server/include/util.h

#ifndef UTIL_H__
#define UTIL_H__

//#define PREFER_MALLOC

#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);

// 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; }

// lots of stuff taken from FXT

/* Rotate right. This is used in various places for checksumming */
//TODO: this sucks, use a better checksum algo
static inline uint32_t
rotate_right (uint32_t c)
{
  return (c << 31) | (c >> 1);
}

// 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 r_max)
  {
    return is_constant (r_max)
             ? this->next () % r_max
             : get_range (r_max);
  }

  // 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 + (*this) (max (r_max - r_min + 1, 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);
    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:	1.37
Committed:	Thu Feb 15 15:43:36 2007 UTC (17 years, 3 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.36:	+39 -0 lines
Log Message:	- useless µ-opts - use maximum norm in get_rangevector (a bit, should use more)
#	Content
1	#ifndef UTIL_H__
2	#define UTIL_H__
3
4	//#define PREFER_MALLOC
5
6	#if __GNUC__ >= 3
7	# define is_constant(c) __builtin_constant_p (c)
8	#else
9	# define is_constant(c) 0
10	#endif
11
12	#include <cstddef>
13	#include <cmath>
14	#include <new>
15	#include <vector>
16
17	#include <glib.h>
18
19	#include <shstr.h>
20	#include <traits.h>
21
22	// use a gcc extension for auto declarations until ISO C++ sanctifies them
23	#define AUTODECL(var,expr) typeof(expr) var = (expr)
24
25	// very ugly macro that basicaly declares and initialises a variable
26	// that is in scope for the next statement only
27	// works only for stuff that can be assigned 0 and converts to false
28	// (note: works great for pointers)
29	// most ugly macro I ever wrote
30	#define declvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
31
32	// in range including end
33	#define IN_RANGE_INC(val,beg,end) \
34	((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
35
36	// in range excluding end
37	#define IN_RANGE_EXC(val,beg,end) \
38	((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
39
40	void fork_abort (const char *msg);
41
42	// rationale for using (U) not (T) is to reduce signed/unsigned issues,
43	// as a is often a constant while b is the variable. it is still a bug, though.
44	template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
45	template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
46	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; }
47
48	template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
49
50	// lots of stuff taken from FXT
51
52	/* Rotate right. This is used in various places for checksumming */
53	//TODO: this sucks, use a better checksum algo
54	static inline uint32_t
55	rotate_right (uint32_t c)
56	{
57	return (c << 31) \| (c >> 1);
58	}
59
60	// Return abs(a-b)
61	// Both a and b must not have the most significant bit set
62	static inline uint32_t
63	upos_abs_diff (uint32_t a, uint32_t b)
64	{
65	long d1 = b - a;
66	long d2 = (d1 & (d1 >> 31)) << 1;
67
68	return d1 - d2; // == (b - d) - (a + d);
69	}
70
71	// Both a and b must not have the most significant bit set
72	static inline uint32_t
73	upos_min (uint32_t a, uint32_t b)
74	{
75	int32_t d = b - a;
76	d &= d >> 31;
77	return a + d;
78	}
79
80	// Both a and b must not have the most significant bit set
81	static inline uint32_t
82	upos_max (uint32_t a, uint32_t b)
83	{
84	int32_t d = b - a;
85	d &= d >> 31;
86	return b - d;
87	}
88
89	// this is much faster than crossfires original algorithm
90	// on modern cpus
91	inline int
92	isqrt (int n)
93	{
94	return (int)sqrtf ((float)n);
95	}
96
97	// this is only twice as fast as naive sqrtf (dxdy+dydy)
98	#if 0
99	// and has a max. error of 6 in the range -100..+100.
100	#else
101	// and has a max. error of 9 in the range -100..+100.
102	#endif
103	inline int
104	idistance (int dx, int dy)
105	{
106	unsigned int dx_ = abs (dx);
107	unsigned int dy_ = abs (dy);
108
109	#if 0
110	return dx_ > dy_
111	? (dx_ * 61685 + dy_ * 26870) >> 16
112	: (dy_ * 61685 + dx_ * 26870) >> 16;
113	#else
114	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
115	#endif
116	}
117
118	/*
119	* absdir(int): Returns a number between 1 and 8, which represent
120	* the "absolute" direction of a number (it actually takes care of
121	* "overflow" in previous calculations of a direction).
122	*/
123	inline int
124	absdir (int d)
125	{
126	return ((d - 1) & 7) + 1;
127	}
128
129	// makes dynamically allocated objects zero-initialised
130	struct zero_initialised
131	{
132	void operator new (size_t s, void p)
133	{
134	memset (p, 0, s);
135	return p;
136	}
137
138	void *operator new (size_t s)
139	{
140	return g_slice_alloc0 (s);
141	}
142
143	void *operator new[] (size_t s)
144	{
145	return g_slice_alloc0 (s);
146	}
147
148	void operator delete (void *p, size_t s)
149	{
150	g_slice_free1 (s, p);
151	}
152
153	void operator delete[] (void *p, size_t s)
154	{
155	g_slice_free1 (s, p);
156	}
157	};
158
159	void *salloc_ (int n) throw (std::bad_alloc);
160	void salloc_ (int n, void src) throw (std::bad_alloc);
161
162	// strictly the same as g_slice_alloc, but never returns 0
163	template<typename T>
164	inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
165
166	// also copies src into the new area, like "memdup"
167	// if src is 0, clears the memory
168	template<typename T>
169	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
170
171	// clears the memory
172	template<typename T>
173	inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
174
175	// for symmetry
176	template<typename T>
177	inline void sfree (T *ptr, int n = 1) throw ()
178	{
179	#ifdef PREFER_MALLOC
180	free (ptr);
181	#else
182	g_slice_free1 (n * sizeof (T), (void *)ptr);
183	#endif
184	}
185
186	// a STL-compatible allocator that uses g_slice
187	// boy, this is verbose
188	template<typename Tp>
189	struct slice_allocator
190	{
191	typedef size_t size_type;
192	typedef ptrdiff_t difference_type;
193	typedef Tp *pointer;
194	typedef const Tp *const_pointer;
195	typedef Tp &reference;
196	typedef const Tp &const_reference;
197	typedef Tp value_type;
198
199	template <class U>
200	struct rebind
201	{
202	typedef slice_allocator<U> other;
203	};
204
205	slice_allocator () throw () { }
206	slice_allocator (const slice_allocator &o) throw () { }
207	template<typename Tp2>
208	slice_allocator (const slice_allocator<Tp2> &) throw () { }
209
210	~slice_allocator () { }
211
212	pointer address (reference x) const { return &x; }
213	const_pointer address (const_reference x) const { return &x; }
214
215	pointer allocate (size_type n, const_pointer = 0)
216	{
217	return salloc<Tp> (n);
218	}
219
220	void deallocate (pointer p, size_type n)
221	{
222	sfree<Tp> (p, n);
223	}
224
225	size_type max_size ()const throw ()
226	{
227	return size_t (-1) / sizeof (Tp);
228	}
229
230	void construct (pointer p, const Tp &val)
231	{
232	::new (p) Tp (val);
233	}
234
235	void destroy (pointer p)
236	{
237	p->~Tp ();
238	}
239	};
240
241	// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
242	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
243	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
244	struct tausworthe_random_generator
245	{
246	// generator
247	uint32_t state [4];
248
249	void operator =(const tausworthe_random_generator &src)
250	{
251	state [0] = src.state [0];
252	state [1] = src.state [1];
253	state [2] = src.state [2];
254	state [3] = src.state [3];
255	}
256
257	void seed (uint32_t seed);
258	uint32_t next ();
259
260	// uniform distribution
261	uint32_t operator ()(uint32_t r_max)
262	{
263	return is_constant (r_max)
264	? this->next () % r_max
265	: get_range (r_max);
266	}
267
268	// return a number within (min .. max)
269	int operator () (int r_min, int r_max)
270	{
271	return is_constant (r_min) && is_constant (r_max)
272	? r_min + (*this) (max (r_max - r_min + 1, 1))
273	: get_range (r_min, r_max);
274	}
275
276	double operator ()()
277	{
278	return this->next () / (double)0xFFFFFFFFU;
279	}
280
281	protected:
282	uint32_t get_range (uint32_t r_max);
283	int get_range (int r_min, int r_max);
284	};
285
286	typedef tausworthe_random_generator rand_gen;
287
288	extern rand_gen rndm;
289
290	template<class T>
291	struct refptr
292	{
293	T *p;
294
295	refptr () : p(0) { }
296	refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
297	refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
298	~refptr () { if (p) p->refcnt_dec (); }
299
300	const refptr<T> &operator =(T *o)
301	{
302	if (p) p->refcnt_dec ();
303	p = o;
304	if (p) p->refcnt_inc ();
305
306	return *this;
307	}
308
309	const refptr<T> &operator =(const refptr<T> o)
310	{
311	*this = o.p;
312	return *this;
313	}
314
315	T &operator * () const { return *p; }
316	T *operator ->() const { return p; }
317
318	operator T *() const { return p; }
319	};
320
321	typedef refptr<maptile> maptile_ptr;
322	typedef refptr<object> object_ptr;
323	typedef refptr<archetype> arch_ptr;
324	typedef refptr<client> client_ptr;
325	typedef refptr<player> player_ptr;
326
327	struct str_hash
328	{
329	std::size_t operator ()(const char *s) const
330	{
331	unsigned long hash = 0;
332
333	/* use the one-at-a-time hash function, which supposedly is
334	* better than the djb2-like one used by perl5.005, but
335	* certainly is better then the bug used here before.
336	* see http://burtleburtle.net/bob/hash/doobs.html
337	*/
338	while (*s)
339	{
340	hash += *s++;
341	hash += hash << 10;
342	hash ^= hash >> 6;
343	}
344
345	hash += hash << 3;
346	hash ^= hash >> 11;
347	hash += hash << 15;
348
349	return hash;
350	}
351	};
352
353	struct str_equal
354	{
355	bool operator ()(const char a, const char b) const
356	{
357	return !strcmp (a, b);
358	}
359	};
360
361	template<class T>
362	struct unordered_vector : std::vector<T, slice_allocator<T> >
363	{
364	typedef typename unordered_vector::iterator iterator;
365
366	void erase (unsigned int pos)
367	{
368	if (pos < this->size () - 1)
369	(this)[pos] = (this)[this->size () - 1];
370
371	this->pop_back ();
372	}
373
374	void erase (iterator i)
375	{
376	erase ((unsigned int )(i - this->begin ()));
377	}
378	};
379
380	template<class T, int T::* index>
381	struct object_vector : std::vector<T , slice_allocator<T > >
382	{
383	void insert (T *obj)
384	{
385	assert (!(obj->*index));
386	push_back (obj);
387	obj->*index = this->size ();
388	}
389
390	void insert (T &obj)
391	{
392	insert (&obj);
393	}
394
395	void erase (T *obj)
396	{
397	assert (obj->*index);
398	int pos = obj->*index;
399	obj->*index = 0;
400
401	if (pos < this->size ())
402	{
403	(this)[pos - 1] = (this)[this->size () - 1];
404	(this)[pos - 1]->index = pos;
405	}
406
407	this->pop_back ();
408	}
409
410	void erase (T &obj)
411	{
412	errase (&obj);
413	}
414	};
415
416	// basically does what strncpy should do, but appends "..." to strings exceeding length
417	void assign (char dst, const char src, int maxlen);
418
419	// type-safe version of assign
420	template<int N>
421	inline void assign (char (&dst)[N], const char *src)
422	{
423	assign ((char *)&dst, src, N);
424	}
425
426	typedef double tstamp;
427
428	// return current time as timestampe
429	tstamp now ();
430
431	int similar_direction (int a, int b);
432
433	#endif
434