minetest/src/utility.h

/*
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.
*/

#ifndef UTILITY_HEADER
#define UTILITY_HEADER

#include <iostream>
#include <fstream>
#include <string>
#include <sstream>
#include <vector>
#include <jthread.h>
#include <jmutex.h>
#include <jmutexautolock.h>

#include "common_irrlicht.h"
#include "debug.h"
#include "strfnd.h"
#include "exceptions.h"
#include "porting.h"

extern const v3s16 g_6dirs[6];

extern const v3s16 g_26dirs[26];

// 26th is (0,0,0)
extern const v3s16 g_27dirs[27];

inline void writeU64(u8 *data, u64 i)
{
	data[0] = ((i>>56)&0xff);
	data[1] = ((i>>48)&0xff);
	data[2] = ((i>>40)&0xff);
	data[3] = ((i>>32)&0xff);
	data[4] = ((i>>24)&0xff);
	data[5] = ((i>>16)&0xff);
	data[6] = ((i>> 8)&0xff);
	data[7] = ((i>> 0)&0xff);
}

inline void writeU32(u8 *data, u32 i)
{
	data[0] = ((i>>24)&0xff);
	data[1] = ((i>>16)&0xff);
	data[2] = ((i>> 8)&0xff);
	data[3] = ((i>> 0)&0xff);
}

inline void writeU16(u8 *data, u16 i)
{
	data[0] = ((i>> 8)&0xff);
	data[1] = ((i>> 0)&0xff);
}

inline void writeU8(u8 *data, u8 i)
{
	data[0] = ((i>> 0)&0xff);
}

inline u64 readU64(u8 *data)
{
	return ((u64)data[0]<<56) | ((u64)data[1]<<48)
		| ((u64)data[2]<<40) | ((u64)data[3]<<32)
		| ((u64)data[4]<<24) | ((u64)data[5]<<16)
		| ((u64)data[6]<<8) | ((u64)data[7]<<0);
}

inline u32 readU32(u8 *data)
{
	return (data[0]<<24) | (data[1]<<16) | (data[2]<<8) | (data[3]<<0);
}

inline u16 readU16(u8 *data)
{
	return (data[0]<<8) | (data[1]<<0);
}

inline u8 readU8(u8 *data)
{
	return (data[0]<<0);
}

inline void writeS32(u8 *data, s32 i){
	writeU32(data, (u32)i);
}
inline s32 readS32(u8 *data){
	return (s32)readU32(data);
}

inline void writeF1000(u8 *data, f32 i){
	writeS32(data, i*1000);
}
inline f32 readF1000(u8 *data){
	return (f32)readS32(data)/1000.;
}

inline void writeS16(u8 *data, s16 i){
	writeU16(data, (u16)i);
}
inline s16 readS16(u8 *data){
	return (s16)readU16(data);
}

inline void writeV3S32(u8 *data, v3s32 p)
{
	writeS32(&data[0], p.X);
	writeS32(&data[4], p.Y);
	writeS32(&data[8], p.Z);
}
inline v3s32 readV3S32(u8 *data)
{
	v3s32 p;
	p.X = readS32(&data[0]);
	p.Y = readS32(&data[4]);
	p.Z = readS32(&data[8]);
	return p;
}

inline void writeV3F1000(u8 *data, v3f p)
{
	writeF1000(&data[0], p.X);
	writeF1000(&data[4], p.Y);
	writeF1000(&data[8], p.Z);
}
inline v3f readV3F1000(u8 *data)
{
	v3f p;
	p.X = (float)readF1000(&data[0]);
	p.Y = (float)readF1000(&data[4]);
	p.Z = (float)readF1000(&data[8]);
	return p;
}

inline void writeV2S16(u8 *data, v2s16 p)
{
	writeS16(&data[0], p.X);
	writeS16(&data[2], p.Y);
}

inline v2s16 readV2S16(u8 *data)
{
	v2s16 p;
	p.X = readS16(&data[0]);
	p.Y = readS16(&data[2]);
	return p;
}

inline void writeV2S32(u8 *data, v2s32 p)
{
	writeS32(&data[0], p.X);
	writeS32(&data[2], p.Y);
}

inline v2s32 readV2S32(u8 *data)
{
	v2s32 p;
	p.X = readS32(&data[0]);
	p.Y = readS32(&data[2]);
	return p;
}

inline void writeV3S16(u8 *data, v3s16 p)
{
	writeS16(&data[0], p.X);
	writeS16(&data[2], p.Y);
	writeS16(&data[4], p.Z);
}

inline v3s16 readV3S16(u8 *data)
{
	v3s16 p;
	p.X = readS16(&data[0]);
	p.Y = readS16(&data[2]);
	p.Z = readS16(&data[4]);
	return p;
}

/*
	The above stuff directly interfaced to iostream
*/

inline void writeU8(std::ostream &os, u8 p)
{
	char buf[1];
	writeU8((u8*)buf, p);
	os.write(buf, 1);
}
inline u8 readU8(std::istream &is)
{
	char buf[1];
	is.read(buf, 1);
	return readU8((u8*)buf);
}

inline void writeU16(std::ostream &os, u16 p)
{
	char buf[2];
	writeU16((u8*)buf, p);
	os.write(buf, 2);
}
inline u16 readU16(std::istream &is)
{
	char buf[2];
	is.read(buf, 2);
	return readU16((u8*)buf);
}

inline void writeU32(std::ostream &os, u16 p)
{
	char buf[4];
	writeU16((u8*)buf, p);
	os.write(buf, 4);
}
inline u16 readU32(std::istream &is)
{
	char buf[4];
	is.read(buf, 4);
	return readU32((u8*)buf);
}

inline void writeF1000(std::ostream &os, f32 p)
{
	char buf[2];
	writeF1000((u8*)buf, p);
	os.write(buf, 2);
}
inline f32 readF1000(std::istream &is)
{
	char buf[2];
	is.read(buf, 2);
	// TODO: verify if this gets rid of the valgrind warning
	//if(is.gcount() != 2)
	//	return 0;
	return readF1000((u8*)buf);
}

inline void writeV3F1000(std::ostream &os, v3f p)
{
	char buf[12];
	writeV3F1000((u8*)buf, p);
	os.write(buf, 12);
}
inline v3f readV3F1000(std::istream &is)
{
	char buf[12];
	is.read(buf, 12);
	return readV3F1000((u8*)buf);
}

/*
	None of these are used at the moment
*/

template <typename T>
class SharedPtr
{
public:
	SharedPtr(T *t=NULL)
	{
		refcount = new int;
		*refcount = 1;
		ptr = t;
	}
	SharedPtr(SharedPtr<T> &t)
	{
		//*this = t;
		drop();
		refcount = t.refcount;
		(*refcount)++;
		ptr = t.ptr;
	}
	~SharedPtr()
	{
		drop();
	}
	SharedPtr<T> & operator=(T *t)
	{
		drop();
		refcount = new int;
		*refcount = 1;
		ptr = t;
		return *this;
	}
	SharedPtr<T> & operator=(SharedPtr<T> &t)
	{
		drop();
		refcount = t.refcount;
		(*refcount)++;
		ptr = t.ptr;
		return *this;
	}
	T* operator->()
	{
		return ptr;
	}
	T & operator*()
	{
		return *ptr;
	}
	bool operator!=(T *t)
	{
		return ptr != t;
	}
	bool operator==(T *t)
	{
		return ptr == t;
	}
	T & operator[](unsigned int i)
	{
		return ptr[i];
	}
private:
	void drop()
	{
		assert((*refcount) > 0);
		(*refcount)--;
		if(*refcount == 0)
		{
			delete refcount;
			if(ptr != NULL)
				delete ptr;
		}
	}
	T *ptr;
	int *refcount;
};

template <typename T>
class Buffer
{
public:
	Buffer(unsigned int size)
	{
		m_size = size;
		data = new T[size];
	}
	Buffer(const Buffer &buffer)
	{
		m_size = buffer.m_size;
		data = new T[buffer.m_size];
		memcpy(data, buffer.data, buffer.m_size);
	}
	Buffer(T *t, unsigned int size)
	{
		m_size = size;
		data = new T[size];
		memcpy(data, t, size);
	}
	~Buffer()
	{
		delete[] data;
	}
	T & operator[](unsigned int i) const
	{
		return data[i];
	}
	T * operator*() const
	{
		return data;
	}
	unsigned int getSize() const
	{
		return m_size;
	}
private:
	T *data;
	unsigned int m_size;
};

template <typename T>
class SharedBuffer
{
public:
	SharedBuffer()
	{
		m_size = 0;
		data = NULL;
		refcount = new unsigned int;
		(*refcount) = 1;
	}
	SharedBuffer(unsigned int size)
	{
		m_size = size;
		if(m_size != 0)
			data = new T[m_size];
		else
			data = NULL;
		refcount = new unsigned int;
		(*refcount) = 1;
	}
	SharedBuffer(const SharedBuffer &buffer)
	{
		//std::cout<<"SharedBuffer(const SharedBuffer &buffer)"<<std::endl;
		m_size = buffer.m_size;
		data = buffer.data;
		refcount = buffer.refcount;
		(*refcount)++;
	}
	SharedBuffer & operator=(const SharedBuffer & buffer)
	{
		//std::cout<<"SharedBuffer & operator=(const SharedBuffer & buffer)"<<std::endl;
		if(this == &buffer)
			return *this;
		drop();
		m_size = buffer.m_size;
		data = buffer.data;
		refcount = buffer.refcount;
		(*refcount)++;
		return *this;
	}
	/*
		Copies whole buffer
	*/
	SharedBuffer(T *t, unsigned int size)
	{
		m_size = size;
		if(m_size != 0)
		{
			data = new T[m_size];
			memcpy(data, t, m_size);
		}
		else
			data = NULL;
		refcount = new unsigned int;
		(*refcount) = 1;
	}
	/*
		Copies whole buffer
	*/
	SharedBuffer(const Buffer<T> &buffer)
	{
		m_size = buffer.getSize();
		if(m_size != 0)
		{
			data = new T[m_size];
			memcpy(data, *buffer, buffer.getSize());
		}
		else
			data = NULL;
		refcount = new unsigned int;
		(*refcount) = 1;
	}
	~SharedBuffer()
	{
		drop();
	}
	T & operator[](unsigned int i) const
	{
		//assert(i < m_size)
		return data[i];
	}
	T * operator*() const
	{
		return data;
	}
	unsigned int getSize() const
	{
		return m_size;
	}
private:
	void drop()
	{
		assert((*refcount) > 0);
		(*refcount)--;
		if(*refcount == 0)
		{
			if(data)
				delete[] data;
			delete refcount;
		}
	}
	T *data;
	unsigned int m_size;
	unsigned int *refcount;
};

inline SharedBuffer<u8> SharedBufferFromString(const char *string)
{
	SharedBuffer<u8> b((u8*)string, strlen(string)+1);
	return b;
}

template<typename T>
class MutexedVariable
{
public:
	MutexedVariable(T value):
		m_value(value)
	{
		m_mutex.Init();
	}

	T get()
	{
		JMutexAutoLock lock(m_mutex);
		return m_value;
	}

	void set(T value)
	{
		JMutexAutoLock lock(m_mutex);
		m_value = value;
	}
	
	// You'll want to grab this in a SharedPtr
	JMutexAutoLock * getLock()
	{
		return new JMutexAutoLock(m_mutex);
	}
	
	// You pretty surely want to grab the lock when accessing this
	T m_value;

private:
	JMutex m_mutex;
};

/*
	TimeTaker
*/

class TimeTaker
{
public:
	TimeTaker(const char *name, u32 *result=NULL);

	~TimeTaker()
	{
		stop();
	}

	u32 stop(bool quiet=false);

	u32 getTime();

private:
	const char *m_name;
	u32 m_time1;
	bool m_running;
	u32 *m_result;
};

// Calculates the borders of a "d-radius" cube
inline void getFacePositions(core::list<v3s16> &list, u16 d)
{
	if(d == 0)
	{
		list.push_back(v3s16(0,0,0));
		return;
	}
	if(d == 1)
	{
		/*
			This is an optimized sequence of coordinates.
		*/
		list.push_back(v3s16( 0, 1, 0)); // top
		list.push_back(v3s16( 0, 0, 1)); // back
		list.push_back(v3s16(-1, 0, 0)); // left
		list.push_back(v3s16( 1, 0, 0)); // right
		list.push_back(v3s16( 0, 0,-1)); // front
		list.push_back(v3s16( 0,-1, 0)); // bottom
		// 6
		list.push_back(v3s16(-1, 0, 1)); // back left
		list.push_back(v3s16( 1, 0, 1)); // back right
		list.push_back(v3s16(-1, 0,-1)); // front left
		list.push_back(v3s16( 1, 0,-1)); // front right
		list.push_back(v3s16(-1,-1, 0)); // bottom left
		list.push_back(v3s16( 1,-1, 0)); // bottom right
		list.push_back(v3s16( 0,-1, 1)); // bottom back
		list.push_back(v3s16( 0,-1,-1)); // bottom front
		list.push_back(v3s16(-1, 1, 0)); // top left
		list.push_back(v3s16( 1, 1, 0)); // top right
		list.push_back(v3s16( 0, 1, 1)); // top back
		list.push_back(v3s16( 0, 1,-1)); // top front
		// 18
		list.push_back(v3s16(-1, 1, 1)); // top back-left
		list.push_back(v3s16( 1, 1, 1)); // top back-right
		list.push_back(v3s16(-1, 1,-1)); // top front-left
		list.push_back(v3s16( 1, 1,-1)); // top front-right
		list.push_back(v3s16(-1,-1, 1)); // bottom back-left
		list.push_back(v3s16( 1,-1, 1)); // bottom back-right
		list.push_back(v3s16(-1,-1,-1)); // bottom front-left
		list.push_back(v3s16( 1,-1,-1)); // bottom front-right
		// 26
		return;
	}

	// Take blocks in all sides, starting from y=0 and going +-y
	for(s16 y=0; y<=d-1; y++)
	{
		// Left and right side, including borders
		for(s16 z=-d; z<=d; z++)
		{
			list.push_back(v3s16(d,y,z));
			list.push_back(v3s16(-d,y,z));
			if(y != 0)
			{
				list.push_back(v3s16(d,-y,z));
				list.push_back(v3s16(-d,-y,z));
			}
		}
		// Back and front side, excluding borders
		for(s16 x=-d+1; x<=d-1; x++)
		{
			list.push_back(v3s16(x,y,d));
			list.push_back(v3s16(x,y,-d));
			if(y != 0)
			{
				list.push_back(v3s16(x,-y,d));
				list.push_back(v3s16(x,-y,-d));
			}
		}
	}

	// Take the bottom and top face with borders
	// -d<x<d, y=+-d, -d<z<d
	for(s16 x=-d; x<=d; x++)
	for(s16 z=-d; z<=d; z++)
	{
		list.push_back(v3s16(x,-d,z));
		list.push_back(v3s16(x,d,z));
	}
}

class IndentationRaiser
{
public:
	IndentationRaiser(u16 *indentation)
	{
		m_indentation = indentation;
		(*m_indentation)++;
	}
	~IndentationRaiser()
	{
		(*m_indentation)--;
	}
private:
	u16 *m_indentation;
};

inline s16 getContainerPos(s16 p, s16 d)
{
	return (p>=0 ? p : p-d+1) / d;
}

inline v2s16 getContainerPos(v2s16 p, s16 d)
{
	return v2s16(
		getContainerPos(p.X, d),
		getContainerPos(p.Y, d)
	);
}

inline v3s16 getContainerPos(v3s16 p, s16 d)
{
	return v3s16(
		getContainerPos(p.X, d),
		getContainerPos(p.Y, d),
		getContainerPos(p.Z, d)
	);
}

inline v2s16 getContainerPos(v2s16 p, v2s16 d)
{
	return v2s16(
		getContainerPos(p.X, d.X),
		getContainerPos(p.Y, d.Y)
	);
}

inline v3s16 getContainerPos(v3s16 p, v3s16 d)
{
	return v3s16(
		getContainerPos(p.X, d.X),
		getContainerPos(p.Y, d.Y),
		getContainerPos(p.Z, d.Z)
	);
}

inline bool isInArea(v3s16 p, s16 d)
{
	return (
		p.X >= 0 && p.X < d &&
		p.Y >= 0 && p.Y < d &&
		p.Z >= 0 && p.Z < d
	);
}

inline bool isInArea(v2s16 p, s16 d)
{
	return (
		p.X >= 0 && p.X < d &&
		p.Y >= 0 && p.Y < d
	);
}

inline bool isInArea(v3s16 p, v3s16 d)
{
	return (
		p.X >= 0 && p.X < d.X &&
		p.Y >= 0 && p.Y < d.Y &&
		p.Z >= 0 && p.Z < d.Z
	);
}

inline s16 rangelim(s16 i, s16 max)
{
	if(i < 0)
		return 0;
	if(i > max)
		return max;
	return i;
}

#define rangelim(d, min, max) ((d) < (min) ? (min) : ((d)>(max)?(max):(d)))

inline v3s16 arealim(v3s16 p, s16 d)
{
	if(p.X < 0)
		p.X = 0;
	if(p.Y < 0)
		p.Y = 0;
	if(p.Z < 0)
		p.Z = 0;
	if(p.X > d-1)
		p.X = d-1;
	if(p.Y > d-1)
		p.Y = d-1;
	if(p.Z > d-1)
		p.Z = d-1;
	return p;
}

inline std::wstring narrow_to_wide(const std::string& mbs)
{
	size_t wcl = mbs.size();
	Buffer<wchar_t> wcs(wcl+1);
	size_t l = mbstowcs(*wcs, mbs.c_str(), wcl);
	if(l == (size_t)(-1))
		return L"<invalid multibyte string>";
	wcs[l] = 0;
	return *wcs;
}

inline std::string wide_to_narrow(const std::wstring& wcs)
{
	size_t mbl = wcs.size()*4;
	SharedBuffer<char> mbs(mbl+1);
	size_t l = wcstombs(*mbs, wcs.c_str(), mbl);
	if(l == (size_t)(-1))
		mbs[0] = 0;
	else
		mbs[l] = 0;
	return *mbs;
}

// Split a string using the given delimiter. Returns a vector containing
// the component parts.
inline std::vector<std::wstring> str_split(const std::wstring &str, wchar_t delimiter)
{
	std::vector<std::wstring> parts;
	std::wstringstream sstr(str);
	std::wstring part;
	while(std::getline(sstr, part, delimiter))
		parts.push_back(part);
	return parts;
}


/*
	See test.cpp for example cases.
	wraps degrees to the range of -360...360
	NOTE: Wrapping to 0...360 is not used because pitch needs negative values.
*/
inline float wrapDegrees(float f)
{
	// Take examples of f=10, f=720.5, f=-0.5, f=-360.5
	// This results in
	// 10, 720, -1, -361
	int i = floor(f);
	// 0, 2, 0, -1
	int l = i / 360;
	// NOTE: This would be used for wrapping to 0...360
	// 0, 2, -1, -2
	/*if(i < 0)
		l -= 1;*/
	// 0, 720, 0, -360
	int k = l * 360;
	// 10, 0.5, -0.5, -0.5
	f -= float(k);
	return f;
}

inline std::string lowercase(const std::string &s)
{
	std::string s2;
	for(size_t i=0; i<s.size(); i++)
	{
		char c = s[i];
		if(c >= 'A' && c <= 'Z')
			c -= 'A' - 'a';
		s2 += c;
	}
	return s2;
}

inline bool is_yes(const std::string &s)
{
	std::string s2 = lowercase(trim(s));
	if(s2 == "y" || s2 == "yes" || s2 == "true" || s2 == "1")
		return true;
	return false;
}

inline s32 stoi(const std::string &s, s32 min, s32 max)
{
	s32 i = atoi(s.c_str());
	if(i < min)
		i = min;
	if(i > max)
		i = max;
	return i;
}


// MSVC2010 includes it's own versions of these
#if !defined(_MSC_VER) || _MSC_VER < 1600

inline s32 stoi(std::string s)
{
	return atoi(s.c_str());
}

inline s32 stoi(std::wstring s)
{
	return atoi(wide_to_narrow(s).c_str());
}

inline float stof(std::string s)
{
	float f;
	std::istringstream ss(s);
	ss>>f;
	return f;
}

#endif

inline std::string itos(s32 i)
{
	std::ostringstream o;
	o<<i;
	return o.str();
}

inline std::string ftos(float f)
{
	std::ostringstream o;
	o<<f;
	return o.str();
}

inline void str_replace(std::string & str, std::string const & pattern,
		std::string const & replacement)
{
	std::string::size_type start = str.find(pattern, 0);
	while(start != str.npos)
	{
		str.replace(start, pattern.size(), replacement);
		start = str.find(pattern, start+replacement.size());
	}
}

inline void str_replace_char(std::string & str, char from, char to)
{
	for(unsigned int i=0; i<str.size(); i++)
	{
		if(str[i] == from)
			str[i] = to;
	}
}

/*
	A base class for simple background thread implementation
*/

class SimpleThread : public JThread
{
	bool run;
	JMutex run_mutex;

public:

	SimpleThread():
		JThread(),
		run(true)
	{
		run_mutex.Init();
	}

	virtual ~SimpleThread()
	{}

	virtual void * Thread() = 0;

	bool getRun()
	{
		JMutexAutoLock lock(run_mutex);
		return run;
	}
	void setRun(bool a_run)
	{
		JMutexAutoLock lock(run_mutex);
		run = a_run;
	}

	void stop()
	{
		setRun(false);
		while(IsRunning())
			sleep_ms(100);
	}
};

/*
	Config stuff
*/

enum ValueType
{
	VALUETYPE_STRING,
	VALUETYPE_FLAG // Doesn't take any arguments
};

struct ValueSpec
{
	ValueSpec(ValueType a_type, const char *a_help=NULL)
	{
		type = a_type;
		help = a_help;
	}
	ValueType type;
	const char *help;
};

class Settings
{
public:
	Settings()
	{
		m_mutex.Init();
	}

	void writeLines(std::ostream &os)
	{
		JMutexAutoLock lock(m_mutex);
		
		for(core::map<std::string, std::string>::Iterator
				i = m_settings.getIterator();
				i.atEnd() == false; i++)
		{
			std::string name = i.getNode()->getKey();
			std::string value = i.getNode()->getValue();
			os<<name<<" = "<<value<<"\n";
		}
	}

	bool parseConfigLine(const std::string &line)
	{
		JMutexAutoLock lock(m_mutex);
		
		std::string trimmedline = trim(line);
		
		// Ignore comments
		if(trimmedline[0] == '#')
			return true;

		//dstream<<"trimmedline=\""<<trimmedline<<"\""<<std::endl;

		Strfnd sf(trim(line));

		std::string name = sf.next("=");
		name = trim(name);

		if(name == "")
			return true;
		
		std::string value = sf.next("\n");
		value = trim(value);

		/*dstream<<"Config name=\""<<name<<"\" value=\""
				<<value<<"\""<<std::endl;*/
		
		m_settings[name] = value;
		
		return true;
	}

	// Returns false on EOF
	bool parseConfigObject(std::istream &is)
	{
		if(is.eof())
			return false;
		
		/*
			NOTE: This function might be expanded to allow multi-line
			      settings.
		*/
		std::string line;
		std::getline(is, line);
		//dstream<<"got line: \""<<line<<"\""<<std::endl;

		return parseConfigLine(line);
	}

	/*
		Read configuration file

		Returns true on success
	*/
	bool readConfigFile(const char *filename)
	{
		std::ifstream is(filename);
		if(is.good() == false)
		{
			dstream<<"Error opening configuration file \""
					<<filename<<"\""<<std::endl;
			return false;
		}

		dstream<<"Parsing configuration file: \""
				<<filename<<"\""<<std::endl;
				
		while(parseConfigObject(is));
		
		return true;
	}

	/*
		Reads a configuration object from stream (usually a single line)
		and adds it to dst.
		
		Preserves comments and empty lines.

		Settings that were added to dst are also added to updated.
		key of updated is setting name, value of updated is dummy.

		Returns false on EOF
	*/
	bool getUpdatedConfigObject(std::istream &is,
			core::list<std::string> &dst,
			core::map<std::string, bool> &updated)
	{
		JMutexAutoLock lock(m_mutex);
		
		if(is.eof())
			return false;
		
		// NOTE: This function will be expanded to allow multi-line settings
		std::string line;
		std::getline(is, line);

		std::string trimmedline = trim(line);

		std::string line_end = "";
		if(is.eof() == false)
			line_end = "\n";
		
		// Ignore comments
		if(trimmedline[0] == '#')
		{
			dst.push_back(line+line_end);
			return true;
		}

		Strfnd sf(trim(line));

		std::string name = sf.next("=");
		name = trim(name);

		if(name == "")
		{
			dst.push_back(line+line_end);
			return true;
		}
		
		std::string value = sf.next("\n");
		value = trim(value);
		
		if(m_settings.find(name))
		{
			std::string newvalue = m_settings[name];
			
			if(newvalue != value)
			{
				dstream<<"Changing value of \""<<name<<"\" = \""
						<<value<<"\" -> \""<<newvalue<<"\""
						<<std::endl;
			}

			dst.push_back(name + " = " + newvalue + line_end);

			updated[name] = true;
		}
		
		return true;
	}

	/*
		Updates configuration file

		Returns true on success
	*/
	bool updateConfigFile(const char *filename)
	{
		dstream<<"Updating configuration file: \""
				<<filename<<"\""<<std::endl;
		
		core::list<std::string> objects;
		core::map<std::string, bool> updated;
		
		// Read and modify stuff
		{
			std::ifstream is(filename);
			if(is.good() == false)
			{
				dstream<<"INFO: updateConfigFile():"
						" Error opening configuration file"
						" for reading: \""
						<<filename<<"\""<<std::endl;
			}
			else
			{
				while(getUpdatedConfigObject(is, objects, updated));
			}
		}
		
		JMutexAutoLock lock(m_mutex);
		
		// Write stuff back
		{
			std::ofstream os(filename);
			if(os.good() == false)
			{
				dstream<<"Error opening configuration file"
						" for writing: \""
						<<filename<<"\""<<std::endl;
				return false;
			}
			
			/*
				Write updated stuff
			*/
			for(core::list<std::string>::Iterator
					i = objects.begin();
					i != objects.end(); i++)
			{
				os<<(*i);
			}

			/*
				Write stuff that was not already in the file
			*/
			for(core::map<std::string, std::string>::Iterator
					i = m_settings.getIterator();
					i.atEnd() == false; i++)
			{
				if(updated.find(i.getNode()->getKey()))
					continue;
				std::string name = i.getNode()->getKey();
				std::string value = i.getNode()->getValue();
				dstream<<"Adding \""<<name<<"\" = \""<<value<<"\""
						<<std::endl;
				os<<name<<" = "<<value<<"\n";
			}
		}
		
		return true;
	}

	/*
		NOTE: Types of allowed_options are ignored

		returns true on success
	*/
	bool parseCommandLine(int argc, char *argv[],
			core::map<std::string, ValueSpec> &allowed_options)
	{
		int i=1;
		for(;;)
		{
			if(i >= argc)
				break;
			std::string argname = argv[i];
			if(argname.substr(0, 2) != "--")
			{
				dstream<<"Invalid command-line parameter \""
						<<argname<<"\": --<option> expected."<<std::endl;
				return false;
			}
			i++;

			std::string name = argname.substr(2);

			core::map<std::string, ValueSpec>::Node *n;
			n = allowed_options.find(name);
			if(n == NULL)
			{
				dstream<<"Unknown command-line parameter \""
						<<argname<<"\""<<std::endl;
				return false;
			}

			ValueType type = n->getValue().type;

			std::string value = "";
			
			if(type == VALUETYPE_FLAG)
			{
				value = "true";
			}
			else
			{
				if(i >= argc)
				{
					dstream<<"Invalid command-line parameter \""
							<<name<<"\": missing value"<<std::endl;
					return false;
				}
				value = argv[i];
				i++;
			}
			

			dstream<<"Valid command-line parameter: \""
					<<name<<"\" = \""<<value<<"\""
					<<std::endl;
			set(name, value);
		}

		return true;
	}

	void set(std::string name, std::string value)
	{
		JMutexAutoLock lock(m_mutex);
		
		m_settings[name] = value;
	}

	void setDefault(std::string name, std::string value)
	{
		JMutexAutoLock lock(m_mutex);
		
		m_defaults[name] = value;
	}

	bool exists(std::string name)
	{
		JMutexAutoLock lock(m_mutex);
		
		return (m_settings.find(name) || m_defaults.find(name));
	}

	std::string get(std::string name)
	{
		JMutexAutoLock lock(m_mutex);
		
		core::map<std::string, std::string>::Node *n;
		n = m_settings.find(name);
		if(n == NULL)
		{
			n = m_defaults.find(name);
			if(n == NULL)
			{
				dstream<<"INFO: Settings: Setting not found: \""
						<<name<<"\""<<std::endl;
				throw SettingNotFoundException("Setting not found");
			}
		}

		return n->getValue();
	}

	bool getBool(std::string name)
	{
		return is_yes(get(name));
	}
	
	bool getFlag(std::string name)
	{
		try
		{
			return getBool(name);
		}
		catch(SettingNotFoundException &e)
		{
			return false;
		}
	}

	// Asks if empty
	bool getBoolAsk(std::string name, std::string question, bool def)
	{
		// If it is in settings
		if(exists(name))
			return getBool(name);
		
		std::string s;
		char templine[10];
		std::cout<<question<<" [y/N]: ";
		std::cin.getline(templine, 10);
		s = templine;

		if(s == "")
			return def;

		return is_yes(s);
	}

	float getFloat(std::string name)
	{
		return stof(get(name));
	}

	u16 getU16(std::string name)
	{
		return stoi(get(name), 0, 65535);
	}

	u16 getU16Ask(std::string name, std::string question, u16 def)
	{
		// If it is in settings
		if(exists(name))
			return getU16(name);
		
		std::string s;
		char templine[10];
		std::cout<<question<<" ["<<def<<"]: ";
		std::cin.getline(templine, 10);
		s = templine;

		if(s == "")
			return def;

		return stoi(s, 0, 65535);
	}

	s16 getS16(std::string name)
	{
		return stoi(get(name), -32768, 32767);
	}

	s32 getS32(std::string name)
	{
		return stoi(get(name));
	}

	v3f getV3F(std::string name)
	{
		v3f value;
		Strfnd f(get(name));
		f.next("(");
		value.X = stof(f.next(","));
		value.Y = stof(f.next(","));
		value.Z = stof(f.next(")"));
		return value;
	}

	u64 getU64(std::string name)
	{
		u64 value = 0;
		std::string s = get(name);
		std::istringstream ss(s);
		ss>>value;
		return value;
	}

	void setBool(std::string name, bool value)
	{
		if(value)
			set(name, "true");
		else
			set(name, "false");
	}

	void setS32(std::string name, s32 value)
	{
		set(name, itos(value));
	}

	void setFloat(std::string name, float value)
	{
		set(name, ftos(value));
	}

	void setV3F(std::string name, v3f value)
	{
		std::ostringstream os;
		os<<"("<<value.X<<","<<value.Y<<","<<value.Z<<")";
		set(name, os.str());
	}

	void setU64(std::string name, u64 value)
	{
		std::ostringstream os;
		os<<value;
		set(name, os.str());
	}

	void clear()
	{
		JMutexAutoLock lock(m_mutex);
		
		m_settings.clear();
		m_defaults.clear();
	}

	Settings & operator+=(Settings &other)
	{
		JMutexAutoLock lock(m_mutex);
		JMutexAutoLock lock2(other.m_mutex);
		
		if(&other == this)
			return *this;

		for(core::map<std::string, std::string>::Iterator
				i = other.m_settings.getIterator();
				i.atEnd() == false; i++)
		{
			m_settings.insert(i.getNode()->getKey(),
					i.getNode()->getValue());
		}
		
		for(core::map<std::string, std::string>::Iterator
				i = other.m_defaults.getIterator();
				i.atEnd() == false; i++)
		{
			m_defaults.insert(i.getNode()->getKey(),
					i.getNode()->getValue());
		}

		return *this;

	}

	Settings & operator=(Settings &other)
	{
		JMutexAutoLock lock(m_mutex);
		JMutexAutoLock lock2(other.m_mutex);
		
		if(&other == this)
			return *this;

		clear();
		(*this) += other;
		
		return *this;
	}

private:
	core::map<std::string, std::string> m_settings;
	core::map<std::string, std::string> m_defaults;
	// All methods that access m_settings/m_defaults directly should lock this.
	JMutex m_mutex;
};

/*
	FIFO queue (well, actually a FILO also)
*/
template<typename T>
class Queue
{
public:
	void push_back(T t)
	{
		m_list.push_back(t);
	}
	
	T pop_front()
	{
		if(m_list.size() == 0)
			throw ItemNotFoundException("Queue: queue is empty");

		typename core::list<T>::Iterator begin = m_list.begin();
		T t = *begin;
		m_list.erase(begin);
		return t;
	}
	T pop_back()
	{
		if(m_list.size() == 0)
			throw ItemNotFoundException("Queue: queue is empty");

		typename core::list<T>::Iterator last = m_list.getLast();
		T t = *last;
		m_list.erase(last);
		return t;
	}

	u32 size()
	{
		return m_list.size();
	}

protected:
	core::list<T> m_list;
};

/*
	Thread-safe FIFO queue (well, actually a FILO also)
*/

template<typename T>
class MutexedQueue
{
public:
	MutexedQueue()
	{
		m_mutex.Init();
	}
	u32 size()
	{
		JMutexAutoLock lock(m_mutex);
		return m_list.size();
	}
	void push_back(T t)
	{
		JMutexAutoLock lock(m_mutex);
		m_list.push_back(t);
	}
	T pop_front(u32 wait_time_max_ms=0)
	{
		u32 wait_time_ms = 0;

		for(;;)
		{
			{
				JMutexAutoLock lock(m_mutex);

				if(m_list.size() > 0)
				{
					typename core::list<T>::Iterator begin = m_list.begin();
					T t = *begin;
					m_list.erase(begin);
					return t;
				}

				if(wait_time_ms >= wait_time_max_ms)
					throw ItemNotFoundException("MutexedQueue: queue is empty");
			}

			// Wait a while before trying again
			sleep_ms(10);
			wait_time_ms += 10;
		}
	}
	T pop_back(u32 wait_time_max_ms=0)
	{
		u32 wait_time_ms = 0;

		for(;;)
		{
			{
				JMutexAutoLock lock(m_mutex);

				if(m_list.size() > 0)
				{
					typename core::list<T>::Iterator last = m_list.getLast();
					T t = *last;
					m_list.erase(last);
					return t;
				}

				if(wait_time_ms >= wait_time_max_ms)
					throw ItemNotFoundException("MutexedQueue: queue is empty");
			}

			// Wait a while before trying again
			sleep_ms(10);
			wait_time_ms += 10;
		}
	}

	JMutex & getMutex()
	{
		return m_mutex;
	}

	core::list<T> & getList()
	{
		return m_list;
	}

protected:
	JMutex m_mutex;
	core::list<T> m_list;
};

/*
	A single worker thread - multiple client threads queue framework.
*/

template<typename Caller, typename Data>
class CallerInfo
{
public:
	Caller caller;
	Data data;
};

template<typename Key, typename T, typename Caller, typename CallerData>
class GetResult
{
public:
	Key key;
	T item;
	core::list<CallerInfo<Caller, CallerData> > callers;
};

template<typename Key, typename T, typename Caller, typename CallerData>
class ResultQueue: public MutexedQueue< GetResult<Key, T, Caller, CallerData> >
{
};

template<typename Key, typename T, typename Caller, typename CallerData>
class GetRequest
{
public:
	GetRequest()
	{
		dest = NULL;
	}
	GetRequest(ResultQueue<Key,T, Caller, CallerData> *a_dest)
	{
		dest = a_dest;
	}
	GetRequest(ResultQueue<Key,T, Caller, CallerData> *a_dest,
			Key a_key)
	{
		dest = a_dest;
		key = a_key;
	}
	~GetRequest()
	{
	}
	
	Key key;
	ResultQueue<Key, T, Caller, CallerData> *dest;
	core::list<CallerInfo<Caller, CallerData> > callers;
};

template<typename Key, typename T, typename Caller, typename CallerData>
class RequestQueue
{
public:
	u32 size()
	{
		return m_queue.size();
	}

	void add(Key key, Caller caller, CallerData callerdata,
			ResultQueue<Key, T, Caller, CallerData> *dest)
	{
		JMutexAutoLock lock(m_queue.getMutex());
		
		/*
			If the caller is already on the list, only update CallerData
		*/
		for(typename core::list< GetRequest<Key, T, Caller, CallerData> >::Iterator
				i = m_queue.getList().begin();
				i != m_queue.getList().end(); i++)
		{
			GetRequest<Key, T, Caller, CallerData> &request = *i;

			if(request.key == key)
			{
				for(typename core::list< CallerInfo<Caller, CallerData> >::Iterator
						i = request.callers.begin();
						i != request.callers.end(); i++)
				{
					CallerInfo<Caller, CallerData> &ca = *i;
					if(ca.caller == caller)
					{
						ca.data = callerdata;
						return;
					}
				}
				CallerInfo<Caller, CallerData> ca;
				ca.caller = caller;
				ca.data = callerdata;
				request.callers.push_back(ca);
				return;
			}
		}

		/*
			Else add a new request to the queue
		*/

		GetRequest<Key, T, Caller, CallerData> request;
		request.key = key;
		CallerInfo<Caller, CallerData> ca;
		ca.caller = caller;
		ca.data = callerdata;
		request.callers.push_back(ca);
		request.dest = dest;
		
		m_queue.getList().push_back(request);
	}

	GetRequest<Key, T, Caller, CallerData> pop(bool wait_if_empty=false)
	{
		return m_queue.pop_front(wait_if_empty);
	}

private:
	MutexedQueue< GetRequest<Key, T, Caller, CallerData> > m_queue;
};

/*
	Pseudo-random (VC++ rand() sucks)
*/
int myrand(void);
void mysrand(unsigned seed);
#define MYRAND_MAX 32767

inline int myrand_range(int min, int max)
{
	if(max-min > MYRAND_MAX)
	{
		dstream<<"WARNING: myrand_range: max-min > MYRAND_MAX"<<std::endl;
		assert(0);
	}
	if(min > max)
	{
		assert(0);
		return max;
	}
	return (myrand()%(max-min+1))+min;
}

/*
	Miscellaneous functions
*/

bool isBlockInSight(v3s16 blockpos_b, v3f camera_pos, v3f camera_dir, f32 range,
		f32 *distance_ptr=NULL);

/*
	Queue with unique values with fast checking of value existence
*/

template<typename Value>
class UniqueQueue
{
public:
	
	/*
		Does nothing if value is already queued.
		Return value:
			true: value added
			false: value already exists
	*/
	bool push_back(Value value)
	{
		// Check if already exists
		if(m_map.find(value) != NULL)
			return false;

		// Add
		m_map.insert(value, 0);
		m_list.push_back(value);
		
		return true;
	}

	Value pop_front()
	{
		typename core::list<Value>::Iterator i = m_list.begin();
		Value value = *i;
		m_map.remove(value);
		m_list.erase(i);
		return value;
	}

	u32 size()
	{
		assert(m_list.size() == m_map.size());
		return m_list.size();
	}

private:
	core::map<Value, u8> m_map;
	core::list<Value> m_list;
};

#if 1
template<typename Key, typename Value>
class MutexedMap
{
public:
	MutexedMap()
	{
		m_mutex.Init();
		assert(m_mutex.IsInitialized());
	}
	
	void set(const Key &name, const Value &value)
	{
		JMutexAutoLock lock(m_mutex);

		m_values[name] = value;
	}
	
	bool get(const Key &name, Value *result)
	{
		JMutexAutoLock lock(m_mutex);

		typename core::map<Key, Value>::Node *n;
		n = m_values.find(name);

		if(n == NULL)
			return false;
		
		if(result != NULL)
			*result = n->getValue();
			
		return true;
	}

private:
	core::map<Key, Value> m_values;
	JMutex m_mutex;
};
#endif

/*
	Generates ids for comparable values.
	Id=0 is reserved for "no value".

	Is fast at:
	- Returning value by id (very fast)
	- Returning id by value
	- Generating a new id for a value

	Is not able to:
	- Remove an id/value pair (is possible to implement but slow)
*/
template<typename T>
class MutexedIdGenerator
{
public:
	MutexedIdGenerator()
	{
		m_mutex.Init();
		assert(m_mutex.IsInitialized());
	}
	
	// Returns true if found
	bool getValue(u32 id, T &value)
	{
		if(id == 0)
			return false;
		JMutexAutoLock lock(m_mutex);
		if(m_id_to_value.size() < id)
			return false;
		value = m_id_to_value[id-1];
		return true;
	}
	
	// If id exists for value, returns the id.
	// Otherwise generates an id for the value.
	u32 getId(const T &value)
	{
		JMutexAutoLock lock(m_mutex);
		typename core::map<T, u32>::Node *n;
		n = m_value_to_id.find(value);
		if(n != NULL)
			return n->getValue();
		m_id_to_value.push_back(value);
		u32 new_id = m_id_to_value.size();
		m_value_to_id.insert(value, new_id);
		return new_id;
	}

private:
	JMutex m_mutex;
	// Values are stored here at id-1 position (id 1 = [0])
	core::array<T> m_id_to_value;
	core::map<T, u32> m_value_to_id;
};

/*
	Checks if a string contains only supplied characters
*/
inline bool string_allowed(const std::string &s, const std::string &allowed_chars)
{
	for(u32 i=0; i<s.size(); i++)
	{
		bool confirmed = false;
		for(u32 j=0; j<allowed_chars.size(); j++)
		{
			if(s[i] == allowed_chars[j])
			{
				confirmed = true;
				break;
			}
		}
		if(confirmed == false)
			return false;
	}
	return true;
}

/*
	Forcefully wraps string into rows using \n
	(no word wrap, used for showing paths in gui)
*/
inline std::string wrap_rows(const std::string &from, u32 rowlen)
{
	std::string to;
	for(u32 i=0; i<from.size(); i++)
	{
		if(i != 0 && i%rowlen == 0)
			to += '\n';
		to += from[i];
	}
	return to;
}

/*
	Some helper stuff
*/
#define MYMIN(a,b) ((a)<(b)?(a):(b))
#define MYMAX(a,b) ((a)>(b)?(a):(b))

/*
	Returns integer position of node in given floating point position
*/
inline v3s16 floatToInt(v3f p, f32 d)
{
	v3s16 p2(
		(p.X + (p.X>0 ? d/2 : -d/2))/d,
		(p.Y + (p.Y>0 ? d/2 : -d/2))/d,
		(p.Z + (p.Z>0 ? d/2 : -d/2))/d);
	return p2;
}

/*
	Returns floating point position of node in given integer position
*/
inline v3f intToFloat(v3s16 p, f32 d)
{
	v3f p2(
		(f32)p.X * d,
		(f32)p.Y * d,
		(f32)p.Z * d
	);
	return p2;
}

/*
	More serialization stuff
*/

// Creates a string with the length as the first two bytes
inline std::string serializeString(const std::string &plain)
{
	//assert(plain.size() <= 65535);
	if(plain.size() > 65535)
		throw SerializationError("String too long for serializeString");
	char buf[2];
	writeU16((u8*)&buf[0], plain.size());
	std::string s;
	s.append(buf, 2);
	s.append(plain);
	return s;
}

// Creates a string with the length as the first two bytes from wide string
inline std::string serializeWideString(const std::wstring &plain)
{
	//assert(plain.size() <= 65535);
	if(plain.size() > 65535)
		throw SerializationError("String too long for serializeString");
	char buf[2];
	writeU16((u8*)buf, plain.size());
	std::string s;
	s.append(buf, 2);
	for(u32 i=0; i<plain.size(); i++)
	{
		writeU16((u8*)buf, plain[i]);
		s.append(buf, 2);
	}
	return s;
}

// Reads a string with the length as the first two bytes
inline std::string deSerializeString(std::istream &is)
{
	char buf[2];
	is.read(buf, 2);
	if(is.gcount() != 2)
		throw SerializationError("deSerializeString: size not read");
	u16 s_size = readU16((u8*)buf);
	if(s_size == 0)
		return "";
	Buffer<char> buf2(s_size);
	is.read(&buf2[0], s_size);
	std::string s;
	s.reserve(s_size);
	s.append(&buf2[0], s_size);
	return s;
}

// Reads a wide string with the length as the first two bytes
inline std::wstring deSerializeWideString(std::istream &is)
{
	char buf[2];
	is.read(buf, 2);
	if(is.gcount() != 2)
		throw SerializationError("deSerializeString: size not read");
	u16 s_size = readU16((u8*)buf);
	if(s_size == 0)
		return L"";
	std::wstring s;
	s.reserve(s_size);
	for(u32 i=0; i<s_size; i++)
	{
		is.read(&buf[0], 2);
		wchar_t c16 = readU16((u8*)buf);
		s.append(&c16, 1);
	}
	return s;
}

// Creates a string with the length as the first four bytes
inline std::string serializeLongString(const std::string &plain)
{
	char buf[4];
	writeU32((u8*)&buf[0], plain.size());
	std::string s;
	s.append(buf, 4);
	s.append(plain);
	return s;
}

// Reads a string with the length as the first four bytes
inline std::string deSerializeLongString(std::istream &is)
{
	char buf[4];
	is.read(buf, 4);
	if(is.gcount() != 4)
		throw SerializationError("deSerializeLongString: size not read");
	u32 s_size = readU32((u8*)buf);
	if(s_size == 0)
		return "";
	Buffer<char> buf2(s_size);
	is.read(&buf2[0], s_size);
	std::string s;
	s.reserve(s_size);
	s.append(&buf2[0], s_size);
	return s;
}

//

inline u32 time_to_daynight_ratio(u32 time_of_day)
{
	const s32 daylength = 16;
	const s32 nightlength = 6;
	const s32 daytimelength = 8;
	s32 d = daylength;
	s32 t = (((time_of_day)%24000)/(24000/d));
	if(t < nightlength/2 || t >= d - nightlength/2)
		//return 300;
		return 350;
	else if(t >= d/2 - daytimelength/2 && t < d/2 + daytimelength/2)
		return 1000;
	else
		return 750;
}

// Random helper. Usually d=BS
inline core::aabbox3d<f32> getNodeBox(v3s16 p, float d)
{
	return core::aabbox3d<f32>(
		(float)p.X * d - 0.5*d,
		(float)p.Y * d - 0.5*d,
		(float)p.Z * d - 0.5*d,
		(float)p.X * d + 0.5*d,
		(float)p.Y * d + 0.5*d,
		(float)p.Z * d + 0.5*d
	);
}
	
class IntervalLimiter
{
public:
	IntervalLimiter():
		m_accumulator(0)
	{
	}
	/*
		dtime: time from last call to this method
		wanted_interval: interval wanted
		return value:
			true: action should be skipped
			false: action should be done
	*/
	bool step(float dtime, float wanted_interval)
	{
		m_accumulator += dtime;
		if(m_accumulator < wanted_interval)
			return false;
		m_accumulator -= wanted_interval;
		return true;
	}
protected:
	float m_accumulator;
};

std::string translatePassword(std::string playername, std::wstring password);

#endif