]> git.lizzy.rs Git - dragonfireclient.git/blobdiff - src/map.cpp
Make node timers more efficient
[dragonfireclient.git] / src / map.cpp
index 20dc44139c3b9ed409e38ab1c191e309cbcc70ca..a1f2086ceb012cd58a682c20040ffc40c334f346 100644 (file)
@@ -20,7 +20,6 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "map.h"
 #include "mapsector.h"
 #include "mapblock.h"
-#include "main.h"
 #include "filesys.h"
 #include "voxel.h"
 #include "porting.h"
@@ -43,31 +42,20 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "database.h"
 #include "database-dummy.h"
 #include "database-sqlite3.h"
+#include <deque>
+#include <queue>
 #if USE_LEVELDB
 #include "database-leveldb.h"
 #endif
 #if USE_REDIS
 #include "database-redis.h"
 #endif
+#if USE_POSTGRESQL
+#include "database-postgresql.h"
+#endif
 
 #define PP(x) "("<<(x).X<<","<<(x).Y<<","<<(x).Z<<")"
 
-/*
-       SQLite format specification:
-       - Initially only replaces sectors/ and sectors2/
-
-       If map.sqlite does not exist in the save dir
-       or the block was not found in the database
-       the map will try to load from sectors folder.
-       In either case, map.sqlite will be created
-       and all future saves will save there.
-
-       Structure of map.sqlite:
-       Tables:
-               blocks
-                       (PK) INT pos
-                       BLOB data
-*/
 
 /*
        Map
@@ -334,7 +322,8 @@ void Map::unspreadLight(enum LightBank bank,
                        v3s16 n2pos = pos + dirs[i];
 
                        // Get the block where the node is located
-                       v3s16 blockpos = getNodeBlockPos(n2pos);
+                       v3s16 blockpos, relpos;
+                       getNodeBlockPosWithOffset(n2pos, blockpos, relpos);
 
                        // Only fetch a new block if the block position has changed
                        try {
@@ -350,8 +339,6 @@ void Map::unspreadLight(enum LightBank bank,
                                continue;
                        }
 
-                       // Calculate relative position in block
-                       v3s16 relpos = n2pos - blockpos * MAP_BLOCKSIZE;
                        // Get node straight from the block
                        bool is_valid_position;
                        MapNode n2 = block->getNode(relpos, &is_valid_position);
@@ -418,9 +405,9 @@ void Map::unspreadLight(enum LightBank bank,
        }
 
        /*infostream<<"unspreadLight(): Changed block "
-                       <<blockchangecount<<" times"
-                       <<" for "<<from_nodes.size()<<" nodes"
-                       <<std::endl;*/
+       <<blockchangecount<<" times"
+       <<" for "<<from_nodes.size()<<" nodes"
+       <<std::endl;*/
 
        if(!unlighted_nodes.empty())
                unspreadLight(bank, unlighted_nodes, light_sources, modified_blocks);
@@ -471,14 +458,16 @@ void Map::spreadLight(enum LightBank bank,
        */
        v3s16 blockpos_last;
        MapBlock *block = NULL;
-       // Cache this a bit, too
+               // Cache this a bit, too
        bool block_checked_in_modified = false;
 
        for(std::set<v3s16>::iterator j = from_nodes.begin();
                j != from_nodes.end(); ++j)
        {
                v3s16 pos = *j;
-               v3s16 blockpos = getNodeBlockPos(pos);
+               v3s16 blockpos, relpos;
+
+               getNodeBlockPosWithOffset(pos, blockpos, relpos);
 
                // Only fetch a new block if the block position has changed
                try {
@@ -497,9 +486,6 @@ void Map::spreadLight(enum LightBank bank,
                if(block->isDummy())
                        continue;
 
-               // Calculate relative position in block
-               v3s16 relpos = pos - blockpos_last * MAP_BLOCKSIZE;
-
                // Get node straight from the block
                bool is_valid_position;
                MapNode n = block->getNode(relpos, &is_valid_position);
@@ -513,7 +499,8 @@ void Map::spreadLight(enum LightBank bank,
                        v3s16 n2pos = pos + dirs[i];
 
                        // Get the block where the node is located
-                       v3s16 blockpos = getNodeBlockPos(n2pos);
+                       v3s16 blockpos, relpos;
+                       getNodeBlockPosWithOffset(n2pos, blockpos, relpos);
 
                        // Only fetch a new block if the block position has changed
                        try {
@@ -529,8 +516,6 @@ void Map::spreadLight(enum LightBank bank,
                                continue;
                        }
 
-                       // Calculate relative position in block
-                       v3s16 relpos = n2pos - blockpos * MAP_BLOCKSIZE;
                        // Get node straight from the block
                        MapNode n2 = block->getNode(relpos, &is_valid_position);
                        if (!is_valid_position)
@@ -691,7 +676,7 @@ void Map::updateLighting(enum LightBank bank,
 {
        INodeDefManager *nodemgr = m_gamedef->ndef();
 
-       /*m_dout<<DTIME<<"Map::updateLighting(): "
+       /*m_dout<<"Map::updateLighting(): "
                        <<a_blocks.size()<<" blocks."<<std::endl;*/
 
        //TimeTaker timer("updateLighting");
@@ -700,7 +685,7 @@ void Map::updateLighting(enum LightBank bank,
        //bool debug=true;
        //u32 count_was = modified_blocks.size();
 
-       std::map<v3s16, MapBlock*> blocks_to_update;
+       //std::map<v3s16, MapBlock*> blocks_to_update;
 
        std::set<v3s16> light_sources;
 
@@ -725,7 +710,7 @@ void Map::updateLighting(enum LightBank bank,
                        v3s16 pos = block->getPos();
                        v3s16 posnodes = block->getPosRelative();
                        modified_blocks[pos] = block;
-                       blocks_to_update[pos] = block;
+                       //blocks_to_update[pos] = block;
 
                        /*
                                Clear all light from block
@@ -785,8 +770,7 @@ void Map::updateLighting(enum LightBank bank,
                        }
                        else
                        {
-                               // Invalid lighting bank
-                               assert(0);
+                               assert("Invalid lighting bank" == NULL);
                        }
 
                        /*infostream<<"Bottom for sunlight-propagated block ("
@@ -801,7 +785,7 @@ void Map::updateLighting(enum LightBank bank,
                        }
                        catch(InvalidPositionException &e)
                        {
-                               assert(0);
+                               FATAL_ERROR("Invalid position");
                        }
 
                }
@@ -947,7 +931,7 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
        INodeDefManager *ndef = m_gamedef->ndef();
 
        /*PrintInfo(m_dout);
-       m_dout<<DTIME<<"Map::addNodeAndUpdate(): p=("
+       m_dout<<"Map::addNodeAndUpdate(): p=("
                        <<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/
 
        /*
@@ -1047,7 +1031,7 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
        {
                s16 y = p.Y - 1;
                for(;; y--){
-                       //m_dout<<DTIME<<"y="<<y<<std::endl;
+                       //m_dout<<"y="<<y<<std::endl;
                        v3s16 n2pos(p.X, y, p.Z);
 
                        MapNode n2;
@@ -1134,7 +1118,7 @@ void Map::removeNodeAndUpdate(v3s16 p,
        INodeDefManager *ndef = m_gamedef->ndef();
 
        /*PrintInfo(m_dout);
-       m_dout<<DTIME<<"Map::removeNodeAndUpdate(): p=("
+       m_dout<<"Map::removeNodeAndUpdate(): p=("
                        <<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/
 
        bool node_under_sunlight = true;
@@ -1189,8 +1173,7 @@ void Map::removeNodeAndUpdate(v3s16 p,
                This also clears the lighting.
        */
 
-       MapNode n;
-       n.setContent(replace_material);
+       MapNode n(replace_material);
        setNode(p, n);
 
        for(s32 i=0; i<2; i++)
@@ -1217,14 +1200,14 @@ void Map::removeNodeAndUpdate(v3s16 p,
        if(node_under_sunlight)
        {
                s16 ybottom = propagateSunlight(p, modified_blocks);
-               /*m_dout<<DTIME<<"Node was under sunlight. "
+               /*m_dout<<"Node was under sunlight. "
                                "Propagating sunlight";
-               m_dout<<DTIME<<" -> ybottom="<<ybottom<<std::endl;*/
+               m_dout<<" -> ybottom="<<ybottom<<std::endl;*/
                s16 y = p.Y;
                for(; y >= ybottom; y--)
                {
                        v3s16 p2(p.X, y, p.Z);
-                       /*m_dout<<DTIME<<"lighting neighbors of node ("
+                       /*m_dout<<"lighting neighbors of node ("
                                        <<p2.X<<","<<p2.Y<<","<<p2.Z<<")"
                                        <<std::endl;*/
                        lightNeighbors(LIGHTBANK_DAY, p2, modified_blocks);
@@ -1239,7 +1222,7 @@ void Map::removeNodeAndUpdate(v3s16 p,
                        n.setLight(LIGHTBANK_DAY, 0, ndef);
                        setNode(p, n);
                } else {
-                       assert(0);
+                       FATAL_ERROR("Invalid position");
                }
        }
 
@@ -1420,71 +1403,140 @@ bool Map::getDayNightDiff(v3s16 blockpos)
        return false;
 }
 
+struct TimeOrderedMapBlock {
+       MapSector *sect;
+       MapBlock *block;
+
+       TimeOrderedMapBlock(MapSector *sect, MapBlock *block) :
+               sect(sect),
+               block(block)
+       {}
+
+       bool operator<(const TimeOrderedMapBlock &b) const
+       {
+               return block->getUsageTimer() < b.block->getUsageTimer();
+       };
+};
+
 /*
        Updates usage timers
 */
-void Map::timerUpdate(float dtime, float unload_timeout,
-               std::list<v3s16> *unloaded_blocks)
+void Map::timerUpdate(float dtime, float unload_timeout, u32 max_loaded_blocks,
+               std::vector<v3s16> *unloaded_blocks)
 {
        bool save_before_unloading = (mapType() == MAPTYPE_SERVER);
 
        // Profile modified reasons
        Profiler modprofiler;
 
-       std::list<v2s16> sector_deletion_queue;
+       std::vector<v2s16> sector_deletion_queue;
        u32 deleted_blocks_count = 0;
        u32 saved_blocks_count = 0;
        u32 block_count_all = 0;
 
        beginSave();
-       for(std::map<v2s16, MapSector*>::iterator si = m_sectors.begin();
-               si != m_sectors.end(); ++si)
-       {
-               MapSector *sector = si->second;
 
-               bool all_blocks_deleted = true;
+       // 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;
 
-               std::list<MapBlock*> blocks;
-               sector->getBlocks(blocks);
+                       bool all_blocks_deleted = true;
 
-               for(std::list<MapBlock*>::iterator i = blocks.begin();
-                               i != blocks.end(); ++i)
-               {
-                       MapBlock *block = (*i);
+                       MapBlockVect blocks;
+                       sector->getBlocks(blocks);
 
-                       block->incrementUsageTimer(dtime);
+                       for (MapBlockVect::iterator i = blocks.begin();
+                                       i != blocks.end(); ++i) {
+                               MapBlock *block = (*i);
 
-                       if(block->refGet() == 0 && block->getUsageTimer() > unload_timeout)
-                       {
-                               v3s16 p = block->getPos();
+                               block->incrementUsageTimer(dtime);
 
-                               // Save if modified
-                               if (block->getModified() != MOD_STATE_CLEAN && save_before_unloading)
-                               {
-                                       modprofiler.add(block->getModifiedReason(), 1);
-                                       if (!saveBlock(block))
-                                               continue;
-                                       saved_blocks_count++;
-                               }
+                               if (block->refGet() == 0
+                                               && block->getUsageTimer() > unload_timeout) {
+                                       v3s16 p = block->getPos();
 
-                               // Delete from memory
-                               sector->deleteBlock(block);
+                                       // Save if modified
+                                       if (block->getModified() != MOD_STATE_CLEAN
+                                                       && save_before_unloading) {
+                                               modprofiler.add(block->getModifiedReasonString(), 1);
+                                               if (!saveBlock(block))
+                                                       continue;
+                                               saved_blocks_count++;
+                                       }
+
+                                       // Delete from memory
+                                       sector->deleteBlock(block);
 
-                               if(unloaded_blocks)
-                                       unloaded_blocks->push_back(p);
+                                       if (unloaded_blocks)
+                                               unloaded_blocks->push_back(p);
 
-                               deleted_blocks_count++;
+                                       deleted_blocks_count++;
+                               } else {
+                                       all_blocks_deleted = false;
+                                       block_count_all++;
+                               }
                        }
-                       else
-                       {
-                               all_blocks_deleted = false;
-                               block_count_all++;
+
+                       if (all_blocks_deleted) {
+                               sector_deletion_queue.push_back(si->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;
 
-               if(all_blocks_deleted)
-               {
-                       sector_deletion_queue.push_back(si->first);
+                       MapBlockVect blocks;
+                       sector->getBlocks(blocks);
+
+                       for(MapBlockVect::iterator i = blocks.begin();
+                                       i != blocks.end(); ++i) {
+                               MapBlock *block = (*i);
+
+                               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)) {
+                       TimeOrderedMapBlock b = mapblock_queue.top();
+                       mapblock_queue.pop();
+
+                       MapBlock *block = b.block;
+
+                       if (block->refGet() != 0)
+                               continue;
+
+                       v3s16 p = block->getPos();
+
+                       // Save if modified
+                       if (block->getModified() != MOD_STATE_CLEAN && save_before_unloading) {
+                               modprofiler.add(block->getModifiedReasonString(), 1);
+                               if (!saveBlock(block))
+                                       continue;
+                               saved_blocks_count++;
+                       }
+
+                       // Delete from memory
+                       b.sect->deleteBlock(block);
+
+                       if (unloaded_blocks)
+                               unloaded_blocks->push_back(p);
+
+                       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);
+                       }
                }
        }
        endSave();
@@ -1509,16 +1561,15 @@ void Map::timerUpdate(float dtime, float unload_timeout,
        }
 }
 
-void Map::unloadUnreferencedBlocks(std::list<v3s16> *unloaded_blocks)
+void Map::unloadUnreferencedBlocks(std::vector<v3s16> *unloaded_blocks)
 {
-       timerUpdate(0.0, -1.0, unloaded_blocks);
+       timerUpdate(0.0, -1.0, 0, unloaded_blocks);
 }
 
-void Map::deleteSectors(std::list<v2s16> &list)
+void Map::deleteSectors(std::vector<v2s16> &sectorList)
 {
-       for(std::list<v2s16>::iterator j = list.begin();
-               j != list.end(); ++j)
-       {
+       for(std::vector<v2s16>::iterator j = sectorList.begin();
+               j != sectorList.end(); ++j) {
                MapSector *sector = m_sectors[*j];
                // If sector is in sector cache, remove it from there
                if(m_sector_cache == sector)
@@ -1529,63 +1580,6 @@ void Map::deleteSectors(std::list<v2s16> &list)
        }
 }
 
-#if 0
-void Map::unloadUnusedData(float timeout,
-               core::list<v3s16> *deleted_blocks)
-{
-       core::list<v2s16> sector_deletion_queue;
-       u32 deleted_blocks_count = 0;
-       u32 saved_blocks_count = 0;
-
-       core::map<v2s16, MapSector*>::Iterator si = m_sectors.getIterator();
-       for(; si.atEnd() == false; si++)
-       {
-               MapSector *sector = si.getNode()->getValue();
-
-               bool all_blocks_deleted = true;
-
-               core::list<MapBlock*> blocks;
-               sector->getBlocks(blocks);
-               for(core::list<MapBlock*>::Iterator i = blocks.begin();
-                               i != blocks.end(); i++)
-               {
-                       MapBlock *block = (*i);
-
-                       if(block->getUsageTimer() > timeout)
-                       {
-                               // Save if modified
-                               if(block->getModified() != MOD_STATE_CLEAN)
-                               {
-                                       saveBlock(block);
-                                       saved_blocks_count++;
-                               }
-                               // Delete from memory
-                               sector->deleteBlock(block);
-                               deleted_blocks_count++;
-                       }
-                       else
-                       {
-                               all_blocks_deleted = false;
-                       }
-               }
-
-               if(all_blocks_deleted)
-               {
-                       sector_deletion_queue.push_back(si.getNode()->getKey());
-               }
-       }
-
-       deleteSectors(sector_deletion_queue);
-
-       infostream<<"Map: Unloaded "<<deleted_blocks_count<<" blocks from memory"
-                       <<", of which "<<saved_blocks_count<<" were wr."
-                       <<std::endl;
-
-       //return sector_deletion_queue.getSize();
-       //return deleted_blocks_count;
-}
-#endif
-
 void Map::PrintInfo(std::ostream &out)
 {
        out<<"Map: ";
@@ -1603,6 +1597,16 @@ struct NodeNeighbor {
        NeighborType t;
        v3s16 p;
        bool l; //can liquid
+
+       NodeNeighbor()
+               : n(CONTENT_AIR)
+       { }
+
+       NodeNeighbor(const MapNode &node, NeighborType n_type, v3s16 pos)
+               : n(node),
+                 t(n_type),
+                 p(pos)
+       { }
 };
 
 void Map::transforming_liquid_add(v3s16 p) {
@@ -1613,12 +1617,12 @@ s32 Map::transforming_liquid_size() {
         return m_transforming_liquid.size();
 }
 
-void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
+void Map::transformLiquids(std::map<v3s16, MapBlock*> &modified_blocks)
 {
 
        INodeDefManager *nodemgr = m_gamedef->ndef();
 
-       DSTACK(__FUNCTION_NAME);
+       DSTACK(FUNCTION_NAME);
        //TimeTaker timer("transformLiquids()");
 
        u32 loopcount = 0;
@@ -1628,10 +1632,10 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                infostream<<"transformLiquids(): initial_size="<<initial_size<<std::endl;*/
 
        // list of nodes that due to viscosity have not reached their max level height
-       UniqueQueue<v3s16> must_reflow;
+       std::deque<v3s16> must_reflow;
 
        // List of MapBlocks that will require a lighting update (due to lava)
-       std::map<v3s16, MapBlock*> lighting_modified_blocks;
+       std::map<v3s16, MapBlock *> lighting_modified_blocks;
 
        u32 liquid_loop_max = g_settings->getS32("liquid_loop_max");
        u32 loop_max = liquid_loop_max;
@@ -1653,17 +1657,18 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
        loop_max *= m_transforming_liquid_loop_count_multiplier;
 #endif
 
-       while(m_transforming_liquid.size() != 0)
+       while (m_transforming_liquid.size() != 0)
        {
                // This should be done here so that it is done when continue is used
-               if(loopcount >= initial_size || loopcount >= loop_max)
+               if (loopcount >= initial_size || loopcount >= loop_max)
                        break;
                loopcount++;
 
                /*
                        Get a queued transforming liquid node
                */
-               v3s16 p0 = m_transforming_liquid.pop_front();
+               v3s16 p0 = m_transforming_liquid.front();
+               m_transforming_liquid.pop_front();
 
                MapNode n0 = getNodeNoEx(p0);
 
@@ -1672,21 +1677,24 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                 */
                s8 liquid_level = -1;
                content_t liquid_kind = CONTENT_IGNORE;
-               LiquidType liquid_type = nodemgr->get(n0).liquid_type;
+               content_t floodable_node = CONTENT_AIR;
+               const ContentFeatures &cf = nodemgr->get(n0);
+               LiquidType liquid_type = cf.liquid_type;
                switch (liquid_type) {
                        case LIQUID_SOURCE:
                                liquid_level = LIQUID_LEVEL_SOURCE;
-                               liquid_kind = nodemgr->getId(nodemgr->get(n0).liquid_alternative_flowing);
+                               liquid_kind = nodemgr->getId(cf.liquid_alternative_flowing);
                                break;
                        case LIQUID_FLOWING:
                                liquid_level = (n0.param2 & LIQUID_LEVEL_MASK);
                                liquid_kind = n0.getContent();
                                break;
                        case LIQUID_NONE:
-                               // if this is an air node, it *could* be transformed into a liquid. otherwise,
-                               // continue with the next node.
-                               if (n0.getContent() != CONTENT_AIR)
+                               // if this node is 'floodable', it *could* be transformed
+                               // into a liquid, otherwise, continue with the next node.
+                               if (!cf.floodable)
                                        continue;
+                               floodable_node = n0.getContent();
                                liquid_kind = CONTENT_AIR;
                                break;
                }
@@ -1715,10 +1723,11 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                                        break;
                        }
                        v3s16 npos = p0 + dirs[i];
-                       NodeNeighbor nb = {getNodeNoEx(npos), nt, npos};
+                       NodeNeighbor nb(getNodeNoEx(npos), nt, npos);
+                       const ContentFeatures &cfnb = nodemgr->get(nb.n);
                        switch (nodemgr->get(nb.n.getContent()).liquid_type) {
                                case LIQUID_NONE:
-                                       if (nb.n.getContent() == CONTENT_AIR) {
+                                       if (cfnb.floodable) {
                                                airs[num_airs++] = nb;
                                                // if the current node is a water source the neighbor
                                                // should be enqueded for transformation regardless of whether the
@@ -1726,18 +1735,21 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                                                if (nb.t != NEIGHBOR_UPPER && liquid_type != LIQUID_NONE)
                                                        m_transforming_liquid.push_back(npos);
                                                // if the current node happens to be a flowing node, it will start to flow down here.
-                                               if (nb.t == NEIGHBOR_LOWER) {
+                                               if (nb.t == NEIGHBOR_LOWER)
                                                        flowing_down = true;
-                                               }
                                        } else {
                                                neutrals[num_neutrals++] = nb;
+                                               // If neutral below is ignore prevent water spreading outwards
+                                               if (nb.t == NEIGHBOR_LOWER &&
+                                                               nb.n.getContent() == CONTENT_IGNORE)
+                                                       flowing_down = true;
                                        }
                                        break;
                                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 = nodemgr->getId(nodemgr->get(nb.n).liquid_alternative_flowing);
-                                       if (nodemgr->getId(nodemgr->get(nb.n).liquid_alternative_flowing) != liquid_kind) {
+                                               liquid_kind = nodemgr->getId(cfnb.liquid_alternative_flowing);
+                                       if (nodemgr->getId(cfnb.liquid_alternative_flowing) != liquid_kind) {
                                                neutrals[num_neutrals++] = nb;
                                        } else {
                                                // Do not count bottom source, it will screw things up
@@ -1748,8 +1760,8 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                                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 = nodemgr->getId(nodemgr->get(nb.n).liquid_alternative_flowing);
-                                       if (nodemgr->getId(nodemgr->get(nb.n).liquid_alternative_flowing) != liquid_kind) {
+                                               liquid_kind = nodemgr->getId(cfnb.liquid_alternative_flowing);
+                                       if (nodemgr->getId(cfnb.liquid_alternative_flowing) != liquid_kind) {
                                                neutrals[num_neutrals++] = nb;
                                        } else {
                                                flows[num_flows++] = nb;
@@ -1768,8 +1780,8 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                s8 max_node_level = -1;
 
                u8 range = nodemgr->get(liquid_kind).liquid_range;
-               if (range > LIQUID_LEVEL_MAX+1)
-                       range = LIQUID_LEVEL_MAX+1;
+               if (range > LIQUID_LEVEL_MAX + 1)
+                       range = LIQUID_LEVEL_MAX + 1;
 
                if ((num_sources >= 2 && nodemgr->get(liquid_kind).liquid_renewable) || liquid_type == LIQUID_SOURCE) {
                        // liquid_kind will be set to either the flowing alternative of the node (if it's a liquid)
@@ -1778,10 +1790,11 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                        new_node_content = nodemgr->getId(nodemgr->get(liquid_kind).liquid_alternative_source);
                } else if (num_sources >= 1 && sources[0].t != NEIGHBOR_LOWER) {
                        // liquid_kind is set properly, see above
-                       new_node_content = liquid_kind;
                        max_node_level = new_node_level = LIQUID_LEVEL_MAX;
-                       if (new_node_level < (LIQUID_LEVEL_MAX+1-range))
-                               new_node_content = CONTENT_AIR;
+                       if (new_node_level >= (LIQUID_LEVEL_MAX + 1 - range))
+                               new_node_content = liquid_kind;
+                       else
+                               new_node_content = floodable_node;
                } else {
                        // no surrounding sources, so get the maximum level that can flow into this node
                        for (u16 i = 0; i < num_flows; i++) {
@@ -1792,16 +1805,16 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                                                        max_node_level = LIQUID_LEVEL_MAX;
                                                        if (nb_liquid_level + WATER_DROP_BOOST < LIQUID_LEVEL_MAX)
                                                                max_node_level = nb_liquid_level + WATER_DROP_BOOST;
-                                               } else if (nb_liquid_level > max_node_level)
+                                               } else if (nb_liquid_level > max_node_level) {
                                                        max_node_level = nb_liquid_level;
+                                               }
                                                break;
                                        case NEIGHBOR_LOWER:
                                                break;
                                        case NEIGHBOR_SAME_LEVEL:
                                                if ((flows[i].n.param2 & LIQUID_FLOW_DOWN_MASK) != LIQUID_FLOW_DOWN_MASK &&
-                                                       nb_liquid_level > 0 && nb_liquid_level - 1 > max_node_level) {
+                                                               nb_liquid_level > 0 && nb_liquid_level - 1 > max_node_level)
                                                        max_node_level = nb_liquid_level - 1;
-                                               }
                                                break;
                                }
                        }
@@ -1819,23 +1832,25 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                                        new_node_level = liquid_level + 1;
                                if (new_node_level != max_node_level)
                                        must_reflow.push_back(p0);
-                       } else
+                       } else {
                                new_node_level = max_node_level;
+                       }
 
-                       if (max_node_level >= (LIQUID_LEVEL_MAX+1-range))
+                       if (max_node_level >= (LIQUID_LEVEL_MAX + 1 - range))
                                new_node_content = liquid_kind;
                        else
-                               new_node_content = CONTENT_AIR;
+                               new_node_content = floodable_node;
 
                }
 
                /*
                        check if anything has changed. if not, just continue with the next node.
                 */
-               if (new_node_content == n0.getContent() && (nodemgr->get(n0.getContent()).liquid_type != LIQUID_FLOWING ||
-                                                                                ((n0.param2 & LIQUID_LEVEL_MASK) == (u8)new_node_level &&
-                                                                                ((n0.param2 & LIQUID_FLOW_DOWN_MASK) == LIQUID_FLOW_DOWN_MASK)
-                                                                                == flowing_down)))
+               if (new_node_content == n0.getContent() &&
+                               (nodemgr->get(n0.getContent()).liquid_type != LIQUID_FLOWING ||
+                               ((n0.param2 & LIQUID_LEVEL_MASK) == (u8)new_node_level &&
+                               ((n0.param2 & LIQUID_FLOW_DOWN_MASK) == LIQUID_FLOW_DOWN_MASK)
+                               == flowing_down)))
                        continue;
 
 
@@ -1855,11 +1870,10 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
 
                // Find out whether there is a suspect for this action
                std::string suspect;
-               if(m_gamedef->rollback()){
+               if (m_gamedef->rollback())
                        suspect = m_gamedef->rollback()->getSuspect(p0, 83, 1);
-               }
 
-               if(!suspect.empty()){
+               if (m_gamedef->rollback() && !suspect.empty()) {
                        // Blame suspect
                        RollbackScopeActor rollback_scope(m_gamedef->rollback(), suspect, true);
                        // Get old node for rollback
@@ -1878,10 +1892,10 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
 
                v3s16 blockpos = getNodeBlockPos(p0);
                MapBlock *block = getBlockNoCreateNoEx(blockpos);
-               if(block != NULL) {
+               if (block != NULL) {
                        modified_blocks[blockpos] =  block;
                        // If new or old node emits light, MapBlock requires lighting update
-                       if(nodemgr->get(n0).light_source != 0 ||
+                       if (nodemgr->get(n0).light_source != 0 ||
                                        nodemgr->get(n00).light_source != 0)
                                lighting_modified_blocks[block->getPos()] = block;
                }
@@ -1908,8 +1922,10 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
                }
        }
        //infostream<<"Map::transformLiquids(): loopcount="<<loopcount<<std::endl;
-       while (must_reflow.size() > 0)
-               m_transforming_liquid.push_back(must_reflow.pop_front());
+
+       for (std::deque<v3s16>::iterator iter = must_reflow.begin(); iter != must_reflow.end(); ++iter)
+               m_transforming_liquid.push_back(*iter);
+
        updateLighting(lighting_modified_blocks, modified_blocks);
 
 
@@ -1962,6 +1978,47 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
        }
 }
 
+std::vector<v3s16> Map::findNodesWithMetadata(v3s16 p1, v3s16 p2)
+{
+       std::vector<v3s16> positions_with_meta;
+
+       sortBoxVerticies(p1, p2);
+       v3s16 bpmin = getNodeBlockPos(p1);
+       v3s16 bpmax = getNodeBlockPos(p2);
+
+       VoxelArea area(p1, p2);
+
+       for (s16 z = bpmin.Z; z <= bpmax.Z; z++)
+       for (s16 y = bpmin.Y; y <= bpmax.Y; y++)
+       for (s16 x = bpmin.X; x <= bpmax.X; x++) {
+               v3s16 blockpos(x, y, z);
+
+               MapBlock *block = getBlockNoCreateNoEx(blockpos);
+               if (!block) {
+                       verbosestream << "Map::getNodeMetadata(): Need to emerge "
+                               << PP(blockpos) << std::endl;
+                       block = emergeBlock(blockpos, false);
+               }
+               if (!block) {
+                       infostream << "WARNING: Map::getNodeMetadata(): Block not found"
+                               << std::endl;
+                       continue;
+               }
+
+               v3s16 p_base = blockpos * MAP_BLOCKSIZE;
+               std::vector<v3s16> keys = block->m_node_metadata.getAllKeys();
+               for (size_t i = 0; i != keys.size(); i++) {
+                       v3s16 p(keys[i] + p_base);
+                       if (!area.contains(p))
+                               continue;
+
+                       positions_with_meta.push_back(p);
+               }
+       }
+
+       return positions_with_meta;
+}
+
 NodeMetadata *Map::getNodeMetadata(v3s16 p)
 {
        v3s16 blockpos = getNodeBlockPos(p);
@@ -1973,7 +2030,7 @@ NodeMetadata *Map::getNodeMetadata(v3s16 p)
                block = emergeBlock(blockpos, false);
        }
        if(!block){
-               infostream<<"WARNING: Map::getNodeMetadata(): Block not found"
+               warningstream<<"Map::getNodeMetadata(): Block not found"
                                <<std::endl;
                return NULL;
        }
@@ -1992,7 +2049,7 @@ bool Map::setNodeMetadata(v3s16 p, NodeMetadata *meta)
                block = emergeBlock(blockpos, false);
        }
        if(!block){
-               infostream<<"WARNING: Map::setNodeMetadata(): Block not found"
+               warningstream<<"Map::setNodeMetadata(): Block not found"
                                <<std::endl;
                return false;
        }
@@ -2007,7 +2064,7 @@ void Map::removeNodeMetadata(v3s16 p)
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
        if(block == NULL)
        {
-               infostream<<"WARNING: Map::removeNodeMetadata(): Block not found"
+               warningstream<<"Map::removeNodeMetadata(): Block not found"
                                <<std::endl;
                return;
        }
@@ -2025,16 +2082,18 @@ NodeTimer Map::getNodeTimer(v3s16 p)
                block = emergeBlock(blockpos, false);
        }
        if(!block){
-               infostream<<"WARNING: Map::getNodeTimer(): Block not found"
+               warningstream<<"Map::getNodeTimer(): Block not found"
                                <<std::endl;
                return NodeTimer();
        }
        NodeTimer t = block->m_node_timers.get(p_rel);
-       return t;
+       NodeTimer nt(t.timeout, t.elapsed, p);
+       return nt;
 }
 
-void Map::setNodeTimer(v3s16 p, NodeTimer t)
+void Map::setNodeTimer(const NodeTimer &t)
 {
+       v3s16 p = t.position;
        v3s16 blockpos = getNodeBlockPos(p);
        v3s16 p_rel = p - blockpos*MAP_BLOCKSIZE;
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
@@ -2044,11 +2103,12 @@ void Map::setNodeTimer(v3s16 p, NodeTimer t)
                block = emergeBlock(blockpos, false);
        }
        if(!block){
-               infostream<<"WARNING: Map::setNodeTimer(): Block not found"
+               warningstream<<"Map::setNodeTimer(): Block not found"
                                <<std::endl;
                return;
        }
-       block->m_node_timers.set(p_rel, t);
+       NodeTimer nt(t.timeout, t.elapsed, p_rel);
+       block->m_node_timers.set(nt);
 }
 
 void Map::removeNodeTimer(v3s16 p)
@@ -2058,7 +2118,7 @@ void Map::removeNodeTimer(v3s16 p)
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
        if(block == NULL)
        {
-               infostream<<"WARNING: Map::removeNodeTimer(): Block not found"
+               warningstream<<"Map::removeNodeTimer(): Block not found"
                                <<std::endl;
                return;
        }
@@ -2073,7 +2133,7 @@ ServerMap::ServerMap(std::string savedir, IGameDef *gamedef, EmergeManager *emer
        m_emerge(emerge),
        m_map_metadata_changed(true)
 {
-       verbosestream<<__FUNCTION_NAME<<std::endl;
+       verbosestream<<FUNCTION_NAME<<std::endl;
 
        /*
                Try to load map; if not found, create a new one.
@@ -2085,25 +2145,13 @@ ServerMap::ServerMap(std::string savedir, IGameDef *gamedef, EmergeManager *emer
        bool succeeded = conf.readConfigFile(conf_path.c_str());
        if (!succeeded || !conf.exists("backend")) {
                // fall back to sqlite3
-               dbase = new Database_SQLite3(this, savedir);
                conf.set("backend", "sqlite3");
-       } else {
-               std::string backend = conf.get("backend");
-               if (backend == "dummy")
-                       dbase = new Database_Dummy(this);
-               else if (backend == "sqlite3")
-                       dbase = new Database_SQLite3(this, savedir);
-               #if USE_LEVELDB
-               else if (backend == "leveldb")
-                       dbase = new Database_LevelDB(this, savedir);
-               #endif
-               #if USE_REDIS
-               else if (backend == "redis")
-                       dbase = new Database_Redis(this, savedir);
-               #endif
-               else
-                       throw BaseException("Unknown map backend");
        }
+       std::string backend = conf.get("backend");
+       dbase = createDatabase(backend, savedir, 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;
@@ -2131,7 +2179,7 @@ ServerMap::ServerMap(std::string savedir, IGameDef *gamedef, EmergeManager *emer
                                                          <<" Using default settings."<<std::endl;
                                }
                                catch(FileNotGoodException &e){
-                                       infostream<<"WARNING: Could not load map metadata"
+                                       warningstream<<"Could not load map metadata"
                                                        //<<" Disabling chunk-based generator."
                                                        <<std::endl;
                                        //m_chunksize = 0;
@@ -2155,10 +2203,10 @@ ServerMap::ServerMap(std::string savedir, IGameDef *gamedef, EmergeManager *emer
        }
        catch(std::exception &e)
        {
-               infostream<<"WARNING: ServerMap: Failed to load map from "<<savedir
+               warningstream<<"ServerMap: Failed to load map from "<<savedir
                                <<", exception: "<<e.what()<<std::endl;
                infostream<<"Please remove the map or fix it."<<std::endl;
-               infostream<<"WARNING: Map saving will be disabled."<<std::endl;
+               warningstream<<"Map saving will be disabled."<<std::endl;
        }
 
        infostream<<"Initializing new map."<<std::endl;
@@ -2172,7 +2220,7 @@ ServerMap::ServerMap(std::string savedir, IGameDef *gamedef, EmergeManager *emer
 
 ServerMap::~ServerMap()
 {
-       verbosestream<<__FUNCTION_NAME<<std::endl;
+       verbosestream<<FUNCTION_NAME<<std::endl;
 
        try
        {
@@ -2221,75 +2269,51 @@ s16 ServerMap::getWaterLevel()
        return m_emerge->params.water_level;
 }
 
-bool ServerMap::initBlockMake(BlockMakeData *data, v3s16 blockpos)
+bool ServerMap::initBlockMake(v3s16 blockpos, BlockMakeData *data)
 {
-       bool enable_mapgen_debug_info = m_emerge->mapgen_debug_info;
-       EMERGE_DBG_OUT("initBlockMake(): " PP(blockpos) " - " PP(blockpos));
+       s16 csize = m_emerge->params.chunksize;
+       v3s16 bpmin = EmergeManager::getContainingChunk(blockpos, csize);
+       v3s16 bpmax = bpmin + v3s16(1, 1, 1) * (csize - 1);
 
-       s16 chunksize = m_emerge->params.chunksize;
-       s16 coffset = -chunksize / 2;
-       v3s16 chunk_offset(coffset, coffset, coffset);
-       v3s16 blockpos_div = getContainerPos(blockpos - chunk_offset, chunksize);
-       v3s16 blockpos_min = blockpos_div * chunksize;
-       v3s16 blockpos_max = blockpos_div * chunksize + v3s16(1,1,1)*(chunksize-1);
-       blockpos_min += chunk_offset;
-       blockpos_max += chunk_offset;
+       bool enable_mapgen_debug_info = m_emerge->enable_mapgen_debug_info;
+       EMERGE_DBG_OUT("initBlockMake(): " PP(bpmin) " - " PP(bpmax));
 
-       v3s16 extra_borders(1,1,1);
+       v3s16 extra_borders(1, 1, 1);
+       v3s16 full_bpmin = bpmin - extra_borders;
+       v3s16 full_bpmax = bpmax + extra_borders;
 
        // Do nothing if not inside limits (+-1 because of neighbors)
-       if(blockpos_over_limit(blockpos_min - extra_borders) ||
-               blockpos_over_limit(blockpos_max + extra_borders))
+       if (blockpos_over_limit(full_bpmin) ||
+               blockpos_over_limit(full_bpmax))
                return false;
 
        data->seed = m_emerge->params.seed;
-       data->blockpos_min = blockpos_min;
-       data->blockpos_max = blockpos_max;
+       data->blockpos_min = bpmin;
+       data->blockpos_max = bpmax;
        data->blockpos_requested = blockpos;
        data->nodedef = m_gamedef->ndef();
 
        /*
                Create the whole area of this and the neighboring blocks
        */
-       {
-               //TimeTaker timer("initBlockMake() create area");
-
-               for(s16 x=blockpos_min.X-extra_borders.X;
-                               x<=blockpos_max.X+extra_borders.X; x++)
-               for(s16 z=blockpos_min.Z-extra_borders.Z;
-                               z<=blockpos_max.Z+extra_borders.Z; z++)
-               {
-                       v2s16 sectorpos(x, z);
-                       // Sector metadata is loaded from disk if not already loaded.
-                       ServerMapSector *sector = createSector(sectorpos);
-                       assert(sector);
-                       (void) sector;
-
-                       for(s16 y=blockpos_min.Y-extra_borders.Y;
-                                       y<=blockpos_max.Y+extra_borders.Y; y++)
-                       {
-                               v3s16 p(x,y,z);
-                               //MapBlock *block = createBlock(p);
-                               // 1) get from memory, 2) load from disk
-                               MapBlock *block = emergeBlock(p, false);
-                               // 3) create a blank one
-                               if(block == NULL)
-                               {
-                                       block = createBlock(p);
-
-                                       /*
-                                               Block gets sunlight if this is true.
+       for (s16 x = full_bpmin.X; x <= full_bpmax.X; x++)
+       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);
+               FATAL_ERROR_IF(sector == NULL, "createSector() failed");
+
+               for (s16 y = full_bpmin.Y; y <= full_bpmax.Y; y++) {
+                       v3s16 p(x, y, z);
 
-                                               Refer to the map generator heuristics.
-                                       */
-                                       bool ug = m_emerge->isBlockUnderground(p);
-                                       block->setIsUnderground(ug);
-                               }
+                       MapBlock *block = emergeBlock(p, false);
+                       if (block == NULL) {
+                               block = createBlock(p);
 
-                               // Lighting will not be valid after make_chunk is called
-                               block->setLightingExpired(true);
-                               // Lighting will be calculated
-                               //block->setLightingExpired(false);
+                               // Block gets sunlight if this is true.
+                               // Refer to the map generator heuristics.
+                               bool ug = m_emerge->isBlockUnderground(p);
+                               block->setIsUnderground(ug);
                        }
                }
        }
@@ -2301,21 +2325,14 @@ bool ServerMap::initBlockMake(BlockMakeData *data, v3s16 blockpos)
                neighboring blocks
        */
 
-       // The area that contains this block and it's neighbors
-       v3s16 bigarea_blocks_min = blockpos_min - extra_borders;
-       v3s16 bigarea_blocks_max = blockpos_max + extra_borders;
-
        data->vmanip = new MMVManip(this);
-       //data->vmanip->setMap(this);
-
-       // Add the area
-       {
-               //TimeTaker timer("initBlockMake() initialEmerge");
-               data->vmanip->initialEmerge(bigarea_blocks_min, bigarea_blocks_max);
-       }
+       data->vmanip->initialEmerge(full_bpmin, full_bpmax);
 
-       // 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++) {
+       // 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;
@@ -2327,124 +2344,62 @@ bool ServerMap::initBlockMake(BlockMakeData *data, v3s16 blockpos)
                                n->setValue(flags);
                        }
                }
-       }*/
+       }
+#endif
 
        // Data is ready now.
        return true;
 }
 
 void ServerMap::finishBlockMake(BlockMakeData *data,
-               std::map<v3s16, MapBlock*> &changed_blocks)
+       std::map<v3s16, MapBlock*> *changed_blocks)
 {
-       v3s16 blockpos_min = data->blockpos_min;
-       v3s16 blockpos_max = data->blockpos_max;
-       v3s16 blockpos_requested = data->blockpos_requested;
-       /*infostream<<"finishBlockMake(): ("<<blockpos_requested.X<<","
-                       <<blockpos_requested.Y<<","
-                       <<blockpos_requested.Z<<")"<<std::endl;*/
+       v3s16 bpmin = data->blockpos_min;
+       v3s16 bpmax = data->blockpos_max;
 
-       v3s16 extra_borders(1,1,1);
+       v3s16 extra_borders(1, 1, 1);
+       v3s16 full_bpmin = bpmin - extra_borders;
+       v3s16 full_bpmax = bpmax + extra_borders;
 
-       bool enable_mapgen_debug_info = m_emerge->mapgen_debug_info;
+       bool enable_mapgen_debug_info = m_emerge->enable_mapgen_debug_info;
+       EMERGE_DBG_OUT("finishBlockMake(): " PP(bpmin) " - " PP(bpmax));
 
-       /*infostream<<"Resulting vmanip:"<<std::endl;
-       data->vmanip.print(infostream);*/
+       /*
+               Set lighting to non-expired state in all of them.
+               This is cheating, but it is not fast enough if all of them
+               would actually be updated.
+       */
+       for (s16 x = full_bpmin.X; x <= full_bpmax.X; x++)
+       for (s16 z = full_bpmin.Z; z <= full_bpmax.Z; z++)
+       for (s16 y = full_bpmin.Y; y <= full_bpmax.Y; y++) {
+               MapBlock *block = emergeBlock(v3s16(x, y, z), false);
+               if (!block)
+                       continue;
 
-       // Make sure affected blocks are loaded
-       for(s16 x=blockpos_min.X-extra_borders.X;
-                       x<=blockpos_max.X+extra_borders.X; x++)
-       for(s16 z=blockpos_min.Z-extra_borders.Z;
-                       z<=blockpos_max.Z+extra_borders.Z; z++)
-       for(s16 y=blockpos_min.Y-extra_borders.Y;
-                       y<=blockpos_max.Y+extra_borders.Y; y++)
-       {
-               v3s16 p(x, y, z);
-               // Load from disk if not already in memory
-               emergeBlock(p, false);
+               block->setLightingExpired(false);
        }
 
        /*
                Blit generated stuff to map
                NOTE: blitBackAll adds nearly everything to changed_blocks
        */
-       {
-               // 70ms @cs=8
-               //TimeTaker timer("finishBlockMake() blitBackAll");
-               data->vmanip->blitBackAll(&changed_blocks);
-       }
+       data->vmanip->blitBackAll(changed_blocks);
 
-       EMERGE_DBG_OUT("finishBlockMake: changed_blocks.size()=" << changed_blocks.size());
+       EMERGE_DBG_OUT("finishBlockMake: changed_blocks.size()="
+               << changed_blocks->size());
 
        /*
                Copy transforming liquid information
        */
-       while(data->transforming_liquid.size() > 0)
-       {
-               v3s16 p = data->transforming_liquid.pop_front();
-               m_transforming_liquid.push_back(p);
+       while (data->transforming_liquid.size()) {
+               m_transforming_liquid.push_back(data->transforming_liquid.front());
+               data->transforming_liquid.pop_front();
        }
 
-       /*
-               Do stuff in central blocks
-       */
-
-       /*
-               Update lighting
-       */
-       {
-#if 0
-               TimeTaker t("finishBlockMake lighting update");
-
-               core::map<v3s16, MapBlock*> lighting_update_blocks;
-
-               // Center blocks
-               for(s16 x=blockpos_min.X-extra_borders.X;
-                               x<=blockpos_max.X+extra_borders.X; x++)
-               for(s16 z=blockpos_min.Z-extra_borders.Z;
-                               z<=blockpos_max.Z+extra_borders.Z; z++)
-               for(s16 y=blockpos_min.Y-extra_borders.Y;
-                               y<=blockpos_max.Y+extra_borders.Y; y++)
-               {
-                       v3s16 p(x, y, z);
-                       MapBlock *block = getBlockNoCreateNoEx(p);
-                       assert(block);
-                       lighting_update_blocks.insert(block->getPos(), block);
-               }
-
-               updateLighting(lighting_update_blocks, changed_blocks);
-#endif
-
-               /*
-                       Set lighting to non-expired state in all of them.
-                       This is cheating, but it is not fast enough if all of them
-                       would actually be updated.
-               */
-               for(s16 x=blockpos_min.X-extra_borders.X;
-                               x<=blockpos_max.X+extra_borders.X; x++)
-               for(s16 z=blockpos_min.Z-extra_borders.Z;
-                               z<=blockpos_max.Z+extra_borders.Z; z++)
-               for(s16 y=blockpos_min.Y-extra_borders.Y;
-                               y<=blockpos_max.Y+extra_borders.Y; y++)
-               {
-                       v3s16 p(x, y, z);
-                       MapBlock * block = getBlockNoCreateNoEx(p);
-                       if (block != NULL)
-                               block->setLightingExpired(false);
-               }
-
-#if 0
-               if(enable_mapgen_debug_info == false)
-                       t.stop(true); // Hide output
-#endif
-       }
-
-       /*
-               Go through changed blocks
-       */
-       for(std::map<v3s16, MapBlock*>::iterator i = changed_blocks.begin();
-                       i != changed_blocks.end(); ++i)
-       {
-               MapBlock *block = i->second;
+       for (std::map<v3s16, MapBlock *>::iterator
+                       it = changed_blocks->begin();
+                       it != changed_blocks->end(); ++it) {
+               MapBlock *block = it->second;
                if (!block)
                        continue;
                /*
@@ -2455,20 +2410,19 @@ void ServerMap::finishBlockMake(BlockMakeData *data,
                        Set block as modified
                */
                block->raiseModified(MOD_STATE_WRITE_NEEDED,
-                               "finishBlockMake expireDayNightDiff");
+                       MOD_REASON_EXPIRE_DAYNIGHTDIFF);
        }
 
        /*
                Set central blocks as generated
        */
-       for(s16 x=blockpos_min.X; x<=blockpos_max.X; x++)
-       for(s16 z=blockpos_min.Z; z<=blockpos_max.Z; z++)
-       for(s16 y=blockpos_min.Y; y<=blockpos_max.Y; y++)
-       {
-               v3s16 p(x, y, z);
-               MapBlock *block = getBlockNoCreateNoEx(p);
+       for (s16 x = bpmin.X; x <= bpmax.X; x++)
+       for (s16 z = bpmin.Z; z <= bpmax.Z; z++)
+       for (s16 y = bpmin.Y; y <= bpmax.Y; y++) {
+               MapBlock *block = getBlockNoCreateNoEx(v3s16(x, y, z));
                if (!block)
                        continue;
+
                block->setGenerated(true);
        }
 
@@ -2477,42 +2431,12 @@ void ServerMap::finishBlockMake(BlockMakeData *data,
                NOTE: Will be saved later.
        */
        //save(MOD_STATE_WRITE_AT_UNLOAD);
-
-       /*infostream<<"finishBlockMake() done for ("<<blockpos_requested.X
-                       <<","<<blockpos_requested.Y<<","
-                       <<blockpos_requested.Z<<")"<<std::endl;*/
-
-
-#if 0
-       if(enable_mapgen_debug_info)
-       {
-               /*
-                       Analyze resulting blocks
-               */
-               /*for(s16 x=blockpos_min.X-1; x<=blockpos_max.X+1; x++)
-               for(s16 z=blockpos_min.Z-1; z<=blockpos_max.Z+1; z++)
-               for(s16 y=blockpos_min.Y-1; y<=blockpos_max.Y+1; y++)*/
-               for(s16 x=blockpos_min.X-0; x<=blockpos_max.X+0; x++)
-               for(s16 z=blockpos_min.Z-0; z<=blockpos_max.Z+0; z++)
-               for(s16 y=blockpos_min.Y-0; y<=blockpos_max.Y+0; y++)
-               {
-                       v3s16 p = v3s16(x,y,z);
-                       MapBlock *block = getBlockNoCreateNoEx(p);
-                       char spos[20];
-                       snprintf(spos, 20, "(%2d,%2d,%2d)", x, y, z);
-                       infostream<<"Generated "<<spos<<": "
-                                       <<analyze_block(block)<<std::endl;
-               }
-       }
-#endif
-
-       getBlockNoCreateNoEx(blockpos_requested);
 }
 
-ServerMapSector * ServerMap::createSector(v2s16 p2d)
+ServerMapSector *ServerMap::createSector(v2s16 p2d)
 {
        DSTACKF("%s: p2d=(%d,%d)",
-                       __FUNCTION_NAME,
+                       FUNCTION_NAME,
                        p2d.X, p2d.Y);
 
        /*
@@ -2545,10 +2469,12 @@ ServerMapSector * ServerMap::createSector(v2s16 p2d)
        /*
                Do not create over-limit
        */
-       if(p2d.X < -MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p2d.X > MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p2d.Y < -MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p2d.Y > MAP_GENERATION_LIMIT / MAP_BLOCKSIZE)
+       const static u16 map_gen_limit = MYMIN(MAX_MAP_GENERATION_LIMIT,
+               g_settings->getU16("map_generation_limit"));
+       if(p2d.X < -map_gen_limit / MAP_BLOCKSIZE
+                       || p2d.X >  map_gen_limit / MAP_BLOCKSIZE
+                       || p2d.Y < -map_gen_limit / MAP_BLOCKSIZE
+                       || p2d.Y >  map_gen_limit / MAP_BLOCKSIZE)
                throw InvalidPositionException("createSector(): pos. over limit");
 
        /*
@@ -2577,7 +2503,7 @@ MapBlock * ServerMap::generateBlock(
                std::map<v3s16, MapBlock*> &modified_blocks
 )
 {
-       DSTACKF("%s: p=(%d,%d,%d)", __FUNCTION_NAME, p.X, p.Y, p.Z);
+       DSTACKF("%s: p=(%d,%d,%d)", FUNCTION_NAME, p.X, p.Y, p.Z);
 
        /*infostream<<"generateBlock(): "
                        <<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
@@ -2597,7 +2523,7 @@ MapBlock * ServerMap::generateBlock(
        */
        if(blockpos_over_limit(p))
        {
-               infostream<<__FUNCTION_NAME<<": Block position over limit"<<std::endl;
+               infostream<<FUNCTION_NAME<<": Block position over limit"<<std::endl;
                throw InvalidPositionException("generateBlock(): pos. over limit");
        }
 
@@ -2687,17 +2613,12 @@ MapBlock * ServerMap::generateBlock(
 MapBlock * ServerMap::createBlock(v3s16 p)
 {
        DSTACKF("%s: p=(%d,%d,%d)",
-                       __FUNCTION_NAME, p.X, p.Y, p.Z);
+                       FUNCTION_NAME, p.X, p.Y, p.Z);
 
        /*
                Do not create over-limit
        */
-       if(p.X < -MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.X > MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.Y < -MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.Y > MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.Z < -MAP_GENERATION_LIMIT / MAP_BLOCKSIZE
-       || p.Z > MAP_GENERATION_LIMIT / MAP_BLOCKSIZE)
+       if (blockpos_over_limit(p))
                throw InvalidPositionException("createBlock(): pos. over limit");
 
        v2s16 p2d(p.X, p.Z);
@@ -2710,7 +2631,7 @@ MapBlock * ServerMap::createBlock(v3s16 p)
                      lighting on blocks for them.
        */
        ServerMapSector *sector;
-       try{
+       try {
                sector = (ServerMapSector*)createSector(p2d);
                assert(sector->getId() == MAPSECTOR_SERVER);
        }
@@ -2751,7 +2672,7 @@ MapBlock * ServerMap::createBlock(v3s16 p)
 MapBlock * ServerMap::emergeBlock(v3s16 p, bool create_blank)
 {
        DSTACKF("%s: p=(%d,%d,%d), create_blank=%d",
-                       __FUNCTION_NAME,
+                       FUNCTION_NAME,
                        p.X, p.Y, p.Z, create_blank);
 
        {
@@ -2882,7 +2803,8 @@ s16 ServerMap::findGroundLevel(v2s16 p2d)
 }
 
 bool ServerMap::loadFromFolders() {
-       if(!dbase->Initialized() && !fs::PathExists(m_savedir + DIR_DELIM + "map.sqlite")) // ?
+       if (!dbase->initialized() &&
+                       !fs::PathExists(m_savedir + DIR_DELIM + "map.sqlite"))
                return true;
        return false;
 }
@@ -2891,7 +2813,7 @@ void ServerMap::createDirs(std::string path)
 {
        if(fs::CreateAllDirs(path) == false)
        {
-               m_dout<<DTIME<<"ServerMap: Failed to create directory "
+               m_dout<<"ServerMap: Failed to create directory "
                                <<"\""<<path<<"\""<<std::endl;
                throw BaseException("ServerMap failed to create directory");
        }
@@ -2904,14 +2826,14 @@ std::string ServerMap::getSectorDir(v2s16 pos, int layout)
        {
                case 1:
                        snprintf(cc, 9, "%.4x%.4x",
-                               (unsigned int)pos.X&0xffff,
-                               (unsigned int)pos.Y&0xffff);
+                               (unsigned int) pos.X & 0xffff,
+                               (unsigned int) pos.Y & 0xffff);
 
                        return m_savedir + DIR_DELIM + "sectors" + DIR_DELIM + cc;
                case 2:
-                       snprintf(cc, 9, "%.3x" DIR_DELIM "%.3x",
-                               (unsigned int)pos.X&0xfff,
-                               (unsigned int)pos.Y&0xfff);
+                       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:
@@ -2935,16 +2857,17 @@ v2s16 ServerMap::getSectorPos(std::string dirname)
        {
                // New layout
                fs::RemoveLastPathComponent(dirname, &component, 2);
-               r = sscanf(component.c_str(), "%3x" DIR_DELIM "%3x", &x, &y);
+               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;
+               if(x & 0x800) x |= 0xF000;
+               if(y & 0x800) y |= 0xF000;
        }
        else
        {
-               assert(false);
+               r = -1;
        }
-       assert(r == 2);
+
+       FATAL_ERROR_IF(r != 2, "getSectorPos()");
        v2s16 pos((s16)x, (s16)y);
        return pos;
 }
@@ -2972,10 +2895,9 @@ std::string ServerMap::getBlockFilename(v3s16 p)
 
 void ServerMap::save(ModifiedState save_level)
 {
-       DSTACK(__FUNCTION_NAME);
-       if(m_map_saving_enabled == false)
-       {
-               infostream<<"WARNING: Not saving map, saving disabled."<<std::endl;
+       DSTACK(FUNCTION_NAME);
+       if(m_map_saving_enabled == false) {
+               warningstream<<"Not saving map, saving disabled."<<std::endl;
                return;
        }
 
@@ -2983,8 +2905,7 @@ void ServerMap::save(ModifiedState save_level)
                infostream<<"ServerMap: Saving whole map, this can take time."
                                <<std::endl;
 
-       if(m_map_metadata_changed || save_level == MOD_STATE_CLEAN)
-       {
+       if(m_map_metadata_changed || save_level == MOD_STATE_CLEAN) {
                saveMapMeta();
        }
 
@@ -2999,35 +2920,32 @@ void ServerMap::save(ModifiedState save_level)
        bool save_started = false;
 
        for(std::map<v2s16, MapSector*>::iterator i = m_sectors.begin();
-               i != m_sectors.end(); ++i)
-       {
+               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)
-               {
+               if(sector->differs_from_disk || save_level == MOD_STATE_CLEAN) {
                        saveSectorMeta(sector);
                        sector_meta_count++;
                }
-               std::list<MapBlock*> blocks;
+
+               MapBlockVect blocks;
                sector->getBlocks(blocks);
 
-               for(std::list<MapBlock*>::iterator j = blocks.begin();
-                       j != blocks.end(); ++j)
-               {
+               for(MapBlockVect::iterator j = blocks.begin();
+                       j != blocks.end(); ++j) {
                        MapBlock *block = *j;
 
                        block_count_all++;
 
-                       if(block->getModified() >= (u32)save_level)
-                       {
+                       if(block->getModified() >= (u32)save_level) {
                                // Lazy beginSave()
-                               if(!save_started){
+                               if(!save_started) {
                                        beginSave();
                                        save_started = true;
                                }
 
-                               modprofiler.add(block->getModifiedReason(), 1);
+                               modprofiler.add(block->getModifiedReasonString(), 1);
 
                                saveBlock(block);
                                block_count++;
@@ -3040,6 +2958,7 @@ void ServerMap::save(ModifiedState save_level)
                        }
                }
        }
+
        if(save_started)
                endSave();
 
@@ -3047,8 +2966,7 @@ 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
-                       || block_count != 0)
-       {
+                       || block_count != 0) {
                infostream<<"ServerMap: Written: "
                                <<sector_meta_count<<" sector metadata files, "
                                <<block_count<<" block files"
@@ -3060,30 +2978,28 @@ void ServerMap::save(ModifiedState save_level)
        }
 }
 
-void ServerMap::listAllLoadableBlocks(std::list<v3s16> &dst)
+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;
+       if (loadFromFolders()) {
+               errorstream << "Map::listAllLoadableBlocks(): Result will be missing "
+                               << "all blocks that are stored in flat files." << std::endl;
        }
        dbase->listAllLoadableBlocks(dst);
 }
 
-void ServerMap::listAllLoadedBlocks(std::list<v3s16> &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;
 
-               std::list<MapBlock*> blocks;
+               MapBlockVect blocks;
                sector->getBlocks(blocks);
 
-               for(std::list<MapBlock*>::iterator i = blocks.begin();
-                               i != blocks.end(); ++i)
-               {
-                       MapBlock *block = (*i);
-                       v3s16 p = block->getPos();
+               for(MapBlockVect::iterator i = blocks.begin();
+                               i != blocks.end(); ++i) {
+                       v3s16 p = (*i)->getPos();
                        dst.push_back(p);
                }
        }
@@ -3091,28 +3007,22 @@ void ServerMap::listAllLoadedBlocks(std::list<v3s16> &dst)
 
 void ServerMap::saveMapMeta()
 {
-       DSTACK(__FUNCTION_NAME);
-
-       /*infostream<<"ServerMap::saveMapMeta(): "
-                       <<"seed="<<m_seed
-                       <<std::endl;*/
+       DSTACK(FUNCTION_NAME);
 
        createDirs(m_savedir);
 
        std::string fullpath = m_savedir + DIR_DELIM + "map_meta.txt";
-       std::ostringstream ss(std::ios_base::binary);
-
-       Settings params;
+       std::ostringstream oss(std::ios_base::binary);
+       Settings conf;
 
-       m_emerge->saveParamsToSettings(&params);
-       params.writeLines(ss);
+       m_emerge->params.save(conf);
+       conf.writeLines(oss);
 
-       ss<<"[end_of_params]\n";
+       oss << "[end_of_params]\n";
 
-       if(!fs::safeWriteToFile(fullpath, ss.str()))
-       {
-               infostream<<"ERROR: ServerMap::saveMapMeta(): "
-                               <<"could not write "<<fullpath<<std::endl;
+       if(!fs::safeWriteToFile(fullpath, oss.str())) {
+               errorstream << "ServerMap::saveMapMeta(): "
+                               << "could not write " << fullpath << std::endl;
                throw FileNotGoodException("Cannot save chunk metadata");
        }
 
@@ -3121,24 +3031,24 @@ void ServerMap::saveMapMeta()
 
 void ServerMap::loadMapMeta()
 {
-       DSTACK(__FUNCTION_NAME);
+       DSTACK(FUNCTION_NAME);
+
+       Settings conf;
+       std::string fullpath = m_savedir + DIR_DELIM + "map_meta.txt";
 
-       std::string fullpath = m_savedir + DIR_DELIM "map_meta.txt";
        std::ifstream is(fullpath.c_str(), std::ios_base::binary);
        if (!is.good()) {
                errorstream << "ServerMap::loadMapMeta(): "
-                               << "could not open" << fullpath << std::endl;
+                       "could not open " << fullpath << std::endl;
                throw FileNotGoodException("Cannot open map metadata");
        }
 
-       Settings params;
-
-       if (!params.parseConfigLines(is, "[end_of_params]")) {
+       if (!conf.parseConfigLines(is, "[end_of_params]")) {
                throw SerializationError("ServerMap::loadMapMeta(): "
                                "[end_of_params] not found!");
        }
 
-       m_emerge->loadParamsFromSettings(&params);
+       m_emerge->params.load(conf);
 
        verbosestream << "ServerMap::loadMapMeta(): seed="
                << m_emerge->params.seed << std::endl;
@@ -3146,7 +3056,7 @@ void ServerMap::loadMapMeta()
 
 void ServerMap::saveSectorMeta(ServerMapSector *sector)
 {
-       DSTACK(__FUNCTION_NAME);
+       DSTACK(FUNCTION_NAME);
        // Format used for writing
        u8 version = SER_FMT_VER_HIGHEST_WRITE;
        // Get destination
@@ -3167,7 +3077,7 @@ void ServerMap::saveSectorMeta(ServerMapSector *sector)
 
 MapSector* ServerMap::loadSectorMeta(std::string sectordir, bool save_after_load)
 {
-       DSTACK(__FUNCTION_NAME);
+       DSTACK(FUNCTION_NAME);
        // Get destination
        v2s16 p2d = getSectorPos(sectordir);
 
@@ -3208,9 +3118,7 @@ MapSector* ServerMap::loadSectorMeta(std::string sectordir, bool save_after_load
 
 bool ServerMap::loadSectorMeta(v2s16 p2d)
 {
-       DSTACK(__FUNCTION_NAME);
-
-       MapSector *sector = NULL;
+       DSTACK(FUNCTION_NAME);
 
        // The directory layout we're going to load from.
        //  1 - original sectors/xxxxzzzz/
@@ -3231,7 +3139,7 @@ bool ServerMap::loadSectorMeta(v2s16 p2d)
        }
 
        try{
-               sector = loadSectorMeta(sectordir, loadlayout != 2);
+               loadSectorMeta(sectordir, loadlayout != 2);
        }
        catch(InvalidFilenameException &e)
        {
@@ -3252,7 +3160,7 @@ bool ServerMap::loadSectorMeta(v2s16 p2d)
 #if 0
 bool ServerMap::loadSectorFull(v2s16 p2d)
 {
-       DSTACK(__FUNCTION_NAME);
+       DSTACK(FUNCTION_NAME);
 
        MapSector *sector = NULL;
 
@@ -3321,6 +3229,31 @@ bool ServerMap::loadSectorFull(v2s16 p2d)
 }
 #endif
 
+Database *ServerMap::createDatabase(
+       const std::string &name,
+       const std::string &savedir,
+       Settings &conf)
+{
+       if (name == "sqlite3")
+               return new Database_SQLite3(savedir);
+       if (name == "dummy")
+               return new Database_Dummy();
+       #if USE_LEVELDB
+       else if (name == "leveldb")
+               return new Database_LevelDB(savedir);
+       #endif
+       #if USE_REDIS
+       else if (name == "redis")
+               return new Database_Redis(conf);
+       #endif
+       #if USE_POSTGRESQL
+       else if (name == "postgresql")
+               return new Database_PostgreSQL(conf);
+       #endif
+       else
+               throw BaseException(std::string("Database backend ") + name + " not supported.");
+}
+
 void ServerMap::beginSave()
 {
        dbase->beginSave();
@@ -3342,7 +3275,7 @@ bool ServerMap::saveBlock(MapBlock *block, Database *db)
 
        // Dummy blocks are not written
        if (block->isDummy()) {
-               errorstream << "WARNING: saveBlock: Not writing dummy block "
+               warningstream << "saveBlock: Not writing dummy block "
                        << PP(p3d) << std::endl;
                return true;
        }
@@ -3360,7 +3293,7 @@ bool ServerMap::saveBlock(MapBlock *block, Database *db)
 
        std::string data = o.str();
        bool ret = db->saveBlock(p3d, data);
-       if(ret) {
+       if (ret) {
                // We just wrote it to the disk so clear modified flag
                block->resetModified();
        }
@@ -3370,9 +3303,9 @@ bool ServerMap::saveBlock(MapBlock *block, Database *db)
 void ServerMap::loadBlock(std::string sectordir, std::string blockfile,
                MapSector *sector, bool save_after_load)
 {
-       DSTACK(__FUNCTION_NAME);
+       DSTACK(FUNCTION_NAME);
 
-       std::string fullpath = sectordir+DIR_DELIM+blockfile;
+       std::string fullpath = sectordir + DIR_DELIM + blockfile;
        try {
 
                std::ifstream is(fullpath.c_str(), std::ios_base::binary);
@@ -3432,13 +3365,13 @@ void ServerMap::loadBlock(std::string sectordir, std::string blockfile,
        }
        catch(SerializationError &e)
        {
-               infostream<<"WARNING: Invalid block data on disk "
+               warningstream<<"Invalid block data on disk "
                                <<"fullpath="<<fullpath
                                <<" (SerializationError). "
                                <<"what()="<<e.what()
                                <<std::endl;
                                // Ignoring. A new one will be generated.
-               assert(0);
+               abort();
 
                // TODO: Backup file; name is in fullpath.
        }
@@ -3446,7 +3379,7 @@ void ServerMap::loadBlock(std::string sectordir, std::string blockfile,
 
 void ServerMap::loadBlock(std::string *blob, v3s16 p3d, MapSector *sector, bool save_after_load)
 {
-       DSTACK(__FUNCTION_NAME);
+       DSTACK(FUNCTION_NAME);
 
        try {
                std::istringstream is(*blob, std::ios_base::binary);
@@ -3508,20 +3441,18 @@ void ServerMap::loadBlock(std::string *blob, v3s16 p3d, MapSector *sector, bool
                                        <<"(ignore_world_load_errors)"<<std::endl;
                } else {
                        throw SerializationError("Invalid block data in database");
-                       //assert(0);
                }
        }
 }
 
 MapBlock* ServerMap::loadBlock(v3s16 blockpos)
 {
-       DSTACK(__FUNCTION_NAME);
+       DSTACK(FUNCTION_NAME);
 
        v2s16 p2d(blockpos.X, blockpos.Z);
 
        std::string ret;
-
-       ret = dbase->loadBlock(blockpos);
+       dbase->loadBlock(blockpos, &ret);
        if (ret != "") {
                loadBlock(&ret, blockpos, createSector(p2d), false);
                return getBlockNoCreateNoEx(blockpos);
@@ -3549,6 +3480,7 @@ MapBlock* ServerMap::loadBlock(v3s16 blockpos)
        /*
                Make sure sector is loaded
        */
+
        MapSector *sector = getSectorNoGenerateNoEx(p2d);
        if(sector == NULL)
        {
@@ -3574,7 +3506,7 @@ MapBlock* ServerMap::loadBlock(v3s16 blockpos)
        */
 
        std::string blockfilename = getBlockFilename(blockpos);
-       if(fs::PathExists(sectordir+DIR_DELIM+blockfilename) == false)
+       if(fs::PathExists(sectordir + DIR_DELIM + blockfilename) == false)
                return NULL;
 
        /*
@@ -3584,6 +3516,23 @@ MapBlock* ServerMap::loadBlock(v3s16 blockpos)
        return getBlockNoCreateNoEx(blockpos);
 }
 
+bool ServerMap::deleteBlock(v3s16 blockpos)
+{
+       if (!dbase->deleteBlock(blockpos))
+               return false;
+
+       MapBlock *block = getBlockNoCreateNoEx(blockpos);
+       if (block) {
+               v2s16 p2d(blockpos.X, blockpos.Z);
+               MapSector *sector = getSectorNoGenerateNoEx(p2d);
+               if (!sector)
+                       return false;
+               sector->deleteBlock(block);
+       }
+
+       return true;
+}
+
 void ServerMap::PrintInfo(std::ostream &out)
 {
        out<<"ServerMap: ";
@@ -3660,8 +3609,7 @@ void MMVManip::initialEmerge(v3s16 blockpos_min, v3s16 blockpos_max,
                                block = svrmap->emergeBlock(p, false);
                                if (block == NULL)
                                        block = svrmap->createBlock(p);
-                               else
-                                       block->copyTo(*this);
+                               block->copyTo(*this);
                        } else {
                                flags |= VMANIP_BLOCK_DATA_INEXIST;