +20,10 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #ifndef DATABASE_SQLITE3_HEADER
 #define DATABASE_SQLITE3_HEADER

+#include <cstring>
 #include <string>
 #include "database.h"
+#include "exceptions.h"

 extern "C" {
 #include "sqlite3.h"
@ -30,37 +32,97 @@ extern "C" {
 class Database_SQLite3 : public Database
 {
 public:
-	Database_SQLite3(const std::string &savedir);
-	~Database_SQLite3();
+	virtual ~Database_SQLite3();

 	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 { return m_initialized; }
+protected:
+	Database_SQLite3(const std::string &savedir, const std::string &dbname);

-private:
-	// Open the database
-	void openDatabase();
-	// Create the database structure
-	void createDatabase();
 	// Open and initialize the database if needed
 	void verifyDatabase();

-	void bindPos(sqlite3_stmt *stmt, const v3s16 &pos, int index = 1);
+	// Convertors
+	inline void str_to_sqlite(sqlite3_stmt *s, int iCol, const std::string &str) const
+	{
+		sqlite3_vrfy(sqlite3_bind_text(s, iCol, str.c_str(), str.size(), NULL));
+	}
+
+	inline void str_to_sqlite(sqlite3_stmt *s, int iCol, const char *str) const
+	{
+		sqlite3_vrfy(sqlite3_bind_text(s, iCol, str, strlen(str), NULL));
+	}
+
+	inline void int_to_sqlite(sqlite3_stmt *s, int iCol, int val) const
+	{
+		sqlite3_vrfy(sqlite3_bind_int(s, iCol, val));
+	}
+
+	inline void int64_to_sqlite(sqlite3_stmt *s, int iCol, s64 val) const
+	{
+		sqlite3_vrfy(sqlite3_bind_int64(s, iCol, (sqlite3_int64) val));
+	}
+
+	inline void double_to_sqlite(sqlite3_stmt *s, int iCol, double val) const
+	{
+		sqlite3_vrfy(sqlite3_bind_double(s, iCol, val));
+	}
+
+	inline std::string sqlite_to_string(sqlite3_stmt *s, int iCol)
+	{
+		const char* text = reinterpret_cast<const char*>(sqlite3_column_text(s, iCol));
+		return std::string(text ? text : "");
+	}
+
+	inline s32 sqlite_to_int(sqlite3_stmt *s, int iCol)
+	{
+		return sqlite3_column_int(s, iCol);
+	}
+
+	inline u32 sqlite_to_uint(sqlite3_stmt *s, int iCol)
+	{
+		return (u32) sqlite3_column_int(s, iCol);
+	}
+
+	inline float sqlite_to_float(sqlite3_stmt *s, int iCol)
+	{
+		return (float) sqlite3_column_double(s, iCol);
+	}
+
+	inline const v3f sqlite_to_v3f(sqlite3_stmt *s, int iCol)
+	{
+		return v3f(sqlite_to_float(s, iCol), sqlite_to_float(s, iCol + 1),
+				sqlite_to_float(s, iCol + 2));
+	}
+
+	// Query verifiers helpers
+	inline void sqlite3_vrfy(int s, const std::string &m = "", int r = SQLITE_OK) const
+	{
+		if (s != r)
+			throw DatabaseException(m + ": " + sqlite3_errmsg(m_database));
+	}
+
+	inline void sqlite3_vrfy(const int s, const int r, const std::string &m = "") const
+	{
+		sqlite3_vrfy(s, m, r);
+	}
+
+	// Create the database structure
+	virtual void createDatabase() = 0;
+	virtual void initStatements() = 0;
+
+	sqlite3 *m_database;
+private:
+	// Open the database
+	void openDatabase();

 	bool m_initialized;

 	std::string m_savedir;
+	std::string m_dbname;

-	sqlite3 *m_database;
-	sqlite3_stmt *m_stmt_read;
-	sqlite3_stmt *m_stmt_write;
-	sqlite3_stmt *m_stmt_list;
-	sqlite3_stmt *m_stmt_delete;
 	sqlite3_stmt *m_stmt_begin;
 	sqlite3_stmt *m_stmt_end;

@ -69,4 +131,66 @@ private:
 	static int busyHandler(void *data, int count);
 };

+class MapDatabaseSQLite3 : private Database_SQLite3, public MapDatabase
+{
+public:
+	MapDatabaseSQLite3(const std::string &savedir);
+	virtual ~MapDatabaseSQLite3();
+
+	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);
+
+	void beginSave() { Database_SQLite3::beginSave(); }
+	void endSave() { Database_SQLite3::endSave(); }
+protected:
+	virtual void createDatabase();
+	virtual void initStatements();
+
+private:
+	void bindPos(sqlite3_stmt *stmt, const v3s16 &pos, int index = 1);
+
+	// Map
+	sqlite3_stmt *m_stmt_read;
+	sqlite3_stmt *m_stmt_write;
+	sqlite3_stmt *m_stmt_list;
+	sqlite3_stmt *m_stmt_delete;
+};
+
+class PlayerDatabaseSQLite3 : private Database_SQLite3, public PlayerDatabase
+{
+public:
+	PlayerDatabaseSQLite3(const std::string &savedir);
+	virtual ~PlayerDatabaseSQLite3();
+
+	void savePlayer(RemotePlayer *player);
+	bool loadPlayer(RemotePlayer *player, PlayerSAO *sao);
+	bool removePlayer(const std::string &name);
+	void listPlayers(std::vector<std::string> &res);
+
+protected:
+	virtual void createDatabase();
+	virtual void initStatements();
+
+private:
+	bool playerDataExists(const std::string &name);
+
+	// Players
+	sqlite3_stmt *m_stmt_player_load;
+	sqlite3_stmt *m_stmt_player_add;
+	sqlite3_stmt *m_stmt_player_update;
+	sqlite3_stmt *m_stmt_player_remove;
+	sqlite3_stmt *m_stmt_player_list;
+	sqlite3_stmt *m_stmt_player_load_inventory;
+	sqlite3_stmt *m_stmt_player_load_inventory_items;
+	sqlite3_stmt *m_stmt_player_add_inventory;
+	sqlite3_stmt *m_stmt_player_add_inventory_items;
+	sqlite3_stmt *m_stmt_player_remove_inventory;
+	sqlite3_stmt *m_stmt_player_remove_inventory_items;
+	sqlite3_stmt *m_stmt_player_metadata_load;
+	sqlite3_stmt *m_stmt_player_metadata_remove;
+	sqlite3_stmt *m_stmt_player_metadata_add;
+};
+
 #endif
--- a/src/database.cpp
+++ b/src/database.cpp
@ -48,7 +48,7 @@ static inline s64 pythonmodulo(s64 i, s16 mod)
 }


-s64 Database::getBlockAsInteger(const v3s16 &pos)
+s64 MapDatabase::getBlockAsInteger(const v3s16 &pos)
 {
 	return (u64) pos.Z * 0x1000000 +
 		(u64) pos.Y * 0x1000 +
@ -56,7 +56,7 @@ s64 Database::getBlockAsInteger(const v3s16 &pos)
 }


-v3s16 Database::getIntegerAsBlock(s64 i)
+v3s16 MapDatabase::getIntegerAsBlock(s64 i)
 {
 	v3s16 pos;
 	pos.X = unsigned_to_signed(pythonmodulo(i, 4096), 2048);
--- a/src/database.h
+++ b/src/database.h
@ -29,10 +29,15 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 class Database
 {
 public:
-	virtual ~Database() {}
+	virtual void beginSave() = 0;
+	virtual void endSave() = 0;
+	virtual bool initialized() const { return true; }
+};

-	virtual void beginSave() {}
-	virtual void endSave() {}
+class MapDatabase : public Database
+{
+public:
+	virtual ~MapDatabase() {}

 	virtual bool saveBlock(const v3s16 &pos, const std::string &data) = 0;
 	virtual void loadBlock(const v3s16 &pos, std::string *block) = 0;
@ -42,8 +47,19 @@ public:
 	static v3s16 getIntegerAsBlock(s64 i);

 	virtual void listAllLoadableBlocks(std::vector<v3s16> &dst) = 0;
+};

-	virtual bool initialized() const { return true; }
+class PlayerSAO;
+class RemotePlayer;
+
+class PlayerDatabase
+{
+public:
+	virtual ~PlayerDatabase() {}
+	virtual void savePlayer(RemotePlayer *player) = 0;
+	virtual bool loadPlayer(RemotePlayer *player, PlayerSAO *sao) = 0;
+	virtual bool removePlayer(const std::string &name) = 0;
+	virtual void listPlayers(std::vector<std::string> &res) = 0;
 };

 #endif
--- a/src/main.cpp
+++ b/src/main.cpp
@ -47,6 +47,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #endif
 #ifndef SERVER
 #include "client/clientlauncher.h"
+
 #endif

 #ifdef HAVE_TOUCHSCREENGUI
@ -102,7 +103,7 @@ static bool get_game_from_cmdline(GameParams *game_params, const Settings &cmd_a
 static bool determine_subgame(GameParams *game_params);

 static bool run_dedicated_server(const GameParams &game_params, const Settings &cmd_args);
-static bool migrate_database(const GameParams &game_params, const Settings &cmd_args);
+static bool migrate_map_database(const GameParams &game_params, const Settings &cmd_args);

 /**********************************************************************/

@ -292,6 +293,8 @@ static void set_allowed_options(OptionList *allowed_options)
 			_("Set gameid (\"--gameid list\" prints available ones)"))));
 	allowed_options->insert(std::make_pair("migrate", ValueSpec(VALUETYPE_STRING,
 			_("Migrate from current map backend to another (Only works when using minetestserver or with --server)"))));
+	allowed_options->insert(std::make_pair("migrate-players", ValueSpec(VALUETYPE_STRING,
+		_("Migrate from current players backend to another (Only works when using minetestserver or with --server)"))));
 	allowed_options->insert(std::make_pair("terminal", ValueSpec(VALUETYPE_FLAG,
 			_("Feature an interactive terminal (Only works when using minetestserver or with --server)"))));
 #ifndef SERVER
@ -332,7 +335,7 @@ static void print_allowed_options(const OptionList &allowed_options)
 		if (i->second.type != VALUETYPE_FLAG)
 			os1 << _(" <value>");

-		std::cout << padStringRight(os1.str(), 24);
+		std::cout << padStringRight(os1.str(), 30);

 		if (i->second.help != NULL)
 			std::cout << i->second.help;
@ -828,7 +831,9 @@ static bool run_dedicated_server(const GameParams &game_params, const Settings &

 	// Database migration
 	if (cmd_args.exists("migrate"))
-		return migrate_database(game_params, cmd_args);
+		return migrate_map_database(game_params, cmd_args);
+	else if (cmd_args.exists("migrate-players"))
+		return ServerEnvironment::migratePlayersDatabase(game_params, cmd_args);

 	if (cmd_args.exists("terminal")) {
 #if USE_CURSES
@ -912,7 +917,7 @@ static bool run_dedicated_server(const GameParams &game_params, const Settings &
 	return true;
 }

-static bool migrate_database(const GameParams &game_params, const Settings &cmd_args)
+static bool migrate_map_database(const GameParams &game_params, const Settings &cmd_args)
 {
 	std::string migrate_to = cmd_args.get("migrate");
 	Settings world_mt;
@ -921,20 +926,23 @@ static bool migrate_database(const GameParams &game_params, const Settings &cmd_
 		errorstream << "Cannot read world.mt!" << std::endl;
 		return false;
 	}
+
 	if (!world_mt.exists("backend")) {
 		errorstream << "Please specify your current backend in world.mt:"
 			<< std::endl
-			<< "	backend = {sqlite3|leveldb|redis|dummy}"
+			<< "	backend = {sqlite3|leveldb|redis|dummy|postgresql}"
 			<< std::endl;
 		return false;
 	}
+
 	std::string backend = world_mt.get("backend");
 	if (backend == migrate_to) {
 		errorstream << "Cannot migrate: new backend is same"
 			<< " as the old one" << std::endl;
 		return false;
 	}
-	Database *old_db = ServerMap::createDatabase(backend, game_params.world_path, world_mt),
+
+	MapDatabase *old_db = ServerMap::createDatabase(backend, game_params.world_path, world_mt),
 		*new_db = ServerMap::createDatabase(migrate_to, game_params.world_path, world_mt);

 	u32 count = 0;
@ -976,4 +984,3 @@ static bool migrate_database(const GameParams &game_params, const Settings &cmd_

 	return true;
 }
-
--- a/src/map.cpp
+++ b/src/map.cpp
@ -2286,13 +2286,13 @@ bool ServerMap::loadSectorFull(v2s16 p2d)
 }
 #endif

-Database *ServerMap::createDatabase(
+MapDatabase *ServerMap::createDatabase(
 	const std::string &name,
 	const std::string &savedir,
 	Settings &conf)
 {
 	if (name == "sqlite3")
-		return new Database_SQLite3(savedir);
+		return new MapDatabaseSQLite3(savedir);
 	if (name == "dummy")
 		return new Database_Dummy();
 	#if USE_LEVELDB
@ -2304,8 +2304,11 @@ Database *ServerMap::createDatabase(
 		return new Database_Redis(conf);
 	#endif
 	#if USE_POSTGRESQL
-	else if (name == "postgresql")
-		return new Database_PostgreSQL(conf);
+	else if (name == "postgresql") {
+		std::string connect_string = "";
+		conf.getNoEx("pgsql_connection", connect_string);
+		return new MapDatabasePostgreSQL(connect_string);
+	}
 	#endif
 	else
 		throw BaseException(std::string("Database backend ") + name + " not supported.");
@ -2326,7 +2329,7 @@ bool ServerMap::saveBlock(MapBlock *block)
 	return saveBlock(block, dbase);
 }

-bool ServerMap::saveBlock(MapBlock *block, Database *db)
+bool ServerMap::saveBlock(MapBlock *block, MapDatabase *db)
 {
 	v3s16 p3d = block->getPos();

--- a/src/map.h
+++ b/src/map.h
@ -37,7 +37,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "map_settings_manager.h"

 class Settings;
-class Database;
+class MapDatabase;
 class ClientMap;
 class MapSector;
 class ServerMapSector;
@ -430,7 +430,7 @@ public:
 	/*
 		Database functions
 	*/
-	static Database *createDatabase(const std::string &name, const std::string &savedir, Settings &conf);
+	static MapDatabase *createDatabase(const std::string &name, const std::string &savedir, Settings &conf);

 	// Returns true if the database file does not exist
 	bool loadFromFolders();
@ -458,7 +458,7 @@ public:
 	bool loadSectorMeta(v2s16 p2d);

 	bool saveBlock(MapBlock *block);
-	static bool saveBlock(MapBlock *block, Database *db);
+	static bool saveBlock(MapBlock *block, MapDatabase *db);
 	// This will generate a sector with getSector if not found.
 	void loadBlock(const std::string &sectordir, const std::string &blockfile,
 			MapSector *sector, bool save_after_load=false);
@ -510,7 +510,7 @@ private:
 		This is reset to false when written on disk.
 	*/
 	bool m_map_metadata_changed;
-	Database *dbase;
+	MapDatabase *dbase;
 };


--- a/src/remoteplayer.cpp
+++ b/src/remoteplayer.cpp
@ -67,54 +67,6 @@ RemotePlayer::RemotePlayer(const char *name, IItemDefManager *idef):
 	movement_gravity                = g_settings->getFloat("movement_gravity")                * BS;
 }

-void RemotePlayer::save(std::string savedir, IGameDef *gamedef)
-{
-	/*
-	 * We have to open all possible player files in the players directory
-	 * and check their player names because some file systems are not
-	 * case-sensitive and player names are case-sensitive.
-	 */
-
-	// A player to deserialize files into to check their names
-	RemotePlayer testplayer("", gamedef->idef());
-
-	savedir += DIR_DELIM;
-	std::string path = savedir + m_name;
-	for (u32 i = 0; i < PLAYER_FILE_ALTERNATE_TRIES; i++) {
-		if (!fs::PathExists(path)) {
-			// Open file and serialize
-			std::ostringstream ss(std::ios_base::binary);
-			serialize(ss);
-			if (!fs::safeWriteToFile(path, ss.str())) {
-				infostream << "Failed to write " << path << std::endl;
-			}
-			setModified(false);
-			return;
-		}
-		// Open file and deserialize
-		std::ifstream is(path.c_str(), std::ios_base::binary);
-		if (!is.good()) {
-			infostream << "Failed to open " << path << std::endl;
-			return;
-		}
-		testplayer.deSerialize(is, path, NULL);
-		is.close();
-		if (strcmp(testplayer.getName(), m_name) == 0) {
-			// Open file and serialize
-			std::ostringstream ss(std::ios_base::binary);
-			serialize(ss);
-			if (!fs::safeWriteToFile(path, ss.str())) {
-				infostream << "Failed to write " << path << std::endl;
-			}
-			setModified(false);
-			return;
-		}
-		path = savedir + m_name + itos(i);
-	}
-
-	infostream << "Didn't find free file for player " << m_name << std::endl;
-}
-
 void RemotePlayer::serializeExtraAttributes(std::string &output)
 {
 	assert(m_sao);
--- a/src/remoteplayer.h
+++ b/src/remoteplayer.h
@ -37,11 +37,11 @@ enum RemotePlayerChatResult
 */
 class RemotePlayer : public Player
 {
+	friend class PlayerDatabaseFiles;
 public:
 	RemotePlayer(const char *name, IItemDefManager *idef);
 	virtual ~RemotePlayer() {}

-	void save(std::string savedir, IGameDef *gamedef);
 	void deSerialize(std::istream &is, const std::string &playername, PlayerSAO *sao);

 	PlayerSAO *getPlayerSAO() { return m_sao; }
--- a/src/script/lua_api/l_server.cpp
+++ b/src/script/lua_api/l_server.cpp
@ -334,6 +334,22 @@ int ModApiServer::l_kick_player(lua_State *L)
 	return 1;
 }

+int ModApiServer::l_remove_player(lua_State *L)
+{
+	NO_MAP_LOCK_REQUIRED;
+	std::string name = luaL_checkstring(L, 1);
+	ServerEnvironment *s_env = dynamic_cast<ServerEnvironment *>(getEnv(L));
+	assert(s_env);
+
+	RemotePlayer *player = s_env->getPlayer(name.c_str());
+	if (!player)
+		lua_pushinteger(L, s_env->removePlayerFromDatabase(name) ? 0 : 1);
+	else
+		lua_pushinteger(L, 2);
+
+	return 1;
+}
+
 // unban_player_or_ip()
 int ModApiServer::l_unban_player_or_ip(lua_State *L)
 {
@ -510,6 +526,7 @@ void ModApiServer::Initialize(lua_State *L, int top)
 	API_FCT(get_ban_description);
 	API_FCT(ban_player);
 	API_FCT(kick_player);
+	API_FCT(remove_player);
 	API_FCT(unban_player_or_ip);
 	API_FCT(notify_authentication_modified);

--- a/src/script/lua_api/l_server.h
+++ b/src/script/lua_api/l_server.h
@ -92,6 +92,9 @@ private:
 	// kick_player(name, [message]) -> success
 	static int l_kick_player(lua_State *L);

+	// remove_player(name)
+	static int l_remove_player(lua_State *L);
+
 	// notify_authentication_modified(name)
 	static int l_notify_authentication_modified(lua_State *L);

--- a/src/server.cpp
+++ b/src/server.cpp
@ -60,6 +60,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/base64.h"
 #include "util/sha1.h"
 #include "util/hex.h"
+#include "database.h"

 class ClientNotFoundException : public BaseException
 {
@ -2618,9 +2619,8 @@ void Server::RespawnPlayer(u16 peer_id)

 	bool repositioned = m_script->on_respawnplayer(playersao);
 	if (!repositioned) {
-		v3f pos = findSpawnPos();
 		// setPos will send the new position to client
-		playersao->setPos(pos);
+		playersao->setPos(findSpawnPos());
 	}

 	SendPlayerHP(peer_id);
@ -3442,8 +3442,8 @@ v3f Server::findSpawnPos()
 		s32 range = 1 + i;
 		// We're going to try to throw the player to this position
 		v2s16 nodepos2d = v2s16(
-				-range + (myrand() % (range * 2)),
-				-range + (myrand() % (range * 2)));
+			-range + (myrand() % (range * 2)),
+			-range + (myrand() % (range * 2)));

 		// Get spawn level at point
 		s16 spawn_level = m_emerge->getSpawnLevelAtPoint(nodepos2d);
@ -3516,8 +3516,6 @@ void Server::requestShutdown(const std::string &msg, bool reconnect, float delay

 PlayerSAO* Server::emergePlayer(const char *name, u16 peer_id, u16 proto_version)
 {
-	bool newplayer = false;
-
 	/*
 		Try to get an existing player
 	*/
@ -3538,45 +3536,19 @@ PlayerSAO* Server::emergePlayer(const char *name, u16 peer_id, u16 proto_version
 		return NULL;
 	}

-	// Create a new player active object
-	PlayerSAO *playersao = new PlayerSAO(m_env, peer_id, isSingleplayer());
-	player = m_env->loadPlayer(name, playersao);
-
-	// Create player if it doesn't exist
 	if (!player) {
-		newplayer = true;
-		player = new RemotePlayer(name, this->idef());
-		// Set player position
-		infostream<<"Server: Finding spawn place for player \""
-				<<name<<"\""<<std::endl;
-		playersao->setBasePosition(findSpawnPos());
-
-		// Make sure the player is saved
-		player->setModified(true);
-
-		// Add player to environment
-		m_env->addPlayer(player);
-	} else {
-		// If the player exists, ensure that they respawn inside legal bounds
-		// This fixes an assert crash when the player can't be added
-		// to the environment
-		if (objectpos_over_limit(playersao->getBasePosition())) {
-			actionstream << "Respawn position for player \""
-				<< name << "\" outside limits, resetting" << std::endl;
-			playersao->setBasePosition(findSpawnPos());
-		}
+		player = new RemotePlayer(name, idef());
 	}

-	playersao->initialize(player, getPlayerEffectivePrivs(player->getName()));
+	bool newplayer = false;

+	// Load player
+	PlayerSAO *playersao = m_env->loadPlayer(player, &newplayer, peer_id, isSingleplayer());
+
+	// Complete init with server parts
+	playersao->finalize(player, getPlayerEffectivePrivs(player->getName()));
 	player->protocol_version = proto_version;

-	/* Clean up old HUD elements from previous sessions */
-	player->clearHud();
-
-	/* Add object to environment */
-	m_env->addActiveObject(playersao);
-
 	/* Run scripts */
 	if (newplayer) {
 		m_script->on_newplayer(playersao);
--- a/src/server.h
+++ b/src/server.h
@ -306,6 +306,7 @@ public:
 	bool showFormspec(const char *name, const std::string &formspec, const std::string &formname);
 	Map & getMap() { return m_env->getMap(); }
 	ServerEnvironment & getEnv() { return *m_env; }
+	v3f findSpawnPos();

 	u32 hudAdd(RemotePlayer *player, HudElement *element);
 	bool hudRemove(RemotePlayer *player, u32 id);
@ -472,8 +473,6 @@ private:
 		RemotePlayer *player = NULL);
 	void handleAdminChat(const ChatEventChat *evt);

-	v3f findSpawnPos();
-
 	// When called, connection mutex should be locked
 	RemoteClient* getClient(u16 peer_id,ClientState state_min=CS_Active);
 	RemoteClient* getClientNoEx(u16 peer_id,ClientState state_min=CS_Active);
--- a/src/serverenvironment.cpp
+++ b/src/serverenvironment.cpp
@ -36,6 +36,13 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "util/pointedthing.h"
 #include "threading/mutex_auto_lock.h"
 #include "filesys.h"
+#include "gameparams.h"
+#include "database-dummy.h"
+#include "database-files.h"
+#include "database-sqlite3.h"
+#if USE_POSTGRESQL
+#include "database-postgresql.h"
+#endif

 #define LBM_NAME_ALLOWED_CHARS "abcdefghijklmnopqrstuvwxyz0123456789_:"

@ -365,8 +372,30 @@ ServerEnvironment::ServerEnvironment(ServerMap *map,
 	m_game_time_fraction_counter(0),
 	m_last_clear_objects_time(0),
 	m_recommended_send_interval(0.1),
-	m_max_lag_estimate(0.1)
+	m_max_lag_estimate(0.1),
+	m_player_database(NULL)
 {
+	// Determine which database backend to use
+	std::string conf_path = path_world + DIR_DELIM + "world.mt";
+	Settings conf;
+	bool succeeded = conf.readConfigFile(conf_path.c_str());
+	if (!succeeded || !conf.exists("player_backend")) {
+		// fall back to files
+		conf.set("player_backend", "files");
+		warningstream << "/!\\ You are using old player file backend. "
+				<< "This backend is deprecated and will be removed in next release /!\\"
+				<< std::endl << "Switching to SQLite3 or PostgreSQL is advised, "
+				<< "please read http://wiki.minetest.net/Database_backends." << std::endl;
+
+		if (!conf.updateConfigFile(conf_path.c_str())) {
+			errorstream << "ServerEnvironment::ServerEnvironment(): "
+				<< "Failed to update world.mt!" << std::endl;
+		}
+	}
+
+	std::string name = "";
+	conf.getNoEx("player_backend", name);
+	m_player_database = openPlayerDatabase(name, path_world, conf);
 }

 ServerEnvironment::~ServerEnvironment()
@ -392,6 +421,8 @@ ServerEnvironment::~ServerEnvironment()
 		i != m_players.end(); ++i) {
 		delete (*i);
 	}
+
+	delete m_player_database;
 }

 Map & ServerEnvironment::getMap()
@ -455,6 +486,11 @@ void ServerEnvironment::removePlayer(RemotePlayer *player)
 	}
 }

+bool ServerEnvironment::removePlayerFromDatabase(const std::string &name)
+{
+	return m_player_database->removePlayer(name);
+}
+
 bool ServerEnvironment::line_of_sight(v3f pos1, v3f pos2, float stepsize, v3s16 *p)
 {
 	float distance = pos1.getDistanceFrom(pos2);
@ -495,7 +531,7 @@ void ServerEnvironment::kickAllPlayers(AccessDeniedCode reason,

 void ServerEnvironment::saveLoadedPlayers()
 {
-	std::string players_path = m_path_world + DIR_DELIM "players";
+	std::string players_path = m_path_world + DIR_DELIM + "players";
 	fs::CreateDir(players_path);

 	for (std::vector<RemotePlayer *>::iterator it = m_players.begin();
@ -503,63 +539,63 @@ void ServerEnvironment::saveLoadedPlayers()
 		++it) {
 		if ((*it)->checkModified() ||
 			((*it)->getPlayerSAO() && (*it)->getPlayerSAO()->extendedAttributesModified())) {
-			(*it)->save(players_path, m_server);
+			try {
+				m_player_database->savePlayer(*it);
+			} catch (DatabaseException &e) {
+				errorstream << "Failed to save player " << (*it)->getName() << " exception: "
+					<< e.what() << std::endl;
+				throw;
+			}
 		}
 	}
 }

 void ServerEnvironment::savePlayer(RemotePlayer *player)
 {
-	std::string players_path = m_path_world + DIR_DELIM "players";
-	fs::CreateDir(players_path);
-
-	player->save(players_path, m_server);
+	try {
+		m_player_database->savePlayer(player);
+	} catch (DatabaseException &e) {
+		errorstream << "Failed to save player " << player->getName() << " exception: "
+			<< e.what() << std::endl;
+		throw;
+	}
 }

-RemotePlayer *ServerEnvironment::loadPlayer(const std::string &playername, PlayerSAO *sao)
+PlayerSAO *ServerEnvironment::loadPlayer(RemotePlayer *player, bool *new_player,
+	u16 peer_id, bool is_singleplayer)
 {
-	bool newplayer = false;
-	bool found = false;
-	std::string players_path = m_path_world + DIR_DELIM "players" DIR_DELIM;
-	std::string path = players_path + playername;
+	PlayerSAO *playersao = new PlayerSAO(this, player, peer_id, is_singleplayer);
+	// Create player if it doesn't exist
+	if (!m_player_database->loadPlayer(player, playersao)) {
+		*new_player = true;
+		// Set player position
+		infostream << "Server: Finding spawn place for player \""
+			<< player->getName() << "\"" << std::endl;
+		playersao->setBasePosition(m_server->findSpawnPos());

-	RemotePlayer *player = getPlayer(playername.c_str());
-	if (!player) {
-		player = new RemotePlayer("", m_server->idef());
-		newplayer = true;
-	}
-
-	for (u32 i = 0; i < PLAYER_FILE_ALTERNATE_TRIES; i++) {
-		//// Open file and deserialize
-		std::ifstream is(path.c_str(), std::ios_base::binary);
-		if (!is.good())
-			continue;
-
-		player->deSerialize(is, path, sao);
-		is.close();
-
-		if (player->getName() == playername) {
-			found = true;
-			break;
+		// Make sure the player is saved
+		player->setModified(true);
+	} else {
+		// If the player exists, ensure that they respawn inside legal bounds
+		// This fixes an assert crash when the player can't be added
+		// to the environment
+		if (objectpos_over_limit(playersao->getBasePosition())) {
+			actionstream << "Respawn position for player \""
+				<< player->getName() << "\" outside limits, resetting" << std::endl;
+			playersao->setBasePosition(m_server->findSpawnPos());
 		}
-
-		path = players_path + playername + itos(i);
 	}

-	if (!found) {
-		infostream << "Player file for player " << playername
-			<< " not found" << std::endl;
-		if (newplayer)
-			delete player;
+	// Add player to environment
+	addPlayer(player);

-		return NULL;
-	}
+	/* Clean up old HUD elements from previous sessions */
+	player->clearHud();

-	if (newplayer) {
-		addPlayer(player);
-	}
-	player->setModified(false);
-	return player;
+	/* Add object to environment */
+	addActiveObject(playersao);
+
+	return playersao;
 }

 void ServerEnvironment::saveMeta()
@ -2173,3 +2209,111 @@ void ServerEnvironment::deactivateFarObjects(bool _force_delete)
 		m_active_objects.erase(*i);
 	}
 }
+
+PlayerDatabase *ServerEnvironment::openPlayerDatabase(const std::string &name,
+		const std::string &savedir, const Settings &conf)
+{
+
+	if (name == "sqlite3")
+		return new PlayerDatabaseSQLite3(savedir);
+	else if (name == "dummy")
+		return new Database_Dummy();
+#if USE_POSTGRESQL
+	else if (name == "postgresql") {
+		std::string connect_string = "";
+		conf.getNoEx("pgsql_player_connection", connect_string);
+		return new PlayerDatabasePostgreSQL(connect_string);
+	}
+#endif
+	else if (name == "files")
+		return new PlayerDatabaseFiles(savedir + DIR_DELIM + "players");
+	else
+		throw BaseException(std::string("Database backend ") + name + " not supported.");
+}
+
+bool ServerEnvironment::migratePlayersDatabase(const GameParams &game_params,
+		const Settings &cmd_args)
+{
+	std::string migrate_to = cmd_args.get("migrate-players");
+	Settings world_mt;
+	std::string world_mt_path = game_params.world_path + DIR_DELIM + "world.mt";
+	if (!world_mt.readConfigFile(world_mt_path.c_str())) {
+		errorstream << "Cannot read world.mt!" << std::endl;
+		return false;
+	}
+
+	if (!world_mt.exists("player_backend")) {
+		errorstream << "Please specify your current backend in world.mt:"
+			<< std::endl
+			<< "	player_backend = {files|sqlite3|postgresql}"
+			<< std::endl;
+		return false;
+	}
+
+	std::string backend = world_mt.get("player_backend");
+	if (backend == migrate_to) {
+		errorstream << "Cannot migrate: new backend is same"
+			<< " as the old one" << std::endl;
+		return false;
+	}
+
+	const std::string players_backup_path = game_params.world_path + DIR_DELIM
+		+ "players.bak";
+
+	if (backend == "files") {
+		// Create backup directory
+		fs::CreateDir(players_backup_path);
+	}
+
+	try {
+		PlayerDatabase *srcdb = ServerEnvironment::openPlayerDatabase(backend,
+			game_params.world_path, world_mt);
+		PlayerDatabase *dstdb = ServerEnvironment::openPlayerDatabase(migrate_to,
+			game_params.world_path, world_mt);
+
+		std::vector<std::string> player_list;
+		srcdb->listPlayers(player_list);
+		for (std::vector<std::string>::const_iterator it = player_list.begin();
+			it != player_list.end(); ++it) {
+			actionstream << "Migrating player " << it->c_str() << std::endl;
+			RemotePlayer player(it->c_str(), NULL);
+			PlayerSAO playerSAO(NULL, &player, 15000, false);
+
+			srcdb->loadPlayer(&player, &playerSAO);
+
+			playerSAO.finalize(&player, std::set<std::string>());
+			player.setPlayerSAO(&playerSAO);
+
+			dstdb->savePlayer(&player);
+
+			// For files source, move player files to backup dir
+			if (backend == "files") {
+				fs::Rename(
+					game_params.world_path + DIR_DELIM + "players" + DIR_DELIM + (*it),
+					players_backup_path + DIR_DELIM + (*it));
+			}
+		}
+
+		actionstream << "Successfully migrated " << player_list.size() << " players"
+			<< std::endl;
+		world_mt.set("player_backend", migrate_to);
+		if (!world_mt.updateConfigFile(world_mt_path.c_str()))
+			errorstream << "Failed to update world.mt!" << std::endl;
+		else
+			actionstream << "world.mt updated" << std::endl;
+
+		// When migration is finished from file backend, remove players directory if empty
+		if (backend == "files") {
+			fs::DeleteSingleFileOrEmptyDirectory(game_params.world_path + DIR_DELIM
+				+ "players");
+		}
+
+		delete srcdb;
+		delete dstdb;
+
+	} catch (BaseException &e) {
+		errorstream << "An error occured during migration: " << e.what() << std::endl;
+		return false;
+	}
+	return true;
+}
--- a/src/serverenvironment.h
+++ b/src/serverenvironment.h
@ -27,7 +27,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,

 class IGameDef;
 class ServerMap;
+struct GameParams;
 class RemotePlayer;
+class PlayerDatabase;
 class PlayerSAO;
 class ServerEnvironment;
 class ActiveBlockModifier;
@ -217,9 +219,11 @@ public:
 	// Save players
 	void saveLoadedPlayers();
 	void savePlayer(RemotePlayer *player);
-	RemotePlayer *loadPlayer(const std::string &playername, PlayerSAO *sao);
+	PlayerSAO *loadPlayer(RemotePlayer *player, bool *new_player, u16 peer_id,
+		bool is_singleplayer);
 	void addPlayer(RemotePlayer *player);
 	void removePlayer(RemotePlayer *player);
+	bool removePlayerFromDatabase(const std::string &name);

 	/*
 		Save and load time of day and game timer
@ -334,8 +338,13 @@ public:

 	RemotePlayer *getPlayer(const u16 peer_id);
 	RemotePlayer *getPlayer(const char* name);
+
+	static bool migratePlayersDatabase(const GameParams &game_params,
+			const Settings &cmd_args);
 private:

+	static PlayerDatabase *openPlayerDatabase(const std::string &name,
+			const std::string &savedir, const Settings &conf);
 	/*
 		Internal ActiveObject interface
 		-------------------------------------------
@ -419,6 +428,8 @@ private:
 	// peer_ids in here should be unique, except that there may be many 0s
 	std::vector<RemotePlayer*> m_players;

+	PlayerDatabase *m_player_database;
+
 	// Particles
 	IntervalLimiter m_particle_management_interval;
 	UNORDERED_MAP<u32, float> m_particle_spawners;
--- a/src/unittest/test_player.cpp
+++ b/src/unittest/test_player.cpp
@ -31,59 +31,10 @@ public:
 	const char *getName() { return "TestPlayer"; }

 	void runTests(IGameDef *gamedef);
-
-	void testSave(IGameDef *gamedef);
-	void testLoad(IGameDef *gamedef);
 };

 static TestPlayer g_test_instance;

 void TestPlayer::runTests(IGameDef *gamedef)
 {
-	TEST(testSave, gamedef);
-	TEST(testLoad, gamedef);
-}
-
-void TestPlayer::testSave(IGameDef *gamedef)
-{
-	RemotePlayer rplayer("testplayer_save", gamedef->idef());
-	PlayerSAO sao(NULL, 1, false);
-	sao.initialize(&rplayer, std::set<std::string>());
-	rplayer.setPlayerSAO(&sao);
-	sao.setBreath(10, false);
-	sao.setHPRaw(8);
-	sao.setYaw(0.1f);
-	sao.setPitch(0.6f);
-	sao.setBasePosition(v3f(450.2f, -15.7f, 68.1f));
-	rplayer.save(".", gamedef);
-	UASSERT(fs::PathExists("testplayer_save"));
-}
-
-void TestPlayer::testLoad(IGameDef *gamedef)
-{
-	RemotePlayer rplayer("testplayer_load", gamedef->idef());
-	PlayerSAO sao(NULL, 1, false);
-	sao.initialize(&rplayer, std::set<std::string>());
-	rplayer.setPlayerSAO(&sao);
-	sao.setBreath(10, false);
-	sao.setHPRaw(8);
-	sao.setYaw(0.1f);
-	sao.setPitch(0.6f);
-	sao.setBasePosition(v3f(450.2f, -15.7f, 68.1f));
-	rplayer.save(".", gamedef);
-	UASSERT(fs::PathExists("testplayer_load"));
-
-	RemotePlayer rplayer_load("testplayer_load", gamedef->idef());
-	PlayerSAO sao_load(NULL, 2, false);
-	std::ifstream is("testplayer_load", std::ios_base::binary);
-	UASSERT(is.good());
-	rplayer_load.deSerialize(is, "testplayer_load", &sao_load);
-	is.close();
-
-	UASSERT(strcmp(rplayer_load.getName(), "testplayer_load") == 0);
-	UASSERT(sao_load.getBreath() == 10);
-	UASSERT(sao_load.getHP() == 8);
-	UASSERT(sao_load.getYaw() == 0.1f);
-	UASSERT(sao_load.getPitch() == 0.6f);
-	UASSERT(sao_load.getBasePosition() == v3f(450.2f, -15.7f, 68.1f));
 }