]> git.lizzy.rs Git - minetest.git/blobdiff - src/serverenvironment.cpp
Clean up some auth packet handling related code
[minetest.git] / src / serverenvironment.cpp
index 11c71e28efeeb9f10f6459fd9dc17528145a07cf..f8d84604b0bcc5a16077c09660c5c5ea2e79abbf 100644 (file)
@@ -17,14 +17,16 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */
 
+#include <algorithm>
 #include "serverenvironment.h"
-#include "content_sao.h"
 #include "settings.h"
 #include "log.h"
+#include "mapblock.h"
 #include "nodedef.h"
 #include "nodemetadata.h"
 #include "gamedef.h"
 #include "map.h"
+#include "porting.h"
 #include "profiler.h"
 #include "raycast.h"
 #include "remoteplayer.h"
@@ -36,12 +38,17 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "threading/mutex_auto_lock.h"
 #include "filesys.h"
 #include "gameparams.h"
-#include "database-dummy.h"
-#include "database-files.h"
-#include "database-sqlite3.h"
+#include "database/database-dummy.h"
+#include "database/database-files.h"
+#include "database/database-sqlite3.h"
 #if USE_POSTGRESQL
-#include "database-postgresql.h"
+#include "database/database-postgresql.h"
 #endif
+#if USE_LEVELDB
+#include "database/database-leveldb.h"
+#endif
+#include "server/luaentity_sao.h"
+#include "server/player_sao.h"
 
 #define LBM_NAME_ALLOWED_CHARS "abcdefghijklmnopqrstuvwxyz0123456789_:"
 
@@ -69,9 +76,8 @@ ABMWithState::ABMWithState(ActiveBlockModifier *abm_):
 
 void LBMContentMapping::deleteContents()
 {
-       for (std::vector<LoadingBlockModifierDef *>::iterator it = lbm_list.begin();
-               it != lbm_list.end(); ++it) {
-               delete *it;
+       for (auto &it : lbm_list) {
+               delete it;
        }
 }
 
@@ -79,28 +85,25 @@ void LBMContentMapping::addLBM(LoadingBlockModifierDef *lbm_def, IGameDef *gamed
 {
        // Add the lbm_def to the LBMContentMapping.
        // Unknown names get added to the global NameIdMapping.
-       INodeDefManager *nodedef = gamedef->ndef();
+       const NodeDefManager *nodedef = gamedef->ndef();
 
        lbm_list.push_back(lbm_def);
 
-       for (std::set<std::string>::const_iterator it = lbm_def->trigger_contents.begin();
-               it != lbm_def->trigger_contents.end(); ++it) {
-               std::set<content_t> c_ids;
-               bool found = nodedef->getIds(*it, c_ids);
+       for (const std::string &nodeTrigger: lbm_def->trigger_contents) {
+               std::vector<content_t> c_ids;
+               bool found = nodedef->getIds(nodeTrigger, c_ids);
                if (!found) {
-                       content_t c_id = gamedef->allocateUnknownNodeId(*it);
+                       content_t c_id = gamedef->allocateUnknownNodeId(nodeTrigger);
                        if (c_id == CONTENT_IGNORE) {
                                // Seems it can't be allocated.
-                               warningstream << "Could not internalize node name \"" << *it
+                               warningstream << "Could not internalize node name \"" << nodeTrigger
                                        << "\" while loading LBM \"" << lbm_def->name << "\"." << std::endl;
                                continue;
                        }
-                       c_ids.insert(c_id);
+                       c_ids.push_back(c_id);
                }
 
-               for (std::set<content_t>::const_iterator iit =
-                       c_ids.begin(); iit != c_ids.end(); ++iit) {
-                       content_t c_id = *iit;
+               for (content_t c_id : c_ids) {
                        map[c_id].push_back(lbm_def);
                }
        }
@@ -109,7 +112,7 @@ void LBMContentMapping::addLBM(LoadingBlockModifierDef *lbm_def, IGameDef *gamed
 const std::vector<LoadingBlockModifierDef *> *
 LBMContentMapping::lookup(content_t c) const
 {
-       container_map::const_iterator it = map.find(c);
+       lbm_map::const_iterator it = map.find(c);
        if (it == map.end())
                return NULL;
        // This first dereferences the iterator, returning
@@ -120,20 +123,19 @@ LBMContentMapping::lookup(content_t c) const
 
 LBMManager::~LBMManager()
 {
-       for (std::map<std::string, LoadingBlockModifierDef *>::iterator it =
-               m_lbm_defs.begin(); it != m_lbm_defs.end(); ++it) {
-               delete it->second;
+       for (auto &m_lbm_def : m_lbm_defs) {
+               delete m_lbm_def.second;
        }
-       for (lbm_lookup_map::iterator it = m_lbm_lookup.begin();
-               it != m_lbm_lookup.end(); ++it) {
-               (it->second).deleteContents();
+
+       for (auto &it : m_lbm_lookup) {
+               (it.second).deleteContents();
        }
 }
 
 void LBMManager::addLBMDef(LoadingBlockModifierDef *lbm_def)
 {
        // Precondition, in query mode the map isn't used anymore
-       FATAL_ERROR_IF(m_query_mode == true,
+       FATAL_ERROR_IF(m_query_mode,
                "attempted to modify LBMManager in query mode");
 
        if (!string_allowed(lbm_def->name, LBM_NAME_ALLOWED_CHARS)) {
@@ -164,7 +166,7 @@ void LBMManager::loadIntroductionTimes(const std::string &times,
 
        size_t idx = 0;
        size_t idx_new;
-       while ((idx_new = times.find(";", idx)) != std::string::npos) {
+       while ((idx_new = times.find(';', idx)) != std::string::npos) {
                std::string entry = times.substr(idx, idx_new - idx);
                std::vector<std::string> components = str_split(entry, '~');
                if (components.size() != 2)
@@ -212,12 +214,11 @@ void LBMManager::loadIntroductionTimes(const std::string &times,
        LBMContentMapping &lbms_we_introduce_now = m_lbm_lookup[now];
        LBMContentMapping &lbms_running_always = m_lbm_lookup[U32_MAX];
 
-       for (std::map<std::string, LoadingBlockModifierDef *>::iterator it =
-               m_lbm_defs.begin(); it != m_lbm_defs.end(); ++it) {
-               if (it->second->run_at_every_load) {
-                       lbms_running_always.addLBM(it->second, gamedef);
+       for (auto &m_lbm_def : m_lbm_defs) {
+               if (m_lbm_def.second->run_at_every_load) {
+                       lbms_running_always.addLBM(m_lbm_def.second, gamedef);
                } else {
-                       lbms_we_introduce_now.addLBM(it->second, gamedef);
+                       lbms_we_introduce_now.addLBM(m_lbm_def.second, gamedef);
                }
        }
 
@@ -229,22 +230,20 @@ void LBMManager::loadIntroductionTimes(const std::string &times,
 std::string LBMManager::createIntroductionTimesString()
 {
        // Precondition, we must be in query mode
-       FATAL_ERROR_IF(m_query_mode == false,
+       FATAL_ERROR_IF(!m_query_mode,
                "attempted to query on non fully set up LBMManager");
 
        std::ostringstream oss;
-       for (lbm_lookup_map::iterator it = m_lbm_lookup.begin();
-               it != m_lbm_lookup.end(); ++it) {
-               u32 time = it->first;
-               std::vector<LoadingBlockModifierDef *> &lbm_list = it->second.lbm_list;
-               for (std::vector<LoadingBlockModifierDef *>::iterator iit = lbm_list.begin();
-                       iit != lbm_list.end(); ++iit) {
+       for (const auto &it : m_lbm_lookup) {
+               u32 time = it.first;
+               const std::vector<LoadingBlockModifierDef *> &lbm_list = it.second.lbm_list;
+               for (const auto &lbm_def : lbm_list) {
                        // Don't add if the LBM runs at every load,
                        // then introducement time is hardcoded
                        // and doesn't need to be stored
-                       if ((*iit)->run_at_every_load)
+                       if (lbm_def->run_at_every_load)
                                continue;
-                       oss << (*iit)->name << "~" << time << ";";
+                       oss << lbm_def->name << "~" << time << ";";
                }
        }
        return oss.str();
@@ -253,31 +252,39 @@ std::string LBMManager::createIntroductionTimesString()
 void LBMManager::applyLBMs(ServerEnvironment *env, MapBlock *block, u32 stamp)
 {
        // Precondition, we need m_lbm_lookup to be initialized
-       FATAL_ERROR_IF(m_query_mode == false,
+       FATAL_ERROR_IF(!m_query_mode,
                "attempted to query on non fully set up LBMManager");
        v3s16 pos_of_block = block->getPosRelative();
        v3s16 pos;
        MapNode n;
        content_t c;
        lbm_lookup_map::const_iterator it = getLBMsIntroducedAfter(stamp);
-       for (pos.X = 0; pos.X < MAP_BLOCKSIZE; pos.X++)
-               for (pos.Y = 0; pos.Y < MAP_BLOCKSIZE; pos.Y++)
-                       for (pos.Z = 0; pos.Z < MAP_BLOCKSIZE; pos.Z++)
-                       {
-                               n = block->getNodeNoEx(pos);
-                               c = n.getContent();
-                               for (LBMManager::lbm_lookup_map::const_iterator iit = it;
-                                       iit != m_lbm_lookup.end(); ++iit) {
-                                       const std::vector<LoadingBlockModifierDef *> *lbm_list =
-                                               iit->second.lookup(c);
+       for (; it != m_lbm_lookup.end(); ++it) {
+               // Cache previous version to speedup lookup which has a very high performance
+               // penalty on each call
+               content_t previous_c{};
+               std::vector<LoadingBlockModifierDef *> *lbm_list = nullptr;
+
+               for (pos.X = 0; pos.X < MAP_BLOCKSIZE; pos.X++)
+                       for (pos.Y = 0; pos.Y < MAP_BLOCKSIZE; pos.Y++)
+                               for (pos.Z = 0; pos.Z < MAP_BLOCKSIZE; pos.Z++) {
+                                       n = block->getNodeNoEx(pos);
+                                       c = n.getContent();
+
+                                       // If content_t are not matching perform an LBM lookup
+                                       if (previous_c != c) {
+                                               lbm_list = (std::vector<LoadingBlockModifierDef *> *)
+                                                       it->second.lookup(c);
+                                               previous_c = c;
+                                       }
+
                                        if (!lbm_list)
                                                continue;
-                                       for (std::vector<LoadingBlockModifierDef *>::const_iterator iit =
-                                               lbm_list->begin(); iit != lbm_list->end(); ++iit) {
-                                               (*iit)->trigger(env, pos + pos_of_block, n);
+                                       for (auto lbmdef : *lbm_list) {
+                                               lbmdef->trigger(env, pos + pos_of_block, n);
                                        }
                                }
-                       }
+       }
 }
 
 /*
@@ -299,8 +306,27 @@ void fillRadiusBlock(v3s16 p0, s16 r, std::set<v3s16> &list)
                        }
 }
 
-void ActiveBlockList::update(std::vector<v3s16> &active_positions,
-       s16 radius,
+void fillViewConeBlock(v3s16 p0,
+       const s16 r,
+       const v3f camera_pos,
+       const v3f camera_dir,
+       const float camera_fov,
+       std::set<v3s16> &list)
+{
+       v3s16 p;
+       const s16 r_nodes = r * BS * MAP_BLOCKSIZE;
+       for (p.X = p0.X - r; p.X <= p0.X+r; p.X++)
+       for (p.Y = p0.Y - r; p.Y <= p0.Y+r; p.Y++)
+       for (p.Z = p0.Z - r; p.Z <= p0.Z+r; p.Z++) {
+               if (isBlockInSight(p, camera_pos, camera_dir, camera_fov, r_nodes)) {
+                       list.insert(p);
+               }
+       }
+}
+
+void ActiveBlockList::update(std::vector<PlayerSAO*> &active_players,
+       s16 active_block_range,
+       s16 active_object_range,
        std::set<v3s16> &blocks_removed,
        std::set<v3s16> &blocks_added)
 {
@@ -308,22 +334,34 @@ void ActiveBlockList::update(std::vector<v3s16> &active_positions,
                Create the new list
        */
        std::set<v3s16> newlist = m_forceloaded_list;
-       for(std::vector<v3s16>::iterator i = active_positions.begin();
-               i != active_positions.end(); ++i)
-       {
-               fillRadiusBlock(*i, radius, newlist);
+       m_abm_list = m_forceloaded_list;
+       for (const PlayerSAO *playersao : active_players) {
+               v3s16 pos = getNodeBlockPos(floatToInt(playersao->getBasePosition(), BS));
+               fillRadiusBlock(pos, active_block_range, m_abm_list);
+               fillRadiusBlock(pos, active_block_range, newlist);
+
+               s16 player_ao_range = std::min(active_object_range, playersao->getWantedRange());
+               // only do this if this would add blocks
+               if (player_ao_range > active_block_range) {
+                       v3f camera_dir = v3f(0,0,1);
+                       camera_dir.rotateYZBy(playersao->getLookPitch());
+                       camera_dir.rotateXZBy(playersao->getRotation().Y);
+                       fillViewConeBlock(pos,
+                               player_ao_range,
+                               playersao->getEyePosition(),
+                               camera_dir,
+                               playersao->getFov(),
+                               newlist);
+               }
        }
 
        /*
                Find out which blocks on the old list are not on the new list
        */
        // Go through old list
-       for(std::set<v3s16>::iterator i = m_list.begin();
-               i != m_list.end(); ++i)
-       {
-               v3s16 p = *i;
+       for (v3s16 p : m_list) {
                // If not on new list, it's been removed
-               if(newlist.find(p) == newlist.end())
+               if (newlist.find(p) == newlist.end())
                        blocks_removed.insert(p);
        }
 
@@ -331,10 +369,7 @@ void ActiveBlockList::update(std::vector<v3s16> &active_positions,
                Find out which blocks on the new list are not on the old list
        */
        // Go through new list
-       for(std::set<v3s16>::iterator i = newlist.begin();
-               i != newlist.end(); ++i)
-       {
-               v3s16 p = *i;
+       for (v3s16 p : newlist) {
                // If not on old list, it's been added
                if(m_list.find(p) == m_list.end())
                        blocks_added.insert(p);
@@ -344,10 +379,7 @@ void ActiveBlockList::update(std::vector<v3s16> &active_positions,
                Update m_list
        */
        m_list.clear();
-       for(std::set<v3s16>::iterator i = newlist.begin();
-               i != newlist.end(); ++i)
-       {
-               v3s16 p = *i;
+       for (v3s16 p : newlist) {
                m_list.insert(p);
        }
 }
@@ -356,6 +388,9 @@ void ActiveBlockList::update(std::vector<v3s16> &active_positions,
        ServerEnvironment
 */
 
+// Random device to seed pseudo random generators.
+static std::random_device seed;
+
 ServerEnvironment::ServerEnvironment(ServerMap *map,
        ServerScripting *scriptIface, Server *server,
        const std::string &path_world):
@@ -363,29 +398,68 @@ ServerEnvironment::ServerEnvironment(ServerMap *map,
        m_map(map),
        m_script(scriptIface),
        m_server(server),
-       m_path_world(path_world)
+       m_path_world(path_world),
+       m_rgen(seed())
 {
        // Determine which database backend to use
        std::string conf_path = path_world + DIR_DELIM + "world.mt";
        Settings conf;
+
+       std::string player_backend_name = "sqlite3";
+       std::string auth_backend_name = "sqlite3";
+
        bool succeeded = conf.readConfigFile(conf_path.c_str());
-       if (!succeeded || !conf.exists("player_backend")) {
-               // fall back to files
-               conf.set("player_backend", "files");
+
+       // If we open world.mt read the backend configurations.
+       if (succeeded) {
+               // Read those values before setting defaults
+               bool player_backend_exists = conf.exists("player_backend");
+               bool auth_backend_exists = conf.exists("auth_backend");
+
+               // player backend is not set, assume it's legacy file backend.
+               if (!player_backend_exists) {
+                       // fall back to files
+                       conf.set("player_backend", "files");
+                       player_backend_name = "files";
+
+                       if (!conf.updateConfigFile(conf_path.c_str())) {
+                               errorstream << "ServerEnvironment::ServerEnvironment(): "
+                                               << "Failed to update world.mt!" << std::endl;
+                       }
+               } else {
+                       conf.getNoEx("player_backend", player_backend_name);
+               }
+
+               // auth backend is not set, assume it's legacy file backend.
+               if (!auth_backend_exists) {
+                       conf.set("auth_backend", "files");
+                       auth_backend_name = "files";
+
+                       if (!conf.updateConfigFile(conf_path.c_str())) {
+                               errorstream << "ServerEnvironment::ServerEnvironment(): "
+                                               << "Failed to update world.mt!" << std::endl;
+                       }
+               } else {
+                       conf.getNoEx("auth_backend", auth_backend_name);
+               }
+       }
+
+       if (player_backend_name == "files") {
                warningstream << "/!\\ You are using old player file backend. "
-                               << "This backend is deprecated and will be removed in next release /!\\"
+                               << "This backend is deprecated and will be removed in a future 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;
-               }
+       if (auth_backend_name == "files") {
+               warningstream << "/!\\ You are using old auth file backend. "
+                               << "This backend is deprecated and will be removed in a future release /!\\"
+                               << std::endl << "Switching to SQLite3 is advised, "
+                               << "please read http://wiki.minetest.net/Database_backends." << std::endl;
        }
 
-       std::string name = "";
-       conf.getNoEx("player_backend", name);
-       m_player_database = openPlayerDatabase(name, path_world, conf);
+       m_player_database = openPlayerDatabase(player_backend_name, path_world, conf);
+       m_auth_database = openAuthDatabase(auth_backend_name, path_world, conf);
 }
 
 ServerEnvironment::~ServerEnvironment()
@@ -401,18 +475,17 @@ ServerEnvironment::~ServerEnvironment()
        m_map->drop();
 
        // Delete ActiveBlockModifiers
-       for (std::vector<ABMWithState>::iterator
-               i = m_abms.begin(); i != m_abms.end(); ++i){
-               delete i->abm;
+       for (ABMWithState &m_abm : m_abms) {
+               delete m_abm.abm;
        }
 
        // Deallocate players
-       for (std::vector<RemotePlayer *>::iterator i = m_players.begin();
-               i != m_players.end(); ++i) {
-               delete (*i);
+       for (RemotePlayer *m_player : m_players) {
+               delete m_player;
        }
 
        delete m_player_database;
+       delete m_auth_database;
 }
 
 Map & ServerEnvironment::getMap()
@@ -425,12 +498,10 @@ ServerMap & ServerEnvironment::getServerMap()
        return *m_map;
 }
 
-RemotePlayer *ServerEnvironment::getPlayer(const u16 peer_id)
+RemotePlayer *ServerEnvironment::getPlayer(const session_t peer_id)
 {
-       for (std::vector<RemotePlayer *>::iterator i = m_players.begin();
-               i != m_players.end(); ++i) {
-               RemotePlayer *player = *i;
-               if (player->peer_id == peer_id)
+       for (RemotePlayer *player : m_players) {
+               if (player->getPeerId() == peer_id)
                        return player;
        }
        return NULL;
@@ -438,9 +509,7 @@ RemotePlayer *ServerEnvironment::getPlayer(const u16 peer_id)
 
 RemotePlayer *ServerEnvironment::getPlayer(const char* name)
 {
-       for (std::vector<RemotePlayer *>::iterator i = m_players.begin();
-               i != m_players.end(); ++i) {
-               RemotePlayer *player = *i;
+       for (RemotePlayer *player : m_players) {
                if (strcmp(player->getName(), name) == 0)
                        return player;
        }
@@ -449,15 +518,14 @@ RemotePlayer *ServerEnvironment::getPlayer(const char* name)
 
 void ServerEnvironment::addPlayer(RemotePlayer *player)
 {
-       DSTACK(FUNCTION_NAME);
        /*
                Check that peer_ids are unique.
                Also check that names are unique.
                Exception: there can be multiple players with peer_id=0
        */
        // If peer id is non-zero, it has to be unique.
-       if (player->peer_id != 0)
-               FATAL_ERROR_IF(getPlayer(player->peer_id) != NULL, "Peer id not unique");
+       if (player->getPeerId() != PEER_ID_INEXISTENT)
+               FATAL_ERROR_IF(getPlayer(player->getPeerId()) != NULL, "Peer id not unique");
        // Name has to be unique.
        FATAL_ERROR_IF(getPlayer(player->getName()) != NULL, "Player name not unique");
        // Add.
@@ -481,58 +549,22 @@ 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);
-
-       //calculate normalized direction vector
-       v3f normalized_vector = v3f((pos2.X - pos1.X)/distance,
-               (pos2.Y - pos1.Y)/distance,
-               (pos2.Z - pos1.Z)/distance);
-
-       //find out if there's a node on path between pos1 and pos2
-       for (float i = 1; i < distance; i += stepsize) {
-               v3s16 pos = floatToInt(v3f(normalized_vector.X * i,
-                       normalized_vector.Y * i,
-                       normalized_vector.Z * i) +pos1,BS);
-
-               MapNode n = getMap().getNodeNoEx(pos);
-
-               if(n.param0 != CONTENT_AIR) {
-                       if (p) {
-                               *p = pos;
-                       }
-                       return false;
-               }
-       }
-       return true;
-}
-
 void ServerEnvironment::kickAllPlayers(AccessDeniedCode reason,
        const std::string &str_reason, bool reconnect)
 {
-       for (std::vector<RemotePlayer *>::iterator it = m_players.begin();
-               it != m_players.end(); ++it) {
-               RemotePlayer *player = dynamic_cast<RemotePlayer *>(*it);
-               m_server->DenyAccessVerCompliant(player->peer_id,
-                       player->protocol_version, reason, str_reason, reconnect);
-       }
+       for (RemotePlayer *player : m_players)
+               m_server->DenyAccess(player->getPeerId(), reason, str_reason, reconnect);
 }
 
-void ServerEnvironment::saveLoadedPlayers()
+void ServerEnvironment::saveLoadedPlayers(bool force)
 {
-       std::string players_path = m_path_world + DIR_DELIM + "players";
-       fs::CreateDir(players_path);
-
-       for (std::vector<RemotePlayer *>::iterator it = m_players.begin();
-               it != m_players.end();
-               ++it) {
-               if ((*it)->checkModified() ||
-                       ((*it)->getPlayerSAO() && (*it)->getPlayerSAO()->extendedAttributesModified())) {
+       for (RemotePlayer *player : m_players) {
+               if (force || player->checkModified() || (player->getPlayerSAO() &&
+                               player->getPlayerSAO()->getMeta().isModified())) {
                        try {
-                               m_player_database->savePlayer(*it);
+                               m_player_database->savePlayer(player);
                        } catch (DatabaseException &e) {
-                               errorstream << "Failed to save player " << (*it)->getName() << " exception: "
+                               errorstream << "Failed to save player " << player->getName() << " exception: "
                                        << e.what() << std::endl;
                                throw;
                        }
@@ -552,7 +584,7 @@ void ServerEnvironment::savePlayer(RemotePlayer *player)
 }
 
 PlayerSAO *ServerEnvironment::loadPlayer(RemotePlayer *player, bool *new_player,
-       u16 peer_id, bool is_singleplayer)
+       session_t peer_id, bool is_singleplayer)
 {
        PlayerSAO *playersao = new PlayerSAO(this, player, peer_id, is_singleplayer);
        // Create player if it doesn't exist
@@ -569,8 +601,7 @@ PlayerSAO *ServerEnvironment::loadPlayer(RemotePlayer *player, bool *new_player,
                // 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
-               ServerMap &map = getServerMap();
-               if (map.getMapgenParams()->saoPosOverLimit(playersao->getBasePosition())) {
+               if (objectpos_over_limit(playersao->getBasePosition())) {
                        actionstream << "Respawn position for player \""
                                << player->getName() << "\" outside limits, resetting" << std::endl;
                        playersao->setBasePosition(m_server->findSpawnPos());
@@ -591,12 +622,15 @@ PlayerSAO *ServerEnvironment::loadPlayer(RemotePlayer *player, bool *new_player,
 
 void ServerEnvironment::saveMeta()
 {
+       if (!m_meta_loaded)
+               return;
+
        std::string path = m_path_world + DIR_DELIM "env_meta.txt";
 
        // Open file and serialize
        std::ostringstream ss(std::ios_base::binary);
 
-       Settings args;
+       Settings args("EnvArgsEnd");
        args.setU64("game_time", m_game_time);
        args.setU64("time_of_day", getTimeOfDay());
        args.setU64("last_clear_objects_time", m_last_clear_objects_time);
@@ -605,7 +639,6 @@ void ServerEnvironment::saveMeta()
                m_lbm_mgr.createIntroductionTimesString());
        args.setU64("day_count", m_day_count);
        args.writeLines(ss);
-       ss<<"EnvArgsEnd\n";
 
        if(!fs::safeWriteToFile(path, ss.str()))
        {
@@ -617,6 +650,19 @@ void ServerEnvironment::saveMeta()
 
 void ServerEnvironment::loadMeta()
 {
+       SANITY_CHECK(!m_meta_loaded);
+       m_meta_loaded = true;
+
+       // If file doesn't exist, load default environment metadata
+       if (!fs::PathExists(m_path_world + DIR_DELIM "env_meta.txt")) {
+               infostream << "ServerEnvironment: Loading default environment metadata"
+                       << std::endl;
+               loadDefaultMeta();
+               return;
+       }
+
+       infostream << "ServerEnvironment: Loading environment metadata" << std::endl;
+
        std::string path = m_path_world + DIR_DELIM "env_meta.txt";
 
        // Open file and deserialize
@@ -627,9 +673,9 @@ void ServerEnvironment::loadMeta()
                throw SerializationError("Couldn't load env meta");
        }
 
-       Settings args;
+       Settings args("EnvArgsEnd");
 
-       if (!args.parseConfigLines(is, "EnvArgsEnd")) {
+       if (!args.parseConfigLines(is)) {
                throw SerializationError("ServerEnvironment::loadMeta(): "
                        "EnvArgsEnd not found!");
        }
@@ -642,14 +688,14 @@ void ServerEnvironment::loadMeta()
        }
 
        setTimeOfDay(args.exists("time_of_day") ?
-               // set day to morning by default
-               args.getU64("time_of_day") : 9000);
+               // set day to early morning by default
+               args.getU64("time_of_day") : 5250);
 
        m_last_clear_objects_time = args.exists("last_clear_objects_time") ?
                // If missing, do as if clearObjects was never called
                args.getU64("last_clear_objects_time") : 0;
 
-       std::string lbm_introduction_times = "";
+       std::string lbm_introduction_times;
        try {
                u64 ver = args.getU64("lbm_introduction_times_version");
                if (ver == 1) {
@@ -667,6 +713,9 @@ void ServerEnvironment::loadMeta()
                args.getU64("day_count") : 0;
 }
 
+/**
+ * called if env_meta.txt doesn't exist (e.g. new world)
+ */
 void ServerEnvironment::loadDefaultMeta()
 {
        m_lbm_mgr.loadIntroductionTimes("", m_server, m_game_time);
@@ -676,7 +725,10 @@ struct ActiveABM
 {
        ActiveBlockModifier *abm;
        int chance;
-       std::set<content_t> required_neighbors;
+       std::vector<content_t> required_neighbors;
+       bool check_required_neighbors; // false if required_neighbors is known to be empty
+       s16 min_y;
+       s16 max_y;
 };
 
 class ABMHandler
@@ -692,19 +744,18 @@ class ABMHandler
        {
                if(dtime_s < 0.001)
                        return;
-               INodeDefManager *ndef = env->getGameDef()->ndef();
-               for(std::vector<ABMWithState>::iterator
-                       i = abms.begin(); i != abms.end(); ++i) {
-                       ActiveBlockModifier *abm = i->abm;
+               const NodeDefManager *ndef = env->getGameDef()->ndef();
+               for (ABMWithState &abmws : abms) {
+                       ActiveBlockModifier *abm = abmws.abm;
                        float trigger_interval = abm->getTriggerInterval();
                        if(trigger_interval < 0.001)
                                trigger_interval = 0.001;
                        float actual_interval = dtime_s;
                        if(use_timers){
-                               i->timer += dtime_s;
-                               if(i->timer < trigger_interval)
+                               abmws.timer += dtime_s;
+                               if(abmws.timer < trigger_interval)
                                        continue;
-                               i->timer -= trigger_interval;
+                               abmws.timer -= trigger_interval;
                                actual_interval = trigger_interval;
                        }
                        float chance = abm->getTriggerChance();
@@ -722,24 +773,24 @@ class ABMHandler
                        } else {
                                aabm.chance = chance;
                        }
+                       // y limits
+                       aabm.min_y = abm->getMinY();
+                       aabm.max_y = abm->getMaxY();
 
                        // Trigger neighbors
-                       const std::set<std::string> &required_neighbors_s =
+                       const std::vector<std::string> &required_neighbors_s =
                                abm->getRequiredNeighbors();
-                       for (std::set<std::string>::iterator rn = required_neighbors_s.begin();
-                                       rn != required_neighbors_s.end(); ++rn) {
-                               ndef->getIds(*rn, aabm.required_neighbors);
+                       for (const std::string &required_neighbor_s : required_neighbors_s) {
+                               ndef->getIds(required_neighbor_s, aabm.required_neighbors);
                        }
+                       aabm.check_required_neighbors = !required_neighbors_s.empty();
 
                        // Trigger contents
-                       const std::set<std::string> &contents_s = abm->getTriggerContents();
-                       for (std::set<std::string>::iterator cs = contents_s.begin();
-                                       cs != contents_s.end(); ++cs) {
-                               std::set<content_t> ids;
-                               ndef->getIds(*cs, ids);
-                               for (std::set<content_t>::const_iterator k = ids.begin();
-                                               k != ids.end(); ++k) {
-                                       content_t c = *k;
+                       const std::vector<std::string> &contents_s = abm->getTriggerContents();
+                       for (const std::string &content_s : contents_s) {
+                               std::vector<content_t> ids;
+                               ndef->getIds(content_s, ids);
+                               for (content_t c : ids) {
                                        if (c >= m_aabms.size())
                                                m_aabms.resize(c + 256, NULL);
                                        if (!m_aabms[c])
@@ -752,8 +803,8 @@ class ABMHandler
 
        ~ABMHandler()
        {
-               for (size_t i = 0; i < m_aabms.size(); i++)
-                       delete m_aabms[i];
+               for (auto &aabms : m_aabms)
+                       delete aabms;
        }
 
        // Find out how many objects the given block and its neighbours contain.
@@ -784,11 +835,31 @@ class ABMHandler
                return active_object_count;
 
        }
-       void apply(MapBlock *block)
+       void apply(MapBlock *block, int &blocks_scanned, int &abms_run, int &blocks_cached)
        {
                if(m_aabms.empty() || block->isDummy())
                        return;
 
+               // Check the content type cache first
+               // to see whether there are any ABMs
+               // to be run at all for this block.
+               if (block->contents_cached) {
+                       blocks_cached++;
+                       bool run_abms = false;
+                       for (content_t c : block->contents) {
+                               if (c < m_aabms.size() && m_aabms[c]) {
+                                       run_abms = true;
+                                       break;
+                               }
+                       }
+                       if (!run_abms)
+                               return;
+               } else {
+                       // Clear any caching
+                       block->contents.clear();
+               }
+               blocks_scanned++;
+
                ServerMap *map = &m_env->getServerMap();
 
                u32 active_object_count_wider;
@@ -802,19 +873,29 @@ class ABMHandler
                {
                        const MapNode &n = block->getNodeUnsafe(p0);
                        content_t c = n.getContent();
+                       // Cache content types as we go
+                       if (!block->contents_cached && !block->do_not_cache_contents) {
+                               block->contents.insert(c);
+                               if (block->contents.size() > 64) {
+                                       // Too many different nodes... don't try to cache
+                                       block->do_not_cache_contents = true;
+                                       block->contents.clear();
+                               }
+                       }
 
                        if (c >= m_aabms.size() || !m_aabms[c])
                                continue;
 
                        v3s16 p = p0 + block->getPosRelative();
-                       for(std::vector<ActiveABM>::iterator
-                               i = m_aabms[c]->begin(); i != m_aabms[c]->end(); ++i) {
-                               if(myrand() % i->chance != 0)
+                       for (ActiveABM &aabm : *m_aabms[c]) {
+                               if ((p.Y < aabm.min_y) || (p.Y > aabm.max_y))
+                                       continue;
+
+                               if (myrand() % aabm.chance != 0)
                                        continue;
 
                                // Check neighbors
-                               if(!i->required_neighbors.empty())
-                               {
+                               if (aabm.check_required_neighbors) {
                                        v3s16 p1;
                                        for(p1.X = p0.X-1; p1.X <= p0.X+1; p1.X++)
                                        for(p1.Y = p0.Y-1; p1.Y <= p0.Y+1; p1.Y++)
@@ -830,23 +911,21 @@ class ABMHandler
                                                        c = n.getContent();
                                                } else {
                                                        // otherwise consult the map
-                                                       MapNode n = map->getNodeNoEx(p1 + block->getPosRelative());
+                                                       MapNode n = map->getNode(p1 + block->getPosRelative());
                                                        c = n.getContent();
                                                }
-                                               std::set<content_t>::const_iterator k;
-                                               k = i->required_neighbors.find(c);
-                                               if(k != i->required_neighbors.end()){
+                                               if (CONTAINS(aabm.required_neighbors, c))
                                                        goto neighbor_found;
-                                               }
                                        }
                                        // No required neighbor found
                                        continue;
                                }
                                neighbor_found:
 
+                               abms_run++;
                                // Call all the trigger variations
-                               i->abm->trigger(m_env, p, n);
-                               i->abm->trigger(m_env, p, n,
+                               aabm.abm->trigger(m_env, p, n);
+                               aabm.abm->trigger(m_env, p, n,
                                        active_object_count, active_object_count_wider);
 
                                // Count surrounding objects again if the abms added any
@@ -856,6 +935,7 @@ class ABMHandler
                                }
                        }
                }
+               block->contents_cached = !block->do_not_cache_contents;
        }
 };
 
@@ -902,24 +982,19 @@ void ServerEnvironment::activateBlock(MapBlock *block, u32 additional_dtime)
                block->m_node_timers.step((float)dtime_s);
        if (!elapsed_timers.empty()) {
                MapNode n;
-               for (std::vector<NodeTimer>::iterator
-                       i = elapsed_timers.begin();
-                       i != elapsed_timers.end(); ++i){
-                       n = block->getNodeNoEx(i->position);
-                       v3s16 p = i->position + block->getPosRelative();
-                       if (m_script->node_on_timer(p, n, i->elapsed))
-                               block->setNodeTimer(NodeTimer(i->timeout, 0, i->position));
+               for (const NodeTimer &elapsed_timer : elapsed_timers) {
+                       n = block->getNodeNoEx(elapsed_timer.position);
+                       v3s16 p = elapsed_timer.position + block->getPosRelative();
+                       if (m_script->node_on_timer(p, n, elapsed_timer.elapsed))
+                               block->setNodeTimer(NodeTimer(elapsed_timer.timeout, 0,
+                                       elapsed_timer.position));
                }
        }
-
-       /* Handle ActiveBlockModifiers */
-       ABMHandler abmhandler(m_abms, dtime_s, this, false);
-       abmhandler.apply(block);
 }
 
 void ServerEnvironment::addActiveBlockModifier(ActiveBlockModifier *abm)
 {
-       m_abms.push_back(ABMWithState(abm));
+       m_abms.emplace_back(abm);
 }
 
 void ServerEnvironment::addLoadingBlockModifierDef(LoadingBlockModifierDef *lbm)
@@ -929,11 +1004,13 @@ void ServerEnvironment::addLoadingBlockModifierDef(LoadingBlockModifierDef *lbm)
 
 bool ServerEnvironment::setNode(v3s16 p, const MapNode &n)
 {
-       INodeDefManager *ndef = m_server->ndef();
-       MapNode n_old = m_map->getNodeNoEx(p);
+       const NodeDefManager *ndef = m_server->ndef();
+       MapNode n_old = m_map->getNode(p);
+
+       const ContentFeatures &cf_old = ndef->get(n_old);
 
        // Call destructor
-       if (ndef->get(n_old).has_on_destruct)
+       if (cf_old.has_on_destruct)
                m_script->node_on_destruct(p, n_old);
 
        // Replace node
@@ -944,11 +1021,15 @@ bool ServerEnvironment::setNode(v3s16 p, const MapNode &n)
        m_map->updateVManip(p);
 
        // Call post-destructor
-       if (ndef->get(n_old).has_after_destruct)
+       if (cf_old.has_after_destruct)
                m_script->node_after_destruct(p, n_old);
 
+       // Retrieve node content features
+       // if new node is same as old, reuse old definition to prevent a lookup
+       const ContentFeatures &cf_new = n_old == n ? cf_old : ndef->get(n);
+
        // Call constructor
-       if (ndef->get(n).has_on_construct)
+       if (cf_new.has_on_construct)
                m_script->node_on_construct(p, n);
 
        return true;
@@ -956,8 +1037,8 @@ bool ServerEnvironment::setNode(v3s16 p, const MapNode &n)
 
 bool ServerEnvironment::removeNode(v3s16 p)
 {
-       INodeDefManager *ndef = m_server->ndef();
-       MapNode n_old = m_map->getNodeNoEx(p);
+       const NodeDefManager *ndef = m_server->ndef();
+       MapNode n_old = m_map->getNode(p);
 
        // Call destructor
        if (ndef->get(n_old).has_on_destruct)
@@ -990,46 +1071,106 @@ bool ServerEnvironment::swapNode(v3s16 p, const MapNode &n)
        return true;
 }
 
-void ServerEnvironment::getObjectsInsideRadius(std::vector<u16> &objects, v3f pos,
-       float radius)
+u8 ServerEnvironment::findSunlight(v3s16 pos) const
 {
-       for (ServerActiveObjectMap::iterator i = m_active_objects.begin();
-               i != m_active_objects.end(); ++i) {
-               ServerActiveObject* obj = i->second;
-               u16 id = i->first;
-               v3f objectpos = obj->getBasePosition();
-               if (objectpos.getDistanceFrom(pos) > radius)
-                       continue;
-               objects.push_back(id);
+       // Directions for neighbouring nodes with specified order
+       static const v3s16 dirs[] = {
+               v3s16(-1, 0, 0), v3s16(1, 0, 0), v3s16(0, 0, -1), v3s16(0, 0, 1),
+               v3s16(0, -1, 0), v3s16(0, 1, 0)
+       };
+
+       const NodeDefManager *ndef = m_server->ndef();
+
+       // found_light remembers the highest known sunlight value at pos
+       u8 found_light = 0;
+
+       struct stack_entry {
+               v3s16 pos;
+               s16 dist;
+       };
+       std::stack<stack_entry> stack;
+       stack.push({pos, 0});
+
+       std::unordered_map<s64, s8> dists;
+       dists[MapDatabase::getBlockAsInteger(pos)] = 0;
+
+       while (!stack.empty()) {
+               struct stack_entry e = stack.top();
+               stack.pop();
+
+               v3s16 currentPos = e.pos;
+               s8 dist = e.dist + 1;
+
+               for (const v3s16& off : dirs) {
+                       v3s16 neighborPos = currentPos + off;
+                       s64 neighborHash = MapDatabase::getBlockAsInteger(neighborPos);
+
+                       // Do not walk neighborPos multiple times unless the distance to the start
+                       // position is shorter
+                       auto it = dists.find(neighborHash);
+                       if (it != dists.end() && dist >= it->second)
+                               continue;
+
+                       // Position to walk
+                       bool is_position_ok;
+                       MapNode node = m_map->getNode(neighborPos, &is_position_ok);
+                       if (!is_position_ok) {
+                               // This happens very rarely because the map at currentPos is loaded
+                               m_map->emergeBlock(neighborPos, false);
+                               node = m_map->getNode(neighborPos, &is_position_ok);
+                               if (!is_position_ok)
+                                       continue;  // not generated
+                       }
+
+                       const ContentFeatures &def = ndef->get(node);
+                       if (!def.sunlight_propagates) {
+                               // Do not test propagation here again
+                               dists[neighborHash] = -1;
+                               continue;
+                       }
+
+                       // Sunlight could have come from here
+                       dists[neighborHash] = dist;
+                       u8 daylight = node.param1 & 0x0f;
+
+                       // In the special case where sunlight shines from above and thus
+                       // does not decrease with upwards distance, daylight is always
+                       // bigger than nightlight, which never reaches 15
+                       int possible_finlight = daylight - dist;
+                       if (possible_finlight <= found_light) {
+                               // Light from here cannot make a brighter light at currentPos than
+                               // found_light
+                               continue;
+                       }
+
+                       u8 nightlight = node.param1 >> 4;
+                       if (daylight > nightlight) {
+                               // Found a valid daylight
+                               found_light = possible_finlight;
+                       } else {
+                               // Sunlight may be darker, so walk the neighbours
+                               stack.push({neighborPos, dist});
+                       }
+               }
        }
+       return found_light;
 }
 
 void ServerEnvironment::clearObjects(ClearObjectsMode mode)
 {
        infostream << "ServerEnvironment::clearObjects(): "
                << "Removing all active objects" << std::endl;
-       std::vector<u16> objects_to_remove;
-       for (ServerActiveObjectMap::iterator i = m_active_objects.begin();
-               i != m_active_objects.end(); ++i) {
-               ServerActiveObject* obj = i->second;
+       auto cb_removal = [this] (ServerActiveObject *obj, u16 id) {
                if (obj->getType() == ACTIVEOBJECT_TYPE_PLAYER)
-                       continue;
-               u16 id = i->first;
+                       return false;
+
                // Delete static object if block is loaded
-               if (obj->m_static_exists) {
-                       MapBlock *block = m_map->getBlockNoCreateNoEx(obj->m_static_block);
-                       if (block) {
-                               block->m_static_objects.remove(id);
-                               block->raiseModified(MOD_STATE_WRITE_NEEDED,
-                                       MOD_REASON_CLEAR_ALL_OBJECTS);
-                               obj->m_static_exists = false;
-                       }
-               }
+               deleteStaticFromBlock(obj, id, MOD_REASON_CLEAR_ALL_OBJECTS, true);
+
                // If known by some client, don't delete immediately
                if (obj->m_known_by_count > 0) {
-                       obj->m_pending_deactivation = true;
-                       obj->m_removed = true;
-                       continue;
+                       obj->markForRemoval();
+                       return false;
                }
 
                // Tell the object about removal
@@ -1040,15 +1181,11 @@ void ServerEnvironment::clearObjects(ClearObjectsMode mode)
                // Delete active object
                if (obj->environmentDeletes())
                        delete obj;
-               // Id to be removed from m_active_objects
-               objects_to_remove.push_back(id);
-       }
 
-       // Remove references from m_active_objects
-       for (std::vector<u16>::iterator i = objects_to_remove.begin();
-               i != objects_to_remove.end(); ++i) {
-               m_active_objects.erase(*i);
-       }
+               return true;
+       };
+
+       m_ao_manager.clear(cb_removal);
 
        // Get list of loaded blocks
        std::vector<v3s16> loaded_blocks;
@@ -1072,14 +1209,12 @@ void ServerEnvironment::clearObjects(ClearObjectsMode mode)
                loadable_blocks = loaded_blocks;
        }
 
-       infostream << "ServerEnvironment::clearObjects(): "
+       actionstream << "ServerEnvironment::clearObjects(): "
                << "Now clearing objects in " << loadable_blocks.size()
                << " blocks" << std::endl;
 
        // Grab a reference on each loaded block to avoid unloading it
-       for (std::vector<v3s16>::iterator i = loaded_blocks.begin();
-               i != loaded_blocks.end(); ++i) {
-               v3s16 p = *i;
+       for (v3s16 p : loaded_blocks) {
                MapBlock *block = m_map->getBlockNoCreateNoEx(p);
                assert(block != NULL);
                block->refGrab();
@@ -1095,7 +1230,7 @@ void ServerEnvironment::clearObjects(ClearObjectsMode mode)
        u32 num_blocks_checked = 0;
        u32 num_blocks_cleared = 0;
        u32 num_objs_cleared = 0;
-       for (std::vector<v3s16>::iterator i = loadable_blocks.begin();
+       for (auto i = loadable_blocks.begin();
                i != loadable_blocks.end(); ++i) {
                v3s16 p = *i;
                MapBlock *block = m_map->emergeBlock(p, false);
@@ -1120,7 +1255,7 @@ void ServerEnvironment::clearObjects(ClearObjectsMode mode)
                        num_blocks_checked % report_interval == 0) {
                        float percent = 100.0 * (float)num_blocks_checked /
                                loadable_blocks.size();
-                       infostream << "ServerEnvironment::clearObjects(): "
+                       actionstream << "ServerEnvironment::clearObjects(): "
                                << "Cleared " << num_objs_cleared << " objects"
                                << " in " << num_blocks_cleared << " blocks ("
                                << percent << "%)" << std::endl;
@@ -1132,9 +1267,7 @@ void ServerEnvironment::clearObjects(ClearObjectsMode mode)
        m_map->unloadUnreferencedBlocks();
 
        // Drop references that were added above
-       for (std::vector<v3s16>::iterator i = loaded_blocks.begin();
-               i != loaded_blocks.end(); ++i) {
-               v3s16 p = *i;
+       for (v3s16 p : loaded_blocks) {
                MapBlock *block = m_map->getBlockNoCreateNoEx(p);
                assert(block);
                block->refDrop();
@@ -1142,17 +1275,14 @@ void ServerEnvironment::clearObjects(ClearObjectsMode mode)
 
        m_last_clear_objects_time = m_game_time;
 
-       infostream << "ServerEnvironment::clearObjects(): "
+       actionstream << "ServerEnvironment::clearObjects(): "
                << "Finished: Cleared " << num_objs_cleared << " objects"
                << " in " << num_blocks_cleared << " blocks" << std::endl;
 }
 
 void ServerEnvironment::step(float dtime)
 {
-       DSTACK(FUNCTION_NAME);
-
-       //TimeTaker timer("ServerEnv step");
-
+       ScopeProfiler sp2(g_profiler, "ServerEnv::step()", SPT_AVG);
        /* Step time of day */
        stepTimeOfDay(dtime);
 
@@ -1177,18 +1307,14 @@ void ServerEnvironment::step(float dtime)
                Handle players
        */
        {
-               ScopeProfiler sp(g_profiler, "SEnv: handle players avg", SPT_AVG);
-               for (std::vector<RemotePlayer *>::iterator i = m_players.begin();
-                       i != m_players.end(); ++i) {
-                       RemotePlayer *player = dynamic_cast<RemotePlayer *>(*i);
-                       assert(player);
-
+               ScopeProfiler sp(g_profiler, "ServerEnv: move players", SPT_AVG);
+               for (RemotePlayer *player : m_players) {
                        // Ignore disconnected players
-                       if(player->peer_id == 0)
+                       if (player->getPeerId() == PEER_ID_INEXISTENT)
                                continue;
 
                        // Move
-                       player->move(dtime, this, 100*BS);
+                       player->move(dtime, this, 100 * BS);
                }
        }
 
@@ -1196,36 +1322,34 @@ void ServerEnvironment::step(float dtime)
                Manage active block list
        */
        if (m_active_blocks_management_interval.step(dtime, m_cache_active_block_mgmt_interval)) {
-               ScopeProfiler sp(g_profiler, "SEnv: manage act. block list avg per interval", SPT_AVG);
+               ScopeProfiler sp(g_profiler, "ServerEnv: update active blocks", SPT_AVG);
                /*
                        Get player block positions
                */
-               std::vector<v3s16> players_blockpos;
-               for (std::vector<RemotePlayer *>::iterator i = m_players.begin();
-                       i != m_players.end(); ++i) {
-                       RemotePlayer *player = dynamic_cast<RemotePlayer *>(*i);
-                       assert(player);
-
+               std::vector<PlayerSAO*> players;
+               for (RemotePlayer *player: m_players) {
                        // Ignore disconnected players
-                       if (player->peer_id == 0)
+                       if (player->getPeerId() == PEER_ID_INEXISTENT)
                                continue;
 
                        PlayerSAO *playersao = player->getPlayerSAO();
                        assert(playersao);
 
-                       v3s16 blockpos = getNodeBlockPos(
-                               floatToInt(playersao->getBasePosition(), BS));
-                       players_blockpos.push_back(blockpos);
+                       players.push_back(playersao);
                }
 
                /*
                        Update list of active blocks, collecting changes
                */
+               // use active_object_send_range_blocks since that is max distance
+               // for active objects sent the client anyway
+               static thread_local const s16 active_object_range =
+                               g_settings->getS16("active_object_send_range_blocks");
                static thread_local const s16 active_block_range =
                                g_settings->getS16("active_block_range");
                std::set<v3s16> blocks_removed;
                std::set<v3s16> blocks_added;
-               m_active_blocks.update(players_blockpos, active_block_range,
+               m_active_blocks.update(players, active_block_range, active_object_range,
                        blocks_removed, blocks_added);
 
                /*
@@ -1235,16 +1359,9 @@ void ServerEnvironment::step(float dtime)
                // Convert active objects that are no more in active blocks to static
                deactivateFarObjects(false);
 
-               for(std::set<v3s16>::iterator
-                       i = blocks_removed.begin();
-                       i != blocks_removed.end(); ++i) {
-                       v3s16 p = *i;
-
-                       /* infostream<<"Server: Block " << PP(p)
-                               << " became inactive"<<std::endl; */
-
+               for (const v3s16 &p: blocks_removed) {
                        MapBlock *block = m_map->getBlockNoCreateNoEx(p);
-                       if(block==NULL)
+                       if (!block)
                                continue;
 
                        // Set current time as timestamp (and let it set ChangedFlag)
@@ -1255,21 +1372,15 @@ void ServerEnvironment::step(float dtime)
                        Handle added blocks
                */
 
-               for(std::set<v3s16>::iterator
-                       i = blocks_added.begin();
-                       i != blocks_added.end(); ++i)
-               {
-                       v3s16 p = *i;
-
+               for (const v3s16 &p: blocks_added) {
                        MapBlock *block = m_map->getBlockOrEmerge(p);
-                       if(block==NULL){
+                       if (!block) {
                                m_active_blocks.m_list.erase(p);
+                               m_active_blocks.m_abm_list.erase(p);
                                continue;
                        }
 
                        activateBlock(block);
-                       /* infostream<<"Server: Block " << PP(p)
-                               << " became active"<<std::endl; */
                }
        }
 
@@ -1277,21 +1388,13 @@ void ServerEnvironment::step(float dtime)
                Mess around in active blocks
        */
        if (m_active_blocks_nodemetadata_interval.step(dtime, m_cache_nodetimer_interval)) {
-               ScopeProfiler sp(g_profiler, "SEnv: mess in act. blocks avg per interval", SPT_AVG);
+               ScopeProfiler sp(g_profiler, "ServerEnv: Run node timers", SPT_AVG);
 
                float dtime = m_cache_nodetimer_interval;
 
-               for(std::set<v3s16>::iterator
-                       i = m_active_blocks.m_list.begin();
-                       i != m_active_blocks.m_list.end(); ++i)
-               {
-                       v3s16 p = *i;
-
-                       /*infostream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
-                                       <<") being handled"<<std::endl;*/
-
+               for (const v3s16 &p: m_active_blocks.m_list) {
                        MapBlock *block = m_map->getBlockNoCreateNoEx(p);
-                       if(block==NULL)
+                       if (!block)
                                continue;
 
                        // Reset block usage timer
@@ -1306,65 +1409,72 @@ void ServerEnvironment::step(float dtime)
                                        MOD_REASON_BLOCK_EXPIRED);
 
                        // Run node timers
-                       std::vector<NodeTimer> elapsed_timers =
-                               block->m_node_timers.step((float)dtime);
+                       std::vector<NodeTimer> elapsed_timers = block->m_node_timers.step(dtime);
                        if (!elapsed_timers.empty()) {
                                MapNode n;
-                               for (std::vector<NodeTimer>::iterator i = elapsed_timers.begin();
-                                       i != elapsed_timers.end(); ++i) {
-                                       n = block->getNodeNoEx(i->position);
-                                       p = i->position + block->getPosRelative();
-                                       if (m_script->node_on_timer(p, n, i->elapsed)) {
+                               v3s16 p2;
+                               for (const NodeTimer &elapsed_timer: elapsed_timers) {
+                                       n = block->getNodeNoEx(elapsed_timer.position);
+                                       p2 = elapsed_timer.position + block->getPosRelative();
+                                       if (m_script->node_on_timer(p2, n, elapsed_timer.elapsed)) {
                                                block->setNodeTimer(NodeTimer(
-                                                       i->timeout, 0, i->position));
+                                                       elapsed_timer.timeout, 0, elapsed_timer.position));
                                        }
                                }
                        }
                }
        }
 
-       if (m_active_block_modifier_interval.step(dtime, m_cache_abm_interval))
-               do{ // breakable
-                       if(m_active_block_interval_overload_skip > 0){
-                               ScopeProfiler sp(g_profiler, "SEnv: ABM overload skips");
-                               m_active_block_interval_overload_skip--;
-                               break;
-                       }
-                       ScopeProfiler sp(g_profiler, "SEnv: modify in blocks avg per interval", SPT_AVG);
-                       TimeTaker timer("modify in active blocks per interval");
+       if (m_active_block_modifier_interval.step(dtime, m_cache_abm_interval)) {
+               ScopeProfiler sp(g_profiler, "SEnv: modify in blocks avg per interval", SPT_AVG);
+               TimeTaker timer("modify in active blocks per interval");
 
-                       // Initialize handling of ActiveBlockModifiers
-                       ABMHandler abmhandler(m_abms, m_cache_abm_interval, this, true);
+               // Initialize handling of ActiveBlockModifiers
+               ABMHandler abmhandler(m_abms, m_cache_abm_interval, this, true);
 
-                       for(std::set<v3s16>::iterator
-                               i = m_active_blocks.m_list.begin();
-                               i != m_active_blocks.m_list.end(); ++i)
-                       {
-                               v3s16 p = *i;
+               int blocks_scanned = 0;
+               int abms_run = 0;
+               int blocks_cached = 0;
 
-                               /*infostream<<"Server: Block ("<<p.X<<","<<p.Y<<","<<p.Z
-                                               <<") being handled"<<std::endl;*/
+               std::vector<v3s16> output(m_active_blocks.m_abm_list.size());
 
-                               MapBlock *block = m_map->getBlockNoCreateNoEx(p);
-                               if(block == NULL)
-                                       continue;
+               // Shuffle the active blocks so that each block gets an equal chance
+               // of having its ABMs run.
+               std::copy(m_active_blocks.m_abm_list.begin(), m_active_blocks.m_abm_list.end(), output.begin());
+               std::shuffle(output.begin(), output.end(), m_rgen);
 
-                               // Set current time as timestamp
-                               block->setTimestampNoChangedFlag(m_game_time);
+               int i = 0;
+               // determine the time budget for ABMs
+               u32 max_time_ms = m_cache_abm_interval * 1000 * m_cache_abm_time_budget;
+               for (const v3s16 &p : output) {
+                       MapBlock *block = m_map->getBlockNoCreateNoEx(p);
+                       if (!block)
+                               continue;
 
-                               /* Handle ActiveBlockModifiers */
-                               abmhandler.apply(block);
-                       }
+                       i++;
+
+                       // Set current time as timestamp
+                       block->setTimestampNoChangedFlag(m_game_time);
+
+                       /* Handle ActiveBlockModifiers */
+                       abmhandler.apply(block, blocks_scanned, abms_run, blocks_cached);
 
-                       u32 time_ms = timer.stop(true);
-                       u32 max_time_ms = 200;
-                       if(time_ms > max_time_ms){
-                               warningstream<<"active block modifiers took "
-                                       <<time_ms<<"ms (longer than "
-                                       <<max_time_ms<<"ms)"<<std::endl;
-                               m_active_block_interval_overload_skip = (time_ms / max_time_ms) + 1;
+                       u32 time_ms = timer.getTimerTime();
+
+                       if (time_ms > max_time_ms) {
+                               warningstream << "active block modifiers took "
+                                         << time_ms << "ms (processed " << i << " of "
+                                         << output.size() << " active blocks)" << std::endl;
+                               break;
                        }
-               }while(0);
+               }
+               g_profiler->avg("ServerEnv: active blocks", m_active_blocks.m_abm_list.size());
+               g_profiler->avg("ServerEnv: active blocks cached", blocks_cached);
+               g_profiler->avg("ServerEnv: active blocks scanned for ABMs", blocks_scanned);
+               g_profiler->avg("ServerEnv: ABMs run", abms_run);
+
+               timer.stop(true);
+       }
 
        /*
                Step script environment (run global on_step())
@@ -1375,47 +1485,32 @@ void ServerEnvironment::step(float dtime)
                Step active objects
        */
        {
-               ScopeProfiler sp(g_profiler, "SEnv: step act. objs avg", SPT_AVG);
-               //TimeTaker timer("Step active objects");
-
-               g_profiler->avg("SEnv: num of objects", m_active_objects.size());
+               ScopeProfiler sp(g_profiler, "ServerEnv: Run SAO::step()", SPT_AVG);
 
                // This helps the objects to send data at the same time
                bool send_recommended = false;
                m_send_recommended_timer += dtime;
-               if(m_send_recommended_timer > getSendRecommendedInterval())
-               {
+               if (m_send_recommended_timer > getSendRecommendedInterval()) {
                        m_send_recommended_timer -= getSendRecommendedInterval();
                        send_recommended = true;
                }
 
-               for (ServerActiveObjectMap::iterator i = m_active_objects.begin();
-                       i != m_active_objects.end(); ++i) {
-                       ServerActiveObject* obj = i->second;
-                       // Don't step if is to be removed or stored statically
-                       if(obj->m_removed || obj->m_pending_deactivation)
-                               continue;
+               auto cb_state = [this, dtime, send_recommended] (ServerActiveObject *obj) {
+                       if (obj->isGone())
+                               return;
+
                        // Step object
                        obj->step(dtime, send_recommended);
                        // Read messages from object
-                       while(!obj->m_messages_out.empty())
-                       {
-                               m_active_object_messages.push(
-                                       obj->m_messages_out.front());
-                               obj->m_messages_out.pop();
-                       }
-               }
+                       obj->dumpAOMessagesToQueue(m_active_object_messages);
+               };
+               m_ao_manager.step(dtime, cb_state);
        }
 
        /*
                Manage active objects
        */
-       if(m_object_management_interval.step(dtime, 0.5))
-       {
-               ScopeProfiler sp(g_profiler, "SEnv: remove removed objs avg /.5s", SPT_AVG);
-               /*
-                       Remove objects that satisfy (m_removed && m_known_by_count==0)
-               */
+       if (m_object_management_interval.step(dtime, 0.5)) {
                removeRemovedObjects();
        }
 
@@ -1438,6 +1533,34 @@ void ServerEnvironment::step(float dtime)
                                ++i;
                }
        }
+
+       // Send outdated player inventories
+       for (RemotePlayer *player : m_players) {
+               if (player->getPeerId() == PEER_ID_INEXISTENT)
+                       continue;
+
+               PlayerSAO *sao = player->getPlayerSAO();
+               if (sao && player->inventory.checkModified())
+                       m_server->SendInventory(sao, true);
+       }
+
+       // Send outdated detached inventories
+       m_server->sendDetachedInventories(PEER_ID_INEXISTENT, true);
+}
+
+ServerEnvironment::BlockStatus ServerEnvironment::getBlockStatus(v3s16 blockpos)
+{
+       if (m_active_blocks.contains(blockpos))
+               return BS_ACTIVE;
+
+       const MapBlock *block = m_map->getBlockNoCreateNoEx(blockpos);
+       if (block && !block->isDummy())
+               return BS_LOADED;
+
+       if (m_map->isBlockInQueue(blockpos))
+               return BS_EMERGING;
+
+       return BS_UNKNOWN;
 }
 
 u32 ServerEnvironment::addParticleSpawner(float exptime)
@@ -1470,9 +1593,9 @@ u32 ServerEnvironment::addParticleSpawner(float exptime, u16 attached_id)
 void ServerEnvironment::deleteParticleSpawner(u32 id, bool remove_from_object)
 {
        m_particle_spawners.erase(id);
-       std::unordered_map<u32, u16>::iterator it = m_particle_spawner_attachments.find(id);
+       const auto &it = m_particle_spawner_attachments.find(id);
        if (it != m_particle_spawner_attachments.end()) {
-               u16 obj_id = (*it).second;
+               u16 obj_id = it->second;
                ServerActiveObject *sao = getActiveObject(obj_id);
                if (sao != NULL && remove_from_object) {
                        sao->detachParticleSpawner(id);
@@ -1481,36 +1604,6 @@ void ServerEnvironment::deleteParticleSpawner(u32 id, bool remove_from_object)
        }
 }
 
-ServerActiveObject* ServerEnvironment::getActiveObject(u16 id)
-{
-       ServerActiveObjectMap::const_iterator n = m_active_objects.find(id);
-       return (n != m_active_objects.end() ? n->second : NULL);
-}
-
-bool isFreeServerActiveObjectId(u16 id, ServerActiveObjectMap &objects)
-{
-       if (id == 0)
-               return false;
-
-       return objects.find(id) == objects.end();
-}
-
-u16 getFreeServerActiveObjectId(ServerActiveObjectMap &objects)
-{
-       //try to reuse id's as late as possible
-       static u16 last_used_id = 0;
-       u16 startid = last_used_id;
-       for(;;)
-       {
-               last_used_id ++;
-               if(isFreeServerActiveObjectId(last_used_id, objects))
-                       return last_used_id;
-
-               if(last_used_id == startid)
-                       return 0;
-       }
-}
-
 u16 ServerEnvironment::addActiveObject(ServerActiveObject *object)
 {
        assert(object); // Pre-condition
@@ -1531,45 +1624,11 @@ void ServerEnvironment::getAddedActiveObjects(PlayerSAO *playersao, s16 radius,
        f32 radius_f = radius * BS;
        f32 player_radius_f = player_radius * BS;
 
-       if (player_radius_f < 0)
-               player_radius_f = 0;
-       /*
-               Go through the object list,
-               - discard m_removed objects,
-               - discard objects that are too far away,
-               - discard objects that are found in current_objects.
-               - add remaining objects to added_objects
-       */
-       for (ServerActiveObjectMap::iterator i = m_active_objects.begin();
-               i != m_active_objects.end(); ++i) {
-               u16 id = i->first;
-
-               // Get object
-               ServerActiveObject *object = i->second;
-               if (object == NULL)
-                       continue;
-
-               // Discard if removed or deactivating
-               if(object->m_removed || object->m_pending_deactivation)
-                       continue;
+       if (player_radius_f < 0.0f)
+               player_radius_f = 0.0f;
 
-               f32 distance_f = object->getBasePosition().
-                       getDistanceFrom(playersao->getBasePosition());
-               if (object->getType() == ACTIVEOBJECT_TYPE_PLAYER) {
-                       // Discard if too far
-                       if (distance_f > player_radius_f && player_radius_f != 0)
-                               continue;
-               } else if (distance_f > radius_f)
-                       continue;
-
-               // Discard if already on current_objects
-               std::set<u16>::iterator n;
-               n = current_objects.find(id);
-               if(n != current_objects.end())
-                       continue;
-               // Add to added_objects
-               added_objects.push(id);
-       }
+       m_ao_manager.getAddedActiveObjectsAroundPos(playersao->getBasePosition(), radius_f,
+               player_radius_f, current_objects, added_objects);
 }
 
 /*
@@ -1589,16 +1648,12 @@ void ServerEnvironment::getRemovedActiveObjects(PlayerSAO *playersao, s16 radius
        /*
                Go through current_objects; object is removed if:
                - object is not found in m_active_objects (this is actually an
-                 error condition; objects should be set m_removed=true and removed
-                 only after all clients have been informed about removal), or
-               - object has m_removed=true, or
+                 error condition; objects should be removed only after all clients
+                 have been informed about removal), or
+               - object is to be removed or deactivated, or
                - object is too far away
        */
-       for(std::set<u16>::iterator
-               i = current_objects.begin();
-               i != current_objects.end(); ++i)
-       {
-               u16 id = *i;
+       for (u16 id : current_objects) {
                ServerActiveObject *object = getActiveObject(id);
 
                if (object == NULL) {
@@ -1608,7 +1663,7 @@ void ServerEnvironment::getRemovedActiveObjects(PlayerSAO *playersao, s16 radius
                        continue;
                }
 
-               if (object->m_removed || object->m_pending_deactivation) {
+               if (object->isGone()) {
                        removed_objects.push(id);
                        continue;
                }
@@ -1632,12 +1687,10 @@ void ServerEnvironment::setStaticForActiveObjectsInBlock(
        if (!block)
                return;
 
-       for (std::map<u16, StaticObject>::iterator
-               so_it = block->m_static_objects.m_active.begin();
-               so_it != block->m_static_objects.m_active.end(); ++so_it) {
+       for (auto &so_it : block->m_static_objects.m_active) {
                // Get the ServerActiveObject counterpart to this StaticObject
-               ServerActiveObjectMap::const_iterator ao_it = m_active_objects.find(so_it->first);
-               if (ao_it == m_active_objects.end()) {
+               ServerActiveObject *sao = m_ao_manager.getActiveObject(so_it.first);
+               if (!sao) {
                        // If this ever happens, there must be some kind of nasty bug.
                        errorstream << "ServerEnvironment::setStaticForObjectsInBlock(): "
                                "Object from MapBlock::m_static_objects::m_active not found "
@@ -1645,34 +1698,33 @@ void ServerEnvironment::setStaticForActiveObjectsInBlock(
                        continue;
                }
 
-               ServerActiveObject *sao = ao_it->second;
                sao->m_static_exists = static_exists;
                sao->m_static_block  = static_block;
        }
 }
 
-ActiveObjectMessage ServerEnvironment::getActiveObjectMessage()
+bool ServerEnvironment::getActiveObjectMessage(ActiveObjectMessage *dest)
 {
        if(m_active_object_messages.empty())
-               return ActiveObjectMessage(0);
+               return false;
 
-       ActiveObjectMessage message = m_active_object_messages.front();
+       *dest = std::move(m_active_object_messages.front());
        m_active_object_messages.pop();
-       return message;
+       return true;
 }
 
 void ServerEnvironment::getSelectedActiveObjects(
        const core::line3d<f32> &shootline_on_map,
        std::vector<PointedThing> &objects)
 {
-       std::vector<u16> objectIds;
-       getObjectsInsideRadius(objectIds, shootline_on_map.start,
-               shootline_on_map.getLength() + 10.0f);
+       std::vector<ServerActiveObject *> objs;
+       getObjectsInsideRadius(objs, shootline_on_map.start,
+               shootline_on_map.getLength() + 10.0f, nullptr);
        const v3f line_vector = shootline_on_map.getVector();
 
-       for (u32 i = 0; i < objectIds.size(); i++) {
-               ServerActiveObject* obj = getActiveObject(objectIds[i]);
-
+       for (auto obj : objs) {
+               if (obj->isGone())
+                       continue;
                aabb3f selection_box;
                if (!obj->getSelectionBox(&selection_box))
                        continue;
@@ -1686,9 +1738,9 @@ void ServerEnvironment::getSelectedActiveObjects(
                v3s16 current_normal;
                if (boxLineCollision(offsetted_box, shootline_on_map.start, line_vector,
                                &current_intersection, &current_normal)) {
-                       objects.push_back(PointedThing(
-                               (s16) objectIds[i], current_intersection, current_normal,
-                               (current_intersection - shootline_on_map.start).getLengthSQ()));
+                       objects.emplace_back(
+                               (s16) obj->getId(), current_intersection, current_normal,
+                               (current_intersection - shootline_on_map.start).getLengthSQ());
                }
        }
 }
@@ -1700,65 +1752,20 @@ void ServerEnvironment::getSelectedActiveObjects(
 u16 ServerEnvironment::addActiveObjectRaw(ServerActiveObject *object,
        bool set_changed, u32 dtime_s)
 {
-       assert(object); // Pre-condition
-       if(object->getId() == 0){
-               u16 new_id = getFreeServerActiveObjectId(m_active_objects);
-               if(new_id == 0)
-               {
-                       errorstream<<"ServerEnvironment::addActiveObjectRaw(): "
-                               <<"no free ids available"<<std::endl;
-                       if(object->environmentDeletes())
-                               delete object;
-                       return 0;
-               }
-               object->setId(new_id);
-       }
-       else{
-               verbosestream<<"ServerEnvironment::addActiveObjectRaw(): "
-                       <<"supplied with id "<<object->getId()<<std::endl;
-       }
-
-       if(!isFreeServerActiveObjectId(object->getId(), m_active_objects)) {
-               errorstream<<"ServerEnvironment::addActiveObjectRaw(): "
-                       <<"id is not free ("<<object->getId()<<")"<<std::endl;
-               if(object->environmentDeletes())
-                       delete object;
-               return 0;
-       }
-
-       if (objectpos_over_limit(object->getBasePosition())) {
-               v3f p = object->getBasePosition();
-               warningstream << "ServerEnvironment::addActiveObjectRaw(): "
-                       << "object position (" << p.X << "," << p.Y << "," << p.Z
-                       << ") outside maximum range" << std::endl;
-               if (object->environmentDeletes())
-                       delete object;
+       if (!m_ao_manager.registerObject(object)) {
                return 0;
        }
 
-       /*infostream<<"ServerEnvironment::addActiveObjectRaw(): "
-                       <<"added (id="<<object->getId()<<")"<<std::endl;*/
-
-       m_active_objects[object->getId()] = object;
-
-       verbosestream<<"ServerEnvironment::addActiveObjectRaw(): "
-               <<"Added id="<<object->getId()<<"; there are now "
-               <<m_active_objects.size()<<" active objects."
-               <<std::endl;
-
        // Register reference in scripting api (must be done before post-init)
        m_script->addObjectReference(object);
        // Post-initialize object
        object->addedToEnvironment(dtime_s);
 
        // Add static data to block
-       if(object->isStaticAllowed())
-       {
+       if (object->isStaticAllowed()) {
                // Add static object to active static list of the block
                v3f objectpos = object->getBasePosition();
-               std::string staticdata = "";
-               object->getStaticData(&staticdata);
-               StaticObject s_obj(object->getType(), objectpos, staticdata);
+               StaticObject s_obj(object, objectpos);
                // Add to the block where the object is located in
                v3s16 blockpos = getNodeBlockPos(floatToInt(objectpos, BS));
                MapBlock *block = m_map->emergeBlock(blockpos);
@@ -1782,71 +1789,58 @@ u16 ServerEnvironment::addActiveObjectRaw(ServerActiveObject *object,
 }
 
 /*
-       Remove objects that satisfy (m_removed && m_known_by_count==0)
+       Remove objects that satisfy (isGone() && m_known_by_count==0)
 */
 void ServerEnvironment::removeRemovedObjects()
 {
-       std::vector<u16> objects_to_remove;
-       for(ServerActiveObjectMap::iterator i = m_active_objects.begin();
-               i != m_active_objects.end(); ++i) {
-               u16 id = i->first;
-               ServerActiveObject* obj = i->second;
+       ScopeProfiler sp(g_profiler, "ServerEnvironment::removeRemovedObjects()", SPT_AVG);
+
+       auto clear_cb = [this] (ServerActiveObject *obj, u16 id) {
                // This shouldn't happen but check it
-               if(obj == NULL)
-               {
-                       infostream<<"NULL object found in ServerEnvironment"
-                               <<" while finding removed objects. id="<<id<<std::endl;
-                       // Id to be removed from m_active_objects
-                       objects_to_remove.push_back(id);
-                       continue;
+               if (!obj) {
+                       errorstream << "ServerEnvironment::removeRemovedObjects(): "
+                                       << "NULL object found. id=" << id << std::endl;
+                       return true;
                }
 
                /*
-                       We will delete objects that are marked as removed or thatare
-                       waiting for deletion after deactivation
+                       We will handle objects marked for removal or deactivation
                */
-               if (!obj->m_removed && !obj->m_pending_deactivation)
-                       continue;
+               if (!obj->isGone())
+                       return false;
 
                /*
-                       Delete static data from block if is marked as removed
+                       Delete static data from block if removed
                */
-               if(obj->m_static_exists && obj->m_removed)
-               {
-                       MapBlock *block = m_map->emergeBlock(obj->m_static_block, false);
-                       if (block) {
-                               block->m_static_objects.remove(id);
-                               block->raiseModified(MOD_STATE_WRITE_NEEDED,
-                                       MOD_REASON_REMOVE_OBJECTS_REMOVE);
-                               obj->m_static_exists = false;
-                       } else {
-                               infostream<<"Failed to emerge block from which an object to "
-                                       <<"be removed was loaded from. id="<<id<<std::endl;
-                       }
-               }
+               if (obj->isPendingRemoval())
+                       deleteStaticFromBlock(obj, id, MOD_REASON_REMOVE_OBJECTS_REMOVE, false);
 
-               // If m_known_by_count > 0, don't actually remove. On some future
+               // If still known by clients, don't actually remove. On some future
                // invocation this will be 0, which is when removal will continue.
                if(obj->m_known_by_count > 0)
-                       continue;
+                       return false;
 
                /*
-                       Move static data from active to stored if not marked as removed
+                       Move static data from active to stored if deactivated
                */
-               if(obj->m_static_exists && !obj->m_removed){
+               if (!obj->isPendingRemoval() && obj->m_static_exists) {
                        MapBlock *block = m_map->emergeBlock(obj->m_static_block, false);
                        if (block) {
-                               std::map<u16, StaticObject>::iterator i =
-                                       block->m_static_objects.m_active.find(id);
-                               if(i != block->m_static_objects.m_active.end()){
+                               const auto i = block->m_static_objects.m_active.find(id);
+                               if (i != block->m_static_objects.m_active.end()) {
                                        block->m_static_objects.m_stored.push_back(i->second);
                                        block->m_static_objects.m_active.erase(id);
                                        block->raiseModified(MOD_STATE_WRITE_NEEDED,
                                                MOD_REASON_REMOVE_OBJECTS_DEACTIVATE);
+                               } else {
+                                       warningstream << "ServerEnvironment::removeRemovedObjects(): "
+                                                       << "id=" << id << " m_static_exists=true but "
+                                                       << "static data doesn't actually exist in "
+                                                       << PP(obj->m_static_block) << std::endl;
                                }
                        } else {
-                               infostream<<"Failed to emerge block from which an object to "
-                                       <<"be deactivated was loaded from. id="<<id<<std::endl;
+                               infostream << "Failed to emerge block from which an object to "
+                                               << "be deactivated was loaded from. id=" << id << std::endl;
                        }
                }
 
@@ -1856,17 +1850,13 @@ void ServerEnvironment::removeRemovedObjects()
                m_script->removeObjectReference(obj);
 
                // Delete
-               if(obj->environmentDeletes())
+               if (obj->environmentDeletes())
                        delete obj;
 
-               // Id to be removed from m_active_objects
-               objects_to_remove.push_back(id);
-       }
-       // Remove references from m_active_objects
-       for(std::vector<u16>::iterator i = objects_to_remove.begin();
-               i != objects_to_remove.end(); ++i) {
-               m_active_objects.erase(*i);
-       }
+               return true;
+       };
+
+       m_ao_manager.clear(clear_cb);
 }
 
 static void print_hexdump(std::ostream &o, const std::string &data)
@@ -1884,9 +1874,9 @@ static void print_hexdump(std::ostream &o, const std::string &data)
                        int i = i0 + di;
                        char buf[4];
                        if(di<thislinelength)
-                               snprintf(buf, 4, "%.2x ", data[i]);
+                               porting::mt_snprintf(buf, sizeof(buf), "%.2x ", data[i]);
                        else
-                               snprintf(buf, 4, "   ");
+                               porting::mt_snprintf(buf, sizeof(buf), "   ");
                        o<<buf;
                }
                o<<" ";
@@ -1903,6 +1893,18 @@ static void print_hexdump(std::ostream &o, const std::string &data)
        }
 }
 
+ServerActiveObject* ServerEnvironment::createSAO(ActiveObjectType type, v3f pos,
+               const std::string &data)
+{
+       switch (type) {
+               case ACTIVEOBJECT_TYPE_LUAENTITY:
+                       return new LuaEntitySAO(this, pos, data);
+               default:
+                       warningstream << "ServerActiveObject: No factory for type=" << type << std::endl;
+       }
+       return nullptr;
+}
+
 /*
        Convert stored objects from blocks near the players to active.
 */
@@ -1934,16 +1936,12 @@ void ServerEnvironment::activateObjects(MapBlock *block, u32 dtime_s)
 
        // Activate stored objects
        std::vector<StaticObject> new_stored;
-       for (std::vector<StaticObject>::iterator
-               i = block->m_static_objects.m_stored.begin();
-               i != block->m_static_objects.m_stored.end(); ++i) {
-               StaticObject &s_obj = *i;
-
+       for (const StaticObject &s_obj : block->m_static_objects.m_stored) {
                // Create an active object from the data
-               ServerActiveObject *obj = ServerActiveObject::create
-                       ((ActiveObjectType) s_obj.type, this, 0, s_obj.pos, s_obj.data);
+               ServerActiveObject *obj = createSAO((ActiveObjectType) s_obj.type, s_obj.pos,
+                       s_obj.data);
                // If couldn't create object, store static data back.
-               if(obj == NULL) {
+               if (!obj) {
                        errorstream<<"ServerEnvironment::activateObjects(): "
                                <<"failed to create active object from static object "
                                <<"in block "<<PP(s_obj.pos/BS)
@@ -1959,28 +1957,14 @@ void ServerEnvironment::activateObjects(MapBlock *block, u32 dtime_s)
                // This will also add the object to the active static list
                addActiveObjectRaw(obj, false, dtime_s);
        }
+
        // Clear stored list
        block->m_static_objects.m_stored.clear();
        // Add leftover failed stuff to stored list
-       for(std::vector<StaticObject>::iterator
-               i = new_stored.begin();
-               i != new_stored.end(); ++i) {
-               StaticObject &s_obj = *i;
+       for (const StaticObject &s_obj : new_stored) {
                block->m_static_objects.m_stored.push_back(s_obj);
        }
 
-       // Turn the active counterparts of activated objects not pending for
-       // deactivation
-       for(std::map<u16, StaticObject>::iterator
-               i = block->m_static_objects.m_active.begin();
-               i != block->m_static_objects.m_active.end(); ++i)
-       {
-               u16 id = i->first;
-               ServerActiveObject *object = getActiveObject(id);
-               assert(object);
-               object->m_pending_deactivation = false;
-       }
-
        /*
                Note: Block hasn't really been modified here.
                The objects have just been activated and moved from the stored
@@ -2004,25 +1988,19 @@ void ServerEnvironment::activateObjects(MapBlock *block, u32 dtime_s)
 */
 void ServerEnvironment::deactivateFarObjects(bool _force_delete)
 {
-       std::vector<u16> objects_to_remove;
-       for (ServerActiveObjectMap::iterator i = m_active_objects.begin();
-               i != m_active_objects.end(); ++i) {
+       auto cb_deactivate = [this, _force_delete] (ServerActiveObject *obj, u16 id) {
                // force_delete might be overriden per object
                bool force_delete = _force_delete;
 
-               ServerActiveObject* obj = i->second;
-               assert(obj);
-
-               // Do not deactivate if static data creation not allowed
-               if(!force_delete && !obj->isStaticAllowed())
-                       continue;
+               // Do not deactivate if disallowed
+               if (!force_delete && !obj->shouldUnload())
+                       return false;
 
-               // If pending deactivation, let removeRemovedObjects() do it
-               if(!force_delete && obj->m_pending_deactivation)
-                       continue;
+               // removeRemovedObjects() is responsible for these
+               if (!force_delete && obj->isGone())
+                       return false;
 
-               u16 id = i->first;
-               v3f objectpos = obj->getBasePosition();
+               const v3f &objectpos = obj->getBasePosition();
 
                // The block in which the object resides in
                v3s16 blockpos_o = getNodeBlockPos(floatToInt(objectpos, BS));
@@ -2030,52 +2008,30 @@ void ServerEnvironment::deactivateFarObjects(bool _force_delete)
                // If object's static data is stored in a deactivated block and object
                // is actually located in an active block, re-save to the block in
                // which the object is actually located in.
-               if(!force_delete &&
-                       obj->m_static_exists &&
-                       !m_active_blocks.contains(obj->m_static_block) &&
-                       m_active_blocks.contains(blockpos_o))
-               {
-                       v3s16 old_static_block = obj->m_static_block;
+               if (!force_delete && obj->m_static_exists &&
+                  !m_active_blocks.contains(obj->m_static_block) &&
+                  m_active_blocks.contains(blockpos_o)) {
 
+                       // Delete from block where object was located
+                       deleteStaticFromBlock(obj, id, MOD_REASON_STATIC_DATA_REMOVED, false);
+
+                       StaticObject s_obj(obj, objectpos);
                        // Save to block where object is located
-                       MapBlock *block = m_map->emergeBlock(blockpos_o, false);
-                       if(!block){
-                               errorstream<<"ServerEnvironment::deactivateFarObjects(): "
-                                       <<"Could not save object id="<<id
-                                       <<" to it's current block "<<PP(blockpos_o)
-                                       <<std::endl;
-                               continue;
-                       }
-                       std::string staticdata_new = "";
-                       obj->getStaticData(&staticdata_new);
-                       StaticObject s_obj(obj->getType(), objectpos, staticdata_new);
-                       block->m_static_objects.insert(id, s_obj);
-                       obj->m_static_block = blockpos_o;
-                       block->raiseModified(MOD_STATE_WRITE_NEEDED,
-                               MOD_REASON_STATIC_DATA_ADDED);
+                       saveStaticToBlock(blockpos_o, id, obj, s_obj, MOD_REASON_STATIC_DATA_ADDED);
 
-                       // Delete from block where object was located
-                       block = m_map->emergeBlock(old_static_block, false);
-                       if(!block){
-                               errorstream<<"ServerEnvironment::deactivateFarObjects(): "
-                                       <<"Could not delete object id="<<id
-                                       <<" from it's previous block "<<PP(old_static_block)
-                                       <<std::endl;
-                               continue;
-                       }
-                       block->m_static_objects.remove(id);
-                       block->raiseModified(MOD_STATE_WRITE_NEEDED,
-                               MOD_REASON_STATIC_DATA_REMOVED);
-                       continue;
+                       return false;
                }
 
-               // If block is active, don't remove
-               if(!force_delete && m_active_blocks.contains(blockpos_o))
-                       continue;
+               // If block is still active, don't remove
+               bool still_active = obj->isStaticAllowed() ?
+                       m_active_blocks.contains(blockpos_o) :
+                       getMap().getBlockNoCreateNoEx(blockpos_o) != nullptr;
+               if (!force_delete && still_active)
+                       return false;
 
-               verbosestream<<"ServerEnvironment::deactivateFarObjects(): "
-                       <<"deactivating object id="<<id<<" on inactive block "
-                       <<PP(blockpos_o)<<std::endl;
+               verbosestream << "ServerEnvironment::deactivateFarObjects(): "
+                                         << "deactivating object id=" << id << " on inactive block "
+                                         << PP(blockpos_o) << std::endl;
 
                // If known by some client, don't immediately delete.
                bool pending_delete = (obj->m_known_by_count > 0 && !force_delete);
@@ -2083,17 +2039,14 @@ void ServerEnvironment::deactivateFarObjects(bool _force_delete)
                /*
                        Update the static data
                */
-
-               if(obj->isStaticAllowed())
-               {
+               if (obj->isStaticAllowed()) {
                        // Create new static object
-                       std::string staticdata_new = "";
-                       obj->getStaticData(&staticdata_new);
-                       StaticObject s_obj(obj->getType(), objectpos, staticdata_new);
+                       StaticObject s_obj(obj, objectpos);
 
                        bool stays_in_same_block = false;
                        bool data_changed = true;
 
+                       // Check if static data has changed considerably
                        if (obj->m_static_exists) {
                                if (obj->m_static_block == blockpos_o)
                                        stays_in_same_block = true;
@@ -2101,119 +2054,60 @@ void ServerEnvironment::deactivateFarObjects(bool _force_delete)
                                MapBlock *block = m_map->emergeBlock(obj->m_static_block, false);
 
                                if (block) {
-                                       std::map<u16, StaticObject>::iterator n =
-                                               block->m_static_objects.m_active.find(id);
+                                       const auto n = block->m_static_objects.m_active.find(id);
                                        if (n != block->m_static_objects.m_active.end()) {
                                                StaticObject static_old = n->second;
 
                                                float save_movem = obj->getMinimumSavedMovement();
 
-                                               if (static_old.data == staticdata_new &&
+                                               if (static_old.data == s_obj.data &&
                                                        (static_old.pos - objectpos).getLength() < save_movem)
                                                        data_changed = false;
                                        } else {
-                                               errorstream<<"ServerEnvironment::deactivateFarObjects(): "
-                                                       <<"id="<<id<<" m_static_exists=true but "
-                                                       <<"static data doesn't actually exist in "
-                                                       <<PP(obj->m_static_block)<<std::endl;
+                                               warningstream << "ServerEnvironment::deactivateFarObjects(): "
+                                                               << "id=" << id << " m_static_exists=true but "
+                                                               << "static data doesn't actually exist in "
+                                                               << PP(obj->m_static_block) << std::endl;
                                        }
                                }
                        }
 
+                       /*
+                               While changes are always saved, blocks are only marked as modified
+                               if the object has moved or different staticdata. (see above)
+                       */
                        bool shall_be_written = (!stays_in_same_block || data_changed);
+                       u32 reason = shall_be_written ? MOD_REASON_STATIC_DATA_CHANGED : MOD_REASON_UNKNOWN;
 
                        // Delete old static object
-                       if(obj->m_static_exists)
-                       {
-                               MapBlock *block = m_map->emergeBlock(obj->m_static_block, false);
-                               if(block)
-                               {
-                                       block->m_static_objects.remove(id);
-                                       obj->m_static_exists = false;
-                                       // Only mark block as modified if data changed considerably
-                                       if(shall_be_written)
-                                               block->raiseModified(MOD_STATE_WRITE_NEEDED,
-                                                       MOD_REASON_STATIC_DATA_CHANGED);
-                               }
-                       }
+                       deleteStaticFromBlock(obj, id, reason, false);
 
                        // Add to the block where the object is located in
                        v3s16 blockpos = getNodeBlockPos(floatToInt(objectpos, BS));
-                       // Get or generate the block
-                       MapBlock *block = NULL;
-                       try{
-                               block = m_map->emergeBlock(blockpos);
-                       } catch(InvalidPositionException &e){
-                               // Handled via NULL pointer
-                               // NOTE: emergeBlock's failure is usually determined by it
-                               //       actually returning NULL
-                       }
-
-                       if(block)
-                       {
-                               if (block->m_static_objects.m_stored.size() >= g_settings->getU16("max_objects_per_block")) {
-                                       warningstream << "ServerEnv: Trying to store id = " << obj->getId()
-                                               << " statically but block " << PP(blockpos)
-                                               << " already contains "
-                                               << block->m_static_objects.m_stored.size()
-                                               << " objects."
-                                               << " Forcing delete." << std::endl;
-                                       force_delete = true;
-                               } else {
-                                       // If static counterpart already exists in target block,
-                                       // remove it first.
-                                       // This shouldn't happen because the object is removed from
-                                       // the previous block before this according to
-                                       // obj->m_static_block, but happens rarely for some unknown
-                                       // reason. Unsuccessful attempts have been made to find
-                                       // said reason.
-                                       if(id && block->m_static_objects.m_active.find(id) != block->m_static_objects.m_active.end()){
-                                               warningstream<<"ServerEnv: Performing hack #83274"
-                                                       <<std::endl;
-                                               block->m_static_objects.remove(id);
-                                       }
-                                       // Store static data
-                                       u16 store_id = pending_delete ? id : 0;
-                                       block->m_static_objects.insert(store_id, s_obj);
-
-                                       // Only mark block as modified if data changed considerably
-                                       if(shall_be_written)
-                                               block->raiseModified(MOD_STATE_WRITE_NEEDED,
-                                                       MOD_REASON_STATIC_DATA_CHANGED);
-
-                                       obj->m_static_exists = true;
-                                       obj->m_static_block = block->getPos();
-                               }
-                       }
-                       else{
-                               if(!force_delete){
-                                       v3s16 p = floatToInt(objectpos, BS);
-                                       errorstream<<"ServerEnv: Could not find or generate "
-                                               <<"a block for storing id="<<obj->getId()
-                                               <<" statically (pos="<<PP(p)<<")"<<std::endl;
-                                       continue;
-                               }
-                       }
+                       u16 store_id = pending_delete ? id : 0;
+                       if (!saveStaticToBlock(blockpos, store_id, obj, s_obj, reason))
+                               force_delete = true;
                }
 
+               // Regardless of what happens to the object at this point, deactivate it first.
+               // This ensures that LuaEntity on_deactivate is always called.
+               obj->markForDeactivation();
+
                /*
                        If known by some client, set pending deactivation.
                        Otherwise delete it immediately.
                */
+               if (pending_delete && !force_delete) {
+                       verbosestream << "ServerEnvironment::deactivateFarObjects(): "
+                                                 << "object id=" << id << " is known by clients"
+                                                 << "; not deleting yet" << std::endl;
 
-               if(pending_delete && !force_delete)
-               {
-                       verbosestream<<"ServerEnvironment::deactivateFarObjects(): "
-                               <<"object id="<<id<<" is known by clients"
-                               <<"; not deleting yet"<<std::endl;
-
-                       obj->m_pending_deactivation = true;
-                       continue;
+                       return false;
                }
 
-               verbosestream<<"ServerEnvironment::deactivateFarObjects(): "
-                       <<"object id="<<id<<" is not known by clients"
-                       <<"; deleting"<<std::endl;
+               verbosestream << "ServerEnvironment::deactivateFarObjects(): "
+                                         << "object id=" << id << " is not known by clients"
+                                         << "; deleting" << std::endl;
 
                // Tell the object about removal
                obj->removingFromEnvironment();
@@ -2221,17 +2115,76 @@ void ServerEnvironment::deactivateFarObjects(bool _force_delete)
                m_script->removeObjectReference(obj);
 
                // Delete active object
-               if(obj->environmentDeletes())
+               if (obj->environmentDeletes())
                        delete obj;
-               // Id to be removed from m_active_objects
-               objects_to_remove.push_back(id);
+
+               return true;
+       };
+
+       m_ao_manager.clear(cb_deactivate);
+}
+
+void ServerEnvironment::deleteStaticFromBlock(
+               ServerActiveObject *obj, u16 id, u32 mod_reason, bool no_emerge)
+{
+       if (!obj->m_static_exists)
+               return;
+
+       MapBlock *block;
+       if (no_emerge)
+               block = m_map->getBlockNoCreateNoEx(obj->m_static_block);
+       else
+               block = m_map->emergeBlock(obj->m_static_block, false);
+       if (!block) {
+               if (!no_emerge)
+                       errorstream << "ServerEnv: Failed to emerge block " << PP(obj->m_static_block)
+                                       << " when deleting static data of object from it. id=" << id << std::endl;
+               return;
        }
 
-       // Remove references from m_active_objects
-       for(std::vector<u16>::iterator i = objects_to_remove.begin();
-               i != objects_to_remove.end(); ++i) {
-               m_active_objects.erase(*i);
+       block->m_static_objects.remove(id);
+       if (mod_reason != MOD_REASON_UNKNOWN) // Do not mark as modified if requested
+               block->raiseModified(MOD_STATE_WRITE_NEEDED, mod_reason);
+
+       obj->m_static_exists = false;
+}
+
+bool ServerEnvironment::saveStaticToBlock(
+               v3s16 blockpos, u16 store_id,
+               ServerActiveObject *obj, const StaticObject &s_obj,
+               u32 mod_reason)
+{
+       MapBlock *block = nullptr;
+       try {
+               block = m_map->emergeBlock(blockpos);
+       } catch (InvalidPositionException &e) {
+               // Handled via NULL pointer
+               // NOTE: emergeBlock's failure is usually determined by it
+               //       actually returning NULL
        }
+
+       if (!block) {
+               errorstream << "ServerEnv: Failed to emerge block " << PP(obj->m_static_block)
+                               << " when saving static data of object to it. id=" << store_id << std::endl;
+               return false;
+       }
+       if (block->m_static_objects.m_stored.size() >= g_settings->getU16("max_objects_per_block")) {
+               warningstream << "ServerEnv: Trying to store id = " << store_id
+                               << " statically but block " << PP(blockpos)
+                               << " already contains "
+                               << block->m_static_objects.m_stored.size()
+                               << " objects." << std::endl;
+               return false;
+       }
+
+       block->m_static_objects.insert(store_id, s_obj);
+       if (mod_reason != MOD_REASON_UNKNOWN) // Do not mark as modified if requested
+               block->raiseModified(MOD_STATE_WRITE_NEEDED, mod_reason);
+
+       obj->m_static_exists = true;
+       obj->m_static_block = blockpos;
+
+       return true;
 }
 
 PlayerDatabase *ServerEnvironment::openPlayerDatabase(const std::string &name,
@@ -2240,19 +2193,27 @@ PlayerDatabase *ServerEnvironment::openPlayerDatabase(const std::string &name,
 
        if (name == "sqlite3")
                return new PlayerDatabaseSQLite3(savedir);
-       else if (name == "dummy")
+
+       if (name == "dummy")
                return new Database_Dummy();
+
 #if USE_POSTGRESQL
-       else if (name == "postgresql") {
-               std::string connect_string = "";
+       if (name == "postgresql") {
+               std::string connect_string;
                conf.getNoEx("pgsql_player_connection", connect_string);
                return new PlayerDatabasePostgreSQL(connect_string);
        }
 #endif
-       else if (name == "files")
+
+#if USE_LEVELDB
+       if (name == "leveldb")
+               return new PlayerDatabaseLevelDB(savedir);
+#endif
+
+       if (name == "files")
                return new PlayerDatabaseFiles(savedir + DIR_DELIM + "players");
-       else
-               throw BaseException(std::string("Database backend ") + name + " not supported.");
+
+       throw BaseException(std::string("Database backend ") + name + " not supported.");
 }
 
 bool ServerEnvironment::migratePlayersDatabase(const GameParams &game_params,
@@ -2269,7 +2230,7 @@ bool ServerEnvironment::migratePlayersDatabase(const GameParams &game_params,
        if (!world_mt.exists("player_backend")) {
                errorstream << "Please specify your current backend in world.mt:"
                        << std::endl
-                       << "    player_backend = {files|sqlite3|postgresql}"
+                       << "    player_backend = {files|sqlite3|leveldb|postgresql}"
                        << std::endl;
                return false;
        }
@@ -2336,7 +2297,108 @@ bool ServerEnvironment::migratePlayersDatabase(const GameParams &game_params,
                delete dstdb;
 
        } catch (BaseException &e) {
-               errorstream << "An error occured during migration: " << e.what() << std::endl;
+               errorstream << "An error occurred during migration: " << e.what() << std::endl;
+               return false;
+       }
+       return true;
+}
+
+AuthDatabase *ServerEnvironment::openAuthDatabase(
+               const std::string &name, const std::string &savedir, const Settings &conf)
+{
+       if (name == "sqlite3")
+               return new AuthDatabaseSQLite3(savedir);
+
+#if USE_POSTGRESQL
+       if (name == "postgresql") {
+               std::string connect_string;
+               conf.getNoEx("pgsql_auth_connection", connect_string);
+               return new AuthDatabasePostgreSQL(connect_string);
+       }
+#endif
+
+       if (name == "files")
+               return new AuthDatabaseFiles(savedir);
+
+#if USE_LEVELDB
+       if (name == "leveldb")
+               return new AuthDatabaseLevelDB(savedir);
+#endif
+
+       throw BaseException(std::string("Database backend ") + name + " not supported.");
+}
+
+bool ServerEnvironment::migrateAuthDatabase(
+               const GameParams &game_params, const Settings &cmd_args)
+{
+       std::string migrate_to = cmd_args.get("migrate-auth");
+       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;
+       }
+
+       std::string backend = "files";
+       if (world_mt.exists("auth_backend"))
+               backend = world_mt.get("auth_backend");
+       else
+               warningstream << "No auth_backend found in world.mt, "
+                               "assuming \"files\"." << std::endl;
+
+       if (backend == migrate_to) {
+               errorstream << "Cannot migrate: new backend is same"
+                               << " as the old one" << std::endl;
+               return false;
+       }
+
+       try {
+               const std::unique_ptr<AuthDatabase> srcdb(ServerEnvironment::openAuthDatabase(
+                               backend, game_params.world_path, world_mt));
+               const std::unique_ptr<AuthDatabase> dstdb(ServerEnvironment::openAuthDatabase(
+                               migrate_to, game_params.world_path, world_mt));
+
+               std::vector<std::string> names_list;
+               srcdb->listNames(names_list);
+               for (const std::string &name : names_list) {
+                       actionstream << "Migrating auth entry for " << name << std::endl;
+                       bool success;
+                       AuthEntry authEntry;
+                       success = srcdb->getAuth(name, authEntry);
+                       success = success && dstdb->createAuth(authEntry);
+                       if (!success)
+                               errorstream << "Failed to migrate " << name << std::endl;
+               }
+
+               actionstream << "Successfully migrated " << names_list.size()
+                               << " auth entries" << std::endl;
+               world_mt.set("auth_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;
+
+               if (backend == "files") {
+                       // special-case files migration:
+                       // move auth.txt to auth.txt.bak if possible
+                       std::string auth_txt_path =
+                                       game_params.world_path + DIR_DELIM + "auth.txt";
+                       std::string auth_bak_path = auth_txt_path + ".bak";
+                       if (!fs::PathExists(auth_bak_path))
+                               if (fs::Rename(auth_txt_path, auth_bak_path))
+                                       actionstream << "Renamed auth.txt to auth.txt.bak"
+                                                       << std::endl;
+                               else
+                                       errorstream << "Could not rename auth.txt to "
+                                                       "auth.txt.bak" << std::endl;
+                       else
+                               warningstream << "auth.txt.bak already exists, auth.txt "
+                                               "not renamed" << std::endl;
+               }
+
+       } catch (BaseException &e) {
+               errorstream << "An error occurred during migration: " << e.what()
+                           << std::endl;
                return false;
        }
        return true;