minetest/src/map.cpp

/*
Minetest-c55
Copyright (C) 2010-2011 celeron55, Perttu Ahola <celeron55@gmail.com>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/

#include "map.h"
#include "mapsector.h"
#include "mapblock.h"
#include "main.h"
#include "filesys.h"
#include "utility.h"
#include "voxel.h"
#include "porting.h"
#include "mapgen.h"
#include "nodemetadata.h"
#include "settings.h"
#include "log.h"
#include "profiler.h"
#include "nodedef.h"
#include "gamedef.h"

#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
*/

Map::Map(std::ostream &dout, IGameDef *gamedef):
	m_dout(dout),
	m_gamedef(gamedef),
	m_sector_cache(NULL)
{
	/*m_sector_mutex.Init();
	assert(m_sector_mutex.IsInitialized());*/
}

Map::~Map()
{
	/*
		Free all MapSectors
	*/
	core::map<v2s16, MapSector*>::Iterator i = m_sectors.getIterator();
	for(; i.atEnd() == false; i++)
	{
		MapSector *sector = i.getNode()->getValue();
		delete sector;
	}
}

void Map::addEventReceiver(MapEventReceiver *event_receiver)
{
	m_event_receivers.insert(event_receiver, false);
}

void Map::removeEventReceiver(MapEventReceiver *event_receiver)
{
	if(m_event_receivers.find(event_receiver) == NULL)
		return;
	m_event_receivers.remove(event_receiver);
}

void Map::dispatchEvent(MapEditEvent *event)
{
	for(core::map<MapEventReceiver*, bool>::Iterator
			i = m_event_receivers.getIterator();
			i.atEnd()==false; i++)
	{
		MapEventReceiver* event_receiver = i.getNode()->getKey();
		event_receiver->onMapEditEvent(event);
	}
}

MapSector * Map::getSectorNoGenerateNoExNoLock(v2s16 p)
{
	if(m_sector_cache != NULL && p == m_sector_cache_p){
		MapSector * sector = m_sector_cache;
		return sector;
	}
	
	core::map<v2s16, MapSector*>::Node *n = m_sectors.find(p);
	
	if(n == NULL)
		return NULL;
	
	MapSector *sector = n->getValue();
	
	// Cache the last result
	m_sector_cache_p = p;
	m_sector_cache = sector;

	return sector;
}

MapSector * Map::getSectorNoGenerateNoEx(v2s16 p)
{
	return getSectorNoGenerateNoExNoLock(p);
}

MapSector * Map::getSectorNoGenerate(v2s16 p)
{
	MapSector *sector = getSectorNoGenerateNoEx(p);
	if(sector == NULL)
		throw InvalidPositionException();
	
	return sector;
}

MapBlock * Map::getBlockNoCreateNoEx(v3s16 p3d)
{
	v2s16 p2d(p3d.X, p3d.Z);
	MapSector * sector = getSectorNoGenerateNoEx(p2d);
	if(sector == NULL)
		return NULL;
	MapBlock *block = sector->getBlockNoCreateNoEx(p3d.Y);
	return block;
}

MapBlock * Map::getBlockNoCreate(v3s16 p3d)
{	
	MapBlock *block = getBlockNoCreateNoEx(p3d);
	if(block == NULL)
		throw InvalidPositionException();
	return block;
}

bool Map::isNodeUnderground(v3s16 p)
{
	v3s16 blockpos = getNodeBlockPos(p);
	try{
		MapBlock * block = getBlockNoCreate(blockpos);
		return block->getIsUnderground();
	}
	catch(InvalidPositionException &e)
	{
		return false;
	}
}

bool Map::isValidPosition(v3s16 p)
{
	v3s16 blockpos = getNodeBlockPos(p);
	MapBlock *block = getBlockNoCreate(blockpos);
	return (block != NULL);
}

// Returns a CONTENT_IGNORE node if not found
MapNode Map::getNodeNoEx(v3s16 p)
{
	v3s16 blockpos = getNodeBlockPos(p);
	MapBlock *block = getBlockNoCreateNoEx(blockpos);
	if(block == NULL)
		return MapNode(CONTENT_IGNORE);
	v3s16 relpos = p - blockpos*MAP_BLOCKSIZE;
	return block->getNodeNoCheck(relpos);
}

// throws InvalidPositionException if not found
MapNode Map::getNode(v3s16 p)
{
	v3s16 blockpos = getNodeBlockPos(p);
	MapBlock *block = getBlockNoCreateNoEx(blockpos);
	if(block == NULL)
		throw InvalidPositionException();
	v3s16 relpos = p - blockpos*MAP_BLOCKSIZE;
	return block->getNodeNoCheck(relpos);
}

// throws InvalidPositionException if not found
void Map::setNode(v3s16 p, MapNode & n)
{
	v3s16 blockpos = getNodeBlockPos(p);
	MapBlock *block = getBlockNoCreate(blockpos);
	v3s16 relpos = p - blockpos*MAP_BLOCKSIZE;
	// Never allow placing CONTENT_IGNORE, it fucks up stuff
	if(n.getContent() == CONTENT_IGNORE){
		errorstream<<"Map::setNode(): Not allowing to place CONTENT_IGNORE"
				<<" while trying to replace \""
				<<m_gamedef->ndef()->get(block->getNodeNoCheck(relpos)).name
				<<"\" at "<<PP(p)<<" (block "<<PP(blockpos)<<")"<<std::endl;
		debug_stacks_print_to(infostream);
		return;
	}
	block->setNodeNoCheck(relpos, n);
}


/*
	Goes recursively through the neighbours of the node.

	Alters only transparent nodes.

	If the lighting of the neighbour is lower than the lighting of
	the node was (before changing it to 0 at the step before), the
	lighting of the neighbour is set to 0 and then the same stuff
	repeats for the neighbour.

	The ending nodes of the routine are stored in light_sources.
	This is useful when a light is removed. In such case, this
	routine can be called for the light node and then again for
	light_sources to re-light the area without the removed light.

	values of from_nodes are lighting values.
*/
void Map::unspreadLight(enum LightBank bank,
		core::map<v3s16, u8> & from_nodes,
		core::map<v3s16, bool> & light_sources,
		core::map<v3s16, MapBlock*>  & modified_blocks)
{
	INodeDefManager *nodemgr = m_gamedef->ndef();

	v3s16 dirs[6] = {
		v3s16(0,0,1), // back
		v3s16(0,1,0), // top
		v3s16(1,0,0), // right
		v3s16(0,0,-1), // front
		v3s16(0,-1,0), // bottom
		v3s16(-1,0,0), // left
	};
	
	if(from_nodes.size() == 0)
		return;
	
	u32 blockchangecount = 0;

	core::map<v3s16, u8> unlighted_nodes;
	core::map<v3s16, u8>::Iterator j;
	j = from_nodes.getIterator();

	/*
		Initialize block cache
	*/
	v3s16 blockpos_last;
	MapBlock *block = NULL;
	// Cache this a bit, too
	bool block_checked_in_modified = false;
	
	for(; j.atEnd() == false; j++)
	{
		v3s16 pos = j.getNode()->getKey();
		v3s16 blockpos = getNodeBlockPos(pos);
		
		// 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;
		}

		if(block->isDummy())
			continue;

		// Calculate relative position in block
		v3s16 relpos = pos - blockpos_last * MAP_BLOCKSIZE;

		// Get node straight from the block
		MapNode n = block->getNode(relpos);

		u8 oldlight = j.getNode()->getValue();

		// Loop through 6 neighbors
		for(u16 i=0; i<6; i++)
		{
			// Get the position of the neighbor node
			v3s16 n2pos = pos + dirs[i];

			// 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;

						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);

				bool changed = false;

				//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)
				{
					/*
						And the neighbor is transparent and it has some light
					*/
					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.insert(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, true);
				}

				// 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) == NULL)
					{
						modified_blocks.insert(blockpos, block);
					}
					block_checked_in_modified = true;
				}
			}
			catch(InvalidPositionException &e)
			{
				continue;
			}
		}
	}

	/*infostream<<"unspreadLight(): Changed block "
			<<blockchangecount<<" times"
			<<" for "<<from_nodes.size()<<" nodes"
			<<std::endl;*/

	if(unlighted_nodes.size() > 0)
		unspreadLight(bank, unlighted_nodes, light_sources, modified_blocks);
}

/*
	A single-node wrapper of the above
*/
void Map::unLightNeighbors(enum LightBank bank,
		v3s16 pos, u8 lightwas,
		core::map<v3s16, bool> & light_sources,
		core::map<v3s16, MapBlock*>  & modified_blocks)
{
	core::map<v3s16, u8> from_nodes;
	from_nodes.insert(pos, lightwas);

	unspreadLight(bank, from_nodes, light_sources, modified_blocks);
}

/*
	Lights neighbors of from_nodes, collects all them and then
	goes on recursively.
*/
void Map::spreadLight(enum LightBank bank,
		core::map<v3s16, bool> & from_nodes,
		core::map<v3s16, MapBlock*> & modified_blocks)
{
	INodeDefManager *nodemgr = m_gamedef->ndef();

	const v3s16 dirs[6] = {
		v3s16(0,0,1), // back
		v3s16(0,1,0), // top
		v3s16(1,0,0), // right
		v3s16(0,0,-1), // front
		v3s16(0,-1,0), // bottom
		v3s16(-1,0,0), // left
	};

	if(from_nodes.size() == 0)
		return;

	u32 blockchangecount = 0;

	core::map<v3s16, bool> lighted_nodes;
	core::map<v3s16, bool>::Iterator j;
	j = from_nodes.getIterator();

	/*
		Initialize block cache
	*/
	v3s16 blockpos_last;
	MapBlock *block = NULL;
	// Cache this a bit, too
	bool block_checked_in_modified = false;

	for(; j.atEnd() == false; j++)
	//for(; j != from_nodes.end(); j++)
	{
		v3s16 pos = j.getNode()->getKey();
		//v3s16 pos = *j;
		//infostream<<"pos=("<<pos.X<<","<<pos.Y<<","<<pos.Z<<")"<<std::endl;
		v3s16 blockpos = getNodeBlockPos(pos);

		// 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;
		}

		if(block->isDummy())
			continue;

		// Calculate relative position in block
		v3s16 relpos = pos - blockpos_last * MAP_BLOCKSIZE;

		// Get node straight from the block
		MapNode n = block->getNode(relpos);

		u8 oldlight = n.getLight(bank, nodemgr);
		u8 newlight = diminish_light(oldlight);

		// Loop through 6 neighbors
		for(u16 i=0; i<6; i++){
			// Get the position of the neighbor node
			v3s16 n2pos = pos + dirs[i];

			// 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;

						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);

				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, true);
					//lighted_nodes.push_back(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, true);
						//lighted_nodes.push_back(n2pos);
						changed = true;
					}
				}

				// 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) == NULL)
					{
						modified_blocks.insert(blockpos, block);
					}
					block_checked_in_modified = true;
				}
			}
			catch(InvalidPositionException &e)
			{
				continue;
			}
		}
	}

	/*infostream<<"spreadLight(): Changed block "
			<<blockchangecount<<" times"
			<<" for "<<from_nodes.size()<<" nodes"
			<<std::endl;*/

	if(lighted_nodes.size() > 0)
		spreadLight(bank, lighted_nodes, modified_blocks);
}

/*
	A single-node source variation of the above.
*/
void Map::lightNeighbors(enum LightBank bank,
		v3s16 pos,
		core::map<v3s16, MapBlock*> & modified_blocks)
{
	core::map<v3s16, bool> from_nodes;
	from_nodes.insert(pos, true);
	spreadLight(bank, from_nodes, modified_blocks);
}

v3s16 Map::getBrightestNeighbour(enum LightBank bank, v3s16 p)
{
	INodeDefManager *nodemgr = m_gamedef->ndef();

	v3s16 dirs[6] = {
		v3s16(0,0,1), // back
		v3s16(0,1,0), // top
		v3s16(1,0,0), // right
		v3s16(0,0,-1), // front
		v3s16(0,-1,0), // bottom
		v3s16(-1,0,0), // left
	};

	u8 brightest_light = 0;
	v3s16 brightest_pos(0,0,0);
	bool found_something = false;

	// Loop through 6 neighbors
	for(u16 i=0; i<6; i++){
		// Get the position of the neighbor node
		v3s16 n2pos = p + dirs[i];
		MapNode n2;
		try{
			n2 = getNode(n2pos);
		}
		catch(InvalidPositionException &e)
		{
			continue;
		}
		if(n2.getLight(bank, nodemgr) > brightest_light || found_something == false){
			brightest_light = n2.getLight(bank, nodemgr);
			brightest_pos = n2pos;
			found_something = true;
		}
	}

	if(found_something == false)
		throw InvalidPositionException();

	return brightest_pos;
}

/*
	Propagates sunlight down from a node.
	Starting point gets sunlight.

	Returns the lowest y value of where the sunlight went.

	Mud is turned into grass in where the sunlight stops.
*/
s16 Map::propagateSunlight(v3s16 start,
		core::map<v3s16, MapBlock*> & modified_blocks)
{
	INodeDefManager *nodemgr = m_gamedef->ndef();

	s16 y = start.Y;
	for(; ; y--)
	{
		v3s16 pos(start.X, y, start.Z);

		v3s16 blockpos = getNodeBlockPos(pos);
		MapBlock *block;
		try{
			block = getBlockNoCreate(blockpos);
		}
		catch(InvalidPositionException &e)
		{
			break;
		}

		v3s16 relpos = pos - blockpos*MAP_BLOCKSIZE;
		MapNode n = block->getNode(relpos);

		if(nodemgr->get(n).sunlight_propagates)
		{
			n.setLight(LIGHTBANK_DAY, LIGHT_SUN, nodemgr);
			block->setNode(relpos, n);

			modified_blocks.insert(blockpos, block);
		}
		else
		{
			// Sunlight goes no further
			break;
		}
	}
	return y + 1;
}

void Map::updateLighting(enum LightBank bank,
		core::map<v3s16, MapBlock*> & a_blocks,
		core::map<v3s16, MapBlock*> & modified_blocks)
{
	INodeDefManager *nodemgr = m_gamedef->ndef();

	/*m_dout<<DTIME<<"Map::updateLighting(): "
			<<a_blocks.size()<<" blocks."<<std::endl;*/

	//TimeTaker timer("updateLighting");

	// For debugging
	//bool debug=true;
	//u32 count_was = modified_blocks.size();

	core::map<v3s16, MapBlock*> blocks_to_update;

	core::map<v3s16, bool> light_sources;

	core::map<v3s16, u8> unlight_from;

	int num_bottom_invalid = 0;
	
	{
	//TimeTaker t("first stuff");

	core::map<v3s16, MapBlock*>::Iterator i;
	i = a_blocks.getIterator();
	for(; i.atEnd() == false; i++)
	{
		MapBlock *block = i.getNode()->getValue();

		for(;;)
		{
			// Don't bother with dummy blocks.
			if(block->isDummy())
				break;

			v3s16 pos = block->getPos();
			v3s16 posnodes = block->getPosRelative();
			modified_blocks.insert(pos, block);

			blocks_to_update.insert(pos, block);

			/*
				Clear all light from block
			*/
			for(s16 z=0; z<MAP_BLOCKSIZE; z++)
			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[p + posnodes] = true;

					// 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.insert(p_map, oldlight);
					}
				}
				catch(InvalidPositionException &e)
				{
					/*
						This would happen when dealing with a
						dummy block.
					*/
					//assert(0);
					infostream<<"updateLighting(): InvalidPositionException"
							<<std::endl;
				}
			}

			if(bank == LIGHTBANK_DAY)
			{
				bool bottom_valid = block->propagateSunlight(light_sources);

				if(!bottom_valid)
					num_bottom_invalid++;

				// If bottom is valid, we're done.
				if(bottom_valid)
					break;
			}
			else if(bank == LIGHTBANK_NIGHT)
			{
				// For night lighting, sunlight is not propagated
				break;
			}
			else
			{
				// Invalid lighting bank
				assert(0);
			}

			/*infostream<<"Bottom for sunlight-propagated block ("
					<<pos.X<<","<<pos.Y<<","<<pos.Z<<") not valid"
					<<std::endl;*/

			// Bottom sunlight is not valid; get the block and loop to it

			pos.Y--;
			try{
				block = getBlockNoCreate(pos);
			}
			catch(InvalidPositionException &e)
			{
				assert(0);
			}

		}
	}

	}

	/*
		Enable this to disable proper lighting for speeding up map
		generation for testing or whatever
	*/
#if 0
	//if(g_settings->get(""))
	{
		core::map<v3s16, MapBlock*>::Iterator i;
		i = blocks_to_update.getIterator();
		for(; i.atEnd() == false; i++)
		{
			MapBlock *block = i.getNode()->getValue();
			v3s16 p = block->getPos();
			block->setLightingExpired(false);
		}
		return;
	}
#endif

#if 1
	{
		//TimeTaker timer("unspreadLight");
		unspreadLight(bank, unlight_from, light_sources, modified_blocks);
	}

	/*if(debug)
	{
		u32 diff = modified_blocks.size() - count_was;
		count_was = modified_blocks.size();
		infostream<<"unspreadLight modified "<<diff<<std::endl;
	}*/

	{
		//TimeTaker timer("spreadLight");
		spreadLight(bank, light_sources, modified_blocks);
	}

	/*if(debug)
	{
		u32 diff = modified_blocks.size() - count_was;
		count_was = modified_blocks.size();
		infostream<<"spreadLight modified "<<diff<<std::endl;
	}*/
#endif

#if 0
	{
		//MapVoxelManipulator vmanip(this);
		
		// Make a manual voxel manipulator and load all the blocks
		// that touch the requested blocks
		ManualMapVoxelManipulator vmanip(this);

		{
		//TimeTaker timer("initialEmerge");

		core::map<v3s16, MapBlock*>::Iterator i;
		i = blocks_to_update.getIterator();
		for(; i.atEnd() == false; i++)
		{
			MapBlock *block = i.getNode()->getValue();
			v3s16 p = block->getPos();

			// Add all surrounding blocks
			vmanip.initialEmerge(p - v3s16(1,1,1), p + v3s16(1,1,1));

			/*
				Add all surrounding blocks that have up-to-date lighting
				NOTE: This doesn't quite do the job (not everything
					  appropriate is lighted)
			*/
			/*for(s16 z=-1; z<=1; z++)
			for(s16 y=-1; y<=1; y++)
			for(s16 x=-1; x<=1; x++)
			{
				v3s16 p2 = p + v3s16(x,y,z);
				MapBlock *block = getBlockNoCreateNoEx(p2);
				if(block == NULL)
					continue;
				if(block->isDummy())
					continue;
				if(block->getLightingExpired())
					continue;
				vmanip.initialEmerge(p2, p2);
			}*/

			// Lighting of block will be updated completely
			block->setLightingExpired(false);
		}
		}

		{
			//TimeTaker timer("unSpreadLight");
			vmanip.unspreadLight(bank, unlight_from, light_sources, nodemgr);
		}
		{
			//TimeTaker timer("spreadLight");
			vmanip.spreadLight(bank, light_sources, nodemgr);
		}
		{
			//TimeTaker timer("blitBack");
			vmanip.blitBack(modified_blocks);
		}
		/*infostream<<"emerge_time="<<emerge_time<<std::endl;
		emerge_time = 0;*/
	}
#endif

	//m_dout<<"Done ("<<getTimestamp()<<")"<<std::endl;
}

void Map::updateLighting(core::map<v3s16, MapBlock*> & a_blocks,
		core::map<v3s16, MapBlock*> & modified_blocks)
{
	updateLighting(LIGHTBANK_DAY, a_blocks, modified_blocks);
	updateLighting(LIGHTBANK_NIGHT, a_blocks, modified_blocks);

	/*
		Update information about whether day and night light differ
	*/
	for(core::map<v3s16, MapBlock*>::Iterator
			i = modified_blocks.getIterator();
			i.atEnd() == false; i++)
	{
		MapBlock *block = i.getNode()->getValue();
		block->updateDayNightDiff();
	}
}

/*
*/
void Map::addNodeAndUpdate(v3s16 p, MapNode n,
		core::map<v3s16, MapBlock*> &modified_blocks)
{
	INodeDefManager *nodemgr = m_gamedef->ndef();

	/*PrintInfo(m_dout);
	m_dout<<DTIME<<"Map::addNodeAndUpdate(): p=("
			<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/

	/*
		From this node to nodes underneath:
		If lighting is sunlight (1.0), unlight neighbours and
		set lighting to 0.
		Else discontinue.
	*/

	v3s16 toppos = p + v3s16(0,1,0);
	v3s16 bottompos = p + v3s16(0,-1,0);

	bool node_under_sunlight = true;
	core::map<v3s16, bool> light_sources;

	/*
		If there is a node at top and it doesn't have sunlight,
		there has not been any sunlight going down.

		Otherwise there probably is.
	*/
	try{
		MapNode topnode = getNode(toppos);

		if(topnode.getLight(LIGHTBANK_DAY, nodemgr) != LIGHT_SUN)
			node_under_sunlight = false;
	}
	catch(InvalidPositionException &e)
	{
	}

	/*
		Remove all light that has come out of this node
	*/

	enum LightBank banks[] =
	{
		LIGHTBANK_DAY,
		LIGHTBANK_NIGHT
	};
	for(s32 i=0; i<2; i++)
	{
		enum LightBank bank = banks[i];

		u8 lightwas = getNode(p).getLight(bank, nodemgr);

		// Add the block of the added node to modified_blocks
		v3s16 blockpos = getNodeBlockPos(p);
		MapBlock * block = getBlockNoCreate(blockpos);
		assert(block != NULL);
		modified_blocks.insert(blockpos, block);

		assert(isValidPosition(p));

		// Unlight neighbours of node.
		// This means setting light of all consequent dimmer nodes
		// to 0.
		// This also collects the nodes at the border which will spread
		// light again into this.
		unLightNeighbors(bank, p, lightwas, light_sources, modified_blocks);

		n.setLight(bank, 0, nodemgr);
	}

	/*
		If node lets sunlight through and is under sunlight, it has
		sunlight too.
	*/
	if(node_under_sunlight && nodemgr->get(n).sunlight_propagates)
	{
		n.setLight(LIGHTBANK_DAY, LIGHT_SUN, nodemgr);
	}

	/*
		Set the node on the map
	*/

	setNode(p, n);

	/*
		Add intial metadata
	*/
	
	std::string metadata_name = nodemgr->get(n).metadata_name;
	if(metadata_name != ""){
		NodeMetadata *meta = NodeMetadata::create(metadata_name, m_gamedef);
		if(!meta){
			errorstream<<"Failed to create node metadata \""
					<<metadata_name<<"\""<<std::endl;
		} else {
			setNodeMetadata(p, meta);
		}
	}

	/*
		If node is under sunlight and doesn't let sunlight through,
		take all sunlighted nodes under it and clear light from them
		and from where the light has been spread.
		TODO: This could be optimized by mass-unlighting instead
			  of looping
	*/
	if(node_under_sunlight && !nodemgr->get(n).sunlight_propagates)
	{
		s16 y = p.Y - 1;
		for(;; y--){
			//m_dout<<DTIME<<"y="<<y<<std::endl;
			v3s16 n2pos(p.X, y, p.Z);

			MapNode n2;
			try{
				n2 = getNode(n2pos);
			}
			catch(InvalidPositionException &e)
			{
				break;
			}

			if(n2.getLight(LIGHTBANK_DAY, nodemgr) == LIGHT_SUN)
			{
				unLightNeighbors(LIGHTBANK_DAY,
						n2pos, n2.getLight(LIGHTBANK_DAY, nodemgr),
						light_sources, modified_blocks);
				n2.setLight(LIGHTBANK_DAY, 0, nodemgr);
				setNode(n2pos, n2);
			}
			else
				break;
		}
	}

	for(s32 i=0; i<2; i++)
	{
		enum LightBank bank = banks[i];

		/*
			Spread light from all nodes that might be capable of doing so
		*/
		spreadLight(bank, light_sources, modified_blocks);
	}

	/*
		Update information about whether day and night light differ
	*/
	for(core::map<v3s16, MapBlock*>::Iterator
			i = modified_blocks.getIterator();
			i.atEnd() == false; i++)
	{
		MapBlock *block = i.getNode()->getValue();
		block->updateDayNightDiff();
	}

	/*
		Add neighboring liquid nodes and the node itself if it is
		liquid (=water node was added) to transform queue.
	*/
	v3s16 dirs[7] = {
		v3s16(0,0,0), // self
		v3s16(0,0,1), // back
		v3s16(0,1,0), // top
		v3s16(1,0,0), // right
		v3s16(0,0,-1), // front
		v3s16(0,-1,0), // bottom
		v3s16(-1,0,0), // left
	};
	for(u16 i=0; i<7; i++)
	{
		try
		{

		v3s16 p2 = p + dirs[i];

		MapNode n2 = getNode(p2);
		if(nodemgr->get(n2).isLiquid() || n2.getContent() == CONTENT_AIR)
		{
			m_transforming_liquid.push_back(p2);
		}

		}catch(InvalidPositionException &e)
		{
		}
	}
}

/*
*/
void Map::removeNodeAndUpdate(v3s16 p,
		core::map<v3s16, MapBlock*> &modified_blocks)
{
	INodeDefManager *nodemgr = m_gamedef->ndef();

	/*PrintInfo(m_dout);
	m_dout<<DTIME<<"Map::removeNodeAndUpdate(): p=("
			<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/

	bool node_under_sunlight = true;

	v3s16 toppos = p + v3s16(0,1,0);

	// Node will be replaced with this
	content_t replace_material = CONTENT_AIR;

	/*
		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);

		if(topnode.getLight(LIGHTBANK_DAY, nodemgr) != LIGHT_SUN)
			node_under_sunlight = false;
	}
	catch(InvalidPositionException &e)
	{
	}

	core::map<v3s16, bool> light_sources;

	enum LightBank banks[] =
	{
		LIGHTBANK_DAY,
		LIGHTBANK_NIGHT
	};
	for(s32 i=0; i<2; i++)
	{
		enum LightBank bank = banks[i];

		/*
			Unlight neighbors (in case the node is a light source)
		*/
		unLightNeighbors(bank, p,
				getNode(p).getLight(bank, nodemgr),
				light_sources, modified_blocks);
	}

	/*
		Remove node metadata
	*/

	removeNodeMetadata(p);

	/*
		Remove the node.
		This also clears the lighting.
	*/

	MapNode n;
	n.setContent(replace_material);
	setNode(p, n);

	for(s32 i=0; i<2; i++)
	{
		enum LightBank bank = banks[i];

		/*
			Recalculate lighting
		*/
		spreadLight(bank, light_sources, modified_blocks);
	}

	// Add the block of the removed node to modified_blocks
	v3s16 blockpos = getNodeBlockPos(p);
	MapBlock * block = getBlockNoCreate(blockpos);
	assert(block != NULL);
	modified_blocks.insert(blockpos, block);

	/*
		If the removed node was under sunlight, propagate the
		sunlight down from it and then light all neighbors
		of the propagated blocks.
	*/
	if(node_under_sunlight)
	{
		s16 ybottom = propagateSunlight(p, modified_blocks);
		/*m_dout<<DTIME<<"Node was under sunlight. "
				"Propagating sunlight";
		m_dout<<DTIME<<" -> 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 ("
					<<p2.X<<","<<p2.Y<<","<<p2.Z<<")"
					<<std::endl;*/
			lightNeighbors(LIGHTBANK_DAY, p2, modified_blocks);
		}
	}
	else
	{
		// Set the lighting of this node to 0
		// TODO: Is this needed? Lighting is cleared up there already.
		try{
			MapNode n = getNode(p);
			n.setLight(LIGHTBANK_DAY, 0, nodemgr);
			setNode(p, n);
		}
		catch(InvalidPositionException &e)
		{
			assert(0);
		}
	}

	for(s32 i=0; i<2; i++)
	{
		enum LightBank bank = banks[i];

		// Get the brightest neighbour node and propagate light from it
		v3s16 n2p = getBrightestNeighbour(bank, p);
		try{
			MapNode n2 = getNode(n2p);
			lightNeighbors(bank, n2p, modified_blocks);
		}
		catch(InvalidPositionException &e)
		{
		}
	}

	/*
		Update information about whether day and night light differ
	*/
	for(core::map<v3s16, MapBlock*>::Iterator
			i = modified_blocks.getIterator();
			i.atEnd() == false; i++)
	{
		MapBlock *block = i.getNode()->getValue();
		block->updateDayNightDiff();
	}

	/*
		Add neighboring liquid nodes and this node to transform queue.
		(it's vital for the node itself to get updated last.)
	*/
	v3s16 dirs[7] = {
		v3s16(0,0,1), // back
		v3s16(0,1,0), // top
		v3s16(1,0,0), // right
		v3s16(0,0,-1), // front
		v3s16(0,-1,0), // bottom
		v3s16(-1,0,0), // left
		v3s16(0,0,0), // self
	};
	for(u16 i=0; i<7; i++)
	{
		try
		{

		v3s16 p2 = p + dirs[i];

		MapNode n2 = getNode(p2);
		if(nodemgr->get(n2).isLiquid() || n2.getContent() == CONTENT_AIR)
		{
			m_transforming_liquid.push_back(p2);
		}

		}catch(InvalidPositionException &e)
		{
		}
	}
}

bool Map::addNodeWithEvent(v3s16 p, MapNode n)
{
	MapEditEvent event;
	event.type = MEET_ADDNODE;
	event.p = p;
	event.n = n;

	bool succeeded = true;
	try{
		core::map<v3s16, MapBlock*> modified_blocks;
		addNodeAndUpdate(p, n, modified_blocks);

		// Copy modified_blocks to event
		for(core::map<v3s16, MapBlock*>::Iterator
				i = modified_blocks.getIterator();
				i.atEnd()==false; i++)
		{
			event.modified_blocks.insert(i.getNode()->getKey(), false);
		}
	}
	catch(InvalidPositionException &e){
		succeeded = false;
	}

	dispatchEvent(&event);

	return succeeded;
}

bool Map::removeNodeWithEvent(v3s16 p)
{
	MapEditEvent event;
	event.type = MEET_REMOVENODE;
	event.p = p;

	bool succeeded = true;
	try{
		core::map<v3s16, MapBlock*> modified_blocks;
		removeNodeAndUpdate(p, modified_blocks);

		// Copy modified_blocks to event
		for(core::map<v3s16, MapBlock*>::Iterator
				i = modified_blocks.getIterator();
				i.atEnd()==false; i++)
		{
			event.modified_blocks.insert(i.getNode()->getKey(), false);
		}
	}
	catch(InvalidPositionException &e){
		succeeded = false;
	}

	dispatchEvent(&event);

	return succeeded;
}

bool Map::dayNightDiffed(v3s16 blockpos)
{
	try{
		v3s16 p = blockpos + v3s16(0,0,0);
		MapBlock *b = getBlockNoCreate(p);
		if(b->dayNightDiffed())
			return true;
	}
	catch(InvalidPositionException &e){}
	// Leading edges
	try{
		v3s16 p = blockpos + v3s16(-1,0,0);
		MapBlock *b = getBlockNoCreate(p);
		if(b->dayNightDiffed())
			return true;
	}
	catch(InvalidPositionException &e){}
	try{
		v3s16 p = blockpos + v3s16(0,-1,0);
		MapBlock *b = getBlockNoCreate(p);
		if(b->dayNightDiffed())
			return true;
	}
	catch(InvalidPositionException &e){}
	try{
		v3s16 p = blockpos + v3s16(0,0,-1);
		MapBlock *b = getBlockNoCreate(p);
		if(b->dayNightDiffed())
			return true;
	}
	catch(InvalidPositionException &e){}
	// Trailing edges
	try{
		v3s16 p = blockpos + v3s16(1,0,0);
		MapBlock *b = getBlockNoCreate(p);
		if(b->dayNightDiffed())
			return true;
	}
	catch(InvalidPositionException &e){}
	try{
		v3s16 p = blockpos + v3s16(0,1,0);
		MapBlock *b = getBlockNoCreate(p);
		if(b->dayNightDiffed())
			return true;
	}
	catch(InvalidPositionException &e){}
	try{
		v3s16 p = blockpos + v3s16(0,0,1);
		MapBlock *b = getBlockNoCreate(p);
		if(b->dayNightDiffed())
			return true;
	}
	catch(InvalidPositionException &e){}

	return false;
}

/*
	Updates usage timers
*/
void Map::timerUpdate(float dtime, float unload_timeout,
		core::list<v3s16> *unloaded_blocks)
{
	bool save_before_unloading = (mapType() == MAPTYPE_SERVER);
	
	// Profile modified reasons
	Profiler modprofiler;
	
	core::list<v2s16> sector_deletion_queue;
	u32 deleted_blocks_count = 0;
	u32 saved_blocks_count = 0;
	u32 block_count_all = 0;

	core::map<v2s16, MapSector*>::Iterator si;

	beginSave();
	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);
			
			block->incrementUsageTimer(dtime);
			
			if(block->getUsageTimer() > unload_timeout)
			{
				v3s16 p = block->getPos();

				// Save if modified
				if(block->getModified() != MOD_STATE_CLEAN
						&& save_before_unloading)
				{
					modprofiler.add(block->getModifiedReason(), 1);
					saveBlock(block);
					saved_blocks_count++;
				}

				// Delete from memory
				sector->deleteBlock(block);

				if(unloaded_blocks)
					unloaded_blocks->push_back(p);

				deleted_blocks_count++;
			}
			else
			{
				all_blocks_deleted = false;
				block_count_all++;
			}
		}

		if(all_blocks_deleted)
		{
			sector_deletion_queue.push_back(si.getNode()->getKey());
		}
	}
	endSave();
	
	// Finally delete the empty sectors
	deleteSectors(sector_deletion_queue);
	
	if(deleted_blocks_count != 0)
	{
		PrintInfo(infostream); // ServerMap/ClientMap:
		infostream<<"Unloaded "<<deleted_blocks_count
				<<" blocks from memory";
		if(save_before_unloading)
			infostream<<", of which "<<saved_blocks_count<<" were written";
		infostream<<", "<<block_count_all<<" blocks in memory";
		infostream<<"."<<std::endl;
		if(saved_blocks_count != 0){
			PrintInfo(infostream); // ServerMap/ClientMap:
			infostream<<"Blocks modified by: "<<std::endl;
			modprofiler.print(infostream);
		}
	}
}

void Map::deleteSectors(core::list<v2s16> &list)
{
	core::list<v2s16>::Iterator j;
	for(j=list.begin(); j!=list.end(); j++)
	{
		MapSector *sector = m_sectors[*j];
		// If sector is in sector cache, remove it from there
		if(m_sector_cache == sector)
			m_sector_cache = NULL;
		// Remove from map and delete
		m_sectors.remove(*j);
		delete sector;
	}
}

#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: ";
}

#define WATER_DROP_BOOST 4

enum NeighborType {
	NEIGHBOR_UPPER,
	NEIGHBOR_SAME_LEVEL,
	NEIGHBOR_LOWER
};
struct NodeNeighbor {
	MapNode n;
	NeighborType t;
	v3s16 p;
};

void Map::transformLiquids(core::map<v3s16, MapBlock*> & modified_blocks)
{
	INodeDefManager *nodemgr = m_gamedef->ndef();

	DSTACK(__FUNCTION_NAME);
	//TimeTaker timer("transformLiquids()");

	u32 loopcount = 0;
	u32 initial_size = m_transforming_liquid.size();

	/*if(initial_size != 0)
		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;
	
	// List of MapBlocks that will require a lighting update (due to lava)
	core::map<v3s16, MapBlock*> lighting_modified_blocks;

	while(m_transforming_liquid.size() != 0)
	{
		// This should be done here so that it is done when continue is used
		if(loopcount >= initial_size * 3)
			break;
		loopcount++;

		/*
			Get a queued transforming liquid node
		*/
		v3s16 p0 = m_transforming_liquid.pop_front();

		MapNode n0 = getNodeNoEx(p0);

		/*
			Collect information about current node
		 */
		s8 liquid_level = -1;
		u8 liquid_kind = CONTENT_IGNORE;
		LiquidType liquid_type = nodemgr->get(n0).liquid_type;
		switch (liquid_type) {
			case LIQUID_SOURCE:
				liquid_level = LIQUID_LEVEL_SOURCE;
				liquid_kind = nodemgr->getId(nodemgr->get(n0).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)
					continue;
				liquid_kind = CONTENT_AIR;
				break;
		}

		/*
			Collect information about the environment
		 */
		const v3s16 *dirs = g_6dirs;
		NodeNeighbor sources[6]; // surrounding sources
		int num_sources = 0;
		NodeNeighbor flows[6]; // surrounding flowing liquid nodes
		int num_flows = 0;
		NodeNeighbor airs[6]; // surrounding air
		int num_airs = 0;
		NodeNeighbor neutrals[6]; // nodes that are solid or another kind of liquid
		int num_neutrals = 0;
		bool flowing_down = false;
		for (u16 i = 0; i < 6; i++) {
			NeighborType nt = NEIGHBOR_SAME_LEVEL;
			switch (i) {
				case 1:
					nt = NEIGHBOR_UPPER;
					break;
				case 4:
					nt = NEIGHBOR_LOWER;
					break;
			}
			v3s16 npos = p0 + dirs[i];
			NodeNeighbor nb = {getNodeNoEx(npos), nt, npos};
			switch (nodemgr->get(nb.n.getContent()).liquid_type) {
				case LIQUID_NONE:
					if (nb.n.getContent() == CONTENT_AIR) {
						airs[num_airs++] = nb;
						// if the current node is a water source the neighbor
						// should be enqueded for transformation regardless of whether the
						// current node changes or not.
						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) {
							flowing_down = true;
						}
					} else {
						neutrals[num_neutrals++] = nb;
					}
					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) {
						neutrals[num_neutrals++] = nb;
					} else {
						// Do not count bottom source, it will screw things up
						if(dirs[i].Y != -1)
							sources[num_sources++] = nb;
					}
					break;
				case LIQUID_FLOWING:
					// if this node is not (yet) of a liquid type, choose the first liquid type we encounter
					if (liquid_kind == CONTENT_AIR)
						liquid_kind = nodemgr->getId(nodemgr->get(nb.n).liquid_alternative_flowing);
					if (nodemgr->getId(nodemgr->get(nb.n).liquid_alternative_flowing) != liquid_kind) {
						neutrals[num_neutrals++] = nb;
					} else {
						flows[num_flows++] = nb;
						if (nb.t == NEIGHBOR_LOWER)
							flowing_down = true;
					}
					break;
			}
		}

		/*
			decide on the type (and possibly level) of the current node
		 */
		content_t new_node_content;
		s8 new_node_level = -1;
		s8 max_node_level = -1;
		if (num_sources >= 2 || liquid_type == LIQUID_SOURCE) {
			// liquid_kind will be set to either the flowing alternative of the node (if it's a liquid)
			// or the flowing alternative of the first of the surrounding sources (if it's air), so
			// it's perfectly safe to use liquid_kind here to determine the new node content.
			new_node_content = 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;
		} else {
			// no surrounding sources, so get the maximum level that can flow into this node
			for (u16 i = 0; i < num_flows; i++) {
				u8 nb_liquid_level = (flows[i].n.param2 & LIQUID_LEVEL_MASK);
				switch (flows[i].t) {
					case NEIGHBOR_UPPER:
						if (nb_liquid_level + WATER_DROP_BOOST > max_node_level) {
							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)
							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) {
							max_node_level = nb_liquid_level - 1;
						}
						break;
				}
			}

			u8 viscosity = nodemgr->get(liquid_kind).liquid_viscosity;
			if (viscosity > 1 && max_node_level != liquid_level) {
				// amount to gain, limited by viscosity
				// must be at least 1 in absolute value
				s8 level_inc = max_node_level - liquid_level;
				if (level_inc < -viscosity || level_inc > viscosity)
					new_node_level = liquid_level + level_inc/viscosity;
				else if (level_inc < 0)
					new_node_level = liquid_level - 1;
				else if (level_inc > 0)
					new_node_level = liquid_level + 1;
				if (new_node_level != max_node_level)
					must_reflow.push_back(p0);
			} else
				new_node_level = max_node_level;

			if (new_node_level >= 0)
				new_node_content = liquid_kind;
			else
				new_node_content = CONTENT_AIR;

		}

		/*
			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)))
			continue;


		/*
			update the current node
		 */
		//bool flow_down_enabled = (flowing_down && ((n0.param2 & LIQUID_FLOW_DOWN_MASK) != LIQUID_FLOW_DOWN_MASK));
		if (nodemgr->get(new_node_content).liquid_type == LIQUID_FLOWING) {
			// set level to last 3 bits, flowing down bit to 4th bit
			n0.param2 = (flowing_down ? LIQUID_FLOW_DOWN_MASK : 0x00) | (new_node_level & LIQUID_LEVEL_MASK);
		} else {
			// set the liquid level and flow bit to 0
			n0.param2 = ~(LIQUID_LEVEL_MASK | LIQUID_FLOW_DOWN_MASK);
		}
		n0.setContent(new_node_content);
		setNode(p0, n0);
		v3s16 blockpos = getNodeBlockPos(p0);
		MapBlock *block = getBlockNoCreateNoEx(blockpos);
		if(block != NULL) {
			modified_blocks.insert(blockpos, block);
			// If node emits light, MapBlock requires lighting update
			if(nodemgr->get(n0).light_source != 0)
				lighting_modified_blocks[block->getPos()] = block;
		}

		/*
			enqueue neighbors for update if neccessary
		 */
		switch (nodemgr->get(n0.getContent()).liquid_type) {
			case LIQUID_SOURCE:
			case LIQUID_FLOWING:
				// make sure source flows into all neighboring nodes
				for (u16 i = 0; i < num_flows; i++)
					if (flows[i].t != NEIGHBOR_UPPER)
						m_transforming_liquid.push_back(flows[i].p);
				for (u16 i = 0; i < num_airs; i++)
					if (airs[i].t != NEIGHBOR_UPPER)
						m_transforming_liquid.push_back(airs[i].p);
				break;
			case LIQUID_NONE:
				// this flow has turned to air; neighboring flows might need to do the same
				for (u16 i = 0; i < num_flows; i++)
					m_transforming_liquid.push_back(flows[i].p);
				break;
		}
	}
	//infostream<<"Map::transformLiquids(): loopcount="<<loopcount<<std::endl;
	while (must_reflow.size() > 0)
		m_transforming_liquid.push_back(must_reflow.pop_front());
	updateLighting(lighting_modified_blocks, modified_blocks);
}

NodeMetadata* Map::getNodeMetadata(v3s16 p)
{
	v3s16 blockpos = getNodeBlockPos(p);
	v3s16 p_rel = p - blockpos*MAP_BLOCKSIZE;
	MapBlock *block = getBlockNoCreateNoEx(blockpos);
	if(!block){
		infostream<<"Map::getNodeMetadata(): Need to emerge "
				<<PP(blockpos)<<std::endl;
		block = emergeBlock(blockpos, false);
	}
	if(!block)
	{
		infostream<<"WARNING: Map::getNodeMetadata(): Block not found"
				<<std::endl;
		return NULL;
	}
	NodeMetadata *meta = block->m_node_metadata->get(p_rel);
	return meta;
}

void Map::setNodeMetadata(v3s16 p, NodeMetadata *meta)
{
	v3s16 blockpos = getNodeBlockPos(p);
	v3s16 p_rel = p - blockpos*MAP_BLOCKSIZE;
	MapBlock *block = getBlockNoCreateNoEx(blockpos);
	if(!block){
		infostream<<"Map::setNodeMetadata(): Need to emerge "
				<<PP(blockpos)<<std::endl;
		block = emergeBlock(blockpos, false);
	}
	if(!block)
	{
		infostream<<"WARNING: Map::setNodeMetadata(): Block not found"
				<<std::endl;
		return;
	}
	block->m_node_metadata->set(p_rel, meta);
}

void Map::removeNodeMetadata(v3s16 p)
{
	v3s16 blockpos = getNodeBlockPos(p);
	v3s16 p_rel = p - blockpos*MAP_BLOCKSIZE;
	MapBlock *block = getBlockNoCreateNoEx(blockpos);
	if(block == NULL)
	{
		infostream<<"WARNING: Map::removeNodeMetadata(): Block not found"
				<<std::endl;
		return;
	}
	block->m_node_metadata->remove(p_rel);
}

void Map::nodeMetadataStep(float dtime,
		core::map<v3s16, MapBlock*> &changed_blocks)
{
	/*
		NOTE:
		Currently there is no way to ensure that all the necessary
		blocks are loaded when this is run. (They might get unloaded)
		NOTE: ^- Actually, that might not be so. In a quick test it
		reloaded a block with a furnace when I walked back to it from
		a distance.
	*/
	core::map<v2s16, MapSector*>::Iterator si;
	si = m_sectors.getIterator();
	for(; si.atEnd() == false; si++)
	{
		MapSector *sector = si.getNode()->getValue();
		core::list< MapBlock * > sectorblocks;
		sector->getBlocks(sectorblocks);
		core::list< MapBlock * >::Iterator i;
		for(i=sectorblocks.begin(); i!=sectorblocks.end(); i++)
		{
			MapBlock *block = *i;
			bool changed = block->m_node_metadata->step(dtime);
			if(changed)
				changed_blocks[block->getPos()] = block;
		}
	}
}

/*
	ServerMap
*/

ServerMap::ServerMap(std::string savedir, IGameDef *gamedef):
	Map(dout_server, gamedef),
	m_seed(0),
	m_map_metadata_changed(true),
	m_database(NULL),
	m_database_read(NULL),
	m_database_write(NULL)
{
	verbosestream<<__FUNCTION_NAME<<std::endl;

	//m_chunksize = 8; // Takes a few seconds

	if (g_settings->get("fixed_map_seed").empty())
	{
		m_seed = (((u64)(myrand()%0xffff)<<0)
				+ ((u64)(myrand()%0xffff)<<16)
				+ ((u64)(myrand()%0xffff)<<32)
				+ ((u64)(myrand()%0xffff)<<48));
	}
	else
	{
		m_seed = g_settings->getU64("fixed_map_seed");
	}

	/*
		Experimental and debug stuff
	*/

	{
	}

	/*
		Try to load map; if not found, create a new one.
	*/

	m_savedir = savedir;
	m_map_saving_enabled = false;

	try
	{
		// If directory exists, check contents and load if possible
		if(fs::PathExists(m_savedir))
		{
			// If directory is empty, it is safe to save into it.
			if(fs::GetDirListing(m_savedir).size() == 0)
			{
				infostream<<"ServerMap: Empty save directory is valid."
						<<std::endl;
				m_map_saving_enabled = true;
			}
			else
			{
				try{
					// Load map metadata (seed, chunksize)
					loadMapMeta();
				}
				catch(FileNotGoodException &e){
					infostream<<"WARNING: Could not load map metadata"
							//<<" Disabling chunk-based generator."
							<<std::endl;
					//m_chunksize = 0;
				}

				infostream<<"ServerMap: Successfully loaded map "
						<<"metadata from "<<savedir
						<<", assuming valid save directory."
						<<" seed="<<m_seed<<"."
						<<std::endl;

				m_map_saving_enabled = true;
				// Map loaded, not creating new one
				return;
			}
		}
		// If directory doesn't exist, it is safe to save to it
		else{
			m_map_saving_enabled = true;
		}
	}
	catch(std::exception &e)
	{
		infostream<<"WARNING: 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;
	}

	infostream<<"Initializing new map."<<std::endl;

	// Create zero sector
	emergeSector(v2s16(0,0));

	// Initially write whole map
	save(MOD_STATE_CLEAN);
}

ServerMap::~ServerMap()
{
	verbosestream<<__FUNCTION_NAME<<std::endl;

	try
	{
		if(m_map_saving_enabled)
		{
			// Save only changed parts
			save(MOD_STATE_WRITE_AT_UNLOAD);
			infostream<<"ServerMap: Saved map to "<<m_savedir<<std::endl;
		}
		else
		{
			infostream<<"ServerMap: Map not saved"<<std::endl;
		}
	}
	catch(std::exception &e)
	{
		infostream<<"ServerMap: Failed to save map to "<<m_savedir
				<<", exception: "<<e.what()<<std::endl;
	}

	/*
		Close database if it was opened
	*/
	if(m_database_read)
		sqlite3_finalize(m_database_read);
	if(m_database_write)
		sqlite3_finalize(m_database_write);
	if(m_database)
		sqlite3_close(m_database);

#if 0
	/*
		Free all MapChunks
	*/
	core::map<v2s16, MapChunk*>::Iterator i = m_chunks.getIterator();
	for(; i.atEnd() == false; i++)
	{
		MapChunk *chunk = i.getNode()->getValue();
		delete chunk;
	}
#endif
}

void ServerMap::initBlockMake(mapgen::BlockMakeData *data, v3s16 blockpos)
{
	bool enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");
	if(enable_mapgen_debug_info)
		infostream<<"initBlockMake(): "
				<<"("<<blockpos.X<<","<<blockpos.Y<<","<<blockpos.Z<<") - "
				<<"("<<blockpos.X<<","<<blockpos.Y<<","<<blockpos.Z<<")"
				<<std::endl;
	
	//s16 chunksize = 3;
	//v3s16 chunk_offset(-1,-1,-1);
	//s16 chunksize = 4;
	//v3s16 chunk_offset(-1,-1,-1);
	s16 chunksize = 5;
	v3s16 chunk_offset(-2,-2,-2);
	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;

	//v3s16 extra_borders(1,1,1);
	v3s16 extra_borders(1,1,1);

	// 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))
	{
		data->no_op = true;
		return;
	}
	
	data->no_op = false;
	data->seed = m_seed;
	data->blockpos_min = blockpos_min;
	data->blockpos_max = blockpos_max;
	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);

			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.

						Refer to the map generator heuristics.
					*/
					bool ug = mapgen::block_is_underground(data->seed, p);
					block->setIsUnderground(ug);
				}

				// Lighting will not be valid after make_chunk is called
				block->setLightingExpired(true);
				// Lighting will be calculated
				//block->setLightingExpired(false);
			}
		}
	}
	
	/*
		Now we have a big empty area.

		Make a ManualMapVoxelManipulator that contains this and the
		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 ManualMapVoxelManipulator(this);
	//data->vmanip->setMap(this);

	// Add the area
	{
		//TimeTaker timer("initBlockMake() initialEmerge");
		data->vmanip->initialEmerge(bigarea_blocks_min, bigarea_blocks_max);
	}

	// Data is ready now.
}

MapBlock* ServerMap::finishBlockMake(mapgen::BlockMakeData *data,
		core::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 extra_borders(1,1,1);

	if(data->no_op)
	{
		//infostream<<"finishBlockMake(): no-op"<<std::endl;
		return NULL;
	}

	bool enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");

	/*infostream<<"Resulting vmanip:"<<std::endl;
	data->vmanip.print(infostream);*/

	// 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);
	}

	/*
		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);
	}

	if(enable_mapgen_debug_info)
		infostream<<"finishBlockMake: changed_blocks.size()="
				<<changed_blocks.size()<<std::endl;

	/*
		Copy transforming liquid information
	*/
	while(data->transforming_liquid.size() > 0)
	{
		v3s16 p = data->transforming_liquid.pop_front();
		m_transforming_liquid.push_back(p);
	}

	/*
		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);
			getBlockNoCreateNoEx(p)->setLightingExpired(false);
		}

#if 0
		if(enable_mapgen_debug_info == false)
			t.stop(true); // Hide output
#endif
	}

	/*
		Go through changed blocks
	*/
	for(core::map<v3s16, MapBlock*>::Iterator i = changed_blocks.getIterator();
			i.atEnd() == false; i++)
	{
		MapBlock *block = i.getNode()->getValue();
		assert(block);
		/*
			Update day/night difference cache of the MapBlocks
		*/
		block->updateDayNightDiff();
		/*
			Set block as modified
		*/
		block->raiseModified(MOD_STATE_WRITE_NEEDED,
				"finishBlockMake updateDayNightDiff");
	}

	/*
		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);
		assert(block);
		block->setGenerated(true);
	}
	
	/*
		Save changed parts of map
		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

	MapBlock *block = getBlockNoCreateNoEx(blockpos_requested);
	assert(block);

	return block;
}

ServerMapSector * ServerMap::createSector(v2s16 p2d)
{
	DSTACKF("%s: p2d=(%d,%d)",
			__FUNCTION_NAME,
			p2d.X, p2d.Y);
	
	/*
		Check if it exists already in memory
	*/
	ServerMapSector *sector = (ServerMapSector*)getSectorNoGenerateNoEx(p2d);
	if(sector != NULL)
		return sector;
	
	/*
		Try to load it from disk (with blocks)
	*/
	//if(loadSectorFull(p2d) == true)

	/*
		Try to load metadata from disk
	*/
#if 0
	if(loadSectorMeta(p2d) == true)
	{
		ServerMapSector *sector = (ServerMapSector*)getSectorNoGenerateNoEx(p2d);
		if(sector == NULL)
		{
			infostream<<"ServerMap::createSector(): loadSectorFull didn't make a sector"<<std::endl;
			throw InvalidPositionException("");
		}
		return sector;
	}
#endif
	/*
		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)
		throw InvalidPositionException("createSector(): pos. over limit");

	/*
		Generate blank sector
	*/
	
	sector = new ServerMapSector(this, p2d, m_gamedef);
	
	// Sector position on map in nodes
	v2s16 nodepos2d = p2d * MAP_BLOCKSIZE;

	/*
		Insert to container
	*/
	m_sectors.insert(p2d, sector);
	
	return sector;
}

/*
	This is a quick-hand function for calling makeBlock().
*/
MapBlock * ServerMap::generateBlock(
		v3s16 p,
		core::map<v3s16, MapBlock*> &modified_blocks
)
{
	DSTACKF("%s: p=(%d,%d,%d)", __FUNCTION_NAME, p.X, p.Y, p.Z);
	
	/*infostream<<"generateBlock(): "
			<<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
			<<std::endl;*/
	
	bool enable_mapgen_debug_info = g_settings->getBool("enable_mapgen_debug_info");

	TimeTaker timer("generateBlock");
	
	//MapBlock *block = original_dummy;
			
	v2s16 p2d(p.X, p.Z);
	v2s16 p2d_nodes = p2d * MAP_BLOCKSIZE;
	
	/*
		Do not generate over-limit
	*/
	if(blockpos_over_limit(p))
	{
		infostream<<__FUNCTION_NAME<<": Block position over limit"<<std::endl;
		throw InvalidPositionException("generateBlock(): pos. over limit");
	}

	/*
		Create block make data
	*/
	mapgen::BlockMakeData data;
	initBlockMake(&data, p);

	/*
		Generate block
	*/
	{
		TimeTaker t("mapgen::make_block()");
		mapgen::make_block(&data);

		if(enable_mapgen_debug_info == false)
			t.stop(true); // Hide output
	}

	/*
		Blit data back on map, update lighting, add mobs and whatever this does
	*/
	finishBlockMake(&data, modified_blocks);

	/*
		Get central block
	*/
	MapBlock *block = getBlockNoCreateNoEx(p);

#if 0
	/*
		Check result
	*/
	if(block)
	{
		bool erroneus_content = false;
		for(s16 z0=0; z0<MAP_BLOCKSIZE; z0++)
		for(s16 y0=0; y0<MAP_BLOCKSIZE; y0++)
		for(s16 x0=0; x0<MAP_BLOCKSIZE; x0++)
		{
			v3s16 p(x0,y0,z0);
			MapNode n = block->getNode(p);
			if(n.getContent() == CONTENT_IGNORE)
			{
				infostream<<"CONTENT_IGNORE at "
						<<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
						<<std::endl;
				erroneus_content = true;
				assert(0);
			}
		}
		if(erroneus_content)
		{
			assert(0);
		}
	}
#endif

#if 0
	/*
		Generate a completely empty block
	*/
	if(block)
	{
		for(s16 z0=0; z0<MAP_BLOCKSIZE; z0++)
		for(s16 x0=0; x0<MAP_BLOCKSIZE; x0++)
		{
			for(s16 y0=0; y0<MAP_BLOCKSIZE; y0++)
			{
				MapNode n;
				n.setContent(CONTENT_AIR);
				block->setNode(v3s16(x0,y0,z0), n);
			}
		}
	}
#endif

	if(enable_mapgen_debug_info == false)
		timer.stop(true); // Hide output

	return block;
}

MapBlock * ServerMap::createBlock(v3s16 p)
{
	DSTACKF("%s: p=(%d,%d,%d)",
			__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)
		throw InvalidPositionException("createBlock(): pos. over limit");
	
	v2s16 p2d(p.X, p.Z);
	s16 block_y = p.Y;
	/*
		This will create or load a sector if not found in memory.
		If block exists on disk, it will be loaded.

		NOTE: On old save formats, this will be slow, as it generates
		      lighting on blocks for them.
	*/
	ServerMapSector *sector;
	try{
		sector = (ServerMapSector*)createSector(p2d);
		assert(sector->getId() == MAPSECTOR_SERVER);
	}
	catch(InvalidPositionException &e)
	{
		infostream<<"createBlock: createSector() failed"<<std::endl;
		throw e;
	}
	/*
		NOTE: This should not be done, or at least the exception
		should not be passed on as std::exception, because it
		won't be catched at all.
	*/
	/*catch(std::exception &e)
	{
		infostream<<"createBlock: createSector() failed: "
				<<e.what()<<std::endl;
		throw e;
	}*/

	/*
		Try to get a block from the sector
	*/

	MapBlock *block = sector->getBlockNoCreateNoEx(block_y);
	if(block)
	{
		if(block->isDummy())
			block->unDummify();
		return block;
	}
	// Create blank
	block = sector->createBlankBlock(block_y);
	return block;
}

MapBlock * ServerMap::emergeBlock(v3s16 p, bool allow_generate)
{
	DSTACKF("%s: p=(%d,%d,%d), allow_generate=%d",
			__FUNCTION_NAME,
			p.X, p.Y, p.Z, allow_generate);
	
	{
		MapBlock *block = getBlockNoCreateNoEx(p);
		if(block && block->isDummy() == false)
			return block;
	}

	{
		MapBlock *block = loadBlock(p);
		if(block)
			return block;
	}

	if(allow_generate)
	{
		core::map<v3s16, MapBlock*> modified_blocks;
		MapBlock *block = generateBlock(p, modified_blocks);
		if(block)
		{
			MapEditEvent event;
			event.type = MEET_OTHER;
			event.p = p;

			// Copy modified_blocks to event
			for(core::map<v3s16, MapBlock*>::Iterator
					i = modified_blocks.getIterator();
					i.atEnd()==false; i++)
			{
				event.modified_blocks.insert(i.getNode()->getKey(), false);
			}

			// Queue event
			dispatchEvent(&event);
								
			return block;
		}
	}

	return NULL;
}

s16 ServerMap::findGroundLevel(v2s16 p2d)
{
#if 0
	/*
		Uh, just do something random...
	*/
	// Find existing map from top to down
	s16 max=63;
	s16 min=-64;
	v3s16 p(p2d.X, max, p2d.Y);
	for(; p.Y>min; p.Y--)
	{
		MapNode n = getNodeNoEx(p);
		if(n.getContent() != CONTENT_IGNORE)
			break;
	}
	if(p.Y == min)
		goto plan_b;
	// If this node is not air, go to plan b
	if(getNodeNoEx(p).getContent() != CONTENT_AIR)
		goto plan_b;
	// Search existing walkable and return it
	for(; p.Y>min; p.Y--)
	{
		MapNode n = getNodeNoEx(p);
		if(content_walkable(n.d) && n.getContent() != CONTENT_IGNORE)
			return p.Y;
	}

	// Move to plan b
plan_b:
#endif

	/*
		Determine from map generator noise functions
	*/
	
	s16 level = mapgen::find_ground_level_from_noise(m_seed, p2d, 1);
	return level;

	//double level = base_rock_level_2d(m_seed, p2d) + AVERAGE_MUD_AMOUNT;
	//return (s16)level;
}

void ServerMap::createDatabase() {
	int e;
	assert(m_database);
	e = sqlite3_exec(m_database,
		"CREATE TABLE IF NOT EXISTS `blocks` ("
			"`pos` INT NOT NULL PRIMARY KEY,"
			"`data` BLOB"
		");"
	, NULL, NULL, NULL);
	if(e == SQLITE_ABORT)
		throw FileNotGoodException("Could not create database structure");
	else
		infostream<<"ServerMap: Database structure was created";
}

void ServerMap::verifyDatabase() {
	if(m_database)
		return;
	
	{
		std::string dbp = m_savedir + DIR_DELIM + "map.sqlite";
		bool needs_create = false;
		int d;
		
		/*
			Open the database connection
		*/
	
		createDirs(m_savedir);
	
		if(!fs::PathExists(dbp))
			needs_create = true;
	
		d = sqlite3_open_v2(dbp.c_str(), &m_database, SQLITE_OPEN_READWRITE | SQLITE_OPEN_CREATE, NULL);
		if(d != SQLITE_OK) {
			infostream<<"WARNING: Database failed to open: "<<sqlite3_errmsg(m_database)<<std::endl;
			throw FileNotGoodException("Cannot open database file");
		}
		
		if(needs_create)
			createDatabase();
	
		d = sqlite3_prepare(m_database, "SELECT `data` FROM `blocks` WHERE `pos`=? LIMIT 1", -1, &m_database_read, NULL);
		if(d != SQLITE_OK) {
			infostream<<"WARNING: Database read statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
			throw FileNotGoodException("Cannot prepare read statement");
		}
		
		d = sqlite3_prepare(m_database, "REPLACE INTO `blocks` VALUES(?, ?)", -1, &m_database_write, NULL);
		if(d != SQLITE_OK) {
			infostream<<"WARNING: Database write statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
			throw FileNotGoodException("Cannot prepare write statement");
		}
		
		d = sqlite3_prepare(m_database, "SELECT `pos` FROM `blocks`", -1, &m_database_list, NULL);
		if(d != SQLITE_OK) {
			infostream<<"WARNING: Database list statment failed to prepare: "<<sqlite3_errmsg(m_database)<<std::endl;
			throw FileNotGoodException("Cannot prepare read statement");
		}
		
		infostream<<"ServerMap: Database opened"<<std::endl;
	}
}

bool ServerMap::loadFromFolders() {
	if(!m_database && !fs::PathExists(m_savedir + DIR_DELIM + "map.sqlite"))
		return true;
	return false;
}

sqlite3_int64 ServerMap::getBlockAsInteger(const v3s16 pos) {
	return (sqlite3_int64)pos.Z*16777216 +
		(sqlite3_int64)pos.Y*4096 + (sqlite3_int64)pos.X;
}

void ServerMap::createDirs(std::string path)
{
	if(fs::CreateAllDirs(path) == false)
	{
		m_dout<<DTIME<<"ServerMap: Failed to create directory "
				<<"\""<<path<<"\""<<std::endl;
		throw BaseException("ServerMap failed to create directory");
	}
}

std::string ServerMap::getSectorDir(v2s16 pos, int layout)
{
	char cc[9];
	switch(layout)
	{
		case 1:
			snprintf(cc, 9, "%.4x%.4x",
				(unsigned int)pos.X&0xffff,
				(unsigned int)pos.Y&0xffff);

			return m_savedir + DIR_DELIM + "sectors" + DIR_DELIM + cc;
		case 2:
			snprintf(cc, 9, "%.3x" DIR_DELIM "%.3x",
				(unsigned int)pos.X&0xfff,
				(unsigned int)pos.Y&0xfff);

			return m_savedir + DIR_DELIM + "sectors2" + DIR_DELIM + cc;
		default:
			assert(false);
	}
}

v2s16 ServerMap::getSectorPos(std::string dirname)
{
	unsigned int x, y;
	int r;
	size_t spos = dirname.rfind(DIR_DELIM_C) + 1;
	assert(spos != std::string::npos);
	if(dirname.size() - spos == 8)
	{
		// Old layout
		r = sscanf(dirname.substr(spos).c_str(), "%4x%4x", &x, &y);
	}
	else if(dirname.size() - spos == 3)
	{
		// New layout
		r = sscanf(dirname.substr(spos-4).c_str(), "%3x" DIR_DELIM "%3x", &x, &y);
		// Sign-extend the 12 bit values up to 16 bits...
		if(x&0x800) x|=0xF000;
		if(y&0x800) y|=0xF000;
	}
	else
	{
		assert(false);
	}
	assert(r == 2);
	v2s16 pos((s16)x, (s16)y);
	return pos;
}

v3s16 ServerMap::getBlockPos(std::string sectordir, std::string blockfile)
{
	v2s16 p2d = getSectorPos(sectordir);

	if(blockfile.size() != 4){
		throw InvalidFilenameException("Invalid block filename");
	}
	unsigned int y;
	int r = sscanf(blockfile.c_str(), "%4x", &y);
	if(r != 1)
		throw InvalidFilenameException("Invalid block filename");
	return v3s16(p2d.X, y, p2d.Y);
}

std::string ServerMap::getBlockFilename(v3s16 p)
{
	char cc[5];
	snprintf(cc, 5, "%.4x", (unsigned int)p.Y&0xffff);
	return cc;
}

void ServerMap::save(ModifiedState save_level)
{
	DSTACK(__FUNCTION_NAME);
	if(m_map_saving_enabled == false)
	{
		infostream<<"WARNING: Not saving map, saving disabled."<<std::endl;
		return;
	}
	
	if(save_level == MOD_STATE_CLEAN)
		infostream<<"ServerMap: Saving whole map, this can take time."
				<<std::endl;
	
	if(m_map_metadata_changed || save_level == MOD_STATE_CLEAN)
	{
		saveMapMeta();
	}

	// Profile modified reasons
	Profiler modprofiler;
	
	u32 sector_meta_count = 0;
	u32 block_count = 0;
	u32 block_count_all = 0; // Number of blocks in memory
	
	// Don't do anything with sqlite unless something is really saved
	bool save_started = false;

	core::map<v2s16, MapSector*>::Iterator i = m_sectors.getIterator();
	for(; i.atEnd() == false; i++)
	{
		ServerMapSector *sector = (ServerMapSector*)i.getNode()->getValue();
		assert(sector->getId() == MAPSECTOR_SERVER);
	
		if(sector->differs_from_disk || save_level == MOD_STATE_CLEAN)
		{
			saveSectorMeta(sector);
			sector_meta_count++;
		}
		core::list<MapBlock*> blocks;
		sector->getBlocks(blocks);
		core::list<MapBlock*>::Iterator j;
		
		for(j=blocks.begin(); j!=blocks.end(); j++)
		{
			MapBlock *block = *j;
			
			block_count_all++;

			if(block->getModified() >= save_level)
			{
				// Lazy beginSave()
				if(!save_started){
					beginSave();
					save_started = true;
				}

				modprofiler.add(block->getModifiedReason(), 1);

				saveBlock(block);
				block_count++;

				/*infostream<<"ServerMap: Written block ("
						<<block->getPos().X<<","
						<<block->getPos().Y<<","
						<<block->getPos().Z<<")"
						<<std::endl;*/
			}
		}
	}
	if(save_started)
		endSave();

	/*
		Only print if something happened or saved whole map
	*/
	if(save_level == MOD_STATE_CLEAN || sector_meta_count != 0
			|| block_count != 0)
	{
		infostream<<"ServerMap: Written: "
				<<sector_meta_count<<" sector metadata files, "
				<<block_count<<" block files"
				<<", "<<block_count_all<<" blocks in memory."
				<<std::endl;
		PrintInfo(infostream); // ServerMap/ClientMap:
		infostream<<"Blocks modified by: "<<std::endl;
		modprofiler.print(infostream);
	}
}

static s32 unsignedToSigned(s32 i, s32 max_positive)
{
	if(i < max_positive)
		return i;
	else
		return i - 2*max_positive;
}

// modulo of a negative number does not work consistently in C
static sqlite3_int64 pythonmodulo(sqlite3_int64 i, sqlite3_int64 mod)
{
	if(i >= 0)
		return i % mod;
	return mod - ((-i) % mod);
}

v3s16 ServerMap::getIntegerAsBlock(sqlite3_int64 i)
{
	s32 x = unsignedToSigned(pythonmodulo(i, 4096), 2048);
	i = (i - x) / 4096;
	s32 y = unsignedToSigned(pythonmodulo(i, 4096), 2048);
	i = (i - y) / 4096;
	s32 z = unsignedToSigned(pythonmodulo(i, 4096), 2048);
	return v3s16(x,y,z);
}

void ServerMap::listAllLoadableBlocks(core::list<v3s16> &dst)
{
	if(loadFromFolders()){
		errorstream<<"Map::listAllLoadableBlocks(): Result will be missing "
				<<"all blocks that are stored in flat files"<<std::endl;
	}
	
	{
		verifyDatabase();
		
		while(sqlite3_step(m_database_list) == SQLITE_ROW)
		{
			sqlite3_int64 block_i = sqlite3_column_int64(m_database_list, 0);
			v3s16 p = getIntegerAsBlock(block_i);
			//dstream<<"block_i="<<block_i<<" p="<<PP(p)<<std::endl;
			dst.push_back(p);
		}
	}
}

void ServerMap::saveMapMeta()
{
	DSTACK(__FUNCTION_NAME);
	
	/*infostream<<"ServerMap::saveMapMeta(): "
			<<"seed="<<m_seed
			<<std::endl;*/

	createDirs(m_savedir);
	
	std::string fullpath = m_savedir + DIR_DELIM + "map_meta.txt";
	std::ofstream os(fullpath.c_str(), std::ios_base::binary);
	if(os.good() == false)
	{
		infostream<<"ERROR: ServerMap::saveMapMeta(): "
				<<"could not open"<<fullpath<<std::endl;
		throw FileNotGoodException("Cannot open chunk metadata");
	}
	
	Settings params;
	params.setU64("seed", m_seed);

	params.writeLines(os);

	os<<"[end_of_params]\n";
	
	m_map_metadata_changed = false;
}

void ServerMap::loadMapMeta()
{
	DSTACK(__FUNCTION_NAME);
	
	/*infostream<<"ServerMap::loadMapMeta(): Loading map metadata"
			<<std::endl;*/

	std::string fullpath = m_savedir + DIR_DELIM + "map_meta.txt";
	std::ifstream is(fullpath.c_str(), std::ios_base::binary);
	if(is.good() == false)
	{
		infostream<<"ERROR: ServerMap::loadMapMeta(): "
				<<"could not open"<<fullpath<<std::endl;
		throw FileNotGoodException("Cannot open map metadata");
	}

	Settings params;

	for(;;)
	{
		if(is.eof())
			throw SerializationError
					("ServerMap::loadMapMeta(): [end_of_params] not found");
		std::string line;
		std::getline(is, line);
		std::string trimmedline = trim(line);
		if(trimmedline == "[end_of_params]")
			break;
		params.parseConfigLine(line);
	}

	m_seed = params.getU64("seed");

	verbosestream<<"ServerMap::loadMapMeta(): "<<"seed="<<m_seed<<std::endl;
}

void ServerMap::saveSectorMeta(ServerMapSector *sector)
{
	DSTACK(__FUNCTION_NAME);
	// Format used for writing
	u8 version = SER_FMT_VER_HIGHEST;
	// Get destination
	v2s16 pos = sector->getPos();
	std::string dir = getSectorDir(pos);
	createDirs(dir);
	
	std::string fullpath = dir + DIR_DELIM + "meta";
	std::ofstream o(fullpath.c_str(), std::ios_base::binary);
	if(o.good() == false)
		throw FileNotGoodException("Cannot open sector metafile");

	sector->serialize(o, version);
	
	sector->differs_from_disk = false;
}

MapSector* ServerMap::loadSectorMeta(std::string sectordir, bool save_after_load)
{
	DSTACK(__FUNCTION_NAME);
	// Get destination
	v2s16 p2d = getSectorPos(sectordir);

	ServerMapSector *sector = NULL;

	std::string fullpath = sectordir + DIR_DELIM + "meta";
	std::ifstream is(fullpath.c_str(), std::ios_base::binary);
	if(is.good() == false)
	{
		// If the directory exists anyway, it probably is in some old
		// format. Just go ahead and create the sector.
		if(fs::PathExists(sectordir))
		{
			/*infostream<<"ServerMap::loadSectorMeta(): Sector metafile "
					<<fullpath<<" doesn't exist but directory does."
					<<" Continuing with a sector with no metadata."
					<<std::endl;*/
			sector = new ServerMapSector(this, p2d, m_gamedef);
			m_sectors.insert(p2d, sector);
		}
		else
		{
			throw FileNotGoodException("Cannot open sector metafile");
		}
	}
	else
	{
		sector = ServerMapSector::deSerialize
				(is, this, p2d, m_sectors, m_gamedef);
		if(save_after_load)
			saveSectorMeta(sector);
	}
	
	sector->differs_from_disk = false;

	return sector;
}

bool ServerMap::loadSectorMeta(v2s16 p2d)
{
	DSTACK(__FUNCTION_NAME);

	MapSector *sector = NULL;

	// The directory layout we're going to load from.
	//  1 - original sectors/xxxxzzzz/
	//  2 - new sectors2/xxx/zzz/
	//  If we load from anything but the latest structure, we will
	//  immediately save to the new one, and remove the old.
	int loadlayout = 1;
	std::string sectordir1 = getSectorDir(p2d, 1);
	std::string sectordir;
	if(fs::PathExists(sectordir1))
	{
		sectordir = sectordir1;
	}
	else
	{
		loadlayout = 2;
		sectordir = getSectorDir(p2d, 2);
	}

	try{
		sector = loadSectorMeta(sectordir, loadlayout != 2);
	}
	catch(InvalidFilenameException &e)
	{
		return false;
	}
	catch(FileNotGoodException &e)
	{
		return false;
	}
	catch(std::exception &e)
	{
		return false;
	}
	
	return true;
}

#if 0
bool ServerMap::loadSectorFull(v2s16 p2d)
{
	DSTACK(__FUNCTION_NAME);

	MapSector *sector = NULL;

	// The directory layout we're going to load from.
	//  1 - original sectors/xxxxzzzz/
	//  2 - new sectors2/xxx/zzz/
	//  If we load from anything but the latest structure, we will
	//  immediately save to the new one, and remove the old.
	int loadlayout = 1;
	std::string sectordir1 = getSectorDir(p2d, 1);
	std::string sectordir;
	if(fs::PathExists(sectordir1))
	{
		sectordir = sectordir1;
	}
	else
	{
		loadlayout = 2;
		sectordir = getSectorDir(p2d, 2);
	}

	try{
		sector = loadSectorMeta(sectordir, loadlayout != 2);
	}
	catch(InvalidFilenameException &e)
	{
		return false;
	}
	catch(FileNotGoodException &e)
	{
		return false;
	}
	catch(std::exception &e)
	{
		return false;
	}
	
	/*
		Load blocks
	*/
	std::vector<fs::DirListNode> list2 = fs::GetDirListing
			(sectordir);
	std::vector<fs::DirListNode>::iterator i2;
	for(i2=list2.begin(); i2!=list2.end(); i2++)
	{
		// We want files
		if(i2->dir)
			continue;
		try{
			loadBlock(sectordir, i2->name, sector, loadlayout != 2);
		}
		catch(InvalidFilenameException &e)
		{
			// This catches unknown crap in directory
		}
	}

	if(loadlayout != 2)
	{
		infostream<<"Sector converted to new layout - deleting "<<
			sectordir1<<std::endl;
		fs::RecursiveDelete(sectordir1);
	}

	return true;
}
#endif

void ServerMap::beginSave() {
	verifyDatabase();
	if(sqlite3_exec(m_database, "BEGIN;", NULL, NULL, NULL) != SQLITE_OK)
		infostream<<"WARNING: beginSave() failed, saving might be slow.";
}

void ServerMap::endSave() {
	verifyDatabase();
	if(sqlite3_exec(m_database, "COMMIT;", NULL, NULL, NULL) != SQLITE_OK)
		infostream<<"WARNING: endSave() failed, map might not have saved.";
}

void ServerMap::saveBlock(MapBlock *block)
{
	DSTACK(__FUNCTION_NAME);
	/*
		Dummy blocks are not written
	*/
	if(block->isDummy())
	{
		/*v3s16 p = block->getPos();
		infostream<<"ServerMap::saveBlock(): WARNING: Not writing dummy block "
				<<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/
		return;
	}

	// Format used for writing
	u8 version = SER_FMT_VER_HIGHEST;
	// Get destination
	v3s16 p3d = block->getPos();
	
	
#if 0
	v2s16 p2d(p3d.X, p3d.Z);
	std::string sectordir = getSectorDir(p2d);

	createDirs(sectordir);

	std::string fullpath = sectordir+DIR_DELIM+getBlockFilename(p3d);
	std::ofstream o(fullpath.c_str(), std::ios_base::binary);
	if(o.good() == false)
		throw FileNotGoodException("Cannot open block data");
#endif
	/*
		[0] u8 serialization version
		[1] data
	*/
	
	verifyDatabase();
	
	std::ostringstream o(std::ios_base::binary);
	
	o.write((char*)&version, 1);
	
	// Write basic data
	block->serialize(o, version, true);
	
	// Write block to database
	
	std::string tmp = o.str();
	const char *bytes = tmp.c_str();
	
	if(sqlite3_bind_int64(m_database_write, 1, getBlockAsInteger(p3d)) != SQLITE_OK)
		infostream<<"WARNING: Block position failed to bind: "<<sqlite3_errmsg(m_database)<<std::endl;
	if(sqlite3_bind_blob(m_database_write, 2, (void *)bytes, o.tellp(), NULL) != SQLITE_OK) // TODO this mught not be the right length
		infostream<<"WARNING: Block data failed to bind: "<<sqlite3_errmsg(m_database)<<std::endl;
	int written = sqlite3_step(m_database_write);
	if(written != SQLITE_DONE)
		infostream<<"WARNING: Block failed to save ("<<p3d.X<<", "<<p3d.Y<<", "<<p3d.Z<<") "
		<<sqlite3_errmsg(m_database)<<std::endl;
	// Make ready for later reuse
	sqlite3_reset(m_database_write);
	
	// We just wrote it to the disk so clear modified flag
	block->resetModified();
}

void ServerMap::loadBlock(std::string sectordir, std::string blockfile, MapSector *sector, bool save_after_load)
{
	DSTACK(__FUNCTION_NAME);

	std::string fullpath = sectordir+DIR_DELIM+blockfile;
	try{

		std::ifstream is(fullpath.c_str(), std::ios_base::binary);
		if(is.good() == false)
			throw FileNotGoodException("Cannot open block file");
		
		v3s16 p3d = getBlockPos(sectordir, blockfile);
		v2s16 p2d(p3d.X, p3d.Z);
		
		assert(sector->getPos() == p2d);
		
		u8 version = SER_FMT_VER_INVALID;
		is.read((char*)&version, 1);

		if(is.fail())
			throw SerializationError("ServerMap::loadBlock(): Failed"
					" to read MapBlock version");

		/*u32 block_size = MapBlock::serializedLength(version);
		SharedBuffer<u8> data(block_size);
		is.read((char*)*data, block_size);*/

		// This will always return a sector because we're the server
		//MapSector *sector = emergeSector(p2d);

		MapBlock *block = NULL;
		bool created_new = false;
		block = sector->getBlockNoCreateNoEx(p3d.Y);
		if(block == NULL)
		{
			block = sector->createBlankBlockNoInsert(p3d.Y);
			created_new = true;
		}
		
		// Read basic data
		block->deSerialize(is, version, true);

		// If it's a new block, insert it to the map
		if(created_new)
			sector->insertBlock(block);
		
		/*
			Save blocks loaded in old format in new format
		*/

		if(version < SER_FMT_VER_HIGHEST || save_after_load)
		{
			saveBlock(block);
			
			// Should be in database now, so delete the old file
			fs::RecursiveDelete(fullpath);
		}
		
		// We just loaded it from the disk, so it's up-to-date.
		block->resetModified();

	}
	catch(SerializationError &e)
	{
		infostream<<"WARNING: Invalid block data on disk "
				<<"fullpath="<<fullpath
				<<" (SerializationError). "
				<<"what()="<<e.what()
				<<std::endl;
				//" Ignoring. A new one will be generated.
		assert(0);

		// TODO: Backup file; name is in fullpath.
	}
}

void ServerMap::loadBlock(std::string *blob, v3s16 p3d, MapSector *sector, bool save_after_load)
{
	DSTACK(__FUNCTION_NAME);

	try {
		std::istringstream is(*blob, std::ios_base::binary);
		
		u8 version = SER_FMT_VER_INVALID;
		is.read((char*)&version, 1);

		if(is.fail())
			throw SerializationError("ServerMap::loadBlock(): Failed"
					" to read MapBlock version");

		/*u32 block_size = MapBlock::serializedLength(version);
		SharedBuffer<u8> data(block_size);
		is.read((char*)*data, block_size);*/

		// This will always return a sector because we're the server
		//MapSector *sector = emergeSector(p2d);

		MapBlock *block = NULL;
		bool created_new = false;
		block = sector->getBlockNoCreateNoEx(p3d.Y);
		if(block == NULL)
		{
			block = sector->createBlankBlockNoInsert(p3d.Y);
			created_new = true;
		}
		
		// Read basic data
		block->deSerialize(is, version, true);
		
		// If it's a new block, insert it to the map
		if(created_new)
			sector->insertBlock(block);
		
		/*
			Save blocks loaded in old format in new format
		*/

		//if(version < SER_FMT_VER_HIGHEST || save_after_load)
		// Only save if asked to; no need to update version
		if(save_after_load)
			saveBlock(block);
		
		// We just loaded it from, so it's up-to-date.
		block->resetModified();

	}
	catch(SerializationError &e)
	{
		infostream<<"WARNING: Invalid block data in database "
				<<" (SerializationError). "
				<<"what()="<<e.what()
				<<std::endl;
				//" Ignoring. A new one will be generated.
		assert(0);

		// TODO: Copy to a backup database.
	}
}

MapBlock* ServerMap::loadBlock(v3s16 blockpos)
{
	DSTACK(__FUNCTION_NAME);

	v2s16 p2d(blockpos.X, blockpos.Z);

	if(!loadFromFolders()) {
		verifyDatabase();
		
		if(sqlite3_bind_int64(m_database_read, 1, getBlockAsInteger(blockpos)) != SQLITE_OK)
			infostream<<"WARNING: Could not bind block position for load: "
				<<sqlite3_errmsg(m_database)<<std::endl;
		if(sqlite3_step(m_database_read) == SQLITE_ROW) {
			/*
				Make sure sector is loaded
			*/
			MapSector *sector = createSector(p2d);
			
			/*
				Load block
			*/
			const char * data = (const char *)sqlite3_column_blob(m_database_read, 0);
			size_t len = sqlite3_column_bytes(m_database_read, 0);
			
			std::string datastr(data, len);
			
			loadBlock(&datastr, blockpos, sector, false);

			sqlite3_step(m_database_read);
			// We should never get more than 1 row, so ok to reset
			sqlite3_reset(m_database_read);

			return getBlockNoCreateNoEx(blockpos);
		}
		sqlite3_reset(m_database_read);
		
		// Not found in database, try the files
	}

	// The directory layout we're going to load from.
	//  1 - original sectors/xxxxzzzz/
	//  2 - new sectors2/xxx/zzz/
	//  If we load from anything but the latest structure, we will
	//  immediately save to the new one, and remove the old.
	int loadlayout = 1;
	std::string sectordir1 = getSectorDir(p2d, 1);
	std::string sectordir;
	if(fs::PathExists(sectordir1))
	{
		sectordir = sectordir1;
	}
	else
	{
		loadlayout = 2;
		sectordir = getSectorDir(p2d, 2);
	}
	
	/*
		Make sure sector is loaded
	*/
	MapSector *sector = getSectorNoGenerateNoEx(p2d);
	if(sector == NULL)
	{
		try{
			sector = loadSectorMeta(sectordir, loadlayout != 2);
		}
		catch(InvalidFilenameException &e)
		{
			return false;
		}
		catch(FileNotGoodException &e)
		{
			return false;
		}
		catch(std::exception &e)
		{
			return false;
		}
	}
	
	/*
		Make sure file exists
	*/

	std::string blockfilename = getBlockFilename(blockpos);
	if(fs::PathExists(sectordir+DIR_DELIM+blockfilename) == false)
		return NULL;

	/*
		Load block and save it to the database
	*/
	loadBlock(sectordir, blockfilename, sector, true);
	return getBlockNoCreateNoEx(blockpos);
}

void ServerMap::PrintInfo(std::ostream &out)
{
	out<<"ServerMap: ";
}

/*
	MapVoxelManipulator
*/

MapVoxelManipulator::MapVoxelManipulator(Map *map)
{
	m_map = map;
}

MapVoxelManipulator::~MapVoxelManipulator()
{
	/*infostream<<"MapVoxelManipulator: blocks: "<<m_loaded_blocks.size()
			<<std::endl;*/
}

void MapVoxelManipulator::emerge(VoxelArea a, s32 caller_id)
{
	TimeTaker timer1("emerge", &emerge_time);

	// Units of these are MapBlocks
	v3s16 p_min = getNodeBlockPos(a.MinEdge);
	v3s16 p_max = getNodeBlockPos(a.MaxEdge);

	VoxelArea block_area_nodes
			(p_min*MAP_BLOCKSIZE, (p_max+1)*MAP_BLOCKSIZE-v3s16(1,1,1));

	addArea(block_area_nodes);

	for(s32 z=p_min.Z; z<=p_max.Z; z++)
	for(s32 y=p_min.Y; y<=p_max.Y; y++)
	for(s32 x=p_min.X; x<=p_max.X; x++)
	{
		v3s16 p(x,y,z);
		core::map<v3s16, bool>::Node *n;
		n = m_loaded_blocks.find(p);
		if(n != NULL)
			continue;
		
		bool block_data_inexistent = false;
		try
		{
			TimeTaker timer1("emerge load", &emerge_load_time);

			/*infostream<<"Loading block (caller_id="<<caller_id<<")"
					<<" ("<<p.X<<","<<p.Y<<","<<p.Z<<")"
					<<" wanted area: ";
			a.print(infostream);
			infostream<<std::endl;*/
			
			MapBlock *block = m_map->getBlockNoCreate(p);
			if(block->isDummy())
				block_data_inexistent = true;
			else
				block->copyTo(*this);
		}
		catch(InvalidPositionException &e)
		{
			block_data_inexistent = true;
		}

		if(block_data_inexistent)
		{
			VoxelArea a(p*MAP_BLOCKSIZE, (p+1)*MAP_BLOCKSIZE-v3s16(1,1,1));
			// Fill with VOXELFLAG_INEXISTENT
			for(s32 z=a.MinEdge.Z; z<=a.MaxEdge.Z; z++)
			for(s32 y=a.MinEdge.Y; y<=a.MaxEdge.Y; y++)
			{
				s32 i = m_area.index(a.MinEdge.X,y,z);
				memset(&m_flags[i], VOXELFLAG_INEXISTENT, MAP_BLOCKSIZE);
			}
		}

		m_loaded_blocks.insert(p, !block_data_inexistent);
	}

	//infostream<<"emerge done"<<std::endl;
}

/*
	SUGG: Add an option to only update eg. water and air nodes.
	      This will make it interfere less with important stuff if
		  run on background.
*/
void MapVoxelManipulator::blitBack
		(core::map<v3s16, MapBlock*> & modified_blocks)
{
	if(m_area.getExtent() == v3s16(0,0,0))
		return;
	
	//TimeTaker timer1("blitBack");

	/*infostream<<"blitBack(): m_loaded_blocks.size()="
			<<m_loaded_blocks.size()<<std::endl;*/
	
	/*
		Initialize block cache
	*/
	v3s16 blockpos_last;
	MapBlock *block = NULL;
	bool block_checked_in_modified = false;

	for(s32 z=m_area.MinEdge.Z; z<=m_area.MaxEdge.Z; z++)
	for(s32 y=m_area.MinEdge.Y; y<=m_area.MaxEdge.Y; y++)
	for(s32 x=m_area.MinEdge.X; x<=m_area.MaxEdge.X; x++)
	{
		v3s16 p(x,y,z);

		u8 f = m_flags[m_area.index(p)];
		if(f & (VOXELFLAG_NOT_LOADED|VOXELFLAG_INEXISTENT))
			continue;

		MapNode &n = m_data[m_area.index(p)];
			
		v3s16 blockpos = getNodeBlockPos(p);
		
		try
		{
			// Get block
			if(block == NULL || blockpos != blockpos_last){
				block = m_map->getBlockNoCreate(blockpos);
				blockpos_last = blockpos;
				block_checked_in_modified = false;
			}
			
			// Calculate relative position in block
			v3s16 relpos = p - blockpos * MAP_BLOCKSIZE;

			// Don't continue if nothing has changed here
			if(block->getNode(relpos) == n)
				continue;

			//m_map->setNode(m_area.MinEdge + p, n);
			block->setNode(relpos, n);
			
			/*
				Make sure block is in modified_blocks
			*/
			if(block_checked_in_modified == false)
			{
				modified_blocks[blockpos] = block;
				block_checked_in_modified = true;
			}
		}
		catch(InvalidPositionException &e)
		{
		}
	}
}

ManualMapVoxelManipulator::ManualMapVoxelManipulator(Map *map):
		MapVoxelManipulator(map),
		m_create_area(false)
{
}

ManualMapVoxelManipulator::~ManualMapVoxelManipulator()
{
}

void ManualMapVoxelManipulator::emerge(VoxelArea a, s32 caller_id)
{
	// Just create the area so that it can be pointed to
	VoxelManipulator::emerge(a, caller_id);
}

void ManualMapVoxelManipulator::initialEmerge(
		v3s16 blockpos_min, v3s16 blockpos_max)
{
	TimeTaker timer1("initialEmerge", &emerge_time);

	// Units of these are MapBlocks
	v3s16 p_min = blockpos_min;
	v3s16 p_max = blockpos_max;

	VoxelArea block_area_nodes
			(p_min*MAP_BLOCKSIZE, (p_max+1)*MAP_BLOCKSIZE-v3s16(1,1,1));
	
	u32 size_MB = block_area_nodes.getVolume()*4/1000000;
	if(size_MB >= 1)
	{
		infostream<<"initialEmerge: area: ";
		block_area_nodes.print(infostream);
		infostream<<" ("<<size_MB<<"MB)";
		infostream<<std::endl;
	}

	addArea(block_area_nodes);

	for(s32 z=p_min.Z; z<=p_max.Z; z++)
	for(s32 y=p_min.Y; y<=p_max.Y; y++)
	for(s32 x=p_min.X; x<=p_max.X; x++)
	{
		v3s16 p(x,y,z);
		core::map<v3s16, bool>::Node *n;
		n = m_loaded_blocks.find(p);
		if(n != NULL)
			continue;
		
		bool block_data_inexistent = false;
		try
		{
			TimeTaker timer1("emerge load", &emerge_load_time);

			MapBlock *block = m_map->getBlockNoCreate(p);
			if(block->isDummy())
				block_data_inexistent = true;
			else
				block->copyTo(*this);
		}
		catch(InvalidPositionException &e)
		{
			block_data_inexistent = true;
		}

		if(block_data_inexistent)
		{
			/*
				Mark area inexistent
			*/
			VoxelArea a(p*MAP_BLOCKSIZE, (p+1)*MAP_BLOCKSIZE-v3s16(1,1,1));
			// Fill with VOXELFLAG_INEXISTENT
			for(s32 z=a.MinEdge.Z; z<=a.MaxEdge.Z; z++)
			for(s32 y=a.MinEdge.Y; y<=a.MaxEdge.Y; y++)
			{
				s32 i = m_area.index(a.MinEdge.X,y,z);
				memset(&m_flags[i], VOXELFLAG_INEXISTENT, MAP_BLOCKSIZE);
			}
		}

		m_loaded_blocks.insert(p, !block_data_inexistent);
	}
}

void ManualMapVoxelManipulator::blitBackAll(
		core::map<v3s16, MapBlock*> * modified_blocks)
{
	if(m_area.getExtent() == v3s16(0,0,0))
		return;
	
	/*
		Copy data of all blocks
	*/
	for(core::map<v3s16, bool>::Iterator
			i = m_loaded_blocks.getIterator();
			i.atEnd() == false; i++)
	{
		v3s16 p = i.getNode()->getKey();
		bool existed = i.getNode()->getValue();
		if(existed == false)
		{
			// The Great Bug was found using this
			/*infostream<<"ManualMapVoxelManipulator::blitBackAll: "
					<<"Inexistent ("<<p.X<<","<<p.Y<<","<<p.Z<<")"
					<<std::endl;*/
			continue;
		}
		MapBlock *block = m_map->getBlockNoCreateNoEx(p);
		if(block == NULL)
		{
			infostream<<"WARNING: "<<__FUNCTION_NAME
					<<": got NULL block "
					<<"("<<p.X<<","<<p.Y<<","<<p.Z<<")"
					<<std::endl;
			continue;
		}

		block->copyFrom(*this);

		if(modified_blocks)
			modified_blocks->insert(p, block);
	}
}

//END