LuaVoxelManip: Add option to allocate blank data
[oweals/minetest.git] / src / map.cpp
index 7903f3050ee2f82b51952388db47e97fb68b281e..05e07212db3d631ac286626f2b3a57f1d9ae7750 100644 (file)
@@ -76,7 +76,11 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 Map::Map(std::ostream &dout, IGameDef *gamedef):
        m_dout(dout),
        m_gamedef(gamedef),
-       m_sector_cache(NULL)
+       m_sector_cache(NULL),
+       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)
 {
 }
 
@@ -186,26 +190,42 @@ bool Map::isValidPosition(v3s16 p)
 }
 
 // Returns a CONTENT_IGNORE node if not found
-MapNode Map::getNodeNoEx(v3s16 p)
+MapNode Map::getNodeNoEx(v3s16 p, bool *is_valid_position)
 {
        v3s16 blockpos = getNodeBlockPos(p);
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
-       if(block == NULL)
+       if (block == NULL) {
+               if (is_valid_position != NULL)
+                       *is_valid_position = false;
                return MapNode(CONTENT_IGNORE);
+       }
+
        v3s16 relpos = p - blockpos*MAP_BLOCKSIZE;
-       return block->getNodeNoCheck(relpos);
+       bool is_valid_p;
+       MapNode node = block->getNodeNoCheck(relpos, &is_valid_p);
+       if (is_valid_position != NULL)
+               *is_valid_position = is_valid_p;
+       return node;
 }
 
+#if 0
+// Deprecated
 // throws InvalidPositionException if not found
+// TODO: Now this is deprecated, getNodeNoEx should be renamed
 MapNode Map::getNode(v3s16 p)
 {
        v3s16 blockpos = getNodeBlockPos(p);
        MapBlock *block = getBlockNoCreateNoEx(blockpos);
-       if(block == NULL)
+       if (block == NULL)
                throw InvalidPositionException();
        v3s16 relpos = p - blockpos*MAP_BLOCKSIZE;
-       return block->getNodeNoCheck(relpos);
+       bool is_valid_position;
+       MapNode node = block->getNodeNoCheck(relpos, &is_valid_position);
+       if (!is_valid_position)
+               throw InvalidPositionException();
+       return node;
 }
+#endif
 
 // throws InvalidPositionException if not found
 void Map::setNode(v3s16 p, MapNode & n)
@@ -215,9 +235,10 @@ void Map::setNode(v3s16 p, MapNode & n)
        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_gamedef->ndef()->get(block->getNodeNoCheck(relpos)).name
+                               <<m_gamedef->ndef()->get(block->getNodeNoCheck(relpos, &temp_bool)).name
                                <<"\" at "<<PP(p)<<" (block "<<PP(blockpos)<<")"<<std::endl;
                debug_stacks_print_to(infostream);
                return;
@@ -259,7 +280,7 @@ void Map::unspreadLight(enum LightBank bank,
                v3s16(-1,0,0), // left
        };
 
-       if(from_nodes.size() == 0)
+       if(from_nodes.empty())
                return;
 
        u32 blockchangecount = 0;
@@ -315,88 +336,83 @@ void Map::unspreadLight(enum LightBank bank,
                        // Get the block where the node is located
                        v3s16 blockpos = getNodeBlockPos(n2pos);
 
-                       try
-                       {
-                               // Only fetch a new block if the block position has changed
-                               try{
-                                       if(block == NULL || blockpos != blockpos_last){
-                                               block = getBlockNoCreate(blockpos);
-                                               blockpos_last = blockpos;
+                       // Only fetch a new block if the block position has changed
+                       try {
+                               if(block == NULL || blockpos != blockpos_last){
+                                       block = getBlockNoCreate(blockpos);
+                                       blockpos_last = blockpos;
 
-                                               block_checked_in_modified = false;
-                                               blockchangecount++;
-                                       }
-                               }
-                               catch(InvalidPositionException &e)
-                               {
-                                       continue;
+                                       block_checked_in_modified = false;
+                                       blockchangecount++;
                                }
+                       }
+                       catch(InvalidPositionException &e) {
+                               continue;
+                       }
 
-                               // Calculate relative position in block
-                               v3s16 relpos = n2pos - blockpos * MAP_BLOCKSIZE;
-                               // Get node straight from the block
-                               MapNode n2 = block->getNode(relpos);
+                       // 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);
+                       if (!is_valid_position)
+                               continue;
 
-                               bool changed = false;
+                       bool changed = false;
 
-                               //TODO: Optimize output by optimizing light_sources?
+                       //TODO: Optimize output by optimizing light_sources?
 
+                       /*
+                               If the neighbor is dimmer than what was specified
+                               as oldlight (the light of the previous node)
+                       */
+                       if(n2.getLight(bank, nodemgr) < oldlight)
+                       {
                                /*
-                                       If the neighbor is dimmer than what was specified
-                                       as oldlight (the light of the previous node)
+                                       And the neighbor is transparent and it has some light
                                */
-                               if(n2.getLight(bank, nodemgr) < oldlight)
+                               if(nodemgr->get(n2).light_propagates
+                                               && n2.getLight(bank, nodemgr) != 0)
                                {
                                        /*
-                                               And the neighbor is transparent and it has some light
+                                               Set light to 0 and add to queue
                                        */
-                                       if(nodemgr->get(n2).light_propagates
-                                                       && n2.getLight(bank, nodemgr) != 0)
-                                       {
-                                               /*
-                                                       Set light to 0 and add to queue
-                                               */
-
-                                               u8 current_light = n2.getLight(bank, nodemgr);
-                                               n2.setLight(bank, 0, nodemgr);
-                                               block->setNode(relpos, n2);
-
-                                               unlighted_nodes[n2pos] = current_light;
-                                               changed = true;
-
-                                               /*
-                                                       Remove from light_sources if it is there
-                                                       NOTE: This doesn't happen nearly at all
-                                               */
-                                               /*if(light_sources.find(n2pos))
-                                               {
-                                                       infostream<<"Removed from light_sources"<<std::endl;
-                                                       light_sources.remove(n2pos);
-                                               }*/
-                                       }
 
-                                       /*// DEBUG
-                                       if(light_sources.find(n2pos) != NULL)
-                                               light_sources.remove(n2pos);*/
-                               }
-                               else{
-                                       light_sources.insert(n2pos);
-                               }
+                                       u8 current_light = n2.getLight(bank, nodemgr);
+                                       n2.setLight(bank, 0, nodemgr);
+                                       block->setNode(relpos, n2);
 
-                               // Add to modified_blocks
-                               if(changed == true && block_checked_in_modified == false)
-                               {
-                                       // If the block is not found in modified_blocks, add.
-                                       if(modified_blocks.find(blockpos) == modified_blocks.end())
+                                       unlighted_nodes[n2pos] = current_light;
+                                       changed = true;
+
+                                       /*
+                                               Remove from light_sources if it is there
+                                               NOTE: This doesn't happen nearly at all
+                                       */
+                                       /*if(light_sources.find(n2pos))
                                        {
-                                               modified_blocks[blockpos] = block;
-                                       }
-                                       block_checked_in_modified = true;
+                                               infostream<<"Removed from light_sources"<<std::endl;
+                                               light_sources.remove(n2pos);
+                                       }*/
                                }
+
+                               /*// DEBUG
+                               if(light_sources.find(n2pos) != NULL)
+                                       light_sources.remove(n2pos);*/
                        }
-                       catch(InvalidPositionException &e)
+                       else{
+                               light_sources.insert(n2pos);
+                       }
+
+                       // Add to modified_blocks
+                       if(changed == true && block_checked_in_modified == false)
                        {
-                               continue;
+                               // If the block is not found in modified_blocks, add.
+                               if(modified_blocks.find(blockpos) == modified_blocks.end())
+                               {
+                                       modified_blocks[blockpos] = block;
+                               }
+                               block_checked_in_modified = true;
                        }
                }
        }
@@ -406,7 +422,7 @@ void Map::unspreadLight(enum LightBank bank,
                        <<" for "<<from_nodes.size()<<" nodes"
                        <<std::endl;*/
 
-       if(unlighted_nodes.size() > 0)
+       if(!unlighted_nodes.empty())
                unspreadLight(bank, unlighted_nodes, light_sources, modified_blocks);
 }
 
@@ -443,7 +459,7 @@ void Map::spreadLight(enum LightBank bank,
                v3s16(-1,0,0), // left
        };
 
-       if(from_nodes.size() == 0)
+       if(from_nodes.empty())
                return;
 
        u32 blockchangecount = 0;
@@ -465,7 +481,7 @@ void Map::spreadLight(enum LightBank bank,
                v3s16 blockpos = getNodeBlockPos(pos);
 
                // Only fetch a new block if the block position has changed
-               try{
+               try {
                        if(block == NULL || blockpos != blockpos_last){
                                block = getBlockNoCreate(blockpos);
                                blockpos_last = blockpos;
@@ -474,8 +490,7 @@ void Map::spreadLight(enum LightBank bank,
                                blockchangecount++;
                        }
                }
-               catch(InvalidPositionException &e)
-               {
+               catch(InvalidPositionException &e) {
                        continue;
                }
 
@@ -486,9 +501,10 @@ void Map::spreadLight(enum LightBank bank,
                v3s16 relpos = pos - blockpos_last * MAP_BLOCKSIZE;
 
                // Get node straight from the block
-               MapNode n = block->getNode(relpos);
+               bool is_valid_position;
+               MapNode n = block->getNode(relpos, &is_valid_position);
 
-               u8 oldlight = n.getLight(bank, nodemgr);
+               u8 oldlight = is_valid_position ? n.getLight(bank, nodemgr) : 0;
                u8 newlight = diminish_light(oldlight);
 
                // Loop through 6 neighbors
@@ -499,67 +515,61 @@ void Map::spreadLight(enum LightBank bank,
                        // Get the block where the node is located
                        v3s16 blockpos = getNodeBlockPos(n2pos);
 
-                       try
-                       {
-                               // Only fetch a new block if the block position has changed
-                               try{
-                                       if(block == NULL || blockpos != blockpos_last){
-                                               block = getBlockNoCreate(blockpos);
-                                               blockpos_last = blockpos;
+                       // Only fetch a new block if the block position has changed
+                       try {
+                               if(block == NULL || blockpos != blockpos_last){
+                                       block = getBlockNoCreate(blockpos);
+                                       blockpos_last = blockpos;
 
-                                               block_checked_in_modified = false;
-                                               blockchangecount++;
-                                       }
-                               }
-                               catch(InvalidPositionException &e)
-                               {
-                                       continue;
+                                       block_checked_in_modified = false;
+                                       blockchangecount++;
                                }
+                       }
+                       catch(InvalidPositionException &e) {
+                               continue;
+                       }
 
-                               // Calculate relative position in block
-                               v3s16 relpos = n2pos - blockpos * MAP_BLOCKSIZE;
-                               // Get node straight from the block
-                               MapNode n2 = block->getNode(relpos);
+                       // 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)
+                               continue;
 
-                               bool changed = false;
-                               /*
-                                       If the neighbor is brighter than the current node,
-                                       add to list (it will light up this node on its turn)
-                               */
-                               if(n2.getLight(bank, nodemgr) > undiminish_light(oldlight))
+                       bool changed = false;
+                       /*
+                               If the neighbor is brighter than the current node,
+                               add to list (it will light up this node on its turn)
+                       */
+                       if(n2.getLight(bank, nodemgr) > undiminish_light(oldlight))
+                       {
+                               lighted_nodes.insert(n2pos);
+                               changed = true;
+                       }
+                       /*
+                               If the neighbor is dimmer than how much light this node
+                               would spread on it, add to list
+                       */
+                       if(n2.getLight(bank, nodemgr) < newlight)
+                       {
+                               if(nodemgr->get(n2).light_propagates)
                                {
+                                       n2.setLight(bank, newlight, nodemgr);
+                                       block->setNode(relpos, n2);
                                        lighted_nodes.insert(n2pos);
                                        changed = true;
                                }
-                               /*
-                                       If the neighbor is dimmer than how much light this node
-                                       would spread on it, add to list
-                               */
-                               if(n2.getLight(bank, nodemgr) < newlight)
-                               {
-                                       if(nodemgr->get(n2).light_propagates)
-                                       {
-                                               n2.setLight(bank, newlight, nodemgr);
-                                               block->setNode(relpos, n2);
-                                               lighted_nodes.insert(n2pos);
-                                               changed = true;
-                                       }
-                               }
+                       }
 
-                               // Add to modified_blocks
-                               if(changed == true && block_checked_in_modified == false)
+                       // Add to modified_blocks
+                       if(changed == true && block_checked_in_modified == false)
+                       {
+                               // If the block is not found in modified_blocks, add.
+                               if(modified_blocks.find(blockpos) == modified_blocks.end())
                                {
-                                       // If the block is not found in modified_blocks, add.
-                                       if(modified_blocks.find(blockpos) == modified_blocks.end())
-                                       {
-                                               modified_blocks[blockpos] = block;
-                                       }
-                                       block_checked_in_modified = true;
+                                       modified_blocks[blockpos] = block;
                                }
-                       }
-                       catch(InvalidPositionException &e)
-                       {
-                               continue;
+                               block_checked_in_modified = true;
                        }
                }
        }
@@ -569,7 +579,7 @@ void Map::spreadLight(enum LightBank bank,
                        <<" for "<<from_nodes.size()<<" nodes"
                        <<std::endl;*/
 
-       if(lighted_nodes.size() > 0)
+       if(!lighted_nodes.empty())
                spreadLight(bank, lighted_nodes, modified_blocks);
 }
 
@@ -607,13 +617,11 @@ v3s16 Map::getBrightestNeighbour(enum LightBank bank, v3s16 p)
                // Get the position of the neighbor node
                v3s16 n2pos = p + dirs[i];
                MapNode n2;
-               try{
-                       n2 = getNode(n2pos);
-               }
-               catch(InvalidPositionException &e)
-               {
+               bool is_valid_position;
+               n2 = getNodeNoEx(n2pos, &is_valid_position);
+               if (!is_valid_position)
                        continue;
-               }
+
                if(n2.getLight(bank, nodemgr) > brightest_light || found_something == false){
                        brightest_light = n2.getLight(bank, nodemgr);
                        brightest_pos = n2pos;
@@ -656,7 +664,10 @@ s16 Map::propagateSunlight(v3s16 start,
                }
 
                v3s16 relpos = pos - blockpos*MAP_BLOCKSIZE;
-               MapNode n = block->getNode(relpos);
+               bool is_valid_position;
+               MapNode n = block->getNode(relpos, &is_valid_position);
+               if (!is_valid_position)
+                       break;
 
                if(nodemgr->get(n).sunlight_propagates)
                {
@@ -723,39 +734,37 @@ void Map::updateLighting(enum LightBank bank,
                        for(s16 x=0; x<MAP_BLOCKSIZE; x++)
                        for(s16 y=0; y<MAP_BLOCKSIZE; y++)
                        {
-
-                               try{
-                                       v3s16 p(x,y,z);
-                                       MapNode n = block->getNode(p);
-                                       u8 oldlight = n.getLight(bank, nodemgr);
-                                       n.setLight(bank, 0, nodemgr);
-                                       block->setNode(p, n);
-
-                                       // If node sources light, add to list
-                                       u8 source = nodemgr->get(n).light_source;
-                                       if(source != 0)
-                                               light_sources.insert(p + posnodes);
-
-                                       // Collect borders for unlighting
-                                       if((x==0 || x == MAP_BLOCKSIZE-1
-                                       || y==0 || y == MAP_BLOCKSIZE-1
-                                       || z==0 || z == MAP_BLOCKSIZE-1)
-                                       && oldlight != 0)
-                                       {
-                                               v3s16 p_map = p + posnodes;
-                                               unlight_from[p_map] = oldlight;
-                                       }
-                               }
-                               catch(InvalidPositionException &e)
-                               {
-                                       /*
-                                               This would happen when dealing with a
-                                               dummy block.
+                               v3s16 p(x,y,z);
+                               bool is_valid_position;
+                               MapNode n = block->getNode(p, &is_valid_position);
+                               if (!is_valid_position) {
+                                       /* This would happen when dealing with a
+                                          dummy block.
                                        */
-                                       //assert(0);
                                        infostream<<"updateLighting(): InvalidPositionException"
                                                        <<std::endl;
+                                       continue;
+                               }
+                               u8 oldlight = n.getLight(bank, nodemgr);
+                               n.setLight(bank, 0, nodemgr);
+                               block->setNode(p, n);
+
+                               // If node sources light, add to list
+                               u8 source = nodemgr->get(n).light_source;
+                               if(source != 0)
+                                       light_sources.insert(p + posnodes);
+
+                               // Collect borders for unlighting
+                               if((x==0 || x == MAP_BLOCKSIZE-1
+                                               || y==0 || y == MAP_BLOCKSIZE-1
+                                               || z==0 || z == MAP_BLOCKSIZE-1)
+                                               && oldlight != 0)
+                               {
+                                       v3s16 p_map = p + posnodes;
+                                       unlight_from[p_map] = oldlight;
                                }
+
+
                        }
 
                        if(bank == LIGHTBANK_DAY)
@@ -965,15 +974,12 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
 
                Otherwise there probably is.
        */
-       try{
-               MapNode topnode = getNode(toppos);
 
-               if(topnode.getLight(LIGHTBANK_DAY, ndef) != LIGHT_SUN)
-                       node_under_sunlight = false;
-       }
-       catch(InvalidPositionException &e)
-       {
-       }
+       bool is_valid_position;
+       MapNode topnode = getNodeNoEx(toppos, &is_valid_position);
+
+       if(is_valid_position && topnode.getLight(LIGHTBANK_DAY, ndef) != LIGHT_SUN)
+               node_under_sunlight = false;
 
        /*
                Remove all light that has come out of this node
@@ -988,7 +994,7 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
        {
                enum LightBank bank = banks[i];
 
-               u8 lightwas = getNode(p).getLight(bank, ndef);
+               u8 lightwas = getNodeNoEx(p).getLight(bank, ndef);
 
                // Add the block of the added node to modified_blocks
                v3s16 blockpos = getNodeBlockPos(p);
@@ -1045,13 +1051,10 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
                        v3s16 n2pos(p.X, y, p.Z);
 
                        MapNode n2;
-                       try{
-                               n2 = getNode(n2pos);
-                       }
-                       catch(InvalidPositionException &e)
-                       {
+
+                       n2 = getNodeNoEx(n2pos, &is_valid_position);
+                       if (!is_valid_position)
                                break;
-                       }
 
                        if(n2.getLight(LIGHTBANK_DAY, ndef) == LIGHT_SUN)
                        {
@@ -1112,20 +1115,14 @@ void Map::addNodeAndUpdate(v3s16 p, MapNode n,
        };
        for(u16 i=0; i<7; i++)
        {
-               try
-               {
-
                v3s16 p2 = p + dirs[i];
 
-               MapNode n2 = getNode(p2);
-               if(ndef->get(n2).isLiquid() || n2.getContent() == CONTENT_AIR)
+               MapNode n2 = getNodeNoEx(p2, &is_valid_position);
+               if(is_valid_position
+                               && (ndef->get(n2).isLiquid() || n2.getContent() == CONTENT_AIR))
                {
                        m_transforming_liquid.push_back(p2);
                }
-
-               }catch(InvalidPositionException &e)
-               {
-               }
        }
 }
 
@@ -1156,15 +1153,11 @@ void Map::removeNodeAndUpdate(v3s16 p,
                If there is a node at top and it doesn't have sunlight,
                there will be no sunlight going down.
        */
-       try{
-               MapNode topnode = getNode(toppos);
+       bool is_valid_position;
+       MapNode topnode = getNodeNoEx(toppos, &is_valid_position);
 
-               if(topnode.getLight(LIGHTBANK_DAY, ndef) != LIGHT_SUN)
-                       node_under_sunlight = false;
-       }
-       catch(InvalidPositionException &e)
-       {
-       }
+       if(is_valid_position && topnode.getLight(LIGHTBANK_DAY, ndef) != LIGHT_SUN)
+               node_under_sunlight = false;
 
        std::set<v3s16> light_sources;
 
@@ -1181,7 +1174,7 @@ void Map::removeNodeAndUpdate(v3s16 p,
                        Unlight neighbors (in case the node is a light source)
                */
                unLightNeighbors(bank, p,
-                               getNode(p).getLight(bank, ndef),
+                               getNodeNoEx(p).getLight(bank, ndef),
                                light_sources, modified_blocks);
        }
 
@@ -1241,13 +1234,11 @@ void Map::removeNodeAndUpdate(v3s16 p,
        {
                // Set the lighting of this node to 0
                // TODO: Is this needed? Lighting is cleared up there already.
-               try{
-                       MapNode n = getNode(p);
+               MapNode n = getNodeNoEx(p, &is_valid_position);
+               if (is_valid_position) {
                        n.setLight(LIGHTBANK_DAY, 0, ndef);
                        setNode(p, n);
-               }
-               catch(InvalidPositionException &e)
-               {
+               } else {
                        assert(0);
                }
        }
@@ -1303,20 +1294,15 @@ void Map::removeNodeAndUpdate(v3s16 p,
        };
        for(u16 i=0; i<7; i++)
        {
-               try
-               {
-
                v3s16 p2 = p + dirs[i];
 
-               MapNode n2 = getNode(p2);
-               if(ndef->get(n2).isLiquid() || n2.getContent() == CONTENT_AIR)
+               bool is_position_valid;
+               MapNode n2 = getNodeNoEx(p2, &is_position_valid);
+               if (is_position_valid
+                               && (ndef->get(n2).isLiquid() || n2.getContent() == CONTENT_AIR))
                {
                        m_transforming_liquid.push_back(p2);
                }
-
-               }catch(InvalidPositionException &e)
-               {
-               }
        }
 }
 
@@ -1629,6 +1615,7 @@ s32 Map::transforming_liquid_size() {
 
 void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
 {
+
        INodeDefManager *nodemgr = m_gamedef->ndef();
 
        DSTACK(__FUNCTION_NAME);
@@ -1646,7 +1633,25 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
        // List of MapBlocks that will require a lighting update (due to lava)
        std::map<v3s16, MapBlock*> lighting_modified_blocks;
 
-       u16 loop_max = g_settings->getU16("liquid_loop_max");
+       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)
        {
@@ -1902,6 +1907,55 @@ void Map::transformLiquids(std::map<v3s16, MapBlock*> & modified_blocks)
        while (must_reflow.size() > 0)
                m_transforming_liquid.push_back(must_reflow.pop_front());
        updateLighting(lighting_modified_blocks, modified_blocks);
+
+
+       /* ----------------------------------------------------------------------
+        * Manage the queue so that it does not grow indefinately
+        */
+       u16 time_until_purge = g_settings->getU16("liquid_queue_purge_time");
+
+       if (time_until_purge == 0)
+               return; // Feature disabled
+
+       time_until_purge *= 1000;       // seconds -> milliseconds
+
+       u32 curr_time = getTime(PRECISION_MILLI);
+       u32 prev_unprocessed = m_unprocessed_count;
+       m_unprocessed_count = m_transforming_liquid.size();
+
+       // if unprocessed block count is decreasing or stable
+       if (m_unprocessed_count <= prev_unprocessed) {
+               m_queue_size_timer_started = false;
+       } else {
+               if (!m_queue_size_timer_started)
+                       m_inc_trending_up_start_time = curr_time;
+               m_queue_size_timer_started = true;
+       }
+
+       // Account for curr_time overflowing
+       if (m_queue_size_timer_started && m_inc_trending_up_start_time > curr_time)
+               m_queue_size_timer_started = false;
+
+       /* If the queue has been growing for more than liquid_queue_purge_time seconds
+        * and the number of unprocessed blocks is still > liquid_loop_max then we
+        * cannot keep up; dump the oldest blocks from the queue so that the queue
+        * has liquid_loop_max items in it
+        */
+       if (m_queue_size_timer_started
+                       && curr_time - m_inc_trending_up_start_time > time_until_purge
+                       && m_unprocessed_count > liquid_loop_max) {
+
+               size_t dump_qty = m_unprocessed_count - liquid_loop_max;
+
+               infostream << "transformLiquids(): DUMPING " << dump_qty
+                          << " blocks from the queue" << std::endl;
+
+               while (dump_qty--)
+                       m_transforming_liquid.pop_front();
+
+               m_queue_size_timer_started = false; // optimistically assume we can keep up now
+               m_unprocessed_count = m_transforming_liquid.size();
+       }
 }
 
 NodeMetadata *Map::getNodeMetadata(v3s16 p)
@@ -3543,8 +3597,31 @@ ManualMapVoxelManipulator::~ManualMapVoxelManipulator()
 {
 }
 
+void ManualMapVoxelManipulator::initializeBlank(v3s16 blockpos_min,
+       v3s16 blockpos_max)
+{
+       // Units of these are MapBlocks
+       v3s16 pmin = blockpos_min;
+       v3s16 pmax = blockpos_max;
+
+       VoxelArea block_area_nodes(pmin * MAP_BLOCKSIZE,
+               (pmax + 1) * MAP_BLOCKSIZE - v3s16(1,1,1));
+
+       addArea(block_area_nodes);
+       u32 extent = m_area.getVolume();
+       for (u32 i = 0; i != extent; i++)
+               m_data[i] = MapNode(CONTENT_IGNORE);
+
+       for (s32 z = pmin.Z; z <= pmax.Z; z++)
+       for (s32 y = pmin.Y; y <= pmax.Y; y++)
+       for (s32 x = pmin.X; x <= pmax.X; x++)
+               m_loaded_blocks[v3s16(x, y, z)] = 0;
+
+       m_is_dirty = false;
+}
+
 void ManualMapVoxelManipulator::initialEmerge(v3s16 blockpos_min,
-                                               v3s16 blockpos_max, bool load_if_inexistent)
+       v3s16 blockpos_max, bool load_if_inexistent)
 {
        TimeTaker timer1("initialEmerge", &emerge_time);