server/include/util.h

/*
 * This file is part of Crossfire TRT, the Multiplayer Online Role Playing Game.
 * 
 * Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
 * 
 * Crossfire TRT 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 Crossfire TRT; if not, write to the Free Software Foundation, Inc. 51
 * Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 * 
 * The authors can be reached via e-mail to <crossfire@schmorp.de>
 */

#ifndef UTIL_H__
#define UTIL_H__

//#define PREFER_MALLOC

#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

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

#include <glib.h>

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

// use a gcc extension for auto declarations until ISO C++ sanctifies them
#define auto(var,expr) typeof(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 declvar(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 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>
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;
}

// 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 g_slice_alloc0 (s);
  }

  void *operator new[] (size_t s)
  {
    return g_slice_alloc0 (s);
  }

  void operator delete (void *p, size_t s)
  {
    g_slice_free1 (s, p);
  }

  void operator delete[] (void *p, size_t s)
  {
    g_slice_free1 (s, p);
  }
};

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 ()
{
#ifdef PREFER_MALLOC
  free (ptr);
#else
  g_slice_free1 (n * sizeof (T), (void *)ptr);
#endif
}

// 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 &o) 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;

template<class T>
struct refptr
{
  T *p;

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

  const refptr<T> &operator =(T *o)
  {
    if (p) p->refcnt_dec ();
    p = o;
    if (p) p->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);
  }
};

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 ()));
  }
};

template<class T, int T::* index>
struct object_vector : std::vector<T *, slice_allocator<T *> >
{
  void insert (T *obj)
  {
    assert (!(obj->*index));
    push_back (obj);
    obj->*index = this->size ();
  }

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

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

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

    this->pop_back ();
  }

  void erase (T &obj)
  {
    errase (&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 timestampe
tstamp now ();

int similar_direction (int a, int b);

// like printf, but returns a std::string
const std::string format (const char *format, ...);

#endif

Revision:	1.46
Committed:	Mon May 28 21:15:56 2007 UTC (16 years, 11 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.45:	+22 -0 lines
Log Message:	- update copyrights in .h files, where applicable - rename preprocess to genkeywords
#	Content
1	/*
2	* This file is part of Crossfire TRT, the Multiplayer Online Role Playing Game.
3	*
4	* Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
5	*
6	* Crossfire TRT is free software; you can redistribute it and/or modify it
7	* under the terms of the GNU General Public License as published by the Free
8	* Software Foundation; either version 2 of the License, or (at your option)
9	* any later version.
10	*
11	* This program is distributed in the hope that it will be useful, but
12	* WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
13	* or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14	* for more details.
15	*
16	* You should have received a copy of the GNU General Public License along
17	* with Crossfire TRT; if not, write to the Free Software Foundation, Inc. 51
18	* Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19	*
20	* The authors can be reached via e-mail to <crossfire@schmorp.de>
21	*/
22
23	#ifndef UTIL_H__
24	#define UTIL_H__
25
26	//#define PREFER_MALLOC
27
28	#if __GNUC__ >= 3
29	# define is_constant(c) __builtin_constant_p (c)
30	# define expect(expr,value) __builtin_expect ((expr),(value))
31	# define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
32	#else
33	# define is_constant(c) 0
34	# define expect(expr,value) (expr)
35	# define prefetch(addr,rw,locality)
36	#endif
37
38	// put into ifs if you are very sure that the expression
39	// is mostly true or mosty false. note that these return
40	// booleans, not the expression.
41	#define expect_false(expr) expect ((expr) != 0, 0)
42	#define expect_true(expr) expect ((expr) != 0, 1)
43
44	#include <cstddef>
45	#include <cmath>
46	#include <new>
47	#include <vector>
48
49	#include <glib.h>
50
51	#include <shstr.h>
52	#include <traits.h>
53
54	// use a gcc extension for auto declarations until ISO C++ sanctifies them
55	#define auto(var,expr) typeof(expr) var = (expr)
56
57	// very ugly macro that basicaly declares and initialises a variable
58	// that is in scope for the next statement only
59	// works only for stuff that can be assigned 0 and converts to false
60	// (note: works great for pointers)
61	// most ugly macro I ever wrote
62	#define declvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
63
64	// in range including end
65	#define IN_RANGE_INC(val,beg,end) \
66	((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
67
68	// in range excluding end
69	#define IN_RANGE_EXC(val,beg,end) \
70	((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
71
72	void fork_abort (const char *msg);
73
74	// rationale for using (U) not (T) is to reduce signed/unsigned issues,
75	// as a is often a constant while b is the variable. it is still a bug, though.
76	template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
77	template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
78	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; }
79
80	template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
81
82	template<typename T>
83	static inline T
84	lerp (T val, T min_in, T max_in, T min_out, T max_out)
85	{
86	return (val - min_in) * (max_out - min_out) / (max_in - min_in) + min_out;
87	}
88
89	// lots of stuff taken from FXT
90
91	/* Rotate right. This is used in various places for checksumming */
92	//TODO: that sucks, use a better checksum algo
93	static inline uint32_t
94	rotate_right (uint32_t c, uint32_t count = 1)
95	{
96	return (c << (32 - count)) \| (c >> count);
97	}
98
99	static inline uint32_t
100	rotate_left (uint32_t c, uint32_t count = 1)
101	{
102	return (c >> (32 - count)) \| (c << count);
103	}
104
105	// Return abs(a-b)
106	// Both a and b must not have the most significant bit set
107	static inline uint32_t
108	upos_abs_diff (uint32_t a, uint32_t b)
109	{
110	long d1 = b - a;
111	long d2 = (d1 & (d1 >> 31)) << 1;
112
113	return d1 - d2; // == (b - d) - (a + d);
114	}
115
116	// Both a and b must not have the most significant bit set
117	static inline uint32_t
118	upos_min (uint32_t a, uint32_t b)
119	{
120	int32_t d = b - a;
121	d &= d >> 31;
122	return a + d;
123	}
124
125	// Both a and b must not have the most significant bit set
126	static inline uint32_t
127	upos_max (uint32_t a, uint32_t b)
128	{
129	int32_t d = b - a;
130	d &= d >> 31;
131	return b - d;
132	}
133
134	// this is much faster than crossfires original algorithm
135	// on modern cpus
136	inline int
137	isqrt (int n)
138	{
139	return (int)sqrtf ((float)n);
140	}
141
142	// this is only twice as fast as naive sqrtf (dxdy+dydy)
143	#if 0
144	// and has a max. error of 6 in the range -100..+100.
145	#else
146	// and has a max. error of 9 in the range -100..+100.
147	#endif
148	inline int
149	idistance (int dx, int dy)
150	{
151	unsigned int dx_ = abs (dx);
152	unsigned int dy_ = abs (dy);
153
154	#if 0
155	return dx_ > dy_
156	? (dx_ * 61685 + dy_ * 26870) >> 16
157	: (dy_ * 61685 + dx_ * 26870) >> 16;
158	#else
159	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
160	#endif
161	}
162
163	/*
164	* absdir(int): Returns a number between 1 and 8, which represent
165	* the "absolute" direction of a number (it actually takes care of
166	* "overflow" in previous calculations of a direction).
167	*/
168	inline int
169	absdir (int d)
170	{
171	return ((d - 1) & 7) + 1;
172	}
173
174	// makes dynamically allocated objects zero-initialised
175	struct zero_initialised
176	{
177	void operator new (size_t s, void p)
178	{
179	memset (p, 0, s);
180	return p;
181	}
182
183	void *operator new (size_t s)
184	{
185	return g_slice_alloc0 (s);
186	}
187
188	void *operator new[] (size_t s)
189	{
190	return g_slice_alloc0 (s);
191	}
192
193	void operator delete (void *p, size_t s)
194	{
195	g_slice_free1 (s, p);
196	}
197
198	void operator delete[] (void *p, size_t s)
199	{
200	g_slice_free1 (s, p);
201	}
202	};
203
204	void *salloc_ (int n) throw (std::bad_alloc);
205	void salloc_ (int n, void src) throw (std::bad_alloc);
206
207	// strictly the same as g_slice_alloc, but never returns 0
208	template<typename T>
209	inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
210
211	// also copies src into the new area, like "memdup"
212	// if src is 0, clears the memory
213	template<typename T>
214	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
215
216	// clears the memory
217	template<typename T>
218	inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
219
220	// for symmetry
221	template<typename T>
222	inline void sfree (T *ptr, int n = 1) throw ()
223	{
224	#ifdef PREFER_MALLOC
225	free (ptr);
226	#else
227	g_slice_free1 (n * sizeof (T), (void *)ptr);
228	#endif
229	}
230
231	// a STL-compatible allocator that uses g_slice
232	// boy, this is verbose
233	template<typename Tp>
234	struct slice_allocator
235	{
236	typedef size_t size_type;
237	typedef ptrdiff_t difference_type;
238	typedef Tp *pointer;
239	typedef const Tp *const_pointer;
240	typedef Tp &reference;
241	typedef const Tp &const_reference;
242	typedef Tp value_type;
243
244	template <class U>
245	struct rebind
246	{
247	typedef slice_allocator<U> other;
248	};
249
250	slice_allocator () throw () { }
251	slice_allocator (const slice_allocator &o) throw () { }
252	template<typename Tp2>
253	slice_allocator (const slice_allocator<Tp2> &) throw () { }
254
255	~slice_allocator () { }
256
257	pointer address (reference x) const { return &x; }
258	const_pointer address (const_reference x) const { return &x; }
259
260	pointer allocate (size_type n, const_pointer = 0)
261	{
262	return salloc<Tp> (n);
263	}
264
265	void deallocate (pointer p, size_type n)
266	{
267	sfree<Tp> (p, n);
268	}
269
270	size_type max_size ()const throw ()
271	{
272	return size_t (-1) / sizeof (Tp);
273	}
274
275	void construct (pointer p, const Tp &val)
276	{
277	::new (p) Tp (val);
278	}
279
280	void destroy (pointer p)
281	{
282	p->~Tp ();
283	}
284	};
285
286	// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
287	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
288	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
289	struct tausworthe_random_generator
290	{
291	// generator
292	uint32_t state [4];
293
294	void operator =(const tausworthe_random_generator &src)
295	{
296	state [0] = src.state [0];
297	state [1] = src.state [1];
298	state [2] = src.state [2];
299	state [3] = src.state [3];
300	}
301
302	void seed (uint32_t seed);
303	uint32_t next ();
304
305	// uniform distribution
306	uint32_t operator ()(uint32_t num)
307	{
308	return is_constant (num)
309	? (next () * (uint64_t)num) >> 32U
310	: get_range (num);
311	}
312
313	// return a number within (min .. max)
314	int operator () (int r_min, int r_max)
315	{
316	return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
317	? r_min + operator ()(r_max - r_min + 1)
318	: get_range (r_min, r_max);
319	}
320
321	double operator ()()
322	{
323	return this->next () / (double)0xFFFFFFFFU;
324	}
325
326	protected:
327	uint32_t get_range (uint32_t r_max);
328	int get_range (int r_min, int r_max);
329	};
330
331	typedef tausworthe_random_generator rand_gen;
332
333	extern rand_gen rndm;
334
335	template<class T>
336	struct refptr
337	{
338	T *p;
339
340	refptr () : p(0) { }
341	refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
342	refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
343	~refptr () { if (p) p->refcnt_dec (); }
344
345	const refptr<T> &operator =(T *o)
346	{
347	if (p) p->refcnt_dec ();
348	p = o;
349	if (p) p->refcnt_inc ();
350
351	return *this;
352	}
353
354	const refptr<T> &operator =(const refptr<T> o)
355	{
356	*this = o.p;
357	return *this;
358	}
359
360	T &operator * () const { return *p; }
361	T *operator ->() const { return p; }
362
363	operator T *() const { return p; }
364	};
365
366	typedef refptr<maptile> maptile_ptr;
367	typedef refptr<object> object_ptr;
368	typedef refptr<archetype> arch_ptr;
369	typedef refptr<client> client_ptr;
370	typedef refptr<player> player_ptr;
371
372	struct str_hash
373	{
374	std::size_t operator ()(const char *s) const
375	{
376	unsigned long hash = 0;
377
378	/* use the one-at-a-time hash function, which supposedly is
379	* better than the djb2-like one used by perl5.005, but
380	* certainly is better then the bug used here before.
381	* see http://burtleburtle.net/bob/hash/doobs.html
382	*/
383	while (*s)
384	{
385	hash += *s++;
386	hash += hash << 10;
387	hash ^= hash >> 6;
388	}
389
390	hash += hash << 3;
391	hash ^= hash >> 11;
392	hash += hash << 15;
393
394	return hash;
395	}
396	};
397
398	struct str_equal
399	{
400	bool operator ()(const char a, const char b) const
401	{
402	return !strcmp (a, b);
403	}
404	};
405
406	template<class T>
407	struct unordered_vector : std::vector<T, slice_allocator<T> >
408	{
409	typedef typename unordered_vector::iterator iterator;
410
411	void erase (unsigned int pos)
412	{
413	if (pos < this->size () - 1)
414	(this)[pos] = (this)[this->size () - 1];
415
416	this->pop_back ();
417	}
418
419	void erase (iterator i)
420	{
421	erase ((unsigned int )(i - this->begin ()));
422	}
423	};
424
425	template<class T, int T::* index>
426	struct object_vector : std::vector<T , slice_allocator<T > >
427	{
428	void insert (T *obj)
429	{
430	assert (!(obj->*index));
431	push_back (obj);
432	obj->*index = this->size ();
433	}
434
435	void insert (T &obj)
436	{
437	insert (&obj);
438	}
439
440	void erase (T *obj)
441	{
442	assert (obj->*index);
443	unsigned int pos = obj->*index;
444	obj->*index = 0;
445
446	if (pos < this->size ())
447	{
448	(this)[pos - 1] = (this)[this->size () - 1];
449	(this)[pos - 1]->index = pos;
450	}
451
452	this->pop_back ();
453	}
454
455	void erase (T &obj)
456	{
457	errase (&obj);
458	}
459	};
460
461	// basically does what strncpy should do, but appends "..." to strings exceeding length
462	void assign (char dst, const char src, int maxlen);
463
464	// type-safe version of assign
465	template<int N>
466	inline void assign (char (&dst)[N], const char *src)
467	{
468	assign ((char *)&dst, src, N);
469	}
470
471	typedef double tstamp;
472
473	// return current time as timestampe
474	tstamp now ();
475
476	int similar_direction (int a, int b);
477
478	// like printf, but returns a std::string
479	const std::string format (const char *format, ...);
480
481	#endif
482