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 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:	1.44
Committed:	Fri May 11 08:00:00 2007 UTC (17 years, 1 month ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.43:	+7 -0 lines
Log Message:	- introduce a notion of cpu load average within the server - use it to more gracefully increase swap intervals in the map-scheduler - add clip and lerp utility functions.
#	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 auto(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	template<typename T>
51	static inline T
52	lerp (T val, T min_in, T max_in, T min_out, T max_out)
53	{
54	return (val - min_in) * (max_out - min_out) / (max_in - min_in) + min_out;
55	}
56
57	// lots of stuff taken from FXT
58
59	/* Rotate right. This is used in various places for checksumming */
60	//TODO: that sucks, use a better checksum algo
61	static inline uint32_t
62	rotate_right (uint32_t c, uint32_t count = 1)
63	{
64	return (c << (32 - count)) \| (c >> count);
65	}
66
67	static inline uint32_t
68	rotate_left (uint32_t c, uint32_t count = 1)
69	{
70	return (c >> (32 - count)) \| (c << count);
71	}
72
73	// Return abs(a-b)
74	// Both a and b must not have the most significant bit set
75	static inline uint32_t
76	upos_abs_diff (uint32_t a, uint32_t b)
77	{
78	long d1 = b - a;
79	long d2 = (d1 & (d1 >> 31)) << 1;
80
81	return d1 - d2; // == (b - d) - (a + d);
82	}
83
84	// Both a and b must not have the most significant bit set
85	static inline uint32_t
86	upos_min (uint32_t a, uint32_t b)
87	{
88	int32_t d = b - a;
89	d &= d >> 31;
90	return a + d;
91	}
92
93	// Both a and b must not have the most significant bit set
94	static inline uint32_t
95	upos_max (uint32_t a, uint32_t b)
96	{
97	int32_t d = b - a;
98	d &= d >> 31;
99	return b - d;
100	}
101
102	// this is much faster than crossfires original algorithm
103	// on modern cpus
104	inline int
105	isqrt (int n)
106	{
107	return (int)sqrtf ((float)n);
108	}
109
110	// this is only twice as fast as naive sqrtf (dxdy+dydy)
111	#if 0
112	// and has a max. error of 6 in the range -100..+100.
113	#else
114	// and has a max. error of 9 in the range -100..+100.
115	#endif
116	inline int
117	idistance (int dx, int dy)
118	{
119	unsigned int dx_ = abs (dx);
120	unsigned int dy_ = abs (dy);
121
122	#if 0
123	return dx_ > dy_
124	? (dx_ * 61685 + dy_ * 26870) >> 16
125	: (dy_ * 61685 + dx_ * 26870) >> 16;
126	#else
127	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
128	#endif
129	}
130
131	/*
132	* absdir(int): Returns a number between 1 and 8, which represent
133	* the "absolute" direction of a number (it actually takes care of
134	* "overflow" in previous calculations of a direction).
135	*/
136	inline int
137	absdir (int d)
138	{
139	return ((d - 1) & 7) + 1;
140	}
141
142	// makes dynamically allocated objects zero-initialised
143	struct zero_initialised
144	{
145	void operator new (size_t s, void p)
146	{
147	memset (p, 0, s);
148	return p;
149	}
150
151	void *operator new (size_t s)
152	{
153	return g_slice_alloc0 (s);
154	}
155
156	void *operator new[] (size_t s)
157	{
158	return g_slice_alloc0 (s);
159	}
160
161	void operator delete (void *p, size_t s)
162	{
163	g_slice_free1 (s, p);
164	}
165
166	void operator delete[] (void *p, size_t s)
167	{
168	g_slice_free1 (s, p);
169	}
170	};
171
172	void *salloc_ (int n) throw (std::bad_alloc);
173	void salloc_ (int n, void src) throw (std::bad_alloc);
174
175	// strictly the same as g_slice_alloc, but never returns 0
176	template<typename T>
177	inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
178
179	// also copies src into the new area, like "memdup"
180	// if src is 0, clears the memory
181	template<typename T>
182	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
183
184	// clears the memory
185	template<typename T>
186	inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
187
188	// for symmetry
189	template<typename T>
190	inline void sfree (T *ptr, int n = 1) throw ()
191	{
192	#ifdef PREFER_MALLOC
193	free (ptr);
194	#else
195	g_slice_free1 (n * sizeof (T), (void *)ptr);
196	#endif
197	}
198
199	// a STL-compatible allocator that uses g_slice
200	// boy, this is verbose
201	template<typename Tp>
202	struct slice_allocator
203	{
204	typedef size_t size_type;
205	typedef ptrdiff_t difference_type;
206	typedef Tp *pointer;
207	typedef const Tp *const_pointer;
208	typedef Tp &reference;
209	typedef const Tp &const_reference;
210	typedef Tp value_type;
211
212	template <class U>
213	struct rebind
214	{
215	typedef slice_allocator<U> other;
216	};
217
218	slice_allocator () throw () { }
219	slice_allocator (const slice_allocator &o) throw () { }
220	template<typename Tp2>
221	slice_allocator (const slice_allocator<Tp2> &) throw () { }
222
223	~slice_allocator () { }
224
225	pointer address (reference x) const { return &x; }
226	const_pointer address (const_reference x) const { return &x; }
227
228	pointer allocate (size_type n, const_pointer = 0)
229	{
230	return salloc<Tp> (n);
231	}
232
233	void deallocate (pointer p, size_type n)
234	{
235	sfree<Tp> (p, n);
236	}
237
238	size_type max_size ()const throw ()
239	{
240	return size_t (-1) / sizeof (Tp);
241	}
242
243	void construct (pointer p, const Tp &val)
244	{
245	::new (p) Tp (val);
246	}
247
248	void destroy (pointer p)
249	{
250	p->~Tp ();
251	}
252	};
253
254	// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
255	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
256	// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
257	struct tausworthe_random_generator
258	{
259	// generator
260	uint32_t state [4];
261
262	void operator =(const tausworthe_random_generator &src)
263	{
264	state [0] = src.state [0];
265	state [1] = src.state [1];
266	state [2] = src.state [2];
267	state [3] = src.state [3];
268	}
269
270	void seed (uint32_t seed);
271	uint32_t next ();
272
273	// uniform distribution
274	uint32_t operator ()(uint32_t num)
275	{
276	return is_constant (num)
277	? (next () * (uint64_t)num) >> 32U
278	: get_range (num);
279	}
280
281	// return a number within (min .. max)
282	int operator () (int r_min, int r_max)
283	{
284	return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
285	? r_min + operator ()(r_max - r_min + 1)
286	: get_range (r_min, r_max);
287	}
288
289	double operator ()()
290	{
291	return this->next () / (double)0xFFFFFFFFU;
292	}
293
294	protected:
295	uint32_t get_range (uint32_t r_max);
296	int get_range (int r_min, int r_max);
297	};
298
299	typedef tausworthe_random_generator rand_gen;
300
301	extern rand_gen rndm;
302
303	template<class T>
304	struct refptr
305	{
306	T *p;
307
308	refptr () : p(0) { }
309	refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
310	refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
311	~refptr () { if (p) p->refcnt_dec (); }
312
313	const refptr<T> &operator =(T *o)
314	{
315	if (p) p->refcnt_dec ();
316	p = o;
317	if (p) p->refcnt_inc ();
318
319	return *this;
320	}
321
322	const refptr<T> &operator =(const refptr<T> o)
323	{
324	*this = o.p;
325	return *this;
326	}
327
328	T &operator * () const { return *p; }
329	T *operator ->() const { return p; }
330
331	operator T *() const { return p; }
332	};
333
334	typedef refptr<maptile> maptile_ptr;
335	typedef refptr<object> object_ptr;
336	typedef refptr<archetype> arch_ptr;
337	typedef refptr<client> client_ptr;
338	typedef refptr<player> player_ptr;
339
340	struct str_hash
341	{
342	std::size_t operator ()(const char *s) const
343	{
344	unsigned long hash = 0;
345
346	/* use the one-at-a-time hash function, which supposedly is
347	* better than the djb2-like one used by perl5.005, but
348	* certainly is better then the bug used here before.
349	* see http://burtleburtle.net/bob/hash/doobs.html
350	*/
351	while (*s)
352	{
353	hash += *s++;
354	hash += hash << 10;
355	hash ^= hash >> 6;
356	}
357
358	hash += hash << 3;
359	hash ^= hash >> 11;
360	hash += hash << 15;
361
362	return hash;
363	}
364	};
365
366	struct str_equal
367	{
368	bool operator ()(const char a, const char b) const
369	{
370	return !strcmp (a, b);
371	}
372	};
373
374	template<class T>
375	struct unordered_vector : std::vector<T, slice_allocator<T> >
376	{
377	typedef typename unordered_vector::iterator iterator;
378
379	void erase (unsigned int pos)
380	{
381	if (pos < this->size () - 1)
382	(this)[pos] = (this)[this->size () - 1];
383
384	this->pop_back ();
385	}
386
387	void erase (iterator i)
388	{
389	erase ((unsigned int )(i - this->begin ()));
390	}
391	};
392
393	template<class T, int T::* index>
394	struct object_vector : std::vector<T , slice_allocator<T > >
395	{
396	void insert (T *obj)
397	{
398	assert (!(obj->*index));
399	push_back (obj);
400	obj->*index = this->size ();
401	}
402
403	void insert (T &obj)
404	{
405	insert (&obj);
406	}
407
408	void erase (T *obj)
409	{
410	assert (obj->*index);
411	unsigned int pos = obj->*index;
412	obj->*index = 0;
413
414	if (pos < this->size ())
415	{
416	(this)[pos - 1] = (this)[this->size () - 1];
417	(this)[pos - 1]->index = pos;
418	}
419
420	this->pop_back ();
421	}
422
423	void erase (T &obj)
424	{
425	errase (&obj);
426	}
427	};
428
429	// basically does what strncpy should do, but appends "..." to strings exceeding length
430	void assign (char dst, const char src, int maxlen);
431
432	// type-safe version of assign
433	template<int N>
434	inline void assign (char (&dst)[N], const char *src)
435	{
436	assign ((char *)&dst, src, N);
437	}
438
439	typedef double tstamp;
440
441	// return current time as timestampe
442	tstamp now ();
443
444	int similar_direction (int a, int b);
445
446	// like printf, but returns a std::string
447	const std::string format (const char *format, ...);
448
449	#endif
450