]> git.lizzy.rs Git - dragonfireclient.git/blobdiff - src/map.cpp
Merge branch 'master' of https://github.com/minetest/minetest
[dragonfireclient.git] / src / map.cpp
index 9e8823f84de5cafb630a97c9941f3acf671e4389..7bc1334b0fbf9aa2238e7abfe29e2006e5c74628 100644 (file)
@@ -37,24 +37,24 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "environment.h"
 #include "reflowscan.h"
 #include "emerge.h"
-#include "mapgen_v6.h"
-#include "mg_biome.h"
+#include "mapgen/mapgen_v6.h"
+#include "mapgen/mg_biome.h"
 #include "config.h"
 #include "server.h"
-#include "database.h"
-#include "database-dummy.h"
-#include "database-sqlite3.h"
+#include "database/database.h"
+#include "database/database-dummy.h"
+#include "database/database-sqlite3.h"
 #include "script/scripting_server.h"
 #include <deque>
 #include <queue>
 #if USE_LEVELDB
-#include "database-leveldb.h"
+#include "database/database-leveldb.h"
 #endif
 #if USE_REDIS
-#include "database-redis.h"
+#include "database/database-redis.h"
 #endif
 #if USE_POSTGRESQL
-#include "database-postgresql.h"
+#include "database/database-postgresql.h"
 #endif
 
 
@@ -62,15 +62,9 @@ with this program; if not, write to the Free Software Foundation, Inc.,
        Map
 */
 
-Map::Map(std::ostream &dout, IGameDef *gamedef):
-       m_dout(dout),
+Map::Map(IGameDef *gamedef):
        m_gamedef(gamedef),
-       m_sector_cache(NULL),
-       m_nodedef(gamedef->ndef()),
-       m_transforming_liquid_loop_count_multiplier(1.0f),
-       m_unprocessed_count(0),
-       m_inc_trending_up_start_time(0),
-       m_queue_size_timer_started(false)
+       m_nodedef(gamedef->ndef())
 {
 }
 
@@ -79,10 +73,8 @@ Map::~Map()
        /*
                Free all MapSectors
        */
-       for(std::map<v2s16, MapSector*>::iterator i = m_sectors.begin();
-               i != m_sectors.end(); ++i)
-       {
-               delete i->second;
+       for (auto &sector : m_sectors) {
+               delete sector.second;
        }
 }
 
@@ -96,17 +88,14 @@ void Map::removeEventReceiver(MapEventReceiver *event_receiver)
        m_event_receivers.erase(event_receiver);
 }
 
-void Map::dispatchEvent(MapEditEvent *event)
+void Map::dispatchEvent(const MapEditEvent &event)
 {
-       for(std::set<MapEventReceiver*>::iterator
-                       i = m_event_receivers.begin();
-                       i != m_event_receivers.end(); ++i)
-       {
-               (*i)->onMapEditEvent(event);
+       for (MapEventReceiver *event_receiver : m_event_receivers) {
+               event_receiver->onMapEditEvent(event);
        }
 }
 
-MapSector * Map::getSectorNoGenerateNoExNoLock(v2s16 p)
+MapSector * Map::getSectorNoGenerateNoLock(v2s16 p)
 {
        if(m_sector_cache != NULL && p == m_sector_cache_p){
                MapSector * sector = m_sector_cache;
@@ -115,7 +104,7 @@ MapSector * Map::getSectorNoGenerateNoExNoLock(v2s16 p)
 
        std::map<v2s16, MapSector*>::iterator n = m_sectors.find(p);
 
-       if(n == m_sectors.end())
+       if (n == m_sectors.end())
                return NULL;
 
        MapSector *sector = n->second;
@@ -127,24 +116,15 @@ MapSector * Map::getSectorNoGenerateNoExNoLock(v2s16 p)
        return sector;
 }
 
-MapSector * Map::getSectorNoGenerateNoEx(v2s16 p)
-{
-       return getSectorNoGenerateNoExNoLock(p);
-}
-
 MapSector * Map::getSectorNoGenerate(v2s16 p)
 {
-       MapSector *sector = getSectorNoGenerateNoEx(p);
-       if(sector == NULL)
-               throw InvalidPositionException();
-
-       return sector;
+       return getSectorNoGenerateNoLock(p);
 }
 
 MapBlock * Map::getBlockNoCreateNoEx(v3s16 p3d)
 {
        v2s16 p2d(p3d.X, p3d.Z);
-       MapSector * sector = getSectorNoGenerateNoEx(p2d);
+       MapSector * sector = getSectorNoGenerate(p2d);
        if(sector == NULL)
                return NULL;
        MapBlock *block = sector->getBlockNoCreateNoEx(p3d.Y);
@@ -159,16 +139,18 @@ MapBlock * Map::getBlockNoCreate(v3s16 p3d)
        return block;
 }
 
-bool Map::isNodeUnderground(v3s16 p)
+void Map::listAllLoadedBlocks(std::vector<v3s16> &dst)
 {
-       v3s16 blockpos = getNodeBlockPos(p);
-       try{
-               MapBlock * block = getBlockNoCreate(blockpos);
-               return block->getIsUnderground();
-       }
-       catch(InvalidPositionException &e)
-       {
-               return false;
+       for (auto &sector_it : m_sectors) {
+               MapSector *sector = sector_it.second;
+
+               MapBlockVect blocks;
+               sector->getBlocks(blocks);
+
+               for (MapBlock *block : blocks) {
+                       v3s16 p = block->getPos();
+                       dst.push_back(p);
+               }
        }
 }
 
@@ -180,14 +162,14 @@ bool Map::isValidPosition(v3s16 p)
 }
 
 // Returns a CONTENT_IGNORE node if not found
-MapNode Map::getNodeNoEx(v3s16 p, bool *is_valid_position)
+MapNode Map::getNode(v3s16 p, bool *is_valid_position)
 {
        v3s16 blockpos = getNodeBlockPos(p);
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
        if (block == NULL) {
                if (is_valid_position != NULL)
                        *is_valid_position = false;
-               return MapNode(CONTENT_IGNORE);
+               return {CONTENT_IGNORE};
        }
 
        v3s16 relpos = p - blockpos*MAP_BLOCKSIZE;
@@ -198,24 +180,22 @@ MapNode Map::getNodeNoEx(v3s16 p, bool *is_valid_position)
        return node;
 }
 
-#if 0
-// Deprecated
-// throws InvalidPositionException if not found
-// TODO: Now this is deprecated, getNodeNoEx should be renamed
-MapNode Map::getNode(v3s16 p)
+static void set_node_in_block(MapBlock *block, v3s16 relpos, MapNode n)
 {
-       v3s16 blockpos = getNodeBlockPos(p);
-       MapBlock *block = getBlockNoCreateNoEx(blockpos);
-       if (block == NULL)
-               throw InvalidPositionException();
-       v3s16 relpos = p - blockpos*MAP_BLOCKSIZE;
-       bool is_valid_position;
-       MapNode node = block->getNodeNoCheck(relpos, &is_valid_position);
-       if (!is_valid_position)
-               throw InvalidPositionException();
-       return node;
+       // Never allow placing CONTENT_IGNORE, it causes problems
+       if(n.getContent() == CONTENT_IGNORE){
+               const NodeDefManager *nodedef = block->getParent()->getNodeDefManager();
+               v3s16 blockpos = block->getPos();
+               v3s16 p = blockpos * MAP_BLOCKSIZE + relpos;
+               bool temp_bool;
+               errorstream<<"Not allowing to place CONTENT_IGNORE"
+                               <<" while trying to replace \""
+                               <<nodedef->get(block->getNodeNoCheck(relpos, &temp_bool)).name
+                               <<"\" at "<<PP(p)<<" (block "<<PP(blockpos)<<")"<<std::endl;
+               return;
+       }
+       block->setNodeNoCheck(relpos, n);
 }
-#endif
 
 // throws InvalidPositionException if not found
 void Map::setNode(v3s16 p, MapNode & n)
@@ -223,17 +203,7 @@ void Map::setNode(v3s16 p, MapNode & n)
        v3s16 blockpos = getNodeBlockPos(p);
        MapBlock *block = getBlockNoCreate(blockpos);
        v3s16 relpos = p - blockpos*MAP_BLOCKSIZE;
-       // Never allow placing CONTENT_IGNORE, it fucks up stuff
-       if(n.getContent() == CONTENT_IGNORE){
-               bool temp_bool;
-               errorstream<<"Map::setNode(): Not allowing to place CONTENT_IGNORE"
-                               <<" while trying to replace \""
-                               <<m_nodedef->get(block->getNodeNoCheck(relpos, &temp_bool)).name
-                               <<"\" at "<<PP(p)<<" (block "<<PP(blockpos)<<")"<<std::endl;
-               debug_stacks_print_to(infostream);
-               return;
-       }
-       block->setNodeNoCheck(relpos, n);
+       set_node_in_block(block, relpos, n);
 }
 
 void Map::addNodeAndUpdate(v3s16 p, MapNode n,
@@ -243,8 +213,14 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
        // Collect old node for rollback
        RollbackNode rollback_oldnode(this, p, m_gamedef);
 
+       v3s16 blockpos = getNodeBlockPos(p);
+       MapBlock *block = getBlockNoCreate(blockpos);
+       if (block->isDummy())
+               throw InvalidPositionException();
+       v3s16 relpos = p - blockpos * MAP_BLOCKSIZE;
+
        // This is needed for updating the lighting
-       MapNode oldnode = getNodeNoEx(p);
+       MapNode oldnode = block->getNodeUnsafe(relpos);
 
        // Remove node metadata
        if (remove_metadata) {
@@ -252,21 +228,29 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
        }
 
        // Set the node on the map
-       // Ignore light (because calling voxalgo::update_lighting_nodes)
-       n.setLight(LIGHTBANK_DAY, 0, m_nodedef);
-       n.setLight(LIGHTBANK_NIGHT, 0, m_nodedef);
-       setNode(p, n);
-
-       // Update lighting
-       std::vector<std::pair<v3s16, MapNode> > oldnodes;
-       oldnodes.push_back(std::pair<v3s16, MapNode>(p, oldnode));
-       voxalgo::update_lighting_nodes(this, oldnodes, modified_blocks);
-
-       for(std::map<v3s16, MapBlock*>::iterator
-                       i = modified_blocks.begin();
-                       i != modified_blocks.end(); ++i)
-       {
-               i->second->expireDayNightDiff();
+       const ContentFeatures &cf = m_nodedef->get(n);
+       const ContentFeatures &oldcf = m_nodedef->get(oldnode);
+       if (cf.lightingEquivalent(oldcf)) {
+               // No light update needed, just copy over the old light.
+               n.setLight(LIGHTBANK_DAY, oldnode.getLightRaw(LIGHTBANK_DAY, oldcf), cf);
+               n.setLight(LIGHTBANK_NIGHT, oldnode.getLightRaw(LIGHTBANK_NIGHT, oldcf), cf);
+               set_node_in_block(block, relpos, n);
+
+               modified_blocks[blockpos] = block;
+       } else {
+               // Ignore light (because calling voxalgo::update_lighting_nodes)
+               n.setLight(LIGHTBANK_DAY, 0, cf);
+               n.setLight(LIGHTBANK_NIGHT, 0, cf);
+               set_node_in_block(block, relpos, n);
+
+               // Update lighting
+               std::vector<std::pair<v3s16, MapNode> > oldnodes;
+               oldnodes.emplace_back(p, oldnode);
+               voxalgo::update_lighting_nodes(this, oldnodes, modified_blocks);
+
+               for (auto &modified_block : modified_blocks) {
+                       modified_block.second->expireDayNightDiff();
+               }
        }
 
        // Report for rollback
@@ -277,31 +261,6 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
                action.setSetNode(p, rollback_oldnode, rollback_newnode);
                m_gamedef->rollback()->reportAction(action);
        }
-
-       /*
-               Add neighboring liquid nodes and this node to transform queue.
-               (it's vital for the node itself to get updated last, if it was removed.)
-        */
-       v3s16 dirs[7] = {
-               v3s16(0,0,1), // back
-               v3s16(0,1,0), // top
-               v3s16(1,0,0), // right
-               v3s16(0,0,-1), // front
-               v3s16(0,-1,0), // bottom
-               v3s16(-1,0,0), // left
-               v3s16(0,0,0), // self
-       };
-       for(u16 i=0; i<7; i++)
-       {
-               v3s16 p2 = p + dirs[i];
-
-               bool is_valid_position;
-               MapNode n2 = getNodeNoEx(p2, &is_valid_position);
-               if(is_valid_position &&
-                               (m_nodedef->get(n2).isLiquid() ||
-                               n2.getContent() == CONTENT_AIR))
-                       m_transforming_liquid.push_back(p2);
-       }
 }
 
 void Map::removeNodeAndUpdate(v3s16 p,
@@ -323,18 +282,15 @@ bool Map::addNodeWithEvent(v3s16 p, MapNode n, bool remove_metadata)
                addNodeAndUpdate(p, n, modified_blocks, remove_metadata);
 
                // Copy modified_blocks to event
-               for(std::map<v3s16, MapBlock*>::iterator
-                               i = modified_blocks.begin();
-                               i != modified_blocks.end(); ++i)
-               {
-                       event.modified_blocks.insert(i->first);
+               for (auto &modified_block : modified_blocks) {
+                       event.modified_blocks.insert(modified_block.first);
                }
        }
        catch(InvalidPositionException &e){
                succeeded = false;
        }
 
-       dispatchEvent(&event);
+       dispatchEvent(event);
 
        return succeeded;
 }
@@ -351,79 +307,19 @@ bool Map::removeNodeWithEvent(v3s16 p)
                removeNodeAndUpdate(p, modified_blocks);
 
                // Copy modified_blocks to event
-               for(std::map<v3s16, MapBlock*>::iterator
-                               i = modified_blocks.begin();
-                               i != modified_blocks.end(); ++i)
-               {
-                       event.modified_blocks.insert(i->first);
+               for (auto &modified_block : modified_blocks) {
+                       event.modified_blocks.insert(modified_block.first);
                }
        }
        catch(InvalidPositionException &e){
                succeeded = false;
        }
 
-       dispatchEvent(&event);
+       dispatchEvent(event);
 
        return succeeded;
 }
 
-bool Map::getDayNightDiff(v3s16 blockpos)
-{
-       try{
-               v3s16 p = blockpos + v3s16(0,0,0);
-               MapBlock *b = getBlockNoCreate(p);
-               if(b->getDayNightDiff())
-                       return true;
-       }
-       catch(InvalidPositionException &e){}
-       // Leading edges
-       try{
-               v3s16 p = blockpos + v3s16(-1,0,0);
-               MapBlock *b = getBlockNoCreate(p);
-               if(b->getDayNightDiff())
-                       return true;
-       }
-       catch(InvalidPositionException &e){}
-       try{
-               v3s16 p = blockpos + v3s16(0,-1,0);
-               MapBlock *b = getBlockNoCreate(p);
-               if(b->getDayNightDiff())
-                       return true;
-       }
-       catch(InvalidPositionException &e){}
-       try{
-               v3s16 p = blockpos + v3s16(0,0,-1);
-               MapBlock *b = getBlockNoCreate(p);
-               if(b->getDayNightDiff())
-                       return true;
-       }
-       catch(InvalidPositionException &e){}
-       // Trailing edges
-       try{
-               v3s16 p = blockpos + v3s16(1,0,0);
-               MapBlock *b = getBlockNoCreate(p);
-               if(b->getDayNightDiff())
-                       return true;
-       }
-       catch(InvalidPositionException &e){}
-       try{
-               v3s16 p = blockpos + v3s16(0,1,0);
-               MapBlock *b = getBlockNoCreate(p);
-               if(b->getDayNightDiff())
-                       return true;
-       }
-       catch(InvalidPositionException &e){}
-       try{
-               v3s16 p = blockpos + v3s16(0,0,1);
-               MapBlock *b = getBlockNoCreate(p);
-               if(b->getDayNightDiff())
-                       return true;
-       }
-       catch(InvalidPositionException &e){}
-
-       return false;
-}
-
 struct TimeOrderedMapBlock {
        MapSector *sect;
        MapBlock *block;
@@ -445,7 +341,7 @@ struct TimeOrderedMapBlock {
 void Map::timerUpdate(float dtime, float unload_timeout, u32 max_loaded_blocks,
                std::vector<v3s16> *unloaded_blocks)
 {
-       bool save_before_unloading = (mapType() == MAPTYPE_SERVER);
+       bool save_before_unloading = maySaveBlocks();
 
        // Profile modified reasons
        Profiler modprofiler;
@@ -455,23 +351,20 @@ void Map::timerUpdate(float dtime, float unload_timeout, u32 max_loaded_blocks,
        u32 saved_blocks_count = 0;
        u32 block_count_all = 0;
 
+       const auto start_time = porting::getTimeUs();
        beginSave();
 
        // If there is no practical limit, we spare creation of mapblock_queue
        if (max_loaded_blocks == U32_MAX) {
-               for (std::map<v2s16, MapSector*>::iterator si = m_sectors.begin();
-                               si != m_sectors.end(); ++si) {
-                       MapSector *sector = si->second;
+               for (auto &sector_it : m_sectors) {
+                       MapSector *sector = sector_it.second;
 
                        bool all_blocks_deleted = true;
 
                        MapBlockVect blocks;
                        sector->getBlocks(blocks);
 
-                       for (MapBlockVect::iterator i = blocks.begin();
-                                       i != blocks.end(); ++i) {
-                               MapBlock *block = (*i);
-
+                       for (MapBlock *block : blocks) {
                                block->incrementUsageTimer(dtime);
 
                                if (block->refGet() == 0
@@ -500,28 +393,26 @@ void Map::timerUpdate(float dtime, float unload_timeout, u32 max_loaded_blocks,
                                }
                        }
 
+                       // Delete sector if we emptied it
                        if (all_blocks_deleted) {
-                               sector_deletion_queue.push_back(si->first);
+                               sector_deletion_queue.push_back(sector_it.first);
                        }
                }
        } else {
                std::priority_queue<TimeOrderedMapBlock> mapblock_queue;
-               for (std::map<v2s16, MapSector*>::iterator si = m_sectors.begin();
-                               si != m_sectors.end(); ++si) {
-                       MapSector *sector = si->second;
+               for (auto &sector_it : m_sectors) {
+                       MapSector *sector = sector_it.second;
 
                        MapBlockVect blocks;
                        sector->getBlocks(blocks);
 
-                       for(MapBlockVect::iterator i = blocks.begin();
-                                       i != blocks.end(); ++i) {
-                               MapBlock *block = (*i);
-
+                       for (MapBlock *block : blocks) {
                                block->incrementUsageTimer(dtime);
                                mapblock_queue.push(TimeOrderedMapBlock(sector, block));
                        }
                }
                block_count_all = mapblock_queue.size();
+
                // Delete old blocks, and blocks over the limit from the memory
                while (!mapblock_queue.empty() && (mapblock_queue.size() > max_loaded_blocks
                                || mapblock_queue.top().block->getUsageTimer() > unload_timeout)) {
@@ -552,15 +443,19 @@ void Map::timerUpdate(float dtime, float unload_timeout, u32 max_loaded_blocks,
                        deleted_blocks_count++;
                        block_count_all--;
                }
+
                // Delete empty sectors
-               for (std::map<v2s16, MapSector*>::iterator si = m_sectors.begin();
-                       si != m_sectors.end(); ++si) {
-                       if (si->second->empty()) {
-                               sector_deletion_queue.push_back(si->first);
+               for (auto &sector_it : m_sectors) {
+                       if (sector_it.second->empty()) {
+                               sector_deletion_queue.push_back(sector_it.first);
                        }
                }
        }
+
        endSave();
+       const auto end_time = porting::getTimeUs();
+
+       reportMetrics(end_time - start_time, saved_blocks_count, block_count_all);
 
        // Finally delete the empty sectors
        deleteSectors(sector_deletion_queue);
@@ -589,14 +484,13 @@ void Map::unloadUnreferencedBlocks(std::vector<v3s16> *unloaded_blocks)
 
 void Map::deleteSectors(std::vector<v2s16> &sectorList)
 {
-       for(std::vector<v2s16>::iterator j = sectorList.begin();
-               j != sectorList.end(); ++j) {
-               MapSector *sector = m_sectors[*j];
+       for (v2s16 j : sectorList) {
+               MapSector *sector = m_sectors[j];
                // If sector is in sector cache, remove it from there
                if(m_sector_cache == sector)
                        m_sector_cache = NULL;
                // Remove from map and delete
-               m_sectors.erase(*j);
+               m_sectors.erase(j);
                delete sector;
        }
 }
@@ -608,42 +502,45 @@ void Map::PrintInfo(std::ostream &out)
 
 #define WATER_DROP_BOOST 4
 
-enum NeighborType {
+const static v3s16 liquid_6dirs[6] = {
+       // order: upper before same level before lower
+       v3s16( 0, 1, 0),
+       v3s16( 0, 0, 1),
+       v3s16( 1, 0, 0),
+       v3s16( 0, 0,-1),
+       v3s16(-1, 0, 0),
+       v3s16( 0,-1, 0)
+};
+
+enum NeighborType : u8 {
        NEIGHBOR_UPPER,
        NEIGHBOR_SAME_LEVEL,
        NEIGHBOR_LOWER
 };
+
 struct NodeNeighbor {
        MapNode n;
        NeighborType t;
        v3s16 p;
-       bool l; //can liquid
 
        NodeNeighbor()
-               : n(CONTENT_AIR)
+               : n(CONTENT_AIR), t(NEIGHBOR_SAME_LEVEL)
        { }
 
-       NodeNeighbor(const MapNode &node, NeighborType n_type, v3s16 pos)
+       NodeNeighbor(const MapNode &node, NeighborType n_type, const v3s16 &pos)
                : n(node),
                  t(n_type),
                  p(pos)
        { }
 };
 
-void Map::transforming_liquid_add(v3s16 p) {
+void ServerMap::transforming_liquid_add(v3s16 p) {
         m_transforming_liquid.push_back(p);
 }
 
-s32 Map::transforming_liquid_size() {
-        return m_transforming_liquid.size();
-}
-
-void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
+void ServerMap::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                ServerEnvironment *env)
 {
-       DSTACK(FUNCTION_NAME);
-       //TimeTaker timer("transformLiquids()");
-
        u32 loopcount = 0;
        u32 initial_size = m_transforming_liquid.size();
 
@@ -658,23 +555,6 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
        u32 liquid_loop_max = g_settings->getS32("liquid_loop_max");
        u32 loop_max = liquid_loop_max;
 
-#if 0
-
-       /* If liquid_loop_max is not keeping up with the queue size increase
-        * loop_max up to a maximum of liquid_loop_max * dedicated_server_step.
-        */
-       if (m_transforming_liquid.size() > loop_max * 2) {
-               // "Burst" mode
-               float server_step = g_settings->getFloat("dedicated_server_step");
-               if (m_transforming_liquid_loop_count_multiplier - 1.0 < server_step)
-                       m_transforming_liquid_loop_count_multiplier *= 1.0 + server_step / 10;
-       } else {
-               m_transforming_liquid_loop_count_multiplier = 1.0;
-       }
-
-       loop_max *= m_transforming_liquid_loop_count_multiplier;
-#endif
-
        while (m_transforming_liquid.size() != 0)
        {
                // This should be done here so that it is done when continue is used
@@ -688,7 +568,7 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                v3s16 p0 = m_transforming_liquid.front();
                m_transforming_liquid.pop_front();
 
-               MapNode n0 = getNodeNoEx(p0);
+               MapNode n0 = getNode(p0);
 
                /*
                        Collect information about current node
@@ -705,7 +585,7 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                switch (liquid_type) {
                        case LIQUID_SOURCE:
                                liquid_level = LIQUID_LEVEL_SOURCE;
-                               liquid_kind = m_nodedef->getId(cf.liquid_alternative_flowing);
+                               liquid_kind = cf.liquid_alternative_flowing_id;
                                break;
                        case LIQUID_FLOWING:
                                liquid_level = (n0.param2 & LIQUID_LEVEL_MASK);
@@ -724,7 +604,6 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                /*
                        Collect information about the environment
                 */
-               const v3s16 *dirs = g_6dirs;
                NodeNeighbor sources[6]; // surrounding sources
                int num_sources = 0;
                NodeNeighbor flows[6]; // surrounding flowing liquid nodes
@@ -738,15 +617,17 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                for (u16 i = 0; i < 6; i++) {
                        NeighborType nt = NEIGHBOR_SAME_LEVEL;
                        switch (i) {
-                               case 1:
+                               case 0:
                                        nt = NEIGHBOR_UPPER;
                                        break;
-                               case 4:
+                               case 5:
                                        nt = NEIGHBOR_LOWER;
                                        break;
+                               default:
+                                       break;
                        }
-                       v3s16 npos = p0 + dirs[i];
-                       NodeNeighbor nb(getNodeNoEx(npos), nt, npos);
+                       v3s16 npos = p0 + liquid_6dirs[i];
+                       NodeNeighbor nb(getNode(npos), nt, npos);
                        const ContentFeatures &cfnb = m_nodedef->get(nb.n);
                        switch (m_nodedef->get(nb.n.getContent()).liquid_type) {
                                case LIQUID_NONE:
@@ -776,20 +657,24 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                                case LIQUID_SOURCE:
                                        // if this node is not (yet) of a liquid type, choose the first liquid type we encounter
                                        if (liquid_kind == CONTENT_AIR)
-                                               liquid_kind = m_nodedef->getId(cfnb.liquid_alternative_flowing);
-                                       if (m_nodedef->getId(cfnb.liquid_alternative_flowing) != liquid_kind) {
+                                               liquid_kind = cfnb.liquid_alternative_flowing_id;
+                                       if (cfnb.liquid_alternative_flowing_id != liquid_kind) {
                                                neutrals[num_neutrals++] = nb;
                                        } else {
                                                // Do not count bottom source, it will screw things up
-                                               if(dirs[i].Y != -1)
+                                               if(nt != NEIGHBOR_LOWER)
                                                        sources[num_sources++] = nb;
                                        }
                                        break;
                                case LIQUID_FLOWING:
-                                       // if this node is not (yet) of a liquid type, choose the first liquid type we encounter
-                                       if (liquid_kind == CONTENT_AIR)
-                                               liquid_kind = m_nodedef->getId(cfnb.liquid_alternative_flowing);
-                                       if (m_nodedef->getId(cfnb.liquid_alternative_flowing) != liquid_kind) {
+                                       if (nb.t != NEIGHBOR_SAME_LEVEL ||
+                                               (nb.n.param2 & LIQUID_FLOW_DOWN_MASK) != LIQUID_FLOW_DOWN_MASK) {
+                                               // if this node is not (yet) of a liquid type, choose the first liquid type we encounter
+                                               // but exclude falling liquids on the same level, they cannot flow here anyway
+                                               if (liquid_kind == CONTENT_AIR)
+                                                       liquid_kind = cfnb.liquid_alternative_flowing_id;
+                                       }
+                                       if (cfnb.liquid_alternative_flowing_id != liquid_kind) {
                                                neutrals[num_neutrals++] = nb;
                                        } else {
                                                flows[num_flows++] = nb;
@@ -815,7 +700,7 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                        // liquid_kind will be set to either the flowing alternative of the node (if it's a liquid)
                        // or the flowing alternative of the first of the surrounding sources (if it's air), so
                        // it's perfectly safe to use liquid_kind here to determine the new node content.
-                       new_node_content = m_nodedef->getId(m_nodedef->get(liquid_kind).liquid_alternative_source);
+                       new_node_content = m_nodedef->get(liquid_kind).liquid_alternative_source_id;
                } else if (num_sources >= 1 && sources[0].t != NEIGHBOR_LOWER) {
                        // liquid_kind is set properly, see above
                        max_node_level = new_node_level = LIQUID_LEVEL_MAX;
@@ -896,8 +781,8 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                        // set level to last 3 bits, flowing down bit to 4th bit
                        n0.param2 = (flowing_down ? LIQUID_FLOW_DOWN_MASK : 0x00) | (new_node_level & LIQUID_LEVEL_MASK);
                } else {
-                       // set the liquid level and flow bit to 0
-                       n0.param2 = ~(LIQUID_LEVEL_MASK | LIQUID_FLOW_DOWN_MASK);
+                       // set the liquid level and flow bits to 0
+                       n0.param2 &= ~(LIQUID_LEVEL_MASK | LIQUID_FLOW_DOWN_MASK);
                }
 
                // change the node.
@@ -939,7 +824,7 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
                MapBlock *block = getBlockNoCreateNoEx(blockpos);
                if (block != NULL) {
                        modified_blocks[blockpos] =  block;
-                       changed_nodes.push_back(std::pair<v3s16, MapNode>(p0, n00));
+                       changed_nodes.emplace_back(p0, n00);
                }
 
                /*
@@ -965,11 +850,11 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
        }
        //infostream<<"Map::transformLiquids(): loopcount="<<loopcount<<std::endl;
 
-       for (std::deque<v3s16>::iterator iter = must_reflow.begin(); iter != must_reflow.end(); ++iter)
-               m_transforming_liquid.push_back(*iter);
+       for (auto &iter : must_reflow)
+               m_transforming_liquid.push_back(iter);
 
        voxalgo::update_lighting_nodes(this, changed_nodes, modified_blocks);
-
+       env->getScriptIface()->on_liquid_transformed(changed_nodes);
 
        /* ----------------------------------------------------------------------
         * Manage the queue so that it does not grow indefinately
@@ -981,7 +866,7 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks,
 
        time_until_purge *= 1000;       // seconds -> milliseconds
 
-       u32 curr_time = getTime(PRECISION_MILLI);
+       u64 curr_time = porting::getTimeMs();
        u32 prev_unprocessed = m_unprocessed_count;
        m_unprocessed_count = m_transforming_liquid.size();
 
@@ -1167,24 +1052,95 @@ void Map::removeNodeTimer(v3s16 p)
        block->m_node_timers.remove(p_rel);
 }
 
-bool Map::isOccluded(v3s16 p0, v3s16 p1, float step, float stepfac,
-               float start_off, float end_off, u32 needed_count)
+bool Map::determineAdditionalOcclusionCheck(const v3s16 &pos_camera,
+       const core::aabbox3d<s16> &block_bounds, v3s16 &check)
+{
+       /*
+               This functions determines the node inside the target block that is
+               closest to the camera position. This increases the occlusion culling
+               accuracy in straight and diagonal corridors.
+               The returned position will be occlusion checked first in addition to the
+               others (8 corners + center).
+               No position is returned if
+               - the closest node is a corner, corners are checked anyway.
+               - the camera is inside the target block, it will never be occluded.
+       */
+#define CLOSEST_EDGE(pos, bounds, axis) \
+       ((pos).axis <= (bounds).MinEdge.axis) ? (bounds).MinEdge.axis : \
+       (bounds).MaxEdge.axis
+
+       bool x_inside = (block_bounds.MinEdge.X <= pos_camera.X) &&
+                       (pos_camera.X <= block_bounds.MaxEdge.X);
+       bool y_inside = (block_bounds.MinEdge.Y <= pos_camera.Y) &&
+                       (pos_camera.Y <= block_bounds.MaxEdge.Y);
+       bool z_inside = (block_bounds.MinEdge.Z <= pos_camera.Z) &&
+                       (pos_camera.Z <= block_bounds.MaxEdge.Z);
+
+       if (x_inside && y_inside && z_inside)
+               return false; // Camera inside target mapblock
+
+       // straight
+       if (x_inside && y_inside) {
+               check = v3s16(pos_camera.X, pos_camera.Y, 0);
+               check.Z = CLOSEST_EDGE(pos_camera, block_bounds, Z);
+               return true;
+       } else if (y_inside && z_inside) {
+               check = v3s16(0, pos_camera.Y, pos_camera.Z);
+               check.X = CLOSEST_EDGE(pos_camera, block_bounds, X);
+               return true;
+       } else if (x_inside && z_inside) {
+               check = v3s16(pos_camera.X, 0, pos_camera.Z);
+               check.Y = CLOSEST_EDGE(pos_camera, block_bounds, Y);
+               return true;
+       }
+
+       // diagonal
+       if (x_inside) {
+               check = v3s16(pos_camera.X, 0, 0);
+               check.Y = CLOSEST_EDGE(pos_camera, block_bounds, Y);
+               check.Z = CLOSEST_EDGE(pos_camera, block_bounds, Z);
+               return true;
+       } else if (y_inside) {
+               check = v3s16(0, pos_camera.Y, 0);
+               check.X = CLOSEST_EDGE(pos_camera, block_bounds, X);
+               check.Z = CLOSEST_EDGE(pos_camera, block_bounds, Z);
+               return true;
+       } else if (z_inside) {
+               check = v3s16(0, 0, pos_camera.Z);
+               check.X = CLOSEST_EDGE(pos_camera, block_bounds, X);
+               check.Y = CLOSEST_EDGE(pos_camera, block_bounds, Y);
+               return true;
+       }
+
+       // Closest node would be a corner, none returned
+       return false;
+}
+
+bool Map::isOccluded(const v3s16 &pos_camera, const v3s16 &pos_target,
+       float step, float stepfac, float offset, float end_offset, u32 needed_count)
 {
-       float d0 = (float)BS * p0.getDistanceFrom(p1);
-       v3s16 u0 = p1 - p0;
-       v3f uf = v3f(u0.X, u0.Y, u0.Z) * BS;
-       uf.normalize();
-       v3f p0f = v3f(p0.X, p0.Y, p0.Z) * BS;
+       v3f direction = intToFloat(pos_target - pos_camera, BS);
+       float distance = direction.getLength();
+
+       // Normalize direction vector
+       if (distance > 0.0f)
+               direction /= distance;
+
+       v3f pos_origin_f = intToFloat(pos_camera, BS);
        u32 count = 0;
-       for(float s=start_off; s<d0+end_off; s+=step){
-               v3f pf = p0f + uf * s;
-               v3s16 p = floatToInt(pf, BS);
-               MapNode n = getNodeNoEx(p);
-               const ContentFeatures &f = m_nodedef->get(n);
-               if(f.drawtype == NDT_NORMAL){
-                       // not transparent, see ContentFeature::updateTextures
+       bool is_valid_position;
+
+       for (; offset < distance + end_offset; offset += step) {
+               v3f pos_node_f = pos_origin_f + direction * offset;
+               v3s16 pos_node = floatToInt(pos_node_f, BS);
+
+               MapNode node = getNode(pos_node, &is_valid_position);
+
+               if (is_valid_position &&
+                               !m_nodedef->get(node).light_propagates) {
+                       // Cannot see through light-blocking nodes --> occluded
                        count++;
-                       if(count >= needed_count)
+                       if (count >= needed_count)
                                return true;
                }
                step *= stepfac;
@@ -1192,56 +1148,69 @@ bool Map::isOccluded(v3s16 p0, v3s16 p1, float step, float stepfac,
        return false;
 }
 
-bool Map::isBlockOccluded(MapBlock *block, v3s16 cam_pos_nodes) {
-       v3s16 cpn = block->getPos() * MAP_BLOCKSIZE;
-       cpn += v3s16(MAP_BLOCKSIZE / 2, MAP_BLOCKSIZE / 2, MAP_BLOCKSIZE / 2);
-       float step = BS * 1;
-       float stepfac = 1.1;
-       float startoff = BS * 1;
+bool Map::isBlockOccluded(MapBlock *block, v3s16 cam_pos_nodes)
+{
+       // Check occlusion for center and all 8 corners of the mapblock
+       // Overshoot a little for less flickering
+       static const s16 bs2 = MAP_BLOCKSIZE / 2 + 1;
+       static const v3s16 dir9[9] = {
+               v3s16( 0,  0,  0),
+               v3s16( 1,  1,  1) * bs2,
+               v3s16( 1,  1, -1) * bs2,
+               v3s16( 1, -1,  1) * bs2,
+               v3s16( 1, -1, -1) * bs2,
+               v3s16(-1,  1,  1) * bs2,
+               v3s16(-1,  1, -1) * bs2,
+               v3s16(-1, -1,  1) * bs2,
+               v3s16(-1, -1, -1) * bs2,
+       };
+
+       v3s16 pos_blockcenter = block->getPosRelative() + (MAP_BLOCKSIZE / 2);
+
+       // Starting step size, value between 1m and sqrt(3)m
+       float step = BS * 1.2f;
+       // Multiply step by each iteraction by 'stepfac' to reduce checks in distance
+       float stepfac = 1.05f;
+
+       float start_offset = BS * 1.0f;
+
        // The occlusion search of 'isOccluded()' must stop short of the target
-       // point by distance 'endoff' (end offset) to not enter the target mapblock.
-       // For the 8 mapblock corners 'endoff' must therefore be the maximum diagonal
-       // of a mapblock, because we must consider all view angles.
+       // point by distance 'end_offset' to not enter the target mapblock.
+       // For the 8 mapblock corners 'end_offset' must therefore be the maximum
+       // diagonal of a mapblock, because we must consider all view angles.
        // sqrt(1^2 + 1^2 + 1^2) = 1.732
-       float endoff = -BS * MAP_BLOCKSIZE * 1.732050807569;
-       v3s16 spn = cam_pos_nodes;
-       s16 bs2 = MAP_BLOCKSIZE / 2 + 1;
+       float end_offset = -BS * MAP_BLOCKSIZE * 1.732f;
+
        // to reduce the likelihood of falsely occluded blocks
        // require at least two solid blocks
        // this is a HACK, we should think of a more precise algorithm
        u32 needed_count = 2;
 
-       return (
-               // For the central point of the mapblock 'endoff' can be halved
-               isOccluded(spn, cpn,
-                       step, stepfac, startoff, endoff / 2.0f, needed_count) &&
-               isOccluded(spn, cpn + v3s16(bs2,bs2,bs2),
-                       step, stepfac, startoff, endoff, needed_count) &&
-               isOccluded(spn, cpn + v3s16(bs2,bs2,-bs2),
-                       step, stepfac, startoff, endoff, needed_count) &&
-               isOccluded(spn, cpn + v3s16(bs2,-bs2,bs2),
-                       step, stepfac, startoff, endoff, needed_count) &&
-               isOccluded(spn, cpn + v3s16(bs2,-bs2,-bs2),
-                       step, stepfac, startoff, endoff, needed_count) &&
-               isOccluded(spn, cpn + v3s16(-bs2,bs2,bs2),
-                       step, stepfac, startoff, endoff, needed_count) &&
-               isOccluded(spn, cpn + v3s16(-bs2,bs2,-bs2),
-                       step, stepfac, startoff, endoff, needed_count) &&
-               isOccluded(spn, cpn + v3s16(-bs2,-bs2,bs2),
-                       step, stepfac, startoff, endoff, needed_count) &&
-               isOccluded(spn, cpn + v3s16(-bs2,-bs2,-bs2),
-                       step, stepfac, startoff, endoff, needed_count));
+       // Additional occlusion check, see comments in that function
+       v3s16 check;
+       if (determineAdditionalOcclusionCheck(cam_pos_nodes, block->getBox(), check)) {
+               // node is always on a side facing the camera, end_offset can be lower
+               if (!isOccluded(cam_pos_nodes, check, step, stepfac, start_offset,
+                               -1.0f, needed_count))
+                       return false;
+       }
+
+       for (const v3s16 &dir : dir9) {
+               if (!isOccluded(cam_pos_nodes, pos_blockcenter + dir, step, stepfac,
+                               start_offset, end_offset, needed_count))
+                       return false;
+       }
+       return true;
 }
 
 /*
        ServerMap
 */
 ServerMap::ServerMap(const std::string &savedir, IGameDef *gamedef,
-               EmergeManager *emerge):
-       Map(dout_server, gamedef),
-       settings_mgr(g_settings, savedir + DIR_DELIM + "map_meta.txt"),
-       m_emerge(emerge),
-       m_map_metadata_changed(true)
+               EmergeManager *emerge, MetricsBackend *mb):
+       Map(gamedef),
+       settings_mgr(savedir + DIR_DELIM + "map_meta.txt"),
+       m_emerge(emerge)
 {
        verbosestream<<FUNCTION_NAME<<std::endl;
 
@@ -1262,21 +1231,30 @@ ServerMap::ServerMap(const std::string &savedir, IGameDef *gamedef,
        }
        std::string backend = conf.get("backend");
        dbase = createDatabase(backend, savedir, conf);
-
+       if (conf.exists("readonly_backend")) {
+               std::string readonly_dir = savedir + DIR_DELIM + "readonly";
+               dbase_ro = createDatabase(conf.get("readonly_backend"), readonly_dir, conf);
+       }
        if (!conf.updateConfigFile(conf_path.c_str()))
                errorstream << "ServerMap::ServerMap(): Failed to update world.mt!" << std::endl;
 
        m_savedir = savedir;
        m_map_saving_enabled = false;
 
-       try
-       {
+       m_save_time_counter = mb->addCounter(
+               "minetest_map_save_time", "Time spent saving blocks (in microseconds)");
+       m_save_count_counter = mb->addCounter(
+               "minetest_map_saved_blocks", "Number of blocks saved");
+       m_loaded_blocks_gauge = mb->addGauge(
+               "minetest_map_loaded_blocks", "Number of loaded blocks");
+
+       m_map_compression_level = rangelim(g_settings->getS16("map_compression_level_disk"), -1, 9);
+
+       try {
                // If directory exists, check contents and load if possible
-               if(fs::PathExists(m_savedir))
-               {
+               if (fs::PathExists(m_savedir)) {
                        // If directory is empty, it is safe to save into it.
-                       if(fs::GetDirListing(m_savedir).size() == 0)
-                       {
+                       if (fs::GetDirListing(m_savedir).empty()) {
                                infostream<<"ServerMap: Empty save directory is valid."
                                                <<std::endl;
                                m_map_saving_enabled = true;
@@ -1310,14 +1288,6 @@ ServerMap::ServerMap(const std::string &savedir, IGameDef *gamedef,
                infostream<<"Please remove the map or fix it."<<std::endl;
                warningstream<<"Map saving will be disabled."<<std::endl;
        }
-
-       infostream<<"Initializing new map."<<std::endl;
-
-       // Create zero sector
-       emergeSector(v2s16(0,0));
-
-       // Initially write whole map
-       save(MOD_STATE_CLEAN);
 }
 
 ServerMap::~ServerMap()
@@ -1326,15 +1296,12 @@ ServerMap::~ServerMap()
 
        try
        {
-               if(m_map_saving_enabled)
-               {
+               if (m_map_saving_enabled) {
                        // Save only changed parts
                        save(MOD_STATE_WRITE_AT_UNLOAD);
-                       infostream<<"ServerMap: Saved map to "<<m_savedir<<std::endl;
-               }
-               else
-               {
-                       infostream<<"ServerMap: Map not saved"<<std::endl;
+                       infostream << "ServerMap: Saved map to " << m_savedir << std::endl;
+               } else {
+                       infostream << "ServerMap: Map not saved" << std::endl;
                }
        }
        catch(std::exception &e)
@@ -1347,18 +1314,7 @@ ServerMap::~ServerMap()
                Close database if it was opened
        */
        delete dbase;
-
-#if 0
-       /*
-               Free all MapChunks
-       */
-       core::map<v2s16, MapChunk*>::Iterator i = m_chunks.getIterator();
-       for(; i.atEnd() == false; i++)
-       {
-               MapChunk *chunk = i.getNode()->getValue();
-               delete chunk;
-       }
-#endif
+       delete dbase_ro;
 }
 
 MapgenParams *ServerMap::getMapgenParams()
@@ -1373,11 +1329,6 @@ u64 ServerMap::getSeed()
        return getMapgenParams()->seed;
 }
 
-s16 ServerMap::getWaterLevel()
-{
-       return getMapgenParams()->water_level;
-}
-
 bool ServerMap::blockpos_over_mapgen_limit(v3s16 p)
 {
        const s16 mapgen_limit_bp = rangelim(
@@ -1397,6 +1348,9 @@ bool ServerMap::initBlockMake(v3s16 blockpos, BlockMakeData *data)
        v3s16 bpmin = EmergeManager::getContainingChunk(blockpos, csize);
        v3s16 bpmax = bpmin + v3s16(1, 1, 1) * (csize - 1);
 
+       if (!m_chunks_in_progress.insert(bpmin).second)
+               return false;
+
        bool enable_mapgen_debug_info = m_emerge->enable_mapgen_debug_info;
        EMERGE_DBG_OUT("initBlockMake(): " PP(bpmin) " - " PP(bpmax));
 
@@ -1412,7 +1366,6 @@ bool ServerMap::initBlockMake(v3s16 blockpos, BlockMakeData *data)
        data->seed = getSeed();
        data->blockpos_min = bpmin;
        data->blockpos_max = bpmax;
-       data->blockpos_requested = blockpos;
        data->nodedef = m_nodedef;
 
        /*
@@ -1422,7 +1375,7 @@ bool ServerMap::initBlockMake(v3s16 blockpos, BlockMakeData *data)
        for (s16 z = full_bpmin.Z; z <= full_bpmax.Z; z++) {
                v2s16 sectorpos(x, z);
                // Sector metadata is loaded from disk if not already loaded.
-               ServerMapSector *sector = createSector(sectorpos);
+               MapSector *sector = createSector(sectorpos);
                FATAL_ERROR_IF(sector == NULL, "createSector() failed");
 
                for (s16 y = full_bpmin.Y; y <= full_bpmax.Y; y++) {
@@ -1450,25 +1403,6 @@ bool ServerMap::initBlockMake(v3s16 blockpos, BlockMakeData *data)
        data->vmanip = new MMVManip(this);
        data->vmanip->initialEmerge(full_bpmin, full_bpmax);
 
-       // Note: we may need this again at some point.
-#if 0
-       // Ensure none of the blocks to be generated were marked as
-       // containing CONTENT_IGNORE
-       for (s16 z = blockpos_min.Z; z <= blockpos_max.Z; z++) {
-               for (s16 y = blockpos_min.Y; y <= blockpos_max.Y; y++) {
-                       for (s16 x = blockpos_min.X; x <= blockpos_max.X; x++) {
-                               core::map<v3s16, u8>::Node *n;
-                               n = data->vmanip->m_loaded_blocks.find(v3s16(x, y, z));
-                               if (n == NULL)
-                                       continue;
-                               u8 flags = n->getValue();
-                               flags &= ~VMANIP_BLOCK_CONTAINS_CIGNORE;
-                               n->setValue(flags);
-                       }
-               }
-       }
-#endif
-
        // Data is ready now.
        return true;
 }
@@ -1479,8 +1413,6 @@ void ServerMap::finishBlockMake(BlockMakeData *data,
        v3s16 bpmin = data->blockpos_min;
        v3s16 bpmax = data->blockpos_max;
 
-       v3s16 extra_borders(1, 1, 1);
-
        bool enable_mapgen_debug_info = m_emerge->enable_mapgen_debug_info;
        EMERGE_DBG_OUT("finishBlockMake(): " PP(bpmin) " - " PP(bpmax));
 
@@ -1501,10 +1433,8 @@ void ServerMap::finishBlockMake(BlockMakeData *data,
                data->transforming_liquid.pop_front();
        }
 
-       for (std::map<v3s16, MapBlock *>::iterator
-                       it = changed_blocks->begin();
-                       it != changed_blocks->end(); ++it) {
-               MapBlock *block = it->second;
+       for (auto &changed_block : *changed_blocks) {
+               MapBlock *block = changed_block.second;
                if (!block)
                        continue;
                /*
@@ -1536,60 +1466,29 @@ void ServerMap::finishBlockMake(BlockMakeData *data,
                NOTE: Will be saved later.
        */
        //save(MOD_STATE_WRITE_AT_UNLOAD);
+       m_chunks_in_progress.erase(bpmin);
 }
 
-ServerMapSector *ServerMap::createSector(v2s16 p2d)
+MapSector *ServerMap::createSector(v2s16 p2d)
 {
-       DSTACKF("%s: p2d=(%d,%d)",
-                       FUNCTION_NAME,
-                       p2d.X, p2d.Y);
-
        /*
                Check if it exists already in memory
        */
-       ServerMapSector *sector = (ServerMapSector*)getSectorNoGenerateNoEx(p2d);
-       if(sector != NULL)
-               return sector;
-
-       /*
-               Try to load it from disk (with blocks)
-       */
-       //if(loadSectorFull(p2d) == true)
-
-       /*
-               Try to load metadata from disk
-       */
-#if 0
-       if(loadSectorMeta(p2d) == true)
-       {
-               ServerMapSector *sector = (ServerMapSector*)getSectorNoGenerateNoEx(p2d);
-               if(sector == NULL)
-               {
-                       infostream<<"ServerMap::createSector(): loadSectorFull didn't make a sector"<<std::endl;
-                       throw InvalidPositionException("");
-               }
+       MapSector *sector = getSectorNoGenerate(p2d);
+       if (sector)
                return sector;
-       }
-#endif
 
        /*
                Do not create over max mapgen limit
        */
-       const s16 max_limit_bp = MAX_MAP_GENERATION_LIMIT / MAP_BLOCKSIZE;
-       if (p2d.X < -max_limit_bp ||
-                       p2d.X >  max_limit_bp ||
-                       p2d.Y < -max_limit_bp ||
-                       p2d.Y >  max_limit_bp)
+       if (blockpos_over_max_limit(v3s16(p2d.X, 0, p2d.Y)))
                throw InvalidPositionException("createSector(): pos. over max mapgen limit");
 
        /*
                Generate blank sector
        */
 
-       sector = new ServerMapSector(this, p2d, m_gamedef);
-
-       // Sector position on map in nodes
-       //v2s16 nodepos2d = p2d * MAP_BLOCKSIZE;
+       sector = new MapSector(this, p2d, m_gamedef);
 
        /*
                Insert to container
@@ -1599,127 +1498,8 @@ ServerMapSector *ServerMap::createSector(v2s16 p2d)
        return sector;
 }
 
-#if 0
-/*
-       This is a quick-hand function for calling makeBlock().
-*/
-MapBlock * ServerMap::generateBlock(
-               v3s16 p,
-               std::map<v3s16, MapBlock*> &modified_blocks
-)
-{
-       DSTACKF("%s: p=(%d,%d,%d)", FUNCTION_NAME, p.X, p.Y, p.Z);
-
-       /*infostream<<"generateBlock(): "
-                       <<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
-                       <<std::endl;*/
-
-       bool enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
-
-       TimeTaker timer("generateBlock");
-
-       //MapBlock *block = original_dummy;
-
-       v2s16 p2d(p.X, p.Z);
-       v2s16 p2d_nodes = p2d * MAP_BLOCKSIZE;
-
-       /*
-               Do not generate over-limit
-       */
-       if(blockpos_over_limit(p))
-       {
-               infostream<<FUNCTION_NAME<<": Block position over limit"<<std::endl;
-               throw InvalidPositionException("generateBlock(): pos. over limit");
-       }
-
-       /*
-               Create block make data
-       */
-       BlockMakeData data;
-       initBlockMake(&data, p);
-
-       /*
-               Generate block
-       */
-       {
-               TimeTaker t("mapgen::make_block()");
-               mapgen->makeChunk(&data);
-               //mapgen::make_block(&data);
-
-               if(enable_mapgen_debug_info == false)
-                       t.stop(true); // Hide output
-       }
-
-       /*
-               Blit data back on map, update lighting, add mobs and whatever this does
-       */
-       finishBlockMake(&data, modified_blocks);
-
-       /*
-               Get central block
-       */
-       MapBlock *block = getBlockNoCreateNoEx(p);
-
-#if 0
-       /*
-               Check result
-       */
-       if(block)
-       {
-               bool erroneus_content = false;
-               for(s16 z0=0; z0<MAP_BLOCKSIZE; z0++)
-               for(s16 y0=0; y0<MAP_BLOCKSIZE; y0++)
-               for(s16 x0=0; x0<MAP_BLOCKSIZE; x0++)
-               {
-                       v3s16 p(x0,y0,z0);
-                       MapNode n = block->getNode(p);
-                       if(n.getContent() == CONTENT_IGNORE)
-                       {
-                               infostream<<"CONTENT_IGNORE at "
-                                               <<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
-                                               <<std::endl;
-                               erroneus_content = true;
-                               assert(0);
-                       }
-               }
-               if(erroneus_content)
-               {
-                       assert(0);
-               }
-       }
-#endif
-
-#if 0
-       /*
-               Generate a completely empty block
-       */
-       if(block)
-       {
-               for(s16 z0=0; z0<MAP_BLOCKSIZE; z0++)
-               for(s16 x0=0; x0<MAP_BLOCKSIZE; x0++)
-               {
-                       for(s16 y0=0; y0<MAP_BLOCKSIZE; y0++)
-                       {
-                               MapNode n;
-                               n.setContent(CONTENT_AIR);
-                               block->setNode(v3s16(x0,y0,z0), n);
-                       }
-               }
-       }
-#endif
-
-       if(enable_mapgen_debug_info == false)
-               timer.stop(true); // Hide output
-
-       return block;
-}
-#endif
-
 MapBlock * ServerMap::createBlock(v3s16 p)
 {
-       DSTACKF("%s: p=(%d,%d,%d)",
-                       FUNCTION_NAME, p.X, p.Y, p.Z);
-
        /*
                Do not create over max mapgen limit
        */
@@ -1735,35 +1515,20 @@ MapBlock * ServerMap::createBlock(v3s16 p)
                NOTE: On old save formats, this will be slow, as it generates
                      lighting on blocks for them.
        */
-       ServerMapSector *sector;
+       MapSector *sector;
        try {
-               sector = (ServerMapSector*)createSector(p2d);
-               assert(sector->getId() == MAPSECTOR_SERVER);
-       }
-       catch(InvalidPositionException &e)
-       {
+               sector = createSector(p2d);
+       } catch (InvalidPositionException &e) {
                infostream<<"createBlock: createSector() failed"<<std::endl;
                throw e;
        }
-       /*
-               NOTE: This should not be done, or at least the exception
-               should not be passed on as std::exception, because it
-               won't be catched at all.
-       */
-       /*catch(std::exception &e)
-       {
-               infostream<<"createBlock: createSector() failed: "
-                               <<e.what()<<std::endl;
-               throw e;
-       }*/
 
        /*
                Try to get a block from the sector
        */
 
        MapBlock *block = sector->getBlockNoCreateNoEx(block_y);
-       if(block)
-       {
+       if (block) {
                if(block->isDummy())
                        block->unDummify();
                return block;
@@ -1776,13 +1541,9 @@ MapBlock * ServerMap::createBlock(v3s16 p)
 
 MapBlock * ServerMap::emergeBlock(v3s16 p, bool create_blank)
 {
-       DSTACKF("%s: p=(%d,%d,%d), create_blank=%d",
-                       FUNCTION_NAME,
-                       p.X, p.Y, p.Z, create_blank);
-
        {
                MapBlock *block = getBlockNoCreateNoEx(p);
-               if(block && block->isDummy() == false)
+               if (block && !block->isDummy())
                        return block;
        }
 
@@ -1793,39 +1554,12 @@ MapBlock * ServerMap::emergeBlock(v3s16 p, bool create_blank)
        }
 
        if (create_blank) {
-               ServerMapSector *sector = createSector(v2s16(p.X, p.Z));
+               MapSector *sector = createSector(v2s16(p.X, p.Z));
                MapBlock *block = sector->createBlankBlock(p.Y);
 
                return block;
        }
 
-#if 0
-       if(allow_generate)
-       {
-               std::map<v3s16, MapBlock*> modified_blocks;
-               MapBlock *block = generateBlock(p, modified_blocks);
-               if(block)
-               {
-                       MapEditEvent event;
-                       event.type = MEET_OTHER;
-                       event.p = p;
-
-                       // Copy modified_blocks to event
-                       for(std::map<v3s16, MapBlock*>::iterator
-                                       i = modified_blocks.begin();
-                                       i != modified_blocks.end(); ++i)
-                       {
-                               event.modified_blocks.insert(i->first);
-                       }
-
-                       // Queue event
-                       dispatchEvent(&event);
-
-                       return block;
-               }
-       }
-#endif
-
        return NULL;
 }
 
@@ -1838,7 +1572,32 @@ MapBlock *ServerMap::getBlockOrEmerge(v3s16 p3d)
        return block;
 }
 
-void ServerMap::prepareBlock(MapBlock *block) {
+bool ServerMap::isBlockInQueue(v3s16 pos)
+{
+       return m_emerge && m_emerge->isBlockInQueue(pos);
+}
+
+void ServerMap::addNodeAndUpdate(v3s16 p, MapNode n,
+               std::map<v3s16, MapBlock*> &modified_blocks,
+               bool remove_metadata)
+{
+       Map::addNodeAndUpdate(p, n, modified_blocks, remove_metadata);
+
+       /*
+               Add neighboring liquid nodes and this node to transform queue.
+               (it's vital for the node itself to get updated last, if it was removed.)
+        */
+
+       for (const v3s16 &dir : g_7dirs) {
+               v3s16 p2 = p + dir;
+
+               bool is_valid_position;
+               MapNode n2 = getNode(p2, &is_valid_position);
+               if(is_valid_position &&
+                               (m_nodedef->get(n2).isLiquid() ||
+                               n2.getContent() == CONTENT_AIR))
+                       m_transforming_liquid.push_back(p2);
+       }
 }
 
 // N.B.  This requires no synchronization, since data will not be modified unless
@@ -1857,155 +1616,28 @@ void ServerMap::updateVManip(v3s16 pos)
                return;
 
        s32 idx = vm->m_area.index(pos);
-       vm->m_data[idx] = getNodeNoEx(pos);
+       vm->m_data[idx] = getNode(pos);
        vm->m_flags[idx] &= ~VOXELFLAG_NO_DATA;
 
        vm->m_is_dirty = true;
 }
 
-s16 ServerMap::findGroundLevel(v2s16 p2d)
-{
-#if 0
-       /*
-               Uh, just do something random...
-       */
-       // Find existing map from top to down
-       s16 max=63;
-       s16 min=-64;
-       v3s16 p(p2d.X, max, p2d.Y);
-       for(; p.Y>min; p.Y--)
-       {
-               MapNode n = getNodeNoEx(p);
-               if(n.getContent() != CONTENT_IGNORE)
-                       break;
-       }
-       if(p.Y == min)
-               goto plan_b;
-       // If this node is not air, go to plan b
-       if(getNodeNoEx(p).getContent() != CONTENT_AIR)
-               goto plan_b;
-       // Search existing walkable and return it
-       for(; p.Y>min; p.Y--)
-       {
-               MapNode n = getNodeNoEx(p);
-               if(content_walkable(n.d) && n.getContent() != CONTENT_IGNORE)
-                       return p.Y;
-       }
-
-       // Move to plan b
-plan_b:
-#endif
-
-       /*
-               Determine from map generator noise functions
-       */
-
-       s16 level = m_emerge->getGroundLevelAtPoint(p2d);
-       return level;
-
-       //double level = base_rock_level_2d(m_seed, p2d) + AVERAGE_MUD_AMOUNT;
-       //return (s16)level;
-}
-
-bool ServerMap::loadFromFolders() {
-       if (!dbase->initialized() &&
-                       !fs::PathExists(m_savedir + DIR_DELIM + "map.sqlite"))
-               return true;
-       return false;
-}
-
-void ServerMap::createDirs(std::string path)
-{
-       if(fs::CreateAllDirs(path) == false)
-       {
-               m_dout<<"ServerMap: Failed to create directory "
-                               <<"\""<<path<<"\""<<std::endl;
-               throw BaseException("ServerMap failed to create directory");
-       }
-}
-
-std::string ServerMap::getSectorDir(v2s16 pos, int layout)
-{
-       char cc[9];
-       switch(layout)
-       {
-               case 1:
-                       snprintf(cc, 9, "%.4x%.4x",
-                               (unsigned int) pos.X & 0xffff,
-                               (unsigned int) pos.Y & 0xffff);
-
-                       return m_savedir + DIR_DELIM + "sectors" + DIR_DELIM + cc;
-               case 2:
-                       snprintf(cc, 9, (std::string("%.3x") + DIR_DELIM + "%.3x").c_str(),
-                               (unsigned int) pos.X & 0xfff,
-                               (unsigned int) pos.Y & 0xfff);
-
-                       return m_savedir + DIR_DELIM + "sectors2" + DIR_DELIM + cc;
-               default:
-                       assert(false);
-                       return "";
-       }
-}
-
-v2s16 ServerMap::getSectorPos(const std::string &dirname)
+void ServerMap::reportMetrics(u64 save_time_us, u32 saved_blocks, u32 all_blocks)
 {
-       unsigned int x = 0, y = 0;
-       int r;
-       std::string component;
-       fs::RemoveLastPathComponent(dirname, &component, 1);
-       if(component.size() == 8)
-       {
-               // Old layout
-               r = sscanf(component.c_str(), "%4x%4x", &x, &y);
-       }
-       else if(component.size() == 3)
-       {
-               // New layout
-               fs::RemoveLastPathComponent(dirname, &component, 2);
-               r = sscanf(component.c_str(), (std::string("%3x") + DIR_DELIM + "%3x").c_str(), &x, &y);
-               // Sign-extend the 12 bit values up to 16 bits...
-               if(x & 0x800) x |= 0xF000;
-               if(y & 0x800) y |= 0xF000;
-       }
-       else
-       {
-               r = -1;
-       }
-
-       FATAL_ERROR_IF(r != 2, "getSectorPos()");
-       v2s16 pos((s16)x, (s16)y);
-       return pos;
-}
-
-v3s16 ServerMap::getBlockPos(const std::string &sectordir, const std::string &blockfile)
-{
-       v2s16 p2d = getSectorPos(sectordir);
-
-       if(blockfile.size() != 4){
-               throw InvalidFilenameException("Invalid block filename");
-       }
-       unsigned int y;
-       int r = sscanf(blockfile.c_str(), "%4x", &y);
-       if(r != 1)
-               throw InvalidFilenameException("Invalid block filename");
-       return v3s16(p2d.X, y, p2d.Y);
-}
-
-std::string ServerMap::getBlockFilename(v3s16 p)
-{
-       char cc[5];
-       snprintf(cc, 5, "%.4x", (unsigned int)p.Y&0xffff);
-       return cc;
+       m_loaded_blocks_gauge->set(all_blocks);
+       m_save_time_counter->increment(save_time_us);
+       m_save_count_counter->increment(saved_blocks);
 }
 
 void ServerMap::save(ModifiedState save_level)
 {
-       DSTACK(FUNCTION_NAME);
-       if(m_map_saving_enabled == false) {
+       if (!m_map_saving_enabled) {
                warningstream<<"Not saving map, saving disabled."<<std::endl;
                return;
        }
 
+       const auto start_time = porting::getTimeUs();
+
        if(save_level == MOD_STATE_CLEAN)
                infostream<<"ServerMap: Saving whole map, this can take time."
                                <<std::endl;
@@ -2018,30 +1650,19 @@ void ServerMap::save(ModifiedState save_level)
        // Profile modified reasons
        Profiler modprofiler;
 
-       u32 sector_meta_count = 0;
        u32 block_count = 0;
        u32 block_count_all = 0; // Number of blocks in memory
 
        // Don't do anything with sqlite unless something is really saved
        bool save_started = false;
 
-       for(std::map<v2s16, MapSector*>::iterator i = m_sectors.begin();
-               i != m_sectors.end(); ++i) {
-               ServerMapSector *sector = (ServerMapSector*)i->second;
-               assert(sector->getId() == MAPSECTOR_SERVER);
-
-               if(sector->differs_from_disk || save_level == MOD_STATE_CLEAN) {
-                       saveSectorMeta(sector);
-                       sector_meta_count++;
-               }
+       for (auto &sector_it : m_sectors) {
+               MapSector *sector = sector_it.second;
 
                MapBlockVect blocks;
                sector->getBlocks(blocks);
 
-               for(MapBlockVect::iterator j = blocks.begin();
-                       j != blocks.end(); ++j) {
-                       MapBlock *block = *j;
-
+               for (MapBlock *block : blocks) {
                        block_count_all++;
 
                        if(block->getModified() >= (u32)save_level) {
@@ -2055,12 +1676,6 @@ void ServerMap::save(ModifiedState save_level)
 
                                saveBlock(block);
                                block_count++;
-
-                               /*infostream<<"ServerMap: Written block ("
-                                               <<block->getPos().X<<","
-                                               <<block->getPos().Y<<","
-                                               <<block->getPos().Z<<")"
-                                               <<std::endl;*/
                        }
                }
        }
@@ -2071,221 +1686,28 @@ void ServerMap::save(ModifiedState save_level)
        /*
                Only print if something happened or saved whole map
        */
-       if(save_level == MOD_STATE_CLEAN || sector_meta_count != 0
+       if(save_level == MOD_STATE_CLEAN
                        || block_count != 0) {
-               infostream<<"ServerMap: Written: "
-                               <<sector_meta_count<<" sector metadata files, "
-                               <<block_count<<" block files"
-                               <<", "<<block_count_all<<" blocks in memory."
-                               <<std::endl;
+               infostream << "ServerMap: Written: "
+                               << block_count << " blocks"
+                               << ", " << block_count_all << " blocks in memory."
+                               << std::endl;
                PrintInfo(infostream); // ServerMap/ClientMap:
                infostream<<"Blocks modified by: "<<std::endl;
                modprofiler.print(infostream);
        }
+
+       const auto end_time = porting::getTimeUs();
+       reportMetrics(end_time - start_time, block_count, block_count_all);
 }
 
 void ServerMap::listAllLoadableBlocks(std::vector<v3s16> &dst)
 {
-       if (loadFromFolders()) {
-               errorstream << "Map::listAllLoadableBlocks(): Result will be missing "
-                               << "all blocks that are stored in flat files." << std::endl;
-       }
        dbase->listAllLoadableBlocks(dst);
+       if (dbase_ro)
+               dbase_ro->listAllLoadableBlocks(dst);
 }
 
-void ServerMap::listAllLoadedBlocks(std::vector<v3s16> &dst)
-{
-       for(std::map<v2s16, MapSector*>::iterator si = m_sectors.begin();
-               si != m_sectors.end(); ++si)
-       {
-               MapSector *sector = si->second;
-
-               MapBlockVect blocks;
-               sector->getBlocks(blocks);
-
-               for(MapBlockVect::iterator i = blocks.begin();
-                               i != blocks.end(); ++i) {
-                       v3s16 p = (*i)->getPos();
-                       dst.push_back(p);
-               }
-       }
-}
-
-void ServerMap::saveSectorMeta(ServerMapSector *sector)
-{
-       DSTACK(FUNCTION_NAME);
-       // Format used for writing
-       u8 version = SER_FMT_VER_HIGHEST_WRITE;
-       // Get destination
-       v2s16 pos = sector->getPos();
-       std::string dir = getSectorDir(pos);
-       createDirs(dir);
-
-       std::string fullpath = dir + DIR_DELIM + "meta";
-       std::ostringstream ss(std::ios_base::binary);
-
-       sector->serialize(ss, version);
-
-       if(!fs::safeWriteToFile(fullpath, ss.str()))
-               throw FileNotGoodException("Cannot write sector metafile");
-
-       sector->differs_from_disk = false;
-}
-
-MapSector* ServerMap::loadSectorMeta(std::string sectordir, bool save_after_load)
-{
-       DSTACK(FUNCTION_NAME);
-       // Get destination
-       v2s16 p2d = getSectorPos(sectordir);
-
-       ServerMapSector *sector = NULL;
-
-       std::string fullpath = sectordir + DIR_DELIM + "meta";
-       std::ifstream is(fullpath.c_str(), std::ios_base::binary);
-       if(is.good() == false)
-       {
-               // If the directory exists anyway, it probably is in some old
-               // format. Just go ahead and create the sector.
-               if(fs::PathExists(sectordir))
-               {
-                       /*infostream<<"ServerMap::loadSectorMeta(): Sector metafile "
-                                       <<fullpath<<" doesn't exist but directory does."
-                                       <<" Continuing with a sector with no metadata."
-                                       <<std::endl;*/
-                       sector = new ServerMapSector(this, p2d, m_gamedef);
-                       m_sectors[p2d] = sector;
-               }
-               else
-               {
-                       throw FileNotGoodException("Cannot open sector metafile");
-               }
-       }
-       else
-       {
-               sector = ServerMapSector::deSerialize
-                               (is, this, p2d, m_sectors, m_gamedef);
-               if(save_after_load)
-                       saveSectorMeta(sector);
-       }
-
-       sector->differs_from_disk = false;
-
-       return sector;
-}
-
-bool ServerMap::loadSectorMeta(v2s16 p2d)
-{
-       DSTACK(FUNCTION_NAME);
-
-       // The directory layout we're going to load from.
-       //  1 - original sectors/xxxxzzzz/
-       //  2 - new sectors2/xxx/zzz/
-       //  If we load from anything but the latest structure, we will
-       //  immediately save to the new one, and remove the old.
-       int loadlayout = 1;
-       std::string sectordir1 = getSectorDir(p2d, 1);
-       std::string sectordir;
-       if(fs::PathExists(sectordir1))
-       {
-               sectordir = sectordir1;
-       }
-       else
-       {
-               loadlayout = 2;
-               sectordir = getSectorDir(p2d, 2);
-       }
-
-       try{
-               loadSectorMeta(sectordir, loadlayout != 2);
-       }
-       catch(InvalidFilenameException &e)
-       {
-               return false;
-       }
-       catch(FileNotGoodException &e)
-       {
-               return false;
-       }
-       catch(std::exception &e)
-       {
-               return false;
-       }
-
-       return true;
-}
-
-#if 0
-bool ServerMap::loadSectorFull(v2s16 p2d)
-{
-       DSTACK(FUNCTION_NAME);
-
-       MapSector *sector = NULL;
-
-       // The directory layout we're going to load from.
-       //  1 - original sectors/xxxxzzzz/
-       //  2 - new sectors2/xxx/zzz/
-       //  If we load from anything but the latest structure, we will
-       //  immediately save to the new one, and remove the old.
-       int loadlayout = 1;
-       std::string sectordir1 = getSectorDir(p2d, 1);
-       std::string sectordir;
-       if(fs::PathExists(sectordir1))
-       {
-               sectordir = sectordir1;
-       }
-       else
-       {
-               loadlayout = 2;
-               sectordir = getSectorDir(p2d, 2);
-       }
-
-       try{
-               sector = loadSectorMeta(sectordir, loadlayout != 2);
-       }
-       catch(InvalidFilenameException &e)
-       {
-               return false;
-       }
-       catch(FileNotGoodException &e)
-       {
-               return false;
-       }
-       catch(std::exception &e)
-       {
-               return false;
-       }
-
-       /*
-               Load blocks
-       */
-       std::vector<fs::DirListNode> list2 = fs::GetDirListing
-                       (sectordir);
-       std::vector<fs::DirListNode>::iterator i2;
-       for(i2=list2.begin(); i2!=list2.end(); i2++)
-       {
-               // We want files
-               if(i2->dir)
-                       continue;
-               try{
-                       loadBlock(sectordir, i2->name, sector, loadlayout != 2);
-               }
-               catch(InvalidFilenameException &e)
-               {
-                       // This catches unknown crap in directory
-               }
-       }
-
-       if(loadlayout != 2)
-       {
-               infostream<<"Sector converted to new layout - deleting "<<
-                       sectordir1<<std::endl;
-               fs::RecursiveDelete(sectordir1);
-       }
-
-       return true;
-}
-#endif
-
 MapDatabase *ServerMap::createDatabase(
        const std::string &name,
        const std::string &savedir,
@@ -2296,22 +1718,22 @@ MapDatabase *ServerMap::createDatabase(
        if (name == "dummy")
                return new Database_Dummy();
        #if USE_LEVELDB
-       else if (name == "leveldb")
+       if (name == "leveldb")
                return new Database_LevelDB(savedir);
        #endif
        #if USE_REDIS
-       else if (name == "redis")
+       if (name == "redis")
                return new Database_Redis(conf);
        #endif
        #if USE_POSTGRESQL
-       else if (name == "postgresql") {
-               std::string connect_string = "";
+       if (name == "postgresql") {
+               std::string connect_string;
                conf.getNoEx("pgsql_connection", connect_string);
                return new MapDatabasePostgreSQL(connect_string);
        }
        #endif
-       else
-               throw BaseException(std::string("Database backend ") + name + " not supported.");
+
+       throw BaseException(std::string("Database backend ") + name + " not supported.");
 }
 
 void ServerMap::beginSave()
@@ -2326,10 +1748,10 @@ void ServerMap::endSave()
 
 bool ServerMap::saveBlock(MapBlock *block)
 {
-       return saveBlock(block, dbase);
+       return saveBlock(block, dbase, m_map_compression_level);
 }
 
-bool ServerMap::saveBlock(MapBlock *block, MapDatabase *db)
+bool ServerMap::saveBlock(MapBlock *block, MapDatabase *db, int compression_level)
 {
        v3s16 p3d = block->getPos();
 
@@ -2349,10 +1771,9 @@ bool ServerMap::saveBlock(MapBlock *block, MapDatabase *db)
        */
        std::ostringstream o(std::ios_base::binary);
        o.write((char*) &version, 1);
-       block->serialize(o, version, true);
+       block->serialize(o, version, true, compression_level);
 
-       std::string data = o.str();
-       bool ret = db->saveBlock(p3d, data);
+       bool ret = db->saveBlock(p3d, o.str());
        if (ret) {
                // We just wrote it to the disk so clear modified flag
                block->resetModified();
@@ -2360,89 +1781,8 @@ bool ServerMap::saveBlock(MapBlock *block, MapDatabase *db)
        return ret;
 }
 
-void ServerMap::loadBlock(const std::string &sectordir, const std::string &blockfile,
-               MapSector *sector, bool save_after_load)
-{
-       DSTACK(FUNCTION_NAME);
-
-       std::string fullpath = sectordir + DIR_DELIM + blockfile;
-       try {
-               std::ifstream is(fullpath.c_str(), std::ios_base::binary);
-               if (!is.good())
-                       throw FileNotGoodException("Cannot open block file");
-
-               v3s16 p3d = getBlockPos(sectordir, blockfile);
-               v2s16 p2d(p3d.X, p3d.Z);
-
-               assert(sector->getPos() == p2d);
-
-               u8 version = SER_FMT_VER_INVALID;
-               is.read((char*)&version, 1);
-
-               if(is.fail())
-                       throw SerializationError("ServerMap::loadBlock(): Failed"
-                                       " to read MapBlock version");
-
-               /*u32 block_size = MapBlock::serializedLength(version);
-               SharedBuffer<u8> data(block_size);
-               is.read((char*)*data, block_size);*/
-
-               // This will always return a sector because we're the server
-               //MapSector *sector = emergeSector(p2d);
-
-               MapBlock *block = NULL;
-               bool created_new = false;
-               block = sector->getBlockNoCreateNoEx(p3d.Y);
-               if(block == NULL)
-               {
-                       block = sector->createBlankBlockNoInsert(p3d.Y);
-                       created_new = true;
-               }
-
-               // Read basic data
-               block->deSerialize(is, version, true);
-
-               // If it's a new block, insert it to the map
-               if (created_new) {
-                       sector->insertBlock(block);
-                       ReflowScan scanner(this, m_emerge->ndef);
-                       scanner.scan(block, &m_transforming_liquid);
-               }
-
-               /*
-                       Save blocks loaded in old format in new format
-               */
-
-               if(version < SER_FMT_VER_HIGHEST_WRITE || save_after_load)
-               {
-                       saveBlock(block);
-
-                       // Should be in database now, so delete the old file
-                       fs::RecursiveDelete(fullpath);
-               }
-
-               // We just loaded it from the disk, so it's up-to-date.
-               block->resetModified();
-
-       }
-       catch(SerializationError &e)
-       {
-               warningstream<<"Invalid block data on disk "
-                               <<"fullpath="<<fullpath
-                               <<" (SerializationError). "
-                               <<"what()="<<e.what()
-                               <<std::endl;
-                               // Ignoring. A new one will be generated.
-               abort();
-
-               // TODO: Backup file; name is in fullpath.
-       }
-}
-
 void ServerMap::loadBlock(std::string *blob, v3s16 p3d, MapSector *sector, bool save_after_load)
 {
-       DSTACK(FUNCTION_NAME);
-
        try {
                std::istringstream is(*blob, std::ios_base::binary);
 
@@ -2504,65 +1844,23 @@ void ServerMap::loadBlock(std::string *blob, v3s16 p3d, MapSector *sector, bool
 
 MapBlock* ServerMap::loadBlock(v3s16 blockpos)
 {
-       DSTACK(FUNCTION_NAME);
-
        bool created_new = (getBlockNoCreateNoEx(blockpos) == NULL);
 
        v2s16 p2d(blockpos.X, blockpos.Z);
 
        std::string ret;
        dbase->loadBlock(blockpos, &ret);
-       if (ret != "") {
+       if (!ret.empty()) {
                loadBlock(&ret, blockpos, createSector(p2d), false);
-       } else {
-               // Not found in database, try the files
-
-               // The directory layout we're going to load from.
-               //  1 - original sectors/xxxxzzzz/
-               //  2 - new sectors2/xxx/zzz/
-               //  If we load from anything but the latest structure, we will
-               //  immediately save to the new one, and remove the old.
-               int loadlayout = 1;
-               std::string sectordir1 = getSectorDir(p2d, 1);
-               std::string sectordir;
-               if (fs::PathExists(sectordir1)) {
-                       sectordir = sectordir1;
-               } else {
-                       loadlayout = 2;
-                       sectordir = getSectorDir(p2d, 2);
+       } else if (dbase_ro) {
+               dbase_ro->loadBlock(blockpos, &ret);
+               if (!ret.empty()) {
+                       loadBlock(&ret, blockpos, createSector(p2d), false);
                }
-
-               /*
-               Make sure sector is loaded
-                */
-
-               MapSector *sector = getSectorNoGenerateNoEx(p2d);
-               if (sector == NULL) {
-                       try {
-                               sector = loadSectorMeta(sectordir, loadlayout != 2);
-                       } catch(InvalidFilenameException &e) {
-                               return NULL;
-                       } catch(FileNotGoodException &e) {
-                               return NULL;
-                       } catch(std::exception &e) {
-                               return NULL;
-                       }
-               }
-
-
-               /*
-               Make sure file exists
-                */
-
-               std::string blockfilename = getBlockFilename(blockpos);
-               if (fs::PathExists(sectordir + DIR_DELIM + blockfilename) == false)
-                       return NULL;
-
-               /*
-               Load block and save it to the database
-                */
-               loadBlock(sectordir, blockfilename, sector, true);
+       } else {
+               return NULL;
        }
+
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
        if (created_new && (block != NULL)) {
                std::map<v3s16, MapBlock*> modified_blocks;
@@ -2576,7 +1874,7 @@ MapBlock* ServerMap::loadBlock(v3s16 blockpos)
                        for (it = modified_blocks.begin();
                                        it != modified_blocks.end(); ++it)
                                event.modified_blocks.insert(it->first);
-                       dispatchEvent(&event);
+                       dispatchEvent(event);
                }
        }
        return block;
@@ -2590,7 +1888,7 @@ bool ServerMap::deleteBlock(v3s16 blockpos)
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
        if (block) {
                v2s16 p2d(blockpos.X, blockpos.Z);
-               MapSector *sector = getSectorNoGenerateNoEx(p2d);
+               MapSector *sector = getSectorNoGenerate(p2d);
                if (!sector)
                        return false;
                sector->deleteBlock(block);
@@ -2616,14 +1914,9 @@ bool ServerMap::repairBlockLight(v3s16 blockpos,
 
 MMVManip::MMVManip(Map *map):
                VoxelManipulator(),
-               m_is_dirty(false),
-               m_create_area(false),
                m_map(map)
 {
-}
-
-MMVManip::~MMVManip()
-{
+       assert(map);
 }
 
 void MMVManip::initialEmerge(v3s16 blockpos_min, v3s16 blockpos_max,
@@ -2631,6 +1924,8 @@ void MMVManip::initialEmerge(v3s16 blockpos_min, v3s16 blockpos_max,
 {
        TimeTaker timer1("initialEmerge", &emerge_time);
 
+       assert(m_map);
+
        // Units of these are MapBlocks
        v3s16 p_min = blockpos_min;
        v3s16 p_max = blockpos_max;
@@ -2662,20 +1957,15 @@ void MMVManip::initialEmerge(v3s16 blockpos_min, v3s16 blockpos_max,
                        continue;
 
                bool block_data_inexistent = false;
-               try
                {
-                       TimeTaker timer1("emerge load", &emerge_load_time);
+                       TimeTaker timer2("emerge load", &emerge_load_time);
 
-                       block = m_map->getBlockNoCreate(p);
-                       if(block->isDummy())
+                       block = m_map->getBlockNoCreateNoEx(p);
+                       if (!block || block->isDummy())
                                block_data_inexistent = true;
                        else
                                block->copyTo(*this);
                }
-               catch(InvalidPositionException &e)
-               {
-                       block_data_inexistent = true;
-               }
 
                if(block_data_inexistent)
                {
@@ -2719,26 +2009,54 @@ void MMVManip::blitBackAll(std::map<v3s16, MapBlock*> *modified_blocks,
 {
        if(m_area.getExtent() == v3s16(0,0,0))
                return;
+       assert(m_map);
 
        /*
                Copy data of all blocks
        */
-       for(std::map<v3s16, u8>::iterator
-                       i = m_loaded_blocks.begin();
-                       i != m_loaded_blocks.end(); ++i)
-       {
-               v3s16 p = i->first;
+       for (auto &loaded_block : m_loaded_blocks) {
+               v3s16 p = loaded_block.first;
                MapBlock *block = m_map->getBlockNoCreateNoEx(p);
-               bool existed = !(i->second & VMANIP_BLOCK_DATA_INEXIST);
-               if ((existed == false) || (block == NULL) ||
-                       (overwrite_generated == false && block->isGenerated() == true))
+               bool existed = !(loaded_block.second & VMANIP_BLOCK_DATA_INEXIST);
+               if (!existed || (block == NULL) ||
+                       (!overwrite_generated && block->isGenerated()))
                        continue;
 
                block->copyFrom(*this);
+               block->raiseModified(MOD_STATE_WRITE_NEEDED, MOD_REASON_VMANIP);
 
                if(modified_blocks)
                        (*modified_blocks)[p] = block;
        }
 }
 
+MMVManip *MMVManip::clone() const
+{
+       MMVManip *ret = new MMVManip();
+
+       const s32 size = m_area.getVolume();
+       ret->m_area = m_area;
+       if (m_data) {
+               ret->m_data = new MapNode[size];
+               memcpy(ret->m_data, m_data, size * sizeof(MapNode));
+       }
+       if (m_flags) {
+               ret->m_flags = new u8[size];
+               memcpy(ret->m_flags, m_flags, size * sizeof(u8));
+       }
+
+       ret->m_is_dirty = m_is_dirty;
+       // Even if the copy is disconnected from a map object keep the information
+       // needed to write it back to one
+       ret->m_loaded_blocks = m_loaded_blocks;
+
+       return ret;
+}
+
+void MMVManip::reparent(Map *map)
+{
+       assert(map && !m_map);
+       m_map = map;
+}
+
 //END