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
{
  // 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:	1.34
Committed:	Fri Jan 19 15:15:50 2007 UTC (17 years, 5 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.33:	+22 -4 lines
Log Message:	- goofing around with my skills (overoptimisation to learn something)
#	User	Rev	Content
1	root	1.1	#ifndef UTIL_H__
2			#define UTIL_H__
3
4	root	1.2	#if __GNUC__ >= 3
5			# define is_constant(c) __builtin_constant_p (c)
6			#else
7			# define is_constant(c) 0
8			#endif
9
10	root	1.11	#include <cstddef>
11	root	1.28	#include <cmath>
12	root	1.25	#include <new>
13			#include <vector>
14	root	1.11
15			#include <glib.h>
16
17	root	1.25	#include <shstr.h>
18			#include <traits.h>
19
20	root	1.14	// use a gcc extension for auto declarations until ISO C++ sanctifies them
21			#define AUTODECL(var,expr) typeof(expr) var = (expr)
22
23	root	1.26	// 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	root	1.27	// 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	root	1.31	void fork_abort (const char *msg);
39
40	root	1.32	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	root	1.28	// 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	root	1.30	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
72	root	1.28	#endif
73			}
74
75	root	1.29	/*
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	root	1.28
86	root	1.1	// makes dynamically allocated objects zero-initialised
87			struct zero_initialised
88			{
89	root	1.11	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	root	1.20	void *salloc_ (int n) throw (std::bad_alloc);
117			void salloc_ (int n, void src) throw (std::bad_alloc);
118
119	root	1.12	// strictly the same as g_slice_alloc, but never returns 0
120	root	1.20	template<typename T>
121			inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
122
123	root	1.17	// also copies src into the new area, like "memdup"
124	root	1.18	// if src is 0, clears the memory
125			template<typename T>
126	root	1.20	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
127	root	1.18
128	root	1.21	// 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	root	1.12	// for symmetry
133	root	1.18	template<typename T>
134	root	1.20	inline void sfree (T *ptr, int n = 1) throw ()
135	root	1.12	{
136	root	1.20	g_slice_free1 (n * sizeof (T), (void *)ptr);
137	root	1.12	}
138	root	1.11
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	root	1.18	return salloc<Tp> (n);
171	root	1.11	}
172
173			void deallocate (pointer p, size_type n)
174			{
175	root	1.19	sfree<Tp> (p, n);
176	root	1.11	}
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	root	1.1	};
193
194	root	1.32	// 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	root	1.34	// generator
200	root	1.32	uint32_t state [4];
201
202	root	1.34	void operator =(const tausworthe_random_generator &src)
203			{
204			state [0] = src.state [0];
205			state [1] = src.state [1];
206			state [2] = src.state [2];
207			state [3] = src.state [3];
208			}
209
210			void seed (uint32_t seed);
211	root	1.32	uint32_t next ();
212
213	root	1.34	// uniform distribution
214	root	1.32	uint32_t operator ()(uint32_t r_max)
215			{
216	root	1.34	return is_constant (r_max)
217			? this->next () % r_max
218			: get_range (r_max);
219	root	1.32	}
220
221			// return a number within (min .. max)
222			int operator () (int r_min, int r_max)
223			{
224	root	1.34	return is_constant (r_min) && is_constant (r_max)
225			? r_min + (*this) (max (r_max - r_min + 1, 1))
226			: get_range (r_min, r_max);
227	root	1.32	}
228
229			double operator ()()
230			{
231	root	1.34	return this->next () / (double)0xFFFFFFFFU;
232	root	1.32	}
233	root	1.34
234			protected:
235			uint32_t get_range (uint32_t r_max);
236			int get_range (int r_min, int r_max);
237	root	1.32	};
238
239			typedef tausworthe_random_generator rand_gen;
240
241			extern rand_gen rndm;
242
243	root	1.7	template<class T>
244			struct refptr
245			{
246			T *p;
247
248			refptr () : p(0) { }
249			refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
250			refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
251			~refptr () { if (p) p->refcnt_dec (); }
252
253			const refptr<T> &operator =(T *o)
254			{
255			if (p) p->refcnt_dec ();
256			p = o;
257			if (p) p->refcnt_inc ();
258
259			return *this;
260			}
261
262			const refptr<T> &operator =(const refptr<T> o)
263			{
264			*this = o.p;
265			return *this;
266			}
267
268			T &operator * () const { return *p; }
269			T *operator ->() const { return p; }
270
271			operator T *() const { return p; }
272			};
273
274	root	1.24	typedef refptr<maptile> maptile_ptr;
275	root	1.22	typedef refptr<object> object_ptr;
276			typedef refptr<archetype> arch_ptr;
277	root	1.24	typedef refptr<client> client_ptr;
278			typedef refptr<player> player_ptr;
279	root	1.22
280	root	1.4	struct str_hash
281			{
282			std::size_t operator ()(const char *s) const
283			{
284			unsigned long hash = 0;
285
286			/* use the one-at-a-time hash function, which supposedly is
287			* better than the djb2-like one used by perl5.005, but
288			* certainly is better then the bug used here before.
289			* see http://burtleburtle.net/bob/hash/doobs.html
290			*/
291			while (*s)
292			{
293			hash += *s++;
294			hash += hash << 10;
295			hash ^= hash >> 6;
296			}
297
298			hash += hash << 3;
299			hash ^= hash >> 11;
300			hash += hash << 15;
301
302			return hash;
303			}
304			};
305
306			struct str_equal
307			{
308			bool operator ()(const char a, const char b) const
309			{
310			return !strcmp (a, b);
311			}
312			};
313
314	root	1.26	template<class T>
315			struct unordered_vector : std::vector<T, slice_allocator<T> >
316	root	1.6	{
317	root	1.11	typedef typename unordered_vector::iterator iterator;
318	root	1.6
319			void erase (unsigned int pos)
320			{
321			if (pos < this->size () - 1)
322			(this)[pos] = (this)[this->size () - 1];
323
324			this->pop_back ();
325			}
326
327			void erase (iterator i)
328			{
329			erase ((unsigned int )(i - this->begin ()));
330			}
331			};
332
333	root	1.26	template<class T, int T::* index>
334			struct object_vector : std::vector<T , slice_allocator<T > >
335			{
336			void insert (T *obj)
337			{
338			assert (!(obj->*index));
339			push_back (obj);
340			obj->*index = this->size ();
341			}
342
343			void insert (T &obj)
344			{
345			insert (&obj);
346			}
347
348			void erase (T *obj)
349			{
350			assert (obj->*index);
351			int pos = obj->*index;
352			obj->*index = 0;
353
354			if (pos < this->size ())
355			{
356			(this)[pos - 1] = (this)[this->size () - 1];
357			(this)[pos - 1]->index = pos;
358			}
359
360			this->pop_back ();
361			}
362
363			void erase (T &obj)
364			{
365			errase (&obj);
366			}
367			};
368
369	root	1.10	// basically does what strncpy should do, but appends "..." to strings exceeding length
370			void assign (char dst, const char src, int maxlen);
371
372			// type-safe version of assign
373	root	1.9	template<int N>
374			inline void assign (char (&dst)[N], const char *src)
375			{
376	root	1.10	assign ((char *)&dst, src, N);
377	root	1.9	}
378
379	root	1.17	typedef double tstamp;
380
381			// return current time as timestampe
382			tstamp now ();
383
384	root	1.25	int similar_direction (int a, int b);
385
386	root	1.1	#endif
387