server/include/util.h

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * 
 * Deliantra 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 3 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, see <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <support@deliantra.net>
 */

#ifndef UTIL_H__
#define UTIL_H__

#define DEBUG_POISON 0x00 // poison memory before freeing it if != 0
#define DEBUG_SALLOC  0   // add a debug wrapper around all sallocs
#define PREFER_MALLOC 0   // use malloc and not the slice allocator

#if __GNUC__ >= 3
# define is_constant(c)             __builtin_constant_p (c)
# define expect(expr,value)         __builtin_expect ((expr),(value))
# define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
#else
# define is_constant(c)             0
# define expect(expr,value)         (expr)
# define prefetch(addr,rw,locality)
#endif

#if __GNUC__ < 4 || (__GNUC__ == 4 || __GNUC_MINOR__ < 4)
# define decltype(x) typeof(x)
#endif

// put into ifs if you are very sure that the expression
// is mostly true or mosty false. note that these return
// booleans, not the expression.
#define expect_false(expr) expect ((expr) != 0, 0)
#define expect_true(expr)  expect ((expr) != 0, 1)

#include <pthread.h>

#include <cstddef>
#include <cmath>
#include <new>
#include <vector>

#include <glib.h>

#include <shstr.h>
#include <traits.h>

#if DEBUG_SALLOC
# define g_slice_alloc0(s) debug_slice_alloc0(s)
# define g_slice_alloc(s) debug_slice_alloc(s)
# define g_slice_free1(s,p) debug_slice_free1(s,p)
void *g_slice_alloc (unsigned long size);
void *g_slice_alloc0 (unsigned long size);
void g_slice_free1 (unsigned long size, void *ptr);
#elif PREFER_MALLOC
# define g_slice_alloc0(s) calloc (1, (s))
# define g_slice_alloc(s) malloc ((s))
# define g_slice_free1(s,p) free ((p))
#endif

// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever)
#define auto(var,expr) decltype(expr) var = (expr)

// very ugly macro that basicaly declares and initialises a variable
// that is in scope for the next statement only
// works only for stuff that can be assigned 0 and converts to false
// (note: works great for pointers)
// most ugly macro I ever wrote
#define statementvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)

// in range including end
#define IN_RANGE_INC(val,beg,end) \
  ((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))

// in range excluding end
#define IN_RANGE_EXC(val,beg,end) \
  ((unsigned int)(val) - (unsigned int)(beg) <  (unsigned int)(end) - (unsigned int)(beg))

void cleanup (const char *cause, bool make_core = false);
void fork_abort (const char *msg);

// rationale for using (U) not (T) is to reduce signed/unsigned issues,
// as a is often a constant while b is the variable. it is still a bug, though.
template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? (T)a : v >(T)b ? (T)b : v; }

template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }

template<typename T, typename U, typename V> static inline T min (T a, U b, V c) { return min (a, min (b, c)); }
template<typename T, typename U, typename V> static inline T max (T a, U b, V c) { return max (a, max (b, c)); }

template<typename T>
static inline T
lerp (T val, T min_in, T max_in, T min_out, T max_out)
{
  return (val - min_in) * (max_out - min_out) / (max_in - min_in) + min_out;
}

// lots of stuff taken from FXT

/* Rotate right. This is used in various places for checksumming */
//TODO: that sucks, use a better checksum algo
static inline uint32_t
rotate_right (uint32_t c, uint32_t count = 1)
{
  return (c << (32 - count)) | (c >> count);
}

static inline uint32_t
rotate_left (uint32_t c, uint32_t count = 1)
{
  return (c >> (32 - count)) | (c << count);
}

// Return abs(a-b)
// Both a and b must not have the most significant bit set
static inline uint32_t
upos_abs_diff (uint32_t a, uint32_t b)
{
  long d1 = b - a;
  long d2 = (d1 & (d1 >> 31)) << 1;

  return d1 - d2;               // == (b - d) - (a + d);
}

// Both a and b must not have the most significant bit set
static inline uint32_t
upos_min (uint32_t a, uint32_t b)
{
  int32_t d = b - a;
  d &= d >> 31;
  return a + d;
}

// Both a and b must not have the most significant bit set
static inline uint32_t
upos_max (uint32_t a, uint32_t b)
{
  int32_t d = b - a;
  d &= d >> 31;
  return b - d;
}

// this is much faster than crossfires original algorithm
// on modern cpus
inline int
isqrt (int n)
{
  return (int)sqrtf ((float)n);
}

// this is only twice as fast as naive sqrtf (dx*dy+dy*dy)
#if 0
// and has a max. error of 6 in the range -100..+100.
#else
// and has a max. error of 9 in the range -100..+100.
#endif
inline int 
idistance (int dx, int dy)
{ 
  unsigned int dx_ = abs (dx);
  unsigned int dy_ = abs (dy);

#if 0
  return dx_ > dy_
      ? (dx_ * 61685 + dy_ * 26870) >> 16
      : (dy_ * 61685 + dx_ * 26870) >> 16;
#else
  return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
#endif
}

/*
 * absdir(int): Returns a number between 1 and 8, which represent
 * the "absolute" direction of a number (it actually takes care of
 * "overflow" in previous calculations of a direction).
 */
inline int
absdir (int d)
{
  return ((d - 1) & 7) + 1;
}

extern ssize_t slice_alloc; // statistics

void *salloc_ (int n)            throw (std::bad_alloc);
void *salloc_ (int n, void *src) throw (std::bad_alloc);

// strictly the same as g_slice_alloc, but never returns 0
template<typename T>
inline T *salloc (int n = 1)     throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T));              }

// also copies src into the new area, like "memdup"
// if src is 0, clears the memory
template<typename T>
inline T *salloc (int n, T *src) throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T), (void *)src); }

// clears the memory
template<typename T>
inline T *salloc0(int n = 1)     throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T), 0);           }

// for symmetry
template<typename T>
inline void sfree (T *ptr, int n = 1) throw ()
{
  if (expect_true (ptr))
    {
      slice_alloc -= n * sizeof (T);
      if (DEBUG_POISON) memset (ptr, DEBUG_POISON, n * sizeof (T));
      g_slice_free1 (n * sizeof (T), (void *)ptr);
      assert (slice_alloc >= 0);//D
    }
}

// nulls the pointer
template<typename T>
inline void sfree0 (T *&ptr, int n = 1) throw ()
{
  sfree<T> (ptr, n);
  ptr = 0;
}

// makes dynamically allocated objects zero-initialised
struct zero_initialised
{
  void *operator new (size_t s, void *p)
  {
    memset (p, 0, s);
    return p;
  }

  void *operator new (size_t s)
  {
    return salloc0<char> (s);
  }

  void *operator new[] (size_t s)
  {
    return salloc0<char> (s);
  }

  void operator delete (void *p, size_t s)
  {
    sfree ((char *)p, s);
  }

  void operator delete[] (void *p, size_t s)
  {
    sfree ((char *)p, s);
  }
};

// makes dynamically allocated objects zero-initialised
struct slice_allocated
{
  void *operator new (size_t s, void *p)
  {
    return p;
  }

  void *operator new (size_t s)
  {
    return salloc<char> (s);
  }

  void *operator new[] (size_t s)
  {
    return salloc<char> (s);
  }

  void operator delete (void *p, size_t s)
  {
    sfree ((char *)p, s);
  }

  void operator delete[] (void *p, size_t s)
  {
    sfree ((char *)p, s);
  }
};

// a STL-compatible allocator that uses g_slice
// boy, this is verbose
template<typename Tp>
struct slice_allocator
{
  typedef size_t size_type;
  typedef ptrdiff_t difference_type;
  typedef Tp *pointer;
  typedef const Tp *const_pointer;
  typedef Tp &reference;
  typedef const Tp &const_reference;
  typedef Tp value_type;

  template <class U> 
  struct rebind
  {
    typedef slice_allocator<U> other;
  };

  slice_allocator () throw () { }
  slice_allocator (const slice_allocator &) throw () { }
  template<typename Tp2>
  slice_allocator (const slice_allocator<Tp2> &) throw () { }

  ~slice_allocator () { }

  pointer address (reference x) const { return &x; }
  const_pointer address (const_reference x) const { return &x; }

  pointer allocate (size_type n, const_pointer = 0)
  {
    return salloc<Tp> (n);
  }

  void deallocate (pointer p, size_type n)
  {
    sfree<Tp> (p, n);
  }

  size_type max_size () const throw ()
  {
    return size_t (-1) / sizeof (Tp);
  }

  void construct (pointer p, const Tp &val)
  {
    ::new (p) Tp (val);
  }

  void destroy (pointer p)
  {
    p->~Tp ();
  }
};

// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
struct tausworthe_random_generator
{
  // generator
  uint32_t state [4];

  void operator =(const tausworthe_random_generator &src)
  {
    state [0] = src.state [0];
    state [1] = src.state [1];
    state [2] = src.state [2];
    state [3] = src.state [3];
  }

  void seed (uint32_t seed);
  uint32_t next ();

  // uniform distribution
  uint32_t operator ()(uint32_t num)
  {
    return is_constant (num)
             ? (next () * (uint64_t)num) >> 32U
             : get_range (num);
  }

  // return a number within (min .. max)
  int operator () (int r_min, int r_max)
  {
    return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
              ? r_min + operator ()(r_max - r_min + 1)
              : get_range (r_min, r_max);
  }

  double operator ()()
  {
    return this->next () / (double)0xFFFFFFFFU;
  }

protected:
  uint32_t get_range (uint32_t r_max);
  int get_range (int r_min, int r_max);
};

typedef tausworthe_random_generator rand_gen;

extern rand_gen rndm, rmg_rndm;

INTERFACE_CLASS (attachable)
struct refcnt_base
{
  typedef int refcnt_t;
  mutable refcnt_t ACC (RW, refcnt);

  MTH void refcnt_inc () const { ++refcnt; }
  MTH void refcnt_dec () const { --refcnt; }

  refcnt_base () : refcnt (0) { }
};

// to avoid branches with more advanced compilers
extern refcnt_base::refcnt_t refcnt_dummy;

template<class T>
struct refptr
{
  // p if not null
  refcnt_base::refcnt_t *refcnt_ref () { return p ? &p->refcnt : &refcnt_dummy; }

  void refcnt_dec ()
  {
    if (!is_constant (p))
      --*refcnt_ref ();
    else if (p)
      --p->refcnt;
  }

  void refcnt_inc ()
  {
    if (!is_constant (p))
      ++*refcnt_ref ();
    else if (p)
      ++p->refcnt;
  }

  T *p;

  refptr () : p(0) { }
  refptr (const refptr<T> &p) : p(p.p) { refcnt_inc (); }
  refptr (T *p) : p(p) { refcnt_inc (); }
  ~refptr () { refcnt_dec (); }

  const refptr<T> &operator =(T *o)
  {
    // if decrementing ever destroys we need to reverse the order here
    refcnt_dec ();
    p = o;
    refcnt_inc ();
    return *this;
  }

  const refptr<T> &operator =(const refptr<T> &o)
  {
    *this = o.p;
    return *this;
  }

  T &operator * () const { return *p; }
  T *operator ->() const { return  p; }

  operator T *() const { return p; }
};

typedef refptr<maptile>   maptile_ptr;
typedef refptr<object>    object_ptr;
typedef refptr<archetype> arch_ptr;
typedef refptr<client>    client_ptr;
typedef refptr<player>    player_ptr;

struct str_hash
{
  std::size_t operator ()(const char *s) const
  {
    unsigned long hash = 0;

    /* use the one-at-a-time hash function, which supposedly is
     * better than the djb2-like one used by perl5.005, but
     * certainly is better then the bug used here before.
     * see http://burtleburtle.net/bob/hash/doobs.html
     */
    while (*s)
      {
        hash += *s++;
        hash += hash << 10;
        hash ^= hash >>  6;
      }

    hash += hash <<  3;
    hash ^= hash >> 11;
    hash += hash << 15;

    return hash;
  }
};

struct str_equal
{
  bool operator ()(const char *a, const char *b) const
  {
    return !strcmp (a, b);
  }
};

// Mostly the same as std::vector, but insert/erase can reorder
// the elements, making append(=insert)/remove O(1) instead of O(n).
//
// NOTE: only some forms of erase are available
template<class T>
struct unordered_vector : std::vector<T, slice_allocator<T> >
{
  typedef typename unordered_vector::iterator iterator;

  void erase (unsigned int pos)
  {
    if (pos < this->size () - 1)
      (*this)[pos] = (*this)[this->size () - 1];

    this->pop_back ();
  }

  void erase (iterator i)
  {
    erase ((unsigned int )(i - this->begin ()));
  }
};

// This container blends advantages of linked lists
// (efficiency) with vectors (random access) by
// by using an unordered vector and storing the vector
// index inside the object.
//
// + memory-efficient on most 64 bit archs
// + O(1) insert/remove
// + free unique (but varying) id for inserted objects
// + cache-friendly iteration
// - only works for pointers to structs
//
// NOTE: only some forms of erase/insert are available
typedef int object_vector_index;

template<class T, object_vector_index T::*indexmember>
struct object_vector : std::vector<T *, slice_allocator<T *> >
{
  typedef typename object_vector::iterator iterator;

  bool contains (const T *obj) const
  {
    return obj->*indexmember;
  }

  iterator find (const T *obj)
  {
    return obj->*indexmember
      ? this->begin () + obj->*indexmember - 1
      : this->end ();
  }

  void push_back (T *obj)
  {
    std::vector<T *, slice_allocator<T *> >::push_back (obj);
    obj->*indexmember = this->size ();
  }

  void insert (T *obj)
  {
    push_back (obj);
  }

  void insert (T &obj)
  {
    insert (&obj);
  }

  void erase (T *obj)
  {
    unsigned int pos = obj->*indexmember;
    obj->*indexmember = 0;

    if (pos < this->size ())
      {
        (*this)[pos - 1] = (*this)[this->size () - 1];
        (*this)[pos - 1]->*indexmember = pos;
      }

    this->pop_back ();
  }

  void erase (T &obj)
  {
    erase (&obj);
  }
};

// basically does what strncpy should do, but appends "..." to strings exceeding length
void assign (char *dst, const char *src, int maxlen);

// type-safe version of assign
template<int N>
inline void assign (char (&dst)[N], const char *src)
{
  assign ((char *)&dst, src, N);
}

typedef double tstamp;

// return current time as timestamp
tstamp now ();

int similar_direction (int a, int b);

// like sprintf, but returns a "static" buffer
const char *format (const char *format, ...);

/////////////////////////////////////////////////////////////////////////////
// threads, very very thin wrappers around pthreads

struct thread
{
  pthread_t id;

  void start (void *(*start_routine)(void *), void *arg = 0);

  void cancel ()
  {
    pthread_cancel (id);
  }

  void *join ()
  {
    void *ret;

    if (pthread_join (id, &ret))
      cleanup ("pthread_join failed", 1);

    return ret;
  }
};

// note that mutexes are not classes
typedef pthread_mutex_t smutex;

#if __linux && defined (PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP)
 #define SMUTEX_INITIALISER PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
#else
 #define SMUTEX_INITIALISER PTHREAD_MUTEX_INITIALIZER
#endif

#define SMUTEX(name) smutex name = SMUTEX_INITIALISER
#define SMUTEX_LOCK(name)   pthread_mutex_lock   (&(name))
#define SMUTEX_UNLOCK(name) pthread_mutex_unlock (&(name))

typedef pthread_cond_t scond;

#define SCOND(name) scond name = PTHREAD_COND_INITIALIZER
#define SCOND_SIGNAL(name)     pthread_cond_signal    (&(name))
#define SCOND_BROADCAST(name)  pthread_cond_broadcast (&(name))
#define SCOND_WAIT(name,mutex) pthread_cond_wait      (&(name), &(mutex))

#endif

Revision:	1.75
Committed:	Tue May 6 16:55:26 2008 UTC (16 years ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.74:	+1 -1 lines
Log Message:	update copyright
#	Content
1	/*
2	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	*
4	* Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5	*
6	* Deliantra is free software: you can redistribute it and/or modify
7	* it under the terms of the GNU General Public License as published by
8	* the Free Software Foundation, either version 3 of the License, or
9	* (at your option) any later version.
10	*
11	* This program is distributed in the hope that it will be useful,
12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14	* GNU General Public License for more details.
15	*
16	* You should have received a copy of the GNU General Public License
17	* along with this program. If not, see <http://www.gnu.org/licenses/>.
18	*
19	* The authors can be reached via e-mail to <support@deliantra.net>
20	*/
21
22	#ifndef UTIL_H__
23	#define UTIL_H__
24
25	#define DEBUG_POISON 0x00 // poison memory before freeing it if != 0
26	#define DEBUG_SALLOC 0 // add a debug wrapper around all sallocs
27	#define PREFER_MALLOC 0 // use malloc and not the slice allocator
28
29	#if __GNUC__ >= 3
30	# define is_constant(c) __builtin_constant_p (c)
31	# define expect(expr,value) __builtin_expect ((expr),(value))
32	# define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
33	#else
34	# define is_constant(c) 0
35	# define expect(expr,value) (expr)
36	# define prefetch(addr,rw,locality)
37	#endif
38
39	#if __GNUC__ < 4 \|\| (__GNUC__ == 4 \|\| __GNUC_MINOR__ < 4)
40	# define decltype(x) typeof(x)
41	#endif
42
43	// put into ifs if you are very sure that the expression
44	// is mostly true or mosty false. note that these return
45	// booleans, not the expression.
46	#define expect_false(expr) expect ((expr) != 0, 0)
47	#define expect_true(expr) expect ((expr) != 0, 1)
48
49	#include <pthread.h>
50
51	#include <cstddef>
52	#include <cmath>
53	#include <new>
54	#include <vector>
55
56	#include <glib.h>
57
58	#include <shstr.h>
59	#include <traits.h>
60
61	#if DEBUG_SALLOC
62	# define g_slice_alloc0(s) debug_slice_alloc0(s)
63	# define g_slice_alloc(s) debug_slice_alloc(s)
64	# define g_slice_free1(s,p) debug_slice_free1(s,p)
65	void *g_slice_alloc (unsigned long size);
66	void *g_slice_alloc0 (unsigned long size);
67	void g_slice_free1 (unsigned long size, void *ptr);
68	#elif PREFER_MALLOC
69	# define g_slice_alloc0(s) calloc (1, (s))
70	# define g_slice_alloc(s) malloc ((s))
71	# define g_slice_free1(s,p) free ((p))
72	#endif
73
74	// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever)
75	#define auto(var,expr) decltype(expr) var = (expr)
76
77	// very ugly macro that basicaly declares and initialises a variable
78	// that is in scope for the next statement only
79	// works only for stuff that can be assigned 0 and converts to false
80	// (note: works great for pointers)
81	// most ugly macro I ever wrote
82	#define statementvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
83
84	// in range including end
85	#define IN_RANGE_INC(val,beg,end) \
86	((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
87
88	// in range excluding end
89	#define IN_RANGE_EXC(val,beg,end) \
90	((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
91
92	void cleanup (const char *cause, bool make_core = false);
93	void fork_abort (const char *msg);
94
95	// rationale for using (U) not (T) is to reduce signed/unsigned issues,
96	// as a is often a constant while b is the variable. it is still a bug, though.
97	template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
98	template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
99	template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? (T)a : v >(T)b ? (T)b : v; }
100
101	template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
102
103	template<typename T, typename U, typename V> static inline T min (T a, U b, V c) { return min (a, min (b, c)); }
104	template<typename T, typename U, typename V> static inline T max (T a, U b, V c) { return max (a, max (b, c)); }
105
106	template<typename T>
107	static inline T
108	lerp (T val, T min_in, T max_in, T min_out, T max_out)
109	{
110	return (val - min_in) * (max_out - min_out) / (max_in - min_in) + min_out;
111	}
112
113	// lots of stuff taken from FXT
114
115	/* Rotate right. This is used in various places for checksumming */
116	//TODO: that sucks, use a better checksum algo
117	static inline uint32_t
118	rotate_right (uint32_t c, uint32_t count = 1)
119	{
120	return (c << (32 - count)) \| (c >> count);
121	}
122
123	static inline uint32_t
124	rotate_left (uint32_t c, uint32_t count = 1)
125	{
126	return (c >> (32 - count)) \| (c << count);
127	}
128
129	// Return abs(a-b)
130	// Both a and b must not have the most significant bit set
131	static inline uint32_t
132	upos_abs_diff (uint32_t a, uint32_t b)
133	{
134	long d1 = b - a;
135	long d2 = (d1 & (d1 >> 31)) << 1;
136
137	return d1 - d2; // == (b - d) - (a + d);
138	}
139
140	// Both a and b must not have the most significant bit set
141	static inline uint32_t
142	upos_min (uint32_t a, uint32_t b)
143	{
144	int32_t d = b - a;
145	d &= d >> 31;
146	return a + d;
147	}
148
149	// Both a and b must not have the most significant bit set
150	static inline uint32_t
151	upos_max (uint32_t a, uint32_t b)
152	{
153	int32_t d = b - a;
154	d &= d >> 31;
155	return b - d;
156	}
157
158	// this is much faster than crossfires original algorithm
159	// on modern cpus
160	inline int
161	isqrt (int n)
162	{
163	return (int)sqrtf ((float)n);
164	}
165
166	// this is only twice as fast as naive sqrtf (dxdy+dydy)
167	#if 0
168	// and has a max. error of 6 in the range -100..+100.
169	#else
170	// and has a max. error of 9 in the range -100..+100.
171	#endif
172	inline int
173	idistance (int dx, int dy)
174	{
175	unsigned int dx_ = abs (dx);
176	unsigned int dy_ = abs (dy);
177
178	#if 0
179	return dx_ > dy_
180	? (dx_ * 61685 + dy_ * 26870) >> 16
181	: (dy_ * 61685 + dx_ * 26870) >> 16;
182	#else
183	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
184	#endif
185	}
186
187	/*
188	* absdir(int): Returns a number between 1 and 8, which represent
189	* the "absolute" direction of a number (it actually takes care of
190	* "overflow" in previous calculations of a direction).
191	*/
192	inline int
193	absdir (int d)
194	{
195	return ((d - 1) & 7) + 1;
196	}
197
198	extern ssize_t slice_alloc; // statistics
199
200	void *salloc_ (int n) throw (std::bad_alloc);
201	void salloc_ (int n, void src) throw (std::bad_alloc);
202
203	// strictly the same as g_slice_alloc, but never returns 0
204	template<typename T>
205	inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
206
207	// also copies src into the new area, like "memdup"
208	// if src is 0, clears the memory
209	template<typename T>
210	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
211
212	// clears the memory
213	template<typename T>
214	inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
215
216	// for symmetry
217	template<typename T>
218	inline void sfree (T *ptr, int n = 1) throw ()
219	{
220	if (expect_true (ptr))
221	{
222	slice_alloc -= n * sizeof (T);
223	if (DEBUG_POISON) memset (ptr, DEBUG_POISON, n * sizeof (T));
224	g_slice_free1 (n * sizeof (T), (void *)ptr);
225	assert (slice_alloc >= 0);//D
226	}
227	}
228
229	// nulls the pointer
230	template<typename T>
231	inline void sfree0 (T *&ptr, int n = 1) throw ()
232	{
233	sfree<T> (ptr, n);
234	ptr = 0;
235	}
236
237	// makes dynamically allocated objects zero-initialised
238	struct zero_initialised
239	{
240	void operator new (size_t s, void p)
241	{
242	memset (p, 0, s);
243	return p;
244	}
245
246	void *operator new (size_t s)
247	{
248	return salloc0<char> (s);
249	}
250
251	void *operator new[] (size_t s)
252	{
253	return salloc0<char> (s);
254	}
255
256	void operator delete (void *p, size_t s)
257	{
258	sfree ((char *)p, s);
259	}
260
261	void operator delete[] (void *p, size_t s)
262	{
263	sfree ((char *)p, s);
264	}
265	};
266
267	// makes dynamically allocated objects zero-initialised
268	struct slice_allocated
269	{
270	void operator new (size_t s, void p)
271	{
272	return p;
273	}
274
275	void *operator new (size_t s)
276	{
277	return salloc<char> (s);
278	}
279
280	void *operator new[] (size_t s)
281	{
282	return salloc<char> (s);
283	}
284
285	void operator delete (void *p, size_t s)
286	{
287	sfree ((char *)p, s);
288	}
289
290	void operator delete[] (void *p, size_t s)
291	{
292	sfree ((char *)p, s);
293	}
294	};
295
296	// a STL-compatible allocator that uses g_slice
297	// boy, this is verbose
298	template<typename Tp>
299	struct slice_allocator
300	{
301	typedef size_t size_type;
302	typedef ptrdiff_t difference_type;
303	typedef Tp *pointer;
304	typedef const Tp *const_pointer;
305	typedef Tp &reference;
306	typedef const Tp &const_reference;
307	typedef Tp value_type;
308
309	template <class U>
310	struct rebind
311	{
312	typedef slice_allocator<U> other;
313	};
314
315	slice_allocator () throw () { }
316	slice_allocator (const slice_allocator &) throw () { }
317	template<typename Tp2>
318	slice_allocator (const slice_allocator<Tp2> &) throw () { }
319
320	~slice_allocator () { }
321
322	pointer address (reference x) const { return &x; }
323	const_pointer address (const_reference x) const { return &x; }
324
325	pointer allocate (size_type n, const_pointer = 0)
326	{
327	return salloc<Tp> (n);
328	}
329
330	void deallocate (pointer p, size_type n)
331	{
332	sfree<Tp> (p, n);
333	}
334
335	size_type max_size () const throw ()
336	{
337	return size_t (-1) / sizeof (Tp);
338	}
339
340	void construct (pointer p, const Tp &val)
341	{
342	::new (p) Tp (val);
343	}
344
345	void destroy (pointer p)
346	{
347	p->~Tp ();
348	}
349	};
350
351	// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
352	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
353	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
354	struct tausworthe_random_generator
355	{
356	// generator
357	uint32_t state [4];
358
359	void operator =(const tausworthe_random_generator &src)
360	{
361	state [0] = src.state [0];
362	state [1] = src.state [1];
363	state [2] = src.state [2];
364	state [3] = src.state [3];
365	}
366
367	void seed (uint32_t seed);
368	uint32_t next ();
369
370	// uniform distribution
371	uint32_t operator ()(uint32_t num)
372	{
373	return is_constant (num)
374	? (next () * (uint64_t)num) >> 32U
375	: get_range (num);
376	}
377
378	// return a number within (min .. max)
379	int operator () (int r_min, int r_max)
380	{
381	return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
382	? r_min + operator ()(r_max - r_min + 1)
383	: get_range (r_min, r_max);
384	}
385
386	double operator ()()
387	{
388	return this->next () / (double)0xFFFFFFFFU;
389	}
390
391	protected:
392	uint32_t get_range (uint32_t r_max);
393	int get_range (int r_min, int r_max);
394	};
395
396	typedef tausworthe_random_generator rand_gen;
397
398	extern rand_gen rndm, rmg_rndm;
399
400	INTERFACE_CLASS (attachable)
401	struct refcnt_base
402	{
403	typedef int refcnt_t;
404	mutable refcnt_t ACC (RW, refcnt);
405
406	MTH void refcnt_inc () const { ++refcnt; }
407	MTH void refcnt_dec () const { --refcnt; }
408
409	refcnt_base () : refcnt (0) { }
410	};
411
412	// to avoid branches with more advanced compilers
413	extern refcnt_base::refcnt_t refcnt_dummy;
414
415	template<class T>
416	struct refptr
417	{
418	// p if not null
419	refcnt_base::refcnt_t *refcnt_ref () { return p ? &p->refcnt : &refcnt_dummy; }
420
421	void refcnt_dec ()
422	{
423	if (!is_constant (p))
424	--*refcnt_ref ();
425	else if (p)
426	--p->refcnt;
427	}
428
429	void refcnt_inc ()
430	{
431	if (!is_constant (p))
432	++*refcnt_ref ();
433	else if (p)
434	++p->refcnt;
435	}
436
437	T *p;
438
439	refptr () : p(0) { }
440	refptr (const refptr<T> &p) : p(p.p) { refcnt_inc (); }
441	refptr (T *p) : p(p) { refcnt_inc (); }
442	~refptr () { refcnt_dec (); }
443
444	const refptr<T> &operator =(T *o)
445	{
446	// if decrementing ever destroys we need to reverse the order here
447	refcnt_dec ();
448	p = o;
449	refcnt_inc ();
450	return *this;
451	}
452
453	const refptr<T> &operator =(const refptr<T> &o)
454	{
455	*this = o.p;
456	return *this;
457	}
458
459	T &operator * () const { return *p; }
460	T *operator ->() const { return p; }
461
462	operator T *() const { return p; }
463	};
464
465	typedef refptr<maptile> maptile_ptr;
466	typedef refptr<object> object_ptr;
467	typedef refptr<archetype> arch_ptr;
468	typedef refptr<client> client_ptr;
469	typedef refptr<player> player_ptr;
470
471	struct str_hash
472	{
473	std::size_t operator ()(const char *s) const
474	{
475	unsigned long hash = 0;
476
477	/* use the one-at-a-time hash function, which supposedly is
478	* better than the djb2-like one used by perl5.005, but
479	* certainly is better then the bug used here before.
480	* see http://burtleburtle.net/bob/hash/doobs.html
481	*/
482	while (*s)
483	{
484	hash += *s++;
485	hash += hash << 10;
486	hash ^= hash >> 6;
487	}
488
489	hash += hash << 3;
490	hash ^= hash >> 11;
491	hash += hash << 15;
492
493	return hash;
494	}
495	};
496
497	struct str_equal
498	{
499	bool operator ()(const char a, const char b) const
500	{
501	return !strcmp (a, b);
502	}
503	};
504
505	// Mostly the same as std::vector, but insert/erase can reorder
506	// the elements, making append(=insert)/remove O(1) instead of O(n).
507	//
508	// NOTE: only some forms of erase are available
509	template<class T>
510	struct unordered_vector : std::vector<T, slice_allocator<T> >
511	{
512	typedef typename unordered_vector::iterator iterator;
513
514	void erase (unsigned int pos)
515	{
516	if (pos < this->size () - 1)
517	(this)[pos] = (this)[this->size () - 1];
518
519	this->pop_back ();
520	}
521
522	void erase (iterator i)
523	{
524	erase ((unsigned int )(i - this->begin ()));
525	}
526	};
527
528	// This container blends advantages of linked lists
529	// (efficiency) with vectors (random access) by
530	// by using an unordered vector and storing the vector
531	// index inside the object.
532	//
533	// + memory-efficient on most 64 bit archs
534	// + O(1) insert/remove
535	// + free unique (but varying) id for inserted objects
536	// + cache-friendly iteration
537	// - only works for pointers to structs
538	//
539	// NOTE: only some forms of erase/insert are available
540	typedef int object_vector_index;
541
542	template<class T, object_vector_index T::*indexmember>
543	struct object_vector : std::vector<T , slice_allocator<T > >
544	{
545	typedef typename object_vector::iterator iterator;
546
547	bool contains (const T *obj) const
548	{
549	return obj->*indexmember;
550	}
551
552	iterator find (const T *obj)
553	{
554	return obj->*indexmember
555	? this->begin () + obj->*indexmember - 1
556	: this->end ();
557	}
558
559	void push_back (T *obj)
560	{
561	std::vector<T , slice_allocator<T > >::push_back (obj);
562	obj->*indexmember = this->size ();
563	}
564
565	void insert (T *obj)
566	{
567	push_back (obj);
568	}
569
570	void insert (T &obj)
571	{
572	insert (&obj);
573	}
574
575	void erase (T *obj)
576	{
577	unsigned int pos = obj->*indexmember;
578	obj->*indexmember = 0;
579
580	if (pos < this->size ())
581	{
582	(this)[pos - 1] = (this)[this->size () - 1];
583	(this)[pos - 1]->indexmember = pos;
584	}
585
586	this->pop_back ();
587	}
588
589	void erase (T &obj)
590	{
591	erase (&obj);
592	}
593	};
594
595	// basically does what strncpy should do, but appends "..." to strings exceeding length
596	void assign (char dst, const char src, int maxlen);
597
598	// type-safe version of assign
599	template<int N>
600	inline void assign (char (&dst)[N], const char *src)
601	{
602	assign ((char *)&dst, src, N);
603	}
604
605	typedef double tstamp;
606
607	// return current time as timestamp
608	tstamp now ();
609
610	int similar_direction (int a, int b);
611
612	// like sprintf, but returns a "static" buffer
613	const char format (const char format, ...);
614
615	/////////////////////////////////////////////////////////////////////////////
616	// threads, very very thin wrappers around pthreads
617
618	struct thread
619	{
620	pthread_t id;
621
622	void start (void (start_routine)(void ), void arg = 0);
623
624	void cancel ()
625	{
626	pthread_cancel (id);
627	}
628
629	void *join ()
630	{
631	void *ret;
632
633	if (pthread_join (id, &ret))
634	cleanup ("pthread_join failed", 1);
635
636	return ret;
637	}
638	};
639
640	// note that mutexes are not classes
641	typedef pthread_mutex_t smutex;
642
643	#if __linux && defined (PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP)
644	#define SMUTEX_INITIALISER PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
645	#else
646	#define SMUTEX_INITIALISER PTHREAD_MUTEX_INITIALIZER
647	#endif
648
649	#define SMUTEX(name) smutex name = SMUTEX_INITIALISER
650	#define SMUTEX_LOCK(name) pthread_mutex_lock (&(name))
651	#define SMUTEX_UNLOCK(name) pthread_mutex_unlock (&(name))
652
653	typedef pthread_cond_t scond;
654
655	#define SCOND(name) scond name = PTHREAD_COND_INITIALIZER
656	#define SCOND_SIGNAL(name) pthread_cond_signal (&(name))
657	#define SCOND_BROADCAST(name) pthread_cond_broadcast (&(name))
658	#define SCOND_WAIT(name,mutex) pthread_cond_wait (&(name), &(mutex))
659
660	#endif
661