minetest/src/server.cpp

/*
Minetest-c55
Copyright (C) 2010 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.
*/

/*
(c) 2010 Perttu Ahola <celeron55@gmail.com>
*/

#include "server.h"
#include "utility.h"
#include <iostream>
#include "clientserver.h"
#include "map.h"
#include "jmutexautolock.h"
#include "main.h"
#include "constants.h"
#include "voxel.h"

#define BLOCK_EMERGE_FLAG_FROMDISK (1<<0)

void * ServerThread::Thread()
{
	ThreadStarted();

	DSTACK(__FUNCTION_NAME);

	while(getRun())
	{
		try{
			m_server->AsyncRunStep();
		
			//dout_server<<"Running m_server->Receive()"<<std::endl;
			m_server->Receive();
		}
		catch(con::NoIncomingDataException &e)
		{
		}
#if CATCH_UNHANDLED_EXCEPTIONS
		/*
			This is what has to be done in threads to get suitable debug info
		*/
		catch(std::exception &e)
		{
			dstream<<std::endl<<DTIME<<"An unhandled exception occurred: "
					<<e.what()<<std::endl;
			assert(0);
		}
#endif
	}
	

	return NULL;
}

void * EmergeThread::Thread()
{
	ThreadStarted();

	DSTACK(__FUNCTION_NAME);

	bool debug=false;
#if CATCH_UNHANDLED_EXCEPTIONS
	try
	{
#endif
	
	/*
		Get block info from queue, emerge them and send them
		to clients.

		After queue is empty, exit.
	*/
	while(getRun())
	{
		QueuedBlockEmerge *qptr = m_server->m_emerge_queue.pop();
		if(qptr == NULL)
			break;
		
		SharedPtr<QueuedBlockEmerge> q(qptr);

		v3s16 &p = q->pos;
		
		//derr_server<<"EmergeThread::Thread(): running"<<std::endl;

		//TimeTaker timer("block emerge", g_device);
		
		/*
			Try to emerge it from somewhere.

			If it is only wanted as optional, only loading from disk
			will be allowed.
		*/
		
		/*
			Check if any peer wants it as non-optional. In that case it
			will be generated.

			Also decrement the emerge queue count in clients.
		*/

		bool optional = true;

		{
			core::map<u16, u8>::Iterator i;
			for(i=q->peer_ids.getIterator(); i.atEnd()==false; i++)
			{
				//u16 peer_id = i.getNode()->getKey();

				// Check flags
				u8 flags = i.getNode()->getValue();
				if((flags & BLOCK_EMERGE_FLAG_FROMDISK) == false)
					optional = false;
				
			}
		}

		/*dstream<<"EmergeThread: p="
				<<"("<<p.X<<","<<p.Y<<","<<p.Z<<") "
				<<"optional="<<optional<<std::endl;*/
		
		ServerMap &map = ((ServerMap&)m_server->m_env.getMap());
			
		core::map<v3s16, MapBlock*> changed_blocks;
		core::map<v3s16, MapBlock*> lighting_invalidated_blocks;

		MapBlock *block = NULL;
		bool got_block = true;
		core::map<v3s16, MapBlock*> modified_blocks;
		
		{//envlock

		JMutexAutoLock envlock(m_server->m_env_mutex);

		//TimeTaker timer("block emerge envlock", g_device);
			
		try{
			bool only_from_disk = false;
			
			if(optional)
				only_from_disk = true;

			block = map.emergeBlock(
					p,
					only_from_disk,
					changed_blocks,
					lighting_invalidated_blocks);
			
			// If it is a dummy, block was not found on disk
			if(block->isDummy())
			{
				//dstream<<"EmergeThread: Got a dummy block"<<std::endl;
				got_block = false;
			}
		}
		catch(InvalidPositionException &e)
		{
			// Block not found.
			// This happens when position is over limit.
			got_block = false;
		}
		
		if(got_block)
		{
			if(debug && changed_blocks.size() > 0)
			{
				dout_server<<DTIME<<"Got changed_blocks: ";
				for(core::map<v3s16, MapBlock*>::Iterator i = changed_blocks.getIterator();
						i.atEnd() == false; i++)
				{
					MapBlock *block = i.getNode()->getValue();
					v3s16 p = block->getPos();
					dout_server<<"("<<p.X<<","<<p.Y<<","<<p.Z<<") ";
				}
				dout_server<<std::endl;
			}

			/*
				Update water pressure
			*/

			m_server->UpdateBlockWaterPressure(block, modified_blocks);

			for(core::map<v3s16, MapBlock*>::Iterator i = changed_blocks.getIterator();
					i.atEnd() == false; i++)
			{
				MapBlock *block = i.getNode()->getValue();
				m_server->UpdateBlockWaterPressure(block, modified_blocks);
				//v3s16 p = i.getNode()->getKey();
				//m_server->UpdateBlockWaterPressure(p, modified_blocks);
			}

			/*
				Collect a list of blocks that have been modified in
				addition to the fetched one.
			*/

			// Add all the "changed blocks" to modified_blocks
			for(core::map<v3s16, MapBlock*>::Iterator i = changed_blocks.getIterator();
					i.atEnd() == false; i++)
			{
				MapBlock *block = i.getNode()->getValue();
				modified_blocks.insert(block->getPos(), block);
			}
			
			/*dstream<<"lighting "<<lighting_invalidated_blocks.size()
					<<" blocks"<<std::endl;
			TimeTaker timer("** updateLighting", g_device);*/
			
			// Update lighting without locking the environment mutex,
			// add modified blocks to changed blocks
			map.updateLighting(lighting_invalidated_blocks, modified_blocks);
		}
		// If we got no block, there should be no invalidated blocks
		else
		{
			assert(lighting_invalidated_blocks.size() == 0);
		}

		}//envlock

		/*
			Set sent status of modified blocks on clients
		*/
	
		// NOTE: Server's clients are also behind the connection mutex
		JMutexAutoLock lock(m_server->m_con_mutex);

		/*
			Add the originally fetched block to the modified list
		*/
		if(got_block)
		{
			modified_blocks.insert(p, block);
		}
		
		/*
			Set the modified blocks unsent for all the clients
		*/
		
		for(core::map<u16, RemoteClient*>::Iterator
				i = m_server->m_clients.getIterator();
				i.atEnd() == false; i++)
		{
			RemoteClient *client = i.getNode()->getValue();
			
			if(modified_blocks.size() > 0)
			{
				// Remove block from sent history
				client->SetBlocksNotSent(modified_blocks);
			}
		}
		
	}
#if CATCH_UNHANDLED_EXCEPTIONS
	}//try
	/*
		This is what has to be done in threads to get suitable debug info
	*/
	catch(std::exception &e)
	{
		dstream<<std::endl<<DTIME<<"An unhandled exception occurred: "
				<<e.what()<<std::endl;
		assert(0);
	}
#endif

	return NULL;
}

void RemoteClient::GetNextBlocks(Server *server, float dtime,
		core::array<PrioritySortedBlockTransfer> &dest)
{
	DSTACK(__FUNCTION_NAME);
	
	// Increment timers
	{
		JMutexAutoLock lock(m_blocks_sent_mutex);
		m_nearest_unsent_reset_timer += dtime;
	}

	// Won't send anything if already sending
	{
		JMutexAutoLock lock(m_blocks_sending_mutex);
		
		if(m_blocks_sending.size() >= g_settings.getU16
				("max_simultaneous_block_sends_per_client"))
		{
			//dstream<<"Not sending any blocks, Queue full."<<std::endl;
			return;
		}
	}

	Player *player = server->m_env.getPlayer(peer_id);

	v3f playerpos = player->getPosition();
	v3f playerspeed = player->getSpeed();

	v3s16 center_nodepos = floatToInt(playerpos);

	v3s16 center = getNodeBlockPos(center_nodepos);

	/*
		Get the starting value of the block finder radius.
	*/
	s16 last_nearest_unsent_d;
	s16 d_start;
	{
		JMutexAutoLock lock(m_blocks_sent_mutex);
		
		if(m_last_center != center)
		{
			m_nearest_unsent_d = 0;
			m_last_center = center;
		}

		/*dstream<<"m_nearest_unsent_reset_timer="
				<<m_nearest_unsent_reset_timer<<std::endl;*/
		if(m_nearest_unsent_reset_timer > 5.0)
		{
			m_nearest_unsent_reset_timer = 0;
			m_nearest_unsent_d = 0;
			//dstream<<"Resetting m_nearest_unsent_d"<<std::endl;
		}

		last_nearest_unsent_d = m_nearest_unsent_d;
		
		d_start = m_nearest_unsent_d;
	}

	u16 maximum_simultaneous_block_sends_setting = g_settings.getU16
			("max_simultaneous_block_sends_per_client");
	u16 maximum_simultaneous_block_sends = 
			maximum_simultaneous_block_sends_setting;

	/*
		Check the time from last addNode/removeNode.
		
		Decrease send rate if player is building stuff.
	*/
	{
		SharedPtr<JMutexAutoLock> lock(m_time_from_building.getLock());
		m_time_from_building.m_value += dtime;
		/*if(m_time_from_building.m_value
				< FULL_BLOCK_SEND_ENABLE_MIN_TIME_FROM_BUILDING)*/
		if(m_time_from_building.m_value < g_settings.getFloat(
					"full_block_send_enable_min_time_from_building"))
		{
			maximum_simultaneous_block_sends
				= LIMITED_MAX_SIMULTANEOUS_BLOCK_SENDS;
		}
	}
	
	u32 num_blocks_selected;
	{
		JMutexAutoLock lock(m_blocks_sending_mutex);
		num_blocks_selected = m_blocks_sending.size();
	}
	
	/*
		next time d will be continued from the d from which the nearest
		unsent block was found this time.

		This is because not necessarily any of the blocks found this
		time are actually sent.
	*/
	s32 new_nearest_unsent_d = -1;

	// Serialization version used
	//u8 ser_version = serialization_version;

	//bool has_incomplete_blocks = false;
	
	s16 d_max = g_settings.getS16("max_block_send_distance");
	s16 d_max_gen = g_settings.getS16("max_block_generate_distance");
	
	//dstream<<"Starting from "<<d_start<<std::endl;

	for(s16 d = d_start; d <= d_max; d++)
	{
		//dstream<<"RemoteClient::SendBlocks(): d="<<d<<std::endl;
		
		//if(has_incomplete_blocks == false)
		{
			JMutexAutoLock lock(m_blocks_sent_mutex);
			/*
				If m_nearest_unsent_d was changed by the EmergeThread
				(it can change it to 0 through SetBlockNotSent),
				update our d to it.
				Else update m_nearest_unsent_d
			*/
			if(m_nearest_unsent_d != last_nearest_unsent_d)
			{
				d = m_nearest_unsent_d;
				last_nearest_unsent_d = m_nearest_unsent_d;
			}
		}

		/*
			Get the border/face dot coordinates of a "d-radiused"
			box
		*/
		core::list<v3s16> list;
		getFacePositions(list, d);
		
		core::list<v3s16>::Iterator li;
		for(li=list.begin(); li!=list.end(); li++)
		{
			v3s16 p = *li + center;
			
			/*
				Send throttling
				- Don't allow too many simultaneous transfers
				- EXCEPT when the blocks are very close

				Also, don't send blocks that are already flying.
			*/
			
			u16 maximum_simultaneous_block_sends_now =
					maximum_simultaneous_block_sends;
			
			if(d <= BLOCK_SEND_DISABLE_LIMITS_MAX_D)
			{
				maximum_simultaneous_block_sends_now =
						maximum_simultaneous_block_sends_setting;
			}

			{
				JMutexAutoLock lock(m_blocks_sending_mutex);
				
				// Limit is dynamically lowered when building
				if(num_blocks_selected
						>= maximum_simultaneous_block_sends_now)
				{
					/*dstream<<"Not sending more blocks. Queue full. "
							<<m_blocks_sending.size()
							<<std::endl;*/
					goto queue_full;
				}

				if(m_blocks_sending.find(p) != NULL)
					continue;
			}
			
			/*
				Do not go 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)
				continue;

			bool generate = d <= d_max_gen;
		
			// Limit the generating area vertically to half
			if(abs(p.Y - center.Y) > d_max_gen / 2)
				generate = false;
			
			/*
				Don't send already sent blocks
			*/
			{
				JMutexAutoLock lock(m_blocks_sent_mutex);
				
				if(m_blocks_sent.find(p) != NULL)
					continue;
			}

			/*
				Check if map has this block
			*/
			MapBlock *block = NULL;
			try
			{
				block = server->m_env.getMap().getBlockNoCreate(p);
			}
			catch(InvalidPositionException &e)
			{
			}
			
			bool surely_not_found_on_disk = false;
			if(block != NULL)
			{
				/*if(block->isIncomplete())
				{
					has_incomplete_blocks = true;
					continue;
				}*/

				if(block->isDummy())
				{
					surely_not_found_on_disk = true;
				}
			}

			/*
				If block has been marked to not exist on disk (dummy)
				and generating new ones is not wanted, skip block.
			*/
			if(generate == false && surely_not_found_on_disk == true)
			{
				// get next one.
				continue;
			}

			/*
				Record the lowest d from which a a block has been
				found being not sent and possibly to exist
			*/
			if(new_nearest_unsent_d == -1 || d < new_nearest_unsent_d)
			{
				new_nearest_unsent_d = d;
			}
					
			/*
				Add inexistent block to emerge queue.
			*/
			if(block == NULL || surely_not_found_on_disk)
			{
				/*SharedPtr<JMutexAutoLock> lock
						(m_num_blocks_in_emerge_queue.getLock());*/
				
				//TODO: Get value from somewhere
				// Allow only one block in emerge queue
				if(server->m_emerge_queue.peerItemCount(peer_id) < 1)
				{
					// Add it to the emerge queue and trigger the thread
					
					u8 flags = 0;
					if(generate == false)
						flags |= BLOCK_EMERGE_FLAG_FROMDISK;
					
					server->m_emerge_queue.addBlock(peer_id, p, flags);
					server->m_emergethread.trigger();
				}
				
				// get next one.
				continue;
			}

			/*
				Add block to queue
			*/

			PrioritySortedBlockTransfer q((float)d, p, peer_id);

			dest.push_back(q);

			num_blocks_selected += 1;
		}
	}
queue_full:

	if(new_nearest_unsent_d != -1)
	{
		JMutexAutoLock lock(m_blocks_sent_mutex);
		m_nearest_unsent_d = new_nearest_unsent_d;
	}
}

void RemoteClient::SendObjectData(
		Server *server,
		float dtime,
		core::map<v3s16, bool> &stepped_blocks
	)
{
	DSTACK(__FUNCTION_NAME);

	// Can't send anything without knowing version
	if(serialization_version == SER_FMT_VER_INVALID)
	{
		dstream<<"RemoteClient::SendObjectData(): Not sending, no version."
				<<std::endl;
		return;
	}

	/*
		Send a TOCLIENT_OBJECTDATA packet.
		Sent as unreliable.

		u16 command
		u16 number of player positions
		for each player:
			v3s32 position*100
			v3s32 speed*100
			s32 pitch*100
			s32 yaw*100
		u16 count of blocks
		for each block:
			block objects
	*/

	std::ostringstream os(std::ios_base::binary);
	u8 buf[12];
	
	// Write command
	writeU16(buf, TOCLIENT_OBJECTDATA);
	os.write((char*)buf, 2);
	
	/*
		Get and write player data
	*/

	core::list<Player*> players = server->m_env.getPlayers();

	// Write player count
	u16 playercount = players.size();
	writeU16(buf, playercount);
	os.write((char*)buf, 2);

	core::list<Player*>::Iterator i;
	for(i = players.begin();
			i != players.end(); i++)
	{
		Player *player = *i;

		v3f pf = player->getPosition();
		v3f sf = player->getSpeed();

		v3s32 position_i(pf.X*100, pf.Y*100, pf.Z*100);
		v3s32 speed_i   (sf.X*100, sf.Y*100, sf.Z*100);
		s32   pitch_i   (player->getPitch() * 100);
		s32   yaw_i     (player->getYaw() * 100);
		
		writeU16(buf, player->peer_id);
		os.write((char*)buf, 2);
		writeV3S32(buf, position_i);
		os.write((char*)buf, 12);
		writeV3S32(buf, speed_i);
		os.write((char*)buf, 12);
		writeS32(buf, pitch_i);
		os.write((char*)buf, 4);
		writeS32(buf, yaw_i);
		os.write((char*)buf, 4);
	}
	
	/*
		Get and write object data
	*/

	/*
		Get nearby blocks.
		
		For making players to be able to build to their nearby
		environment (building is not possible on blocks that are not
		in memory):
		- Set blocks changed
		- Add blocks to emerge queue if they are not found

		SUGGESTION: These could be ignored from the backside of the player
	*/

	Player *player = server->m_env.getPlayer(peer_id);

	v3f playerpos = player->getPosition();
	v3f playerspeed = player->getSpeed();

	v3s16 center_nodepos = floatToInt(playerpos);
	v3s16 center = getNodeBlockPos(center_nodepos);

	s16 d_max = g_settings.getS16("active_object_range");
	
	// Number of blocks whose objects were written to bos
	u16 blockcount = 0;

	std::ostringstream bos(std::ios_base::binary);

	for(s16 d = 0; d <= d_max; d++)
	{
		core::list<v3s16> list;
		getFacePositions(list, d);
		
		core::list<v3s16>::Iterator li;
		for(li=list.begin(); li!=list.end(); li++)
		{
			v3s16 p = *li + center;

			/*
				Ignore blocks that haven't been sent to the client
			*/
			{
				JMutexAutoLock sentlock(m_blocks_sent_mutex);
				if(m_blocks_sent.find(p) == NULL)
					continue;
			}
			
			// Try stepping block and add it to a send queue
			try
			{

			// Get block
			MapBlock *block = server->m_env.getMap().getBlockNoCreate(p);

			/*
				Step block if not in stepped_blocks and add to stepped_blocks.
			*/
			if(stepped_blocks.find(p) == NULL)
			{
				block->stepObjects(dtime, true, server->getDayNightRatio());
				stepped_blocks.insert(p, true);
				block->setChangedFlag();
			}

			// Skip block if there are no objects
			if(block->getObjectCount() == 0)
				continue;
			
			/*
				Write objects
			*/

			// Write blockpos
			writeV3S16(buf, p);
			bos.write((char*)buf, 6);

			// Write objects
			block->serializeObjects(bos, serialization_version);

			blockcount++;

			/*
				Stop collecting objects if data is already too big
			*/
			// Sum of player and object data sizes
			s32 sum = (s32)os.tellp() + 2 + (s32)bos.tellp();
			// break out if data too big
			if(sum > MAX_OBJECTDATA_SIZE)
			{
				goto skip_subsequent;
			}
			
			} //try
			catch(InvalidPositionException &e)
			{
				// Not in memory
				// Add it to the emerge queue and trigger the thread.
				// Fetch the block only if it is on disk.
				
				// Grab and increment counter
				/*SharedPtr<JMutexAutoLock> lock
						(m_num_blocks_in_emerge_queue.getLock());
				m_num_blocks_in_emerge_queue.m_value++;*/
				
				// Add to queue as an anonymous fetch from disk
				u8 flags = BLOCK_EMERGE_FLAG_FROMDISK;
				server->m_emerge_queue.addBlock(0, p, flags);
				server->m_emergethread.trigger();
			}
		}
	}

skip_subsequent:

	// Write block count
	writeU16(buf, blockcount);
	os.write((char*)buf, 2);

	// Write block objects
	os<<bos.str();

	/*
		Send data
	*/
	
	//dstream<<"Server: Sending object data to "<<peer_id<<std::endl;

	// Make data buffer
	std::string s = os.str();
	SharedBuffer<u8> data((u8*)s.c_str(), s.size());
	// Send as unreliable
	server->m_con.Send(peer_id, 0, data, false);
}

void RemoteClient::GotBlock(v3s16 p)
{
	JMutexAutoLock lock(m_blocks_sending_mutex);
	JMutexAutoLock lock2(m_blocks_sent_mutex);
	if(m_blocks_sending.find(p) != NULL)
		m_blocks_sending.remove(p);
	else
		dstream<<"RemoteClient::GotBlock(): Didn't find in"
				" m_blocks_sending"<<std::endl;
	m_blocks_sent.insert(p, true);
}

void RemoteClient::SentBlock(v3s16 p)
{
	JMutexAutoLock lock(m_blocks_sending_mutex);
	if(m_blocks_sending.size() > 15)
	{
		dstream<<"RemoteClient::SentBlock(): "
				<<"m_blocks_sending.size()="
				<<m_blocks_sending.size()<<std::endl;
	}
	if(m_blocks_sending.find(p) == NULL)
		m_blocks_sending.insert(p, 0.0);
	else
		dstream<<"RemoteClient::SentBlock(): Sent block"
				" already in m_blocks_sending"<<std::endl;
}

void RemoteClient::SetBlockNotSent(v3s16 p)
{
	JMutexAutoLock sendinglock(m_blocks_sending_mutex);
	JMutexAutoLock sentlock(m_blocks_sent_mutex);

	m_nearest_unsent_d = 0;
	
	if(m_blocks_sending.find(p) != NULL)
		m_blocks_sending.remove(p);
	if(m_blocks_sent.find(p) != NULL)
		m_blocks_sent.remove(p);
}

void RemoteClient::SetBlocksNotSent(core::map<v3s16, MapBlock*> &blocks)
{
	JMutexAutoLock sendinglock(m_blocks_sending_mutex);
	JMutexAutoLock sentlock(m_blocks_sent_mutex);

	m_nearest_unsent_d = 0;
	
	for(core::map<v3s16, MapBlock*>::Iterator
			i = blocks.getIterator();
			i.atEnd()==false; i++)
	{
		v3s16 p = i.getNode()->getKey();

		if(m_blocks_sending.find(p) != NULL)
			m_blocks_sending.remove(p);
		if(m_blocks_sent.find(p) != NULL)
			m_blocks_sent.remove(p);
	}
}

/*
	PlayerInfo
*/

PlayerInfo::PlayerInfo()
{
	name[0] = 0;
}

void PlayerInfo::PrintLine(std::ostream *s)
{
	(*s)<<id<<": \""<<name<<"\" ("
			<<position.X<<","<<position.Y
			<<","<<position.Z<<") ";
	address.print(s);
	(*s)<<" avg_rtt="<<avg_rtt;
	(*s)<<std::endl;
}

u32 PIChecksum(core::list<PlayerInfo> &l)
{
	core::list<PlayerInfo>::Iterator i;
	u32 checksum = 1;
	u32 a = 10;
	for(i=l.begin(); i!=l.end(); i++)
	{
		checksum += a * (i->id+1);
		checksum ^= 0x435aafcd;
		a *= 10;
	}
	return checksum;
}

/*
	Server
*/

Server::Server(
		std::string mapsavedir,
		HMParams hm_params,
		MapParams map_params
	):
	m_env(new ServerMap(mapsavedir, hm_params, map_params), dout_server),
	m_con(PROTOCOL_ID, 512, CONNECTION_TIMEOUT, this),
	m_thread(this),
	m_emergethread(this),
	m_time_of_day(8000),
	m_time_counter(0),
	m_time_of_day_send_timer(0),
	m_uptime(0)
{
	m_flowwater_timer = 0.0;
	m_print_info_timer = 0.0;
	m_objectdata_timer = 0.0;
	m_emergethread_trigger_timer = 0.0;
	m_savemap_timer = 0.0;
	
	m_env_mutex.Init();
	m_con_mutex.Init();
	m_step_dtime_mutex.Init();
	m_step_dtime = 0.0;
}

Server::~Server()
{
	// Stop threads
	stop();

	JMutexAutoLock clientslock(m_con_mutex);

	for(core::map<u16, RemoteClient*>::Iterator
		i = m_clients.getIterator();
		i.atEnd() == false; i++)
	{
		u16 peer_id = i.getNode()->getKey();

		// Delete player
		{
			JMutexAutoLock envlock(m_env_mutex);
			m_env.removePlayer(peer_id);
		}
		
		// Delete client
		delete i.getNode()->getValue();
	}
}

void Server::start(unsigned short port)
{
	DSTACK(__FUNCTION_NAME);
	// Stop thread if already running
	m_thread.stop();
	
	// Initialize connection
	m_con.setTimeoutMs(30);
	m_con.Serve(port);

	// Start thread
	m_thread.setRun(true);
	m_thread.Start();
	
	dout_server<<"Server started on port "<<port<<std::endl;
}

void Server::stop()
{
	DSTACK(__FUNCTION_NAME);
	// Stop threads (set run=false first so both start stopping)
	m_thread.setRun(false);
	m_emergethread.setRun(false);
	m_thread.stop();
	m_emergethread.stop();
	
	dout_server<<"Server threads stopped"<<std::endl;
}

void Server::step(float dtime)
{
	DSTACK(__FUNCTION_NAME);
	// Limit a bit
	if(dtime > 2.0)
		dtime = 2.0;
	{
		JMutexAutoLock lock(m_step_dtime_mutex);
		m_step_dtime += dtime;
	}
}

void Server::AsyncRunStep()
{
	DSTACK(__FUNCTION_NAME);
	
	float dtime;
	{
		JMutexAutoLock lock1(m_step_dtime_mutex);
		dtime = m_step_dtime;
	}
	
	// Send blocks to clients
	SendBlocks(dtime);
	
	if(dtime < 0.001)
		return;
	
	//dstream<<"Server steps "<<dtime<<std::endl;
	//dstream<<"Server::AsyncRunStep(): dtime="<<dtime<<std::endl;
	
	{
		JMutexAutoLock lock1(m_step_dtime_mutex);
		m_step_dtime -= dtime;
	}

	/*
		Update uptime
	*/
	{
		m_uptime.set(m_uptime.get() + dtime);
	}
	
	/*
		Update m_time_of_day
	*/
	{
		m_time_counter += dtime;
		f32 speed = g_settings.getFloat("time_speed") * 24000./(24.*3600);
		u32 units = (u32)(m_time_counter*speed);
		m_time_counter -= (f32)units / speed;
		m_time_of_day.set((m_time_of_day.get() + units) % 24000);
		
		//dstream<<"Server: m_time_of_day = "<<m_time_of_day.get()<<std::endl;

		/*
			Send to clients at constant intervals
		*/

		m_time_of_day_send_timer -= dtime;
		if(m_time_of_day_send_timer < 0.0)
		{
			m_time_of_day_send_timer = g_settings.getFloat("time_send_interval");

			//JMutexAutoLock envlock(m_env_mutex);
			JMutexAutoLock conlock(m_con_mutex);

			for(core::map<u16, RemoteClient*>::Iterator
				i = m_clients.getIterator();
				i.atEnd() == false; i++)
			{
				RemoteClient *client = i.getNode()->getValue();
				//Player *player = m_env.getPlayer(client->peer_id);
				
				SharedBuffer<u8> data = makePacket_TOCLIENT_TIME_OF_DAY(
						m_time_of_day.get());
				// Send as reliable
				m_con.Send(client->peer_id, 0, data, true);
			}
		}
	}

	{
		// Process connection's timeouts
		JMutexAutoLock lock2(m_con_mutex);
		m_con.RunTimeouts(dtime);
	}
	
	{
		// This has to be called so that the client list gets synced
		// with the peer list of the connection
		handlePeerChanges();
	}

	{
		// Step environment
		// This also runs Map's timers
		JMutexAutoLock lock(m_env_mutex);
		m_env.step(dtime);
	}
	
	/*
		Do background stuff
	*/

	/*
		Flow water
	*/
	{
		float interval;
		
		if(g_settings.getBool("endless_water") == false)
			interval = 1.0;
		else
			interval = 0.25;

		float &counter = m_flowwater_timer;
		counter += dtime;
		if(counter >= 0.25 && m_flow_active_nodes.size() > 0)
		{
		
		counter = 0.0;

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

		{

			JMutexAutoLock envlock(m_env_mutex);
			
			MapVoxelManipulator v(&m_env.getMap());
			v.m_disable_water_climb =
					g_settings.getBool("disable_water_climb");
			
			if(g_settings.getBool("endless_water") == false)
				v.flowWater(m_flow_active_nodes, 0, false, 250);
			else
				v.flowWater(m_flow_active_nodes, 0, false, 50);

			v.blitBack(modified_blocks);

			ServerMap &map = ((ServerMap&)m_env.getMap());
			
			// Update lighting
			core::map<v3s16, MapBlock*> lighting_modified_blocks;
			map.updateLighting(modified_blocks, lighting_modified_blocks);
			
			// Add blocks modified by lighting to modified_blocks
			for(core::map<v3s16, MapBlock*>::Iterator
					i = lighting_modified_blocks.getIterator();
					i.atEnd() == false; i++)
			{
				MapBlock *block = i.getNode()->getValue();
				modified_blocks.insert(block->getPos(), block);
			}
		} // envlock

		/*
			Set the modified blocks unsent for all the clients
		*/
		
		JMutexAutoLock lock2(m_con_mutex);

		for(core::map<u16, RemoteClient*>::Iterator
				i = m_clients.getIterator();
				i.atEnd() == false; i++)
		{
			RemoteClient *client = i.getNode()->getValue();
			
			if(modified_blocks.size() > 0)
			{
				// Remove block from sent history
				client->SetBlocksNotSent(modified_blocks);
			}
		}

		} // interval counter
	}
	
	// Periodically print some info
	{
		float &counter = m_print_info_timer;
		counter += dtime;
		if(counter >= 30.0)
		{
			counter = 0.0;

			JMutexAutoLock lock2(m_con_mutex);

			for(core::map<u16, RemoteClient*>::Iterator
				i = m_clients.getIterator();
				i.atEnd() == false; i++)
			{
				//u16 peer_id = i.getNode()->getKey();
				RemoteClient *client = i.getNode()->getValue();
				client->PrintInfo(std::cout);
			}
		}
	}

	/*
		Update digging

		NOTE: Some of this could be moved to RemoteClient
	*/
#if 0
	{
		JMutexAutoLock envlock(m_env_mutex);
		JMutexAutoLock conlock(m_con_mutex);

		for(core::map<u16, RemoteClient*>::Iterator
			i = m_clients.getIterator();
			i.atEnd() == false; i++)
		{
			RemoteClient *client = i.getNode()->getValue();
			Player *player = m_env.getPlayer(client->peer_id);

			JMutexAutoLock digmutex(client->m_dig_mutex);

			if(client->m_dig_tool_item == -1)
				continue;

			client->m_dig_time_remaining -= dtime;

			if(client->m_dig_time_remaining > 0)
			{
				client->m_time_from_building.set(0.0);
				continue;
			}

			v3s16 p_under = client->m_dig_position;
			
			// Mandatory parameter; actually used for nothing
			core::map<v3s16, MapBlock*> modified_blocks;

			u8 material;

			try
			{
				// Get material at position
				material = m_env.getMap().getNode(p_under).d;
				// If it's not diggable, do nothing
				if(content_diggable(material) == false)
				{
					derr_server<<"Server: Not finishing digging: Node not diggable"
							<<std::endl;
					client->m_dig_tool_item = -1;
					break;
				}
			}
			catch(InvalidPositionException &e)
			{
				derr_server<<"Server: Not finishing digging: Node not found"
						<<std::endl;
				client->m_dig_tool_item = -1;
				break;
			}
			
			// Create packet
			u32 replysize = 8;
			SharedBuffer<u8> reply(replysize);
			writeU16(&reply[0], TOCLIENT_REMOVENODE);
			writeS16(&reply[2], p_under.X);
			writeS16(&reply[4], p_under.Y);
			writeS16(&reply[6], p_under.Z);
			// Send as reliable
			m_con.SendToAll(0, reply, true);
			
			if(g_settings.getBool("creative_mode") == false)
			{
				// Add to inventory and send inventory
				InventoryItem *item = new MaterialItem(material, 1);
				player->inventory.addItem("main", item);
				SendInventory(player->peer_id);
			}

			/*
				Remove the node
				(this takes some time so it is done after the quick stuff)
			*/
			m_env.getMap().removeNodeAndUpdate(p_under, modified_blocks);
			
			/*
				Update water
			*/
			
			// Update water pressure around modification
			// This also adds it to m_flow_active_nodes if appropriate

			MapVoxelManipulator v(&m_env.getMap());
			v.m_disable_water_climb =
					g_settings.getBool("disable_water_climb");
			
			VoxelArea area(p_under-v3s16(1,1,1), p_under+v3s16(1,1,1));

			try
			{
				v.updateAreaWaterPressure(area, m_flow_active_nodes);
			}
			catch(ProcessingLimitException &e)
			{
				dstream<<"Processing limit reached (1)"<<std::endl;
			}
			
			v.blitBack(modified_blocks);
		}
	}
#endif

	// Send object positions
	{
		float &counter = m_objectdata_timer;
		counter += dtime;
		if(counter >= g_settings.getFloat("objectdata_interval"))
		{
			JMutexAutoLock lock1(m_env_mutex);
			JMutexAutoLock lock2(m_con_mutex);
			SendObjectData(counter);

			counter = 0.0;
		}
	}
	
	// Trigger emergethread (it gets somehow gets to a
	// non-triggered but bysy state sometimes)
	{
		float &counter = m_emergethread_trigger_timer;
		counter += dtime;
		if(counter >= 2.0)
		{
			counter = 0.0;
			
			m_emergethread.trigger();
		}
	}

	// Save map
	{
		float &counter = m_savemap_timer;
		counter += dtime;
		if(counter >= g_settings.getFloat("server_map_save_interval"))
		{
			counter = 0.0;

			JMutexAutoLock lock(m_env_mutex);

			// Save only changed parts
			m_env.getMap().save(true);

			// Delete unused sectors
			u32 deleted_count = m_env.getMap().deleteUnusedSectors(
					g_settings.getFloat("server_unload_unused_sectors_timeout"));
			if(deleted_count > 0)
			{
				dout_server<<"Server: Unloaded "<<deleted_count
						<<" sectors from memory"<<std::endl;
			}
		}
	}
}

void Server::Receive()
{
	DSTACK(__FUNCTION_NAME);
	u32 data_maxsize = 10000;
	Buffer<u8> data(data_maxsize);
	u16 peer_id;
	u32 datasize;
	try{
		{
			JMutexAutoLock conlock(m_con_mutex);
			datasize = m_con.Receive(peer_id, *data, data_maxsize);
		}

		// This has to be called so that the client list gets synced
		// with the peer list of the connection
		handlePeerChanges();

		ProcessData(*data, datasize, peer_id);
	}
	catch(con::InvalidIncomingDataException &e)
	{
		derr_server<<"Server::Receive(): "
				"InvalidIncomingDataException: what()="
				<<e.what()<<std::endl;
	}
	catch(con::PeerNotFoundException &e)
	{
		//NOTE: This is not needed anymore
		
		// The peer has been disconnected.
		// Find the associated player and remove it.

		/*JMutexAutoLock envlock(m_env_mutex);

		dout_server<<"ServerThread: peer_id="<<peer_id
				<<" has apparently closed connection. "
				<<"Removing player."<<std::endl;

		m_env.removePlayer(peer_id);*/
	}
}

void Server::ProcessData(u8 *data, u32 datasize, u16 peer_id)
{
	DSTACK(__FUNCTION_NAME);
	// Environment is locked first.
	JMutexAutoLock envlock(m_env_mutex);
	JMutexAutoLock conlock(m_con_mutex);
	
	con::Peer *peer;
	try{
		peer = m_con.GetPeer(peer_id);
	}
	catch(con::PeerNotFoundException &e)
	{
		derr_server<<DTIME<<"Server::ProcessData(): Cancelling: peer "
				<<peer_id<<" not found"<<std::endl;
		return;
	}
	
	//u8 peer_ser_ver = peer->serialization_version;
	u8 peer_ser_ver = getClient(peer->id)->serialization_version;

	try
	{

	if(datasize < 2)
		return;

	ToServerCommand command = (ToServerCommand)readU16(&data[0]);
	
	if(command == TOSERVER_INIT)
	{
		// [0] u16 TOSERVER_INIT
		// [2] u8 SER_FMT_VER_HIGHEST
		// [3] u8[20] player_name

		if(datasize < 3)
			return;

		derr_server<<DTIME<<"Server: Got TOSERVER_INIT from "
				<<peer->id<<std::endl;

		// First byte after command is maximum supported
		// serialization version
		u8 client_max = data[2];
		u8 our_max = SER_FMT_VER_HIGHEST;
		// Use the highest version supported by both
		u8 deployed = core::min_(client_max, our_max);
		// If it's lower than the lowest supported, give up.
		if(deployed < SER_FMT_VER_LOWEST)
			deployed = SER_FMT_VER_INVALID;

		//peer->serialization_version = deployed;
		getClient(peer->id)->pending_serialization_version = deployed;

		if(deployed == SER_FMT_VER_INVALID)
		{
			derr_server<<DTIME<<"Server: Cannot negotiate "
					"serialization version with peer "
					<<peer_id<<std::endl;
			return;
		}

		/*
			Set up player
		*/

		Player *player = m_env.getPlayer(peer_id);

		// Check if player doesn't exist
		if(player == NULL)
			throw con::InvalidIncomingDataException
				("Server::ProcessData(): INIT: Player doesn't exist");

		// update name if it was supplied
		if(datasize >= 20+3)
		{
			data[20+3-1] = 0;
			player->updateName((const char*)&data[3]);
		}

		// Now answer with a TOCLIENT_INIT
		
		SharedBuffer<u8> reply(2+1+6);
		writeU16(&reply[0], TOCLIENT_INIT);
		writeU8(&reply[2], deployed);
		writeV3S16(&reply[3], floatToInt(player->getPosition()+v3f(0,BS/2,0)));
		// Send as reliable
		m_con.Send(peer_id, 0, reply, true);

		return;
	}
	if(command == TOSERVER_INIT2)
	{
		derr_server<<DTIME<<"Server: Got TOSERVER_INIT2 from "
				<<peer->id<<std::endl;


		getClient(peer->id)->serialization_version
				= getClient(peer->id)->pending_serialization_version;

		/*
			Send some initialization data
		*/
		
		// Send player info to all players
		SendPlayerInfos();

		// Send inventory to player
		SendInventory(peer->id);
		
		// Send time of day
		{
			SharedBuffer<u8> data = makePacket_TOCLIENT_TIME_OF_DAY(
					m_time_of_day.get());
			m_con.Send(peer->id, 0, data, true);
		}

		// Send information about server to player in chat
		{
			std::wostringstream os(std::ios_base::binary);
			os<<L"# Server: ";
			// Uptime
			os<<L"uptime="<<m_uptime.get();
			// Information about clients
			os<<L", clients={";
			for(core::map<u16, RemoteClient*>::Iterator
				i = m_clients.getIterator();
				i.atEnd() == false; i++)
			{
				// Get client and check that it is valid
				RemoteClient *client = i.getNode()->getValue();
				assert(client->peer_id == i.getNode()->getKey());
				if(client->serialization_version == SER_FMT_VER_INVALID)
					continue;
				// Get name of player
				std::wstring name = L"unknown";
				Player *player = m_env.getPlayer(client->peer_id);
				if(player != NULL)
					name = narrow_to_wide(player->getName());
				// Add name to information string
				os<<name<<L",";
			}
			os<<L"}";
			// Send message
			SendChatMessage(peer_id, os.str());
		}
		
		// Send information about joining in chat
		{
			std::wstring name = L"unknown";
			Player *player = m_env.getPlayer(peer_id);
			if(player != NULL)
				name = narrow_to_wide(player->getName());
			
			std::wstring message;
			message += L"*** ";
			message += name;
			message += L" joined game";
			BroadcastChatMessage(message);
		}

		return;
	}

	if(peer_ser_ver == SER_FMT_VER_INVALID)
	{
		derr_server<<DTIME<<"Server::ProcessData(): Cancelling: Peer"
				" serialization format invalid or not initialized."
				" Skipping incoming command="<<command<<std::endl;
		return;
	}
	
	Player *player = m_env.getPlayer(peer_id);

	if(player == NULL){
		derr_server<<"Server::ProcessData(): Cancelling: "
				"No player for peer_id="<<peer_id
				<<std::endl;
		return;
	}
	if(command == TOSERVER_PLAYERPOS)
	{
		if(datasize < 2+12+12+4+4)
			return;
	
		u32 start = 0;
		v3s32 ps = readV3S32(&data[start+2]);
		v3s32 ss = readV3S32(&data[start+2+12]);
		f32 pitch = (f32)readS32(&data[2+12+12]) / 100.0;
		f32 yaw = (f32)readS32(&data[2+12+12+4]) / 100.0;
		v3f position((f32)ps.X/100., (f32)ps.Y/100., (f32)ps.Z/100.);
		v3f speed((f32)ss.X/100., (f32)ss.Y/100., (f32)ss.Z/100.);
		pitch = wrapDegrees(pitch);
		yaw = wrapDegrees(yaw);
		player->setPosition(position);
		player->setSpeed(speed);
		player->setPitch(pitch);
		player->setYaw(yaw);
		
		/*dout_server<<"Server::ProcessData(): Moved player "<<peer_id<<" to "
				<<"("<<position.X<<","<<position.Y<<","<<position.Z<<")"
				<<" pitch="<<pitch<<" yaw="<<yaw<<std::endl;*/
	}
	else if(command == TOSERVER_GOTBLOCKS)
	{
		if(datasize < 2+1)
			return;
		
		/*
			[0] u16 command
			[2] u8 count
			[3] v3s16 pos_0
			[3+6] v3s16 pos_1
			...
		*/

		u16 count = data[2];
		for(u16 i=0; i<count; i++)
		{
			if((s16)datasize < 2+1+(i+1)*6)
				throw con::InvalidIncomingDataException
					("GOTBLOCKS length is too short");
			v3s16 p = readV3S16(&data[2+1+i*6]);
			/*dstream<<"Server: GOTBLOCKS ("
					<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/
			RemoteClient *client = getClient(peer_id);
			client->GotBlock(p);
		}
	}
	else if(command == TOSERVER_DELETEDBLOCKS)
	{
		if(datasize < 2+1)
			return;
		
		/*
			[0] u16 command
			[2] u8 count
			[3] v3s16 pos_0
			[3+6] v3s16 pos_1
			...
		*/

		u16 count = data[2];
		for(u16 i=0; i<count; i++)
		{
			if((s16)datasize < 2+1+(i+1)*6)
				throw con::InvalidIncomingDataException
					("DELETEDBLOCKS length is too short");
			v3s16 p = readV3S16(&data[2+1+i*6]);
			/*dstream<<"Server: DELETEDBLOCKS ("
					<<p.X<<","<<p.Y<<","<<p.Z<<")"<<std::endl;*/
			RemoteClient *client = getClient(peer_id);
			client->SetBlockNotSent(p);
		}
	}
	else if(command == TOSERVER_CLICK_OBJECT)
	{
		if(datasize < 13)
			return;

		/*
			[0] u16 command
			[2] u8 button (0=left, 1=right)
			[3] v3s16 block
			[9] s16 id
			[11] u16 item
		*/
		u8 button = readU8(&data[2]);
		v3s16 p;
		p.X = readS16(&data[3]);
		p.Y = readS16(&data[5]);
		p.Z = readS16(&data[7]);
		s16 id = readS16(&data[9]);
		//u16 item_i = readU16(&data[11]);

		MapBlock *block = NULL;
		try
		{
			block = m_env.getMap().getBlockNoCreate(p);
		}
		catch(InvalidPositionException &e)
		{
			derr_server<<"CLICK_OBJECT block not found"<<std::endl;
			return;
		}

		MapBlockObject *obj = block->getObject(id);

		if(obj == NULL)
		{
			derr_server<<"CLICK_OBJECT object not found"<<std::endl;
			return;
		}

		//TODO: Check that object is reasonably close
		
		// Left click
		if(button == 0)
		{
			InventoryList *ilist = player->inventory.getList("main");
			if(g_settings.getBool("creative_mode") == false && ilist != NULL)
			{
			
				// Skip if inventory has no free space
				if(ilist->getUsedSlots() == ilist->getSize())
				{
					dout_server<<"Player inventory has no free space"<<std::endl;
					return;
				}
				
				/*
					Create the inventory item
				*/
				InventoryItem *item = NULL;
				// If it is an item-object, take the item from it
				if(obj->getTypeId() == MAPBLOCKOBJECT_TYPE_ITEM)
				{
					item = ((ItemObject*)obj)->createInventoryItem();
				}
				// Else create an item of the object
				else
				{
					item = new MapBlockObjectItem
							(obj->getInventoryString());
				}
				
				// Add to inventory and send inventory
				ilist->addItem(item);
				SendInventory(player->peer_id);
			}

			// Remove from block
			block->removeObject(id);
		}
	}
	else if(command == TOSERVER_GROUND_ACTION)
	{
		if(datasize < 17)
			return;
		/*
			length: 17
			[0] u16 command
			[2] u8 action
			[3] v3s16 nodepos_undersurface
			[9] v3s16 nodepos_abovesurface
			[15] u16 item
			actions:
			0: start digging
			1: place block
			2: stop digging (all parameters ignored)
		*/
		u8 action = readU8(&data[2]);
		v3s16 p_under;
		p_under.X = readS16(&data[3]);
		p_under.Y = readS16(&data[5]);
		p_under.Z = readS16(&data[7]);
		v3s16 p_over;
		p_over.X = readS16(&data[9]);
		p_over.Y = readS16(&data[11]);
		p_over.Z = readS16(&data[13]);
		u16 item_i = readU16(&data[15]);

		//TODO: Check that target is reasonably close
		
		/*
			0: start digging
		*/
		if(action == 0)
		{
			/*
				NOTE: This can be used in the future to check if
				somebody is cheating, by checking the timing.
			*/
		} // action == 0

		/*
			2: stop digging
		*/
		else if(action == 2)
		{
#if 0
			RemoteClient *client = getClient(peer->id);
			JMutexAutoLock digmutex(client->m_dig_mutex);
			client->m_dig_tool_item = -1;
#endif
		}

		/*
			3: Digging completed
		*/
		else if(action == 3)
		{
			// Mandatory parameter; actually used for nothing
			core::map<v3s16, MapBlock*> modified_blocks;

			u8 material;

			try
			{
				// Get material at position
				material = m_env.getMap().getNode(p_under).d;
				// If it's not diggable, do nothing
				if(content_diggable(material) == false)
				{
					derr_server<<"Server: Not finishing digging: Node not diggable"
							<<std::endl;
					return;
				}
			}
			catch(InvalidPositionException &e)
			{
				derr_server<<"Server: Not finishing digging: Node not found"
						<<std::endl;
				return;
			}
			
			//TODO: Send to only other clients
			
			/*
				Send the removal to all other clients
			*/

			// Create packet
			u32 replysize = 8;
			SharedBuffer<u8> reply(replysize);
			writeU16(&reply[0], TOCLIENT_REMOVENODE);
			writeS16(&reply[2], p_under.X);
			writeS16(&reply[4], p_under.Y);
			writeS16(&reply[6], p_under.Z);

			for(core::map<u16, RemoteClient*>::Iterator
				i = m_clients.getIterator();
				i.atEnd() == false; i++)
			{
				// Get client and check that it is valid
				RemoteClient *client = i.getNode()->getValue();
				assert(client->peer_id == i.getNode()->getKey());
				if(client->serialization_version == SER_FMT_VER_INVALID)
					continue;

				// Don't send if it's the same one
				if(peer_id == client->peer_id)
					continue;

				// Send as reliable
				m_con.Send(client->peer_id, 0, reply, true);
			}
			
			/*
				Update and send inventory
			*/

			if(g_settings.getBool("creative_mode") == false)
			{
				// Add to inventory and send inventory
				InventoryItem *item = new MaterialItem(material, 1);
				player->inventory.addItem("main", item);
				SendInventory(player->peer_id);
			}

			/*
				Remove the node
				(this takes some time so it is done after the quick stuff)
			*/
			m_env.getMap().removeNodeAndUpdate(p_under, modified_blocks);
			
			/*
				Update water
			*/
			
			// Update water pressure around modification
			// This also adds it to m_flow_active_nodes if appropriate

			MapVoxelManipulator v(&m_env.getMap());
			v.m_disable_water_climb =
					g_settings.getBool("disable_water_climb");
			
			VoxelArea area(p_under-v3s16(1,1,1), p_under+v3s16(1,1,1));

			try
			{
				v.updateAreaWaterPressure(area, m_flow_active_nodes);
			}
			catch(ProcessingLimitException &e)
			{
				dstream<<"Processing limit reached (1)"<<std::endl;
			}
			
			v.blitBack(modified_blocks);
		}
		
		/*
			1: place block
		*/
		else if(action == 1)
		{

			InventoryList *ilist = player->inventory.getList("main");
			if(ilist == NULL)
				return;

			// Get item
			InventoryItem *item = ilist->getItem(item_i);
			
			// If there is no item, it is not possible to add it anywhere
			if(item == NULL)
				return;
			
			/*
				Handle material items
			*/
			if(std::string("MaterialItem") == item->getName())
			{
				try{
					// Don't add a node if this is not a free space
					MapNode n2 = m_env.getMap().getNode(p_over);
					if(content_buildable_to(n2.d) == false)
						return;
				}
				catch(InvalidPositionException &e)
				{
					derr_server<<"Server: Ignoring ADDNODE: Node not found"
							<<std::endl;
					return;
				}

				// Reset build time counter
				getClient(peer->id)->m_time_from_building.set(0.0);
				
				// Create node data
				MaterialItem *mitem = (MaterialItem*)item;
				MapNode n;
				n.d = mitem->getMaterial();
				if(content_directional(n.d))
					n.dir = packDir(p_under - p_over);

#if 1
				// Create packet
				u32 replysize = 8 + MapNode::serializedLength(peer_ser_ver);
				SharedBuffer<u8> reply(replysize);
				writeU16(&reply[0], TOCLIENT_ADDNODE);
				writeS16(&reply[2], p_over.X);
				writeS16(&reply[4], p_over.Y);
				writeS16(&reply[6], p_over.Z);
				n.serialize(&reply[8], peer_ser_ver);
				// Send as reliable
				m_con.SendToAll(0, reply, true);
				
				/*
					Handle inventory
				*/
				InventoryList *ilist = player->inventory.getList("main");
				if(g_settings.getBool("creative_mode") == false && ilist)
				{
					// Remove from inventory and send inventory
					if(mitem->getCount() == 1)
						ilist->deleteItem(item_i);
					else
						mitem->remove(1);
					// Send inventory
					SendInventory(peer_id);
				}
				
				/*
					Add node.

					This takes some time so it is done after the quick stuff
				*/
				core::map<v3s16, MapBlock*> modified_blocks;
				m_env.getMap().addNodeAndUpdate(p_over, n, modified_blocks);
#endif
#if 0
				/*
					Handle inventory
				*/
				InventoryList *ilist = player->inventory.getList("main");
				if(g_settings.getBool("creative_mode") == false && ilist)
				{
					// Remove from inventory and send inventory
					if(mitem->getCount() == 1)
						ilist->deleteItem(item_i);
					else
						mitem->remove(1);
					// Send inventory
					SendInventory(peer_id);
				}

				/*
					Add node.

					This takes some time so it is done after the quick stuff
				*/
				core::map<v3s16, MapBlock*> modified_blocks;
				m_env.getMap().addNodeAndUpdate(p_over, n, modified_blocks);

				/*
					Set the modified blocks unsent for all the clients
				*/
				
				//JMutexAutoLock lock2(m_con_mutex);

				for(core::map<u16, RemoteClient*>::Iterator
						i = m_clients.getIterator();
						i.atEnd() == false; i++)
				{
					RemoteClient *client = i.getNode()->getValue();
					
					if(modified_blocks.size() > 0)
					{
						// Remove block from sent history
						client->SetBlocksNotSent(modified_blocks);
					}
				}
#endif
				
				/*
					Update water
				*/
				
				// Update water pressure around modification
				// This also adds it to m_flow_active_nodes if appropriate

				MapVoxelManipulator v(&m_env.getMap());
				v.m_disable_water_climb =
						g_settings.getBool("disable_water_climb");
				
				VoxelArea area(p_over-v3s16(1,1,1), p_over+v3s16(1,1,1));

				try
				{
					v.updateAreaWaterPressure(area, m_flow_active_nodes);
				}
				catch(ProcessingLimitException &e)
				{
					dstream<<"Processing limit reached (1)"<<std::endl;
				}
				
				v.blitBack(modified_blocks);
			}
			/*
				Handle other items
			*/
			else
			{
				v3s16 blockpos = getNodeBlockPos(p_over);

				MapBlock *block = NULL;
				try
				{
					block = m_env.getMap().getBlockNoCreate(blockpos);
				}
				catch(InvalidPositionException &e)
				{
					derr_server<<"Error while placing object: "
							"block not found"<<std::endl;
					return;
				}

				v3s16 block_pos_i_on_map = block->getPosRelative();
				v3f block_pos_f_on_map = intToFloat(block_pos_i_on_map);

				v3f pos = intToFloat(p_over);
				pos -= block_pos_f_on_map;
				
				/*dout_server<<"pos="
						<<"("<<pos.X<<","<<pos.Y<<","<<pos.Z<<")"
						<<std::endl;*/

				MapBlockObject *obj = NULL;

				/*
					Handle block object items
				*/
				if(std::string("MBOItem") == item->getName())
				{
					MapBlockObjectItem *oitem = (MapBlockObjectItem*)item;

					/*dout_server<<"Trying to place a MapBlockObjectItem: "
							"inventorystring=\""
							<<oitem->getInventoryString()
							<<"\""<<std::endl;*/
							
					obj = oitem->createObject
							(pos, player->getYaw(), player->getPitch());
				}
				/*
					Handle other items
				*/
				else
				{
					dout_server<<"Placing a miscellaneous item on map"
							<<std::endl;
					/*
						Create an ItemObject that contains the item.
					*/
					ItemObject *iobj = new ItemObject(NULL, -1, pos);
					std::ostringstream os(std::ios_base::binary);
					item->serialize(os);
					dout_server<<"Item string is \""<<os.str()<<"\""<<std::endl;
					iobj->setItemString(os.str());
					obj = iobj;
				}

				if(obj == NULL)
				{
					derr_server<<"WARNING: item resulted in NULL object, "
							<<"not placing onto map"
							<<std::endl;
				}
				else
				{
					block->addObject(obj);

					dout_server<<"Placed object"<<std::endl;

					InventoryList *ilist = player->inventory.getList("main");
					if(g_settings.getBool("creative_mode") == false && ilist)
					{
						// Remove from inventory and send inventory
						ilist->deleteItem(item_i);
						// Send inventory
						SendInventory(peer_id);
					}
				}
			}

		} // action == 1

		/*
			Catch invalid actions
		*/
		else
		{
			derr_server<<"WARNING: Server: Invalid action "
					<<action<<std::endl;
		}
	}
#if 0
	else if(command == TOSERVER_RELEASE)
	{
		if(datasize < 3)
			return;
		/*
			length: 3
			[0] u16 command
			[2] u8 button
		*/
		dstream<<"TOSERVER_RELEASE ignored"<<std::endl;
	}
#endif
	else if(command == TOSERVER_SIGNTEXT)
	{
		/*
			u16 command
			v3s16 blockpos
			s16 id
			u16 textlen
			textdata
		*/
		std::string datastring((char*)&data[2], datasize-2);
		std::istringstream is(datastring, std::ios_base::binary);
		u8 buf[6];
		// Read stuff
		is.read((char*)buf, 6);
		v3s16 blockpos = readV3S16(buf);
		is.read((char*)buf, 2);
		s16 id = readS16(buf);
		is.read((char*)buf, 2);
		u16 textlen = readU16(buf);
		std::string text;
		for(u16 i=0; i<textlen; i++)
		{
			is.read((char*)buf, 1);
			text += (char)buf[0];
		}

		MapBlock *block = NULL;
		try
		{
			block = m_env.getMap().getBlockNoCreate(blockpos);
		}
		catch(InvalidPositionException &e)
		{
			derr_server<<"Error while setting sign text: "
					"block not found"<<std::endl;
			return;
		}

		MapBlockObject *obj = block->getObject(id);
		if(obj == NULL)
		{
			derr_server<<"Error while setting sign text: "
					"object not found"<<std::endl;
			return;
		}
		
		if(obj->getTypeId() != MAPBLOCKOBJECT_TYPE_SIGN)
		{
			derr_server<<"Error while setting sign text: "
					"object is not a sign"<<std::endl;
			return;
		}

		((SignObject*)obj)->setText(text);

		obj->getBlock()->setChangedFlag();
	}
	else if(command == TOSERVER_INVENTORY_ACTION)
	{
		// Ignore inventory changes if in creative mode
		if(g_settings.getBool("creative_mode") == true)
		{
			dstream<<"TOSERVER_INVENTORY_ACTION: ignoring in creative mode"
					<<std::endl;
			return;
		}
		// Strip command and create a stream
		std::string datastring((char*)&data[2], datasize-2);
		dstream<<"TOSERVER_INVENTORY_ACTION: data="<<datastring<<std::endl;
		std::istringstream is(datastring, std::ios_base::binary);
		// Create an action
		InventoryAction *a = InventoryAction::deSerialize(is);
		if(a != NULL)
		{
			/*
				Handle craftresult specially
			*/
			bool disable_action = false;
			if(a->getType() == IACTION_MOVE)
			{
				IMoveAction *ma = (IMoveAction*)a;
				// Don't allow moving anything to craftresult
				if(ma->to_name == "craftresult")
				{
					// Do nothing
					disable_action = true;
				}
				// When something is removed from craftresult
				if(ma->from_name == "craftresult")
				{
					disable_action = true;
					// Remove stuff from craft
					InventoryList *clist = player->inventory.getList("craft");
					if(clist)
					{
						u16 count = ma->count;
						if(count == 0)
							count = 1;
						clist->decrementMaterials(count);
					}
					// Do action
					// Feed action to player inventory
					a->apply(&player->inventory);
					// Eat it
					delete a;
					// If something appeared in craftresult, throw it
					// in the main list
					InventoryList *rlist = player->inventory.getList("craftresult");
					InventoryList *mlist = player->inventory.getList("main");
					if(rlist && mlist && rlist->getUsedSlots() == 1)
					{
						InventoryItem *item1 = rlist->changeItem(0, NULL);
						mlist->addItem(item1);
					}
				}
			}
			if(disable_action == false)
			{
				// Feed action to player inventory
				a->apply(&player->inventory);
				// Eat it
				delete a;
			}
			// Send inventory
			SendInventory(player->peer_id);
		}
		else
		{
			dstream<<"TOSERVER_INVENTORY_ACTION: "
					<<"InventoryAction::deSerialize() returned NULL"
					<<std::endl;
		}
	}
	else if(command == TOSERVER_CHAT_MESSAGE)
	{
		/*
			u16 command
			u16 length
			wstring message
		*/
		u8 buf[6];
		std::string datastring((char*)&data[2], datasize-2);
		std::istringstream is(datastring, std::ios_base::binary);
		
		// Read stuff
		is.read((char*)buf, 2);
		u16 len = readU16(buf);
		
		std::wstring message;
		for(u16 i=0; i<len; i++)
		{
			is.read((char*)buf, 2);
			message += (wchar_t)readU16(buf);
		}

		dstream<<"CHAT: "<<wide_to_narrow(message)<<std::endl;

		/*
			Send the message to all other clients
		*/
		for(core::map<u16, RemoteClient*>::Iterator
			i = m_clients.getIterator();
			i.atEnd() == false; i++)
		{
			// Get client and check that it is valid
			RemoteClient *client = i.getNode()->getValue();
			assert(client->peer_id == i.getNode()->getKey());
			if(client->serialization_version == SER_FMT_VER_INVALID)
				continue;

			// Don't send if it's the same one
			if(peer_id == client->peer_id)
				continue;

			// Get player name of this client
			std::wstring name = L"unknown";
			Player *player = m_env.getPlayer(client->peer_id);
			if(player != NULL)
				name = narrow_to_wide(player->getName());
			
			SendChatMessage(client->peer_id,
					std::wstring(L"<")+name+L"> "+message);
		}
	}
	else
	{
		derr_server<<"WARNING: Server::ProcessData(): Ignoring "
				"unknown command "<<command<<std::endl;
	}
	
	} //try
	catch(SendFailedException &e)
	{
		derr_server<<"Server::ProcessData(): SendFailedException: "
				<<"what="<<e.what()
				<<std::endl;
	}
}

/*void Server::Send(u16 peer_id, u16 channelnum,
		SharedBuffer<u8> data, bool reliable)
{
	JMutexAutoLock lock(m_con_mutex);
	m_con.Send(peer_id, channelnum, data, reliable);
}*/

void Server::SendBlockNoLock(u16 peer_id, MapBlock *block, u8 ver)
{
	DSTACK(__FUNCTION_NAME);
	/*
		Create a packet with the block in the right format
	*/
	
	std::ostringstream os(std::ios_base::binary);
	block->serialize(os, ver);
	std::string s = os.str();
	SharedBuffer<u8> blockdata((u8*)s.c_str(), s.size());

	u32 replysize = 8 + blockdata.getSize();
	SharedBuffer<u8> reply(replysize);
	v3s16 p = block->getPos();
	writeU16(&reply[0], TOCLIENT_BLOCKDATA);
	writeS16(&reply[2], p.X);
	writeS16(&reply[4], p.Y);
	writeS16(&reply[6], p.Z);
	memcpy(&reply[8], *blockdata, blockdata.getSize());

	/*dstream<<"Sending block ("<<p.X<<","<<p.Y<<","<<p.Z<<")"
			<<":  \tpacket size: "<<replysize<<std::endl;*/
	
	/*
		Send packet
	*/
	m_con.Send(peer_id, 1, reply, true);
}

core::list<PlayerInfo> Server::getPlayerInfo()
{
	DSTACK(__FUNCTION_NAME);
	JMutexAutoLock envlock(m_env_mutex);
	JMutexAutoLock conlock(m_con_mutex);
	
	core::list<PlayerInfo> list;

	core::list<Player*> players = m_env.getPlayers();
	
	core::list<Player*>::Iterator i;
	for(i = players.begin();
			i != players.end(); i++)
	{
		PlayerInfo info;

		Player *player = *i;
		try{
			con::Peer *peer = m_con.GetPeer(player->peer_id);
			info.id = peer->id;
			info.address = peer->address;
			info.avg_rtt = peer->avg_rtt;
		}
		catch(con::PeerNotFoundException &e)
		{
			// Outdated peer info
			info.id = 0;
			info.address = Address(0,0,0,0,0);
			info.avg_rtt = 0.0;
		}

		snprintf(info.name, PLAYERNAME_SIZE, "%s", player->getName());
		info.position = player->getPosition();

		list.push_back(info);
	}

	return list;
}

void Server::peerAdded(con::Peer *peer)
{
	DSTACK(__FUNCTION_NAME);
	dout_server<<"Server::peerAdded(): peer->id="
			<<peer->id<<std::endl;
	
	PeerChange c;
	c.type = PEER_ADDED;
	c.peer_id = peer->id;
	c.timeout = false;
	m_peer_change_queue.push_back(c);

#if 0
	// NOTE: Connection is already locked when this is called.
	// NOTE: Environment is already locked when this is called.
	
	// Error check
	core::map<u16, RemoteClient*>::Node *n;
	n = m_clients.find(peer->id);
	// The client shouldn't already exist
	assert(n == NULL);

	// Create client
	RemoteClient *client = new RemoteClient();
	client->peer_id = peer->id;
	m_clients.insert(client->peer_id, client);

	// Create player
	{
		Player *player = m_env.getPlayer(peer->id);
		
		// The player shouldn't already exist
		assert(player == NULL);

		player = new ServerRemotePlayer();
		player->peer_id = peer->id;

		/*
			Set player position
		*/
		
		// We're going to throw the player to this position
		//v2s16 nodepos(29990,29990);
		//v2s16 nodepos(9990,9990);
		v2s16 nodepos(0,0);
		v2s16 sectorpos = getNodeSectorPos(nodepos);
		// Get zero sector (it could have been unloaded to disk)
		m_env.getMap().emergeSector(sectorpos);
		// Get ground height at origin
		f32 groundheight = m_env.getMap().getGroundHeight(nodepos, true);
		// The sector should have been generated -> groundheight exists
		assert(groundheight > GROUNDHEIGHT_VALID_MINVALUE);
		// Don't go underwater
		if(groundheight < WATER_LEVEL)
			groundheight = WATER_LEVEL;

		player->setPosition(intToFloat(v3s16(
				nodepos.X,
				groundheight + 1,
				nodepos.Y
		)));

		/*
			Add player to environment
		*/

		m_env.addPlayer(player);

		/*
			Add stuff to inventory
		*/
		
		if(g_settings.getBool("creative_mode"))
		{
			// Give a good pick
			{
				InventoryItem *item = new ToolItem("STPick", 32000);
				void* r = player->inventory.addItem("main", item);
				assert(r == NULL);
			}
			// Give all materials
			assert(USEFUL_CONTENT_COUNT <= PLAYER_INVENTORY_SIZE);
			for(u16 i=0; i<USEFUL_CONTENT_COUNT; i++)
			{
				// Skip some materials
				if(i == CONTENT_OCEAN)
					continue;

				InventoryItem *item = new MaterialItem(i, 1);
				player->inventory.addItem("main", item);
			}
			// Sign
			{
				InventoryItem *item = new MapBlockObjectItem("Sign Example text");
				void* r = player->inventory.addItem("main", item);
				assert(r == NULL);
			}
			/*// Rat
			{
				InventoryItem *item = new MapBlockObjectItem("Rat");
				bool r = player->inventory.addItem("main", item);
				assert(r == true);
			}*/
		}
		else
		{
			{
				InventoryItem *item = new CraftItem("Stick", 4);
				void* r = player->inventory.addItem("main", item);
				assert(r == NULL);
			}
			{
				InventoryItem *item = new ToolItem("WPick", 32000);
				void* r = player->inventory.addItem("main", item);
				assert(r == NULL);
			}
			{
				InventoryItem *item = new ToolItem("STPick", 32000);
				void* r = player->inventory.addItem("main", item);
				assert(r == NULL);
			}
			/*// Give some lights
			{
				InventoryItem *item = new MaterialItem(CONTENT_TORCH, 999);
				bool r = player->inventory.addItem("main", item);
				assert(r == true);
			}
			// and some signs
			for(u16 i=0; i<4; i++)
			{
				InventoryItem *item = new MapBlockObjectItem("Sign Example text");
				bool r = player->inventory.addItem("main", item);
				assert(r == true);
			}*/
			/*// Give some other stuff
			{
				InventoryItem *item = new MaterialItem(CONTENT_TREE, 999);
				bool r = player->inventory.addItem("main", item);
				assert(r == true);
			}*/
		}
	}
#endif
}

void Server::deletingPeer(con::Peer *peer, bool timeout)
{
	DSTACK(__FUNCTION_NAME);
	dout_server<<"Server::deletingPeer(): peer->id="
			<<peer->id<<", timeout="<<timeout<<std::endl;
	
	PeerChange c;
	c.type = PEER_REMOVED;
	c.peer_id = peer->id;
	c.timeout = timeout;
	m_peer_change_queue.push_back(c);

#if 0
	// NOTE: Connection is already locked when this is called.

	// NOTE: Environment is already locked when this is called.
	// NOTE: Locking environment cannot be moved here because connection
	//       is already locked and env has to be locked before

	// Error check
	core::map<u16, RemoteClient*>::Node *n;
	n = m_clients.find(peer->id);
	// The client should exist
	assert(n != NULL);
	
	// Send information about leaving in chat
	{
		std::wstring name = L"unknown";
		Player *player = m_env.getPlayer(peer->id);
		if(player != NULL)
			name = narrow_to_wide(player->getName());
		
		std::wstring message;
		message += L"*** ";
		message += name;
		message += L" left game";
		BroadcastChatMessage(message);
	}

	// Delete player
	{
		m_env.removePlayer(peer->id);
	}
	
	// Delete client
	delete m_clients[peer->id];
	m_clients.remove(peer->id);

	// Send player info to all clients
	SendPlayerInfos();
#endif
}

void Server::SendObjectData(float dtime)
{
	DSTACK(__FUNCTION_NAME);

	core::map<v3s16, bool> stepped_blocks;
	
	for(core::map<u16, RemoteClient*>::Iterator
		i = m_clients.getIterator();
		i.atEnd() == false; i++)
	{
		u16 peer_id = i.getNode()->getKey();
		RemoteClient *client = i.getNode()->getValue();
		assert(client->peer_id == peer_id);
		
		if(client->serialization_version == SER_FMT_VER_INVALID)
			continue;
		
		client->SendObjectData(this, dtime, stepped_blocks);
	}
}

void Server::SendPlayerInfos()
{
	DSTACK(__FUNCTION_NAME);

	//JMutexAutoLock envlock(m_env_mutex);
	
	core::list<Player*> players = m_env.getPlayers();
	
	u32 player_count = players.getSize();
	u32 datasize = 2+(2+PLAYERNAME_SIZE)*player_count;

	SharedBuffer<u8> data(datasize);
	writeU16(&data[0], TOCLIENT_PLAYERINFO);
	
	u32 start = 2;
	core::list<Player*>::Iterator i;
	for(i = players.begin();
			i != players.end(); i++)
	{
		Player *player = *i;

		/*dstream<<"Server sending player info for player with "
				"peer_id="<<player->peer_id<<std::endl;*/
		
		writeU16(&data[start], player->peer_id);
		snprintf((char*)&data[start+2], PLAYERNAME_SIZE, "%s", player->getName());
		start += 2+PLAYERNAME_SIZE;
	}

	//JMutexAutoLock conlock(m_con_mutex);

	// Send as reliable
	m_con.SendToAll(0, data, true);
}

void Server::SendInventory(u16 peer_id)
{
	DSTACK(__FUNCTION_NAME);
	
	Player* player = m_env.getPlayer(peer_id);

	/*
		Calculate crafting stuff
	*/

	InventoryList *clist = player->inventory.getList("craft");
	InventoryList *rlist = player->inventory.getList("craftresult");
	if(rlist)
	{
		rlist->clearItems();
	}
	if(clist && rlist)
	{
		InventoryItem *items[9];
		for(u16 i=0; i<9; i++)
		{
			items[i] = clist->getItem(i);
		}
		// Sign
		if(clist->getUsedSlots() == 1 && items[0])
		{
			if((std::string)items[0]->getName() == "MaterialItem")
			{
				MaterialItem *mitem = (MaterialItem*)items[0];
				if(mitem->getMaterial() == CONTENT_TREE)
				{
					rlist->addItem(new MapBlockObjectItem("Sign"));
				}
			}
		}
		// Torch
		if(clist->getUsedSlots() == 2 && items[0] && items[3])
		{
			if(
				   (std::string)items[0]->getName() == "MaterialItem"
				&& ((MaterialItem*)items[0])->getMaterial() == CONTENT_COALSTONE
				&& (std::string)items[3]->getName() == "MaterialItem"
				&& ((MaterialItem*)items[3])->getMaterial() == CONTENT_TREE
			)
			{
				rlist->addItem(new MaterialItem(CONTENT_TORCH, 4));
			}
		}
	}

	/*
		Serialize it
	*/

	std::ostringstream os;
	//os.imbue(std::locale("C"));

	player->inventory.serialize(os);

	std::string s = os.str();
	
	SharedBuffer<u8> data(s.size()+2);
	writeU16(&data[0], TOCLIENT_INVENTORY);
	memcpy(&data[2], s.c_str(), s.size());
	
	// Send as reliable
	m_con.Send(peer_id, 0, data, true);
}

void Server::SendChatMessage(u16 peer_id, const std::wstring &message)
{
	DSTACK(__FUNCTION_NAME);
	
	std::ostringstream os(std::ios_base::binary);
	u8 buf[12];
	
	// Write command
	writeU16(buf, TOCLIENT_CHAT_MESSAGE);
	os.write((char*)buf, 2);
	
	// Write length
	writeU16(buf, message.size());
	os.write((char*)buf, 2);
	
	// Write string
	for(u32 i=0; i<message.size(); i++)
	{
		u16 w = message[i];
		writeU16(buf, w);
		os.write((char*)buf, 2);
	}
	
	// Make data buffer
	std::string s = os.str();
	SharedBuffer<u8> data((u8*)s.c_str(), s.size());
	// Send as reliable
	m_con.Send(peer_id, 0, data, true);
}

void Server::BroadcastChatMessage(const std::wstring &message)
{
	for(core::map<u16, RemoteClient*>::Iterator
		i = m_clients.getIterator();
		i.atEnd() == false; i++)
	{
		// Get client and check that it is valid
		RemoteClient *client = i.getNode()->getValue();
		assert(client->peer_id == i.getNode()->getKey());
		if(client->serialization_version == SER_FMT_VER_INVALID)
			continue;

		SendChatMessage(client->peer_id, message);
	}
}

void Server::SendBlocks(float dtime)
{
	DSTACK(__FUNCTION_NAME);

	JMutexAutoLock envlock(m_env_mutex);

	core::array<PrioritySortedBlockTransfer> queue;

	s32 total_sending = 0;

	for(core::map<u16, RemoteClient*>::Iterator
		i = m_clients.getIterator();
		i.atEnd() == false; i++)
	{
		RemoteClient *client = i.getNode()->getValue();
		assert(client->peer_id == i.getNode()->getKey());

		total_sending += client->SendingCount();
		
		if(client->serialization_version == SER_FMT_VER_INVALID)
			continue;
		
		client->GetNextBlocks(this, dtime, queue);
	}

	// Sort.
	// Lowest priority number comes first.
	// Lowest is most important.
	queue.sort();

	JMutexAutoLock conlock(m_con_mutex);

	for(u32 i=0; i<queue.size(); i++)
	{
		//TODO: Calculate limit dynamically
		if(total_sending >= g_settings.getS32
				("max_simultaneous_block_sends_server_total"))
			break;
		
		PrioritySortedBlockTransfer q = queue[i];

		MapBlock *block = NULL;
		try
		{
			block = m_env.getMap().getBlockNoCreate(q.pos);
		}
		catch(InvalidPositionException &e)
		{
			continue;
		}

		RemoteClient *client = getClient(q.peer_id);

		SendBlockNoLock(q.peer_id, block, client->serialization_version);

		client->SentBlock(q.pos);

		total_sending++;
	}
}


RemoteClient* Server::getClient(u16 peer_id)
{
	DSTACK(__FUNCTION_NAME);
	//JMutexAutoLock lock(m_con_mutex);
	core::map<u16, RemoteClient*>::Node *n;
	n = m_clients.find(peer_id);
	// A client should exist for all peers
	assert(n != NULL);
	return n->getValue();
}

void Server::UpdateBlockWaterPressure(MapBlock *block,
			core::map<v3s16, MapBlock*> &modified_blocks)
{
	MapVoxelManipulator v(&m_env.getMap());
	v.m_disable_water_climb =
			g_settings.getBool("disable_water_climb");
	
	VoxelArea area(block->getPosRelative(),
			block->getPosRelative() + v3s16(1,1,1)*(MAP_BLOCKSIZE-1));

	try
	{
		v.updateAreaWaterPressure(area, m_flow_active_nodes);
	}
	catch(ProcessingLimitException &e)
	{
		dstream<<"Processing limit reached (1)"<<std::endl;
	}
	
	v.blitBack(modified_blocks);
}

void Server::handlePeerChange(PeerChange &c)
{
	JMutexAutoLock envlock(m_env_mutex);
	JMutexAutoLock conlock(m_con_mutex);
	
	if(c.type == PEER_ADDED)
	{
		/*
			Add
		*/

		// Error check
		core::map<u16, RemoteClient*>::Node *n;
		n = m_clients.find(c.peer_id);
		// The client shouldn't already exist
		assert(n == NULL);

		// Create client
		RemoteClient *client = new RemoteClient();
		client->peer_id = c.peer_id;
		m_clients.insert(client->peer_id, client);

		// Create player
		{
			Player *player = m_env.getPlayer(c.peer_id);
			
			// The player shouldn't already exist
			assert(player == NULL);

			player = new ServerRemotePlayer();
			player->peer_id = c.peer_id;

			/*
				Set player position
			*/
			
			// We're going to throw the player to this position
			//v2s16 nodepos(29990,29990);
			//v2s16 nodepos(9990,9990);
			v2s16 nodepos(0,0);
			v2s16 sectorpos = getNodeSectorPos(nodepos);
			// Get zero sector (it could have been unloaded to disk)
			m_env.getMap().emergeSector(sectorpos);
			// Get ground height at origin
			f32 groundheight = m_env.getMap().getGroundHeight(nodepos, true);
			// The sector should have been generated -> groundheight exists
			assert(groundheight > GROUNDHEIGHT_VALID_MINVALUE);
			// Don't go underwater
			if(groundheight < WATER_LEVEL)
				groundheight = WATER_LEVEL;

			player->setPosition(intToFloat(v3s16(
					nodepos.X,
					groundheight + 1,
					nodepos.Y
			)));

			/*
				Add player to environment
			*/

			m_env.addPlayer(player);

			/*
				Add stuff to inventory
			*/
			
			if(g_settings.getBool("creative_mode"))
			{
				// Give a good pick
				{
					InventoryItem *item = new ToolItem("STPick", 32000);
					void* r = player->inventory.addItem("main", item);
					assert(r == NULL);
				}
				// Give all materials
				assert(USEFUL_CONTENT_COUNT <= PLAYER_INVENTORY_SIZE);
				for(u16 i=0; i<USEFUL_CONTENT_COUNT; i++)
				{
					// Skip some materials
					if(i == CONTENT_OCEAN)
						continue;

					InventoryItem *item = new MaterialItem(i, 1);
					player->inventory.addItem("main", item);
				}
				// Sign
				{
					InventoryItem *item = new MapBlockObjectItem("Sign Example text");
					void* r = player->inventory.addItem("main", item);
					assert(r == NULL);
				}
				/*// Rat
				{
					InventoryItem *item = new MapBlockObjectItem("Rat");
					bool r = player->inventory.addItem("main", item);
					assert(r == true);
				}*/
			}
			else
			{
				{
					InventoryItem *item = new CraftItem("Stick", 4);
					void* r = player->inventory.addItem("main", item);
					assert(r == NULL);
				}
				{
					InventoryItem *item = new ToolItem("WPick", 32000);
					void* r = player->inventory.addItem("main", item);
					assert(r == NULL);
				}
				{
					InventoryItem *item = new ToolItem("STPick", 32000);
					void* r = player->inventory.addItem("main", item);
					assert(r == NULL);
				}
				/*// Give some lights
				{
					InventoryItem *item = new MaterialItem(CONTENT_TORCH, 999);
					bool r = player->inventory.addItem("main", item);
					assert(r == true);
				}
				// and some signs
				for(u16 i=0; i<4; i++)
				{
					InventoryItem *item = new MapBlockObjectItem("Sign Example text");
					bool r = player->inventory.addItem("main", item);
					assert(r == true);
				}*/
				/*// Give some other stuff
				{
					InventoryItem *item = new MaterialItem(CONTENT_TREE, 999);
					bool r = player->inventory.addItem("main", item);
					assert(r == true);
				}*/
			}
		}

	} // PEER_ADDED
	else if(c.type == PEER_REMOVED)
	{
		/*
			Delete
		*/

		// Error check
		core::map<u16, RemoteClient*>::Node *n;
		n = m_clients.find(c.peer_id);
		// The client should exist
		assert(n != NULL);
		
		// Collect information about leaving in chat
		std::wstring message;
		{
			std::wstring name = L"unknown";
			Player *player = m_env.getPlayer(c.peer_id);
			if(player != NULL)
				name = narrow_to_wide(player->getName());
			
			message += L"*** ";
			message += name;
			message += L" left game";
		}

		// Delete player
		{
			m_env.removePlayer(c.peer_id);
		}
		
		// Delete client
		delete m_clients[c.peer_id];
		m_clients.remove(c.peer_id);

		// Send player info to all remaining clients
		SendPlayerInfos();
		
		// Send leave chat message to all remaining clients
		BroadcastChatMessage(message);
		
	} // PEER_REMOVED
	else
	{
		assert(0);
	}
}

void Server::handlePeerChanges()
{
	while(m_peer_change_queue.size() > 0)
	{
		PeerChange c = m_peer_change_queue.pop_front();

		dout_server<<"Server: Handling peer change: "
				<<"id="<<c.peer_id<<", timeout="<<c.timeout
				<<std::endl;

		handlePeerChange(c);
	}
}