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))

// 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 ();
  }
};

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);
  }
};

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; }

// 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:	1.29
Committed:	Mon Jan 15 01:39:42 2007 UTC (17 years, 4 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.28:	+10 -0 lines
Log Message:	more micro-optimisation, use idistance, min is faster than MIN
#	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	// this is much faster than crossfires original algorithm
39	// on modern cpus
40	inline int
41	isqrt (int n)
42	{
43	return (int)sqrtf ((float)n);
44	}
45
46	// this is only twice as fast as naive sqrtf (dxdy+dydy)
47	#if 0
48	// and has a max. error of 6 in the range -100..+100.
49	#else
50	// and has a max. error of 9 in the range -100..+100.
51	#endif
52	inline int
53	idistance (int dx, int dy)
54	{
55	unsigned int dx_ = abs (dx);
56	unsigned int dy_ = abs (dy);
57
58	#if 0
59	return dx_ > dy_
60	? (dx_ * 61685 + dy_ * 26870) >> 16
61	: (dy_ * 61685 + dx_ * 26870) >> 16;
62	#else
63	return dx + dy - min (dx, dy) * 5 / 8;
64	#endif
65	}
66
67	/*
68	* absdir(int): Returns a number between 1 and 8, which represent
69	* the "absolute" direction of a number (it actually takes care of
70	* "overflow" in previous calculations of a direction).
71	*/
72	inline int
73	absdir (int d)
74	{
75	return ((d - 1) & 7) + 1;
76	}
77
78	// makes dynamically allocated objects zero-initialised
79	struct zero_initialised
80	{
81	void operator new (size_t s, void p)
82	{
83	memset (p, 0, s);
84	return p;
85	}
86
87	void *operator new (size_t s)
88	{
89	return g_slice_alloc0 (s);
90	}
91
92	void *operator new[] (size_t s)
93	{
94	return g_slice_alloc0 (s);
95	}
96
97	void operator delete (void *p, size_t s)
98	{
99	g_slice_free1 (s, p);
100	}
101
102	void operator delete[] (void *p, size_t s)
103	{
104	g_slice_free1 (s, p);
105	}
106	};
107
108	void *salloc_ (int n) throw (std::bad_alloc);
109	void salloc_ (int n, void src) throw (std::bad_alloc);
110
111	// strictly the same as g_slice_alloc, but never returns 0
112	template<typename T>
113	inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
114
115	// also copies src into the new area, like "memdup"
116	// if src is 0, clears the memory
117	template<typename T>
118	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
119
120	// clears the memory
121	template<typename T>
122	inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
123
124	// for symmetry
125	template<typename T>
126	inline void sfree (T *ptr, int n = 1) throw ()
127	{
128	g_slice_free1 (n * sizeof (T), (void *)ptr);
129	}
130
131	// a STL-compatible allocator that uses g_slice
132	// boy, this is verbose
133	template<typename Tp>
134	struct slice_allocator
135	{
136	typedef size_t size_type;
137	typedef ptrdiff_t difference_type;
138	typedef Tp *pointer;
139	typedef const Tp *const_pointer;
140	typedef Tp &reference;
141	typedef const Tp &const_reference;
142	typedef Tp value_type;
143
144	template <class U>
145	struct rebind
146	{
147	typedef slice_allocator<U> other;
148	};
149
150	slice_allocator () throw () { }
151	slice_allocator (const slice_allocator &o) throw () { }
152	template<typename Tp2>
153	slice_allocator (const slice_allocator<Tp2> &) throw () { }
154
155	~slice_allocator () { }
156
157	pointer address (reference x) const { return &x; }
158	const_pointer address (const_reference x) const { return &x; }
159
160	pointer allocate (size_type n, const_pointer = 0)
161	{
162	return salloc<Tp> (n);
163	}
164
165	void deallocate (pointer p, size_type n)
166	{
167	sfree<Tp> (p, n);
168	}
169
170	size_type max_size ()const throw ()
171	{
172	return size_t (-1) / sizeof (Tp);
173	}
174
175	void construct (pointer p, const Tp &val)
176	{
177	::new (p) Tp (val);
178	}
179
180	void destroy (pointer p)
181	{
182	p->~Tp ();
183	}
184	};
185
186	template<class T>
187	struct refptr
188	{
189	T *p;
190
191	refptr () : p(0) { }
192	refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
193	refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
194	~refptr () { if (p) p->refcnt_dec (); }
195
196	const refptr<T> &operator =(T *o)
197	{
198	if (p) p->refcnt_dec ();
199	p = o;
200	if (p) p->refcnt_inc ();
201
202	return *this;
203	}
204
205	const refptr<T> &operator =(const refptr<T> o)
206	{
207	*this = o.p;
208	return *this;
209	}
210
211	T &operator * () const { return *p; }
212	T *operator ->() const { return p; }
213
214	operator T *() const { return p; }
215	};
216
217	typedef refptr<maptile> maptile_ptr;
218	typedef refptr<object> object_ptr;
219	typedef refptr<archetype> arch_ptr;
220	typedef refptr<client> client_ptr;
221	typedef refptr<player> player_ptr;
222
223	struct str_hash
224	{
225	std::size_t operator ()(const char *s) const
226	{
227	unsigned long hash = 0;
228
229	/* use the one-at-a-time hash function, which supposedly is
230	* better than the djb2-like one used by perl5.005, but
231	* certainly is better then the bug used here before.
232	* see http://burtleburtle.net/bob/hash/doobs.html
233	*/
234	while (*s)
235	{
236	hash += *s++;
237	hash += hash << 10;
238	hash ^= hash >> 6;
239	}
240
241	hash += hash << 3;
242	hash ^= hash >> 11;
243	hash += hash << 15;
244
245	return hash;
246	}
247	};
248
249	struct str_equal
250	{
251	bool operator ()(const char a, const char b) const
252	{
253	return !strcmp (a, b);
254	}
255	};
256
257	template<class T>
258	struct unordered_vector : std::vector<T, slice_allocator<T> >
259	{
260	typedef typename unordered_vector::iterator iterator;
261
262	void erase (unsigned int pos)
263	{
264	if (pos < this->size () - 1)
265	(this)[pos] = (this)[this->size () - 1];
266
267	this->pop_back ();
268	}
269
270	void erase (iterator i)
271	{
272	erase ((unsigned int )(i - this->begin ()));
273	}
274	};
275
276	template<class T, int T::* index>
277	struct object_vector : std::vector<T , slice_allocator<T > >
278	{
279	void insert (T *obj)
280	{
281	assert (!(obj->*index));
282	push_back (obj);
283	obj->*index = this->size ();
284	}
285
286	void insert (T &obj)
287	{
288	insert (&obj);
289	}
290
291	void erase (T *obj)
292	{
293	assert (obj->*index);
294	int pos = obj->*index;
295	obj->*index = 0;
296
297	if (pos < this->size ())
298	{
299	(this)[pos - 1] = (this)[this->size () - 1];
300	(this)[pos - 1]->index = pos;
301	}
302
303	this->pop_back ();
304	}
305
306	void erase (T &obj)
307	{
308	errase (&obj);
309	}
310	};
311
312	template<typename T, typename U> static inline T min (T a, U b) { return a < (T)b ? a : (T)b; }
313	template<typename T, typename U> static inline T max (T a, U b) { return a > (T)b ? a : (T)b; }
314	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; }
315
316	template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
317
318	// basically does what strncpy should do, but appends "..." to strings exceeding length
319	void assign (char dst, const char src, int maxlen);
320
321	// type-safe version of assign
322	template<int N>
323	inline void assign (char (&dst)[N], const char *src)
324	{
325	assign ((char *)&dst, src, N);
326	}
327
328	typedef double tstamp;
329
330	// return current time as timestampe
331	tstamp now ();
332
333	int similar_direction (int a, int b);
334
335	#endif
336