server/include/util.h

#ifndef UTIL_H__
#define UTIL_H__

#if __GNUC__ >= 3
# define is_constant(c) __builtin_constant_p (c)
#else
# define is_constant(c) 0
#endif

#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 AUTODECL(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);

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

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

// 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 ()
{
  g_slice_free1 (n * sizeof (T), (void *)ptr);
}

// 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
{
  uint32_t state [4];

  tausworthe_random_generator (uint32_t seed);
  uint32_t next ();

  uint32_t operator ()(uint32_t r_max)
  {
    return next () % r_max;
  }

  // return a number within (min .. max)
  int operator () (int r_min, int r_max)
  {
    return r_min + next () % max (r_max - r_min + 1, 1);
  }

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

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);
    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);

#endif

Revision:	1.32
Committed:	Thu Jan 18 19:32:37 2007 UTC (17 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.31:	+37 -6 lines
Log Message:	just experimenting
#	Content
1	#ifndef UTIL_H__
2	#define UTIL_H__
3
4	#if __GNUC__ >= 3
5	# define is_constant(c) __builtin_constant_p (c)
6	#else
7	# define is_constant(c) 0
8	#endif
9
10	#include <cstddef>
11	#include <cmath>
12	#include <new>
13	#include <vector>
14
15	#include <glib.h>
16
17	#include <shstr.h>
18	#include <traits.h>
19
20	// use a gcc extension for auto declarations until ISO C++ sanctifies them
21	#define AUTODECL(var,expr) typeof(expr) var = (expr)
22
23	// very ugly macro that basicaly declares and initialises a variable
24	// that is in scope for the next statement only
25	// works only for stuff that can be assigned 0 and converts to false
26	// (note: works great for pointers)
27	// most ugly macro I ever wrote
28	#define declvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
29
30	// in range including end
31	#define IN_RANGE_INC(val,beg,end) \
32	((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
33
34	// in range excluding end
35	#define IN_RANGE_EXC(val,beg,end) \
36	((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
37
38	void fork_abort (const char *msg);
39
40	template<typename T, typename U> static inline T min (T a, U b) { return a < (T)b ? a : (T)b; }
41	template<typename T, typename U> static inline T max (T a, U b) { return a > (T)b ? a : (T)b; }
42	template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? a : v >(T)b ? b : v; }
43
44	template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
45
46	// this is much faster than crossfires original algorithm
47	// on modern cpus
48	inline int
49	isqrt (int n)
50	{
51	return (int)sqrtf ((float)n);
52	}
53
54	// this is only twice as fast as naive sqrtf (dxdy+dydy)
55	#if 0
56	// and has a max. error of 6 in the range -100..+100.
57	#else
58	// and has a max. error of 9 in the range -100..+100.
59	#endif
60	inline int
61	idistance (int dx, int dy)
62	{
63	unsigned int dx_ = abs (dx);
64	unsigned int dy_ = abs (dy);
65
66	#if 0
67	return dx_ > dy_
68	? (dx_ * 61685 + dy_ * 26870) >> 16
69	: (dy_ * 61685 + dx_ * 26870) >> 16;
70	#else
71	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
72	#endif
73	}
74
75	/*
76	* absdir(int): Returns a number between 1 and 8, which represent
77	* the "absolute" direction of a number (it actually takes care of
78	* "overflow" in previous calculations of a direction).
79	*/
80	inline int
81	absdir (int d)
82	{
83	return ((d - 1) & 7) + 1;
84	}
85
86	// makes dynamically allocated objects zero-initialised
87	struct zero_initialised
88	{
89	void operator new (size_t s, void p)
90	{
91	memset (p, 0, s);
92	return p;
93	}
94
95	void *operator new (size_t s)
96	{
97	return g_slice_alloc0 (s);
98	}
99
100	void *operator new[] (size_t s)
101	{
102	return g_slice_alloc0 (s);
103	}
104
105	void operator delete (void *p, size_t s)
106	{
107	g_slice_free1 (s, p);
108	}
109
110	void operator delete[] (void *p, size_t s)
111	{
112	g_slice_free1 (s, p);
113	}
114	};
115
116	void *salloc_ (int n) throw (std::bad_alloc);
117	void salloc_ (int n, void src) throw (std::bad_alloc);
118
119	// strictly the same as g_slice_alloc, but never returns 0
120	template<typename T>
121	inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
122
123	// also copies src into the new area, like "memdup"
124	// if src is 0, clears the memory
125	template<typename T>
126	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
127
128	// clears the memory
129	template<typename T>
130	inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
131
132	// for symmetry
133	template<typename T>
134	inline void sfree (T *ptr, int n = 1) throw ()
135	{
136	g_slice_free1 (n * sizeof (T), (void *)ptr);
137	}
138
139	// a STL-compatible allocator that uses g_slice
140	// boy, this is verbose
141	template<typename Tp>
142	struct slice_allocator
143	{
144	typedef size_t size_type;
145	typedef ptrdiff_t difference_type;
146	typedef Tp *pointer;
147	typedef const Tp *const_pointer;
148	typedef Tp &reference;
149	typedef const Tp &const_reference;
150	typedef Tp value_type;
151
152	template <class U>
153	struct rebind
154	{
155	typedef slice_allocator<U> other;
156	};
157
158	slice_allocator () throw () { }
159	slice_allocator (const slice_allocator &o) throw () { }
160	template<typename Tp2>
161	slice_allocator (const slice_allocator<Tp2> &) throw () { }
162
163	~slice_allocator () { }
164
165	pointer address (reference x) const { return &x; }
166	const_pointer address (const_reference x) const { return &x; }
167
168	pointer allocate (size_type n, const_pointer = 0)
169	{
170	return salloc<Tp> (n);
171	}
172
173	void deallocate (pointer p, size_type n)
174	{
175	sfree<Tp> (p, n);
176	}
177
178	size_type max_size ()const throw ()
179	{
180	return size_t (-1) / sizeof (Tp);
181	}
182
183	void construct (pointer p, const Tp &val)
184	{
185	::new (p) Tp (val);
186	}
187
188	void destroy (pointer p)
189	{
190	p->~Tp ();
191	}
192	};
193
194	// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
195	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
196	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
197	struct tausworthe_random_generator
198	{
199	uint32_t state [4];
200
201	tausworthe_random_generator (uint32_t seed);
202	uint32_t next ();
203
204	uint32_t operator ()(uint32_t r_max)
205	{
206	return next () % r_max;
207	}
208
209	// return a number within (min .. max)
210	int operator () (int r_min, int r_max)
211	{
212	return r_min + next () % max (r_max - r_min + 1, 1);
213	}
214
215	double operator ()()
216	{
217	return next () / (double)0xFFFFFFFFU;
218	}
219	};
220
221	typedef tausworthe_random_generator rand_gen;
222
223	extern rand_gen rndm;
224
225	template<class T>
226	struct refptr
227	{
228	T *p;
229
230	refptr () : p(0) { }
231	refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
232	refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
233	~refptr () { if (p) p->refcnt_dec (); }
234
235	const refptr<T> &operator =(T *o)
236	{
237	if (p) p->refcnt_dec ();
238	p = o;
239	if (p) p->refcnt_inc ();
240
241	return *this;
242	}
243
244	const refptr<T> &operator =(const refptr<T> o)
245	{
246	*this = o.p;
247	return *this;
248	}
249
250	T &operator * () const { return *p; }
251	T *operator ->() const { return p; }
252
253	operator T *() const { return p; }
254	};
255
256	typedef refptr<maptile> maptile_ptr;
257	typedef refptr<object> object_ptr;
258	typedef refptr<archetype> arch_ptr;
259	typedef refptr<client> client_ptr;
260	typedef refptr<player> player_ptr;
261
262	struct str_hash
263	{
264	std::size_t operator ()(const char *s) const
265	{
266	unsigned long hash = 0;
267
268	/* use the one-at-a-time hash function, which supposedly is
269	* better than the djb2-like one used by perl5.005, but
270	* certainly is better then the bug used here before.
271	* see http://burtleburtle.net/bob/hash/doobs.html
272	*/
273	while (*s)
274	{
275	hash += *s++;
276	hash += hash << 10;
277	hash ^= hash >> 6;
278	}
279
280	hash += hash << 3;
281	hash ^= hash >> 11;
282	hash += hash << 15;
283
284	return hash;
285	}
286	};
287
288	struct str_equal
289	{
290	bool operator ()(const char a, const char b) const
291	{
292	return !strcmp (a, b);
293	}
294	};
295
296	template<class T>
297	struct unordered_vector : std::vector<T, slice_allocator<T> >
298	{
299	typedef typename unordered_vector::iterator iterator;
300
301	void erase (unsigned int pos)
302	{
303	if (pos < this->size () - 1)
304	(this)[pos] = (this)[this->size () - 1];
305
306	this->pop_back ();
307	}
308
309	void erase (iterator i)
310	{
311	erase ((unsigned int )(i - this->begin ()));
312	}
313	};
314
315	template<class T, int T::* index>
316	struct object_vector : std::vector<T , slice_allocator<T > >
317	{
318	void insert (T *obj)
319	{
320	assert (!(obj->*index));
321	push_back (obj);
322	obj->*index = this->size ();
323	}
324
325	void insert (T &obj)
326	{
327	insert (&obj);
328	}
329
330	void erase (T *obj)
331	{
332	assert (obj->*index);
333	int pos = obj->*index;
334	obj->*index = 0;
335
336	if (pos < this->size ())
337	{
338	(this)[pos - 1] = (this)[this->size () - 1];
339	(this)[pos - 1]->index = pos;
340	}
341
342	this->pop_back ();
343	}
344
345	void erase (T &obj)
346	{
347	errase (&obj);
348	}
349	};
350
351	// basically does what strncpy should do, but appends "..." to strings exceeding length
352	void assign (char dst, const char src, int maxlen);
353
354	// type-safe version of assign
355	template<int N>
356	inline void assign (char (&dst)[N], const char *src)
357	{
358	assign ((char *)&dst, src, N);
359	}
360
361	typedef double tstamp;
362
363	// return current time as timestampe
364	tstamp now ();
365
366	int similar_direction (int a, int b);
367
368	#endif
369