server/include/util.h

#ifndef UTIL_H__
#define UTIL_H__

//#define PREFER_MALLOC

#if __GNUC__ >= 3
# define is_constant(c)             __builtin_constant_p (c)
# define expect(expr,value)         __builtin_expect ((expr),(value))
# define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
#else
# define is_constant(c)             0
# define expect(expr,value)         (expr)
# define prefetch(addr,rw,locality)
#endif

// put into ifs if you are very sure that the expression
// is mostly true or mosty false. note that these return
// booleans, not the expression.
#define expect_false(expr) expect ((expr) != 0, 0)
#define expect_true(expr)  expect ((expr) != 0, 1)

#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:	1.45
Committed:	Sat May 26 15:44:05 2007 UTC (17 years ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_1
Changes since 1.44:	+12 -2 lines
Log Message:	- restore after combined mainboard+harddisk crash - cleanup/fixes for 2.1 release - fix invoke to actually do work - refactor invoke shortcuts, gcc cannot inline varargs functions. - optimised invoke to 4-5 insns in the common case. - optimised (For no good reason) the int-to-ascii conversions of dynbuf_text into division-less and branchless code (of which I am pretty proud). - actually move players to their savebed when they did not use one and the map has been reste in the meantime. does not kill (yet) when too long. - enter_map is now handled completely in perl. - goto is now using generation counting to ensure that only the most-recently-issues goto will succeed. - make some heavy use of __builtin_expect to streamline rare callbacks even more. - optimised thawer.
#	User	Rev	Content
1	root	1.1	#ifndef UTIL_H__
2			#define UTIL_H__
3
4	root	1.36	//#define PREFER_MALLOC
5
6	root	1.2	#if __GNUC__ >= 3
7	root	1.45	# define is_constant(c) __builtin_constant_p (c)
8			# define expect(expr,value) __builtin_expect ((expr),(value))
9			# define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
10	root	1.2	#else
11	root	1.45	# define is_constant(c) 0
12			# define expect(expr,value) (expr)
13			# define prefetch(addr,rw,locality)
14	root	1.2	#endif
15
16	root	1.45	// put into ifs if you are very sure that the expression
17			// is mostly true or mosty false. note that these return
18			// booleans, not the expression.
19			#define expect_false(expr) expect ((expr) != 0, 0)
20			#define expect_true(expr) expect ((expr) != 0, 1)
21
22	root	1.11	#include <cstddef>
23	root	1.28	#include <cmath>
24	root	1.25	#include <new>
25			#include <vector>
26	root	1.11
27			#include <glib.h>
28
29	root	1.25	#include <shstr.h>
30			#include <traits.h>
31
32	root	1.14	// use a gcc extension for auto declarations until ISO C++ sanctifies them
33	root	1.40	#define auto(var,expr) typeof(expr) var = (expr)
34	root	1.14
35	root	1.26	// very ugly macro that basicaly declares and initialises a variable
36			// that is in scope for the next statement only
37			// works only for stuff that can be assigned 0 and converts to false
38			// (note: works great for pointers)
39			// most ugly macro I ever wrote
40			#define declvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
41
42	root	1.27	// in range including end
43			#define IN_RANGE_INC(val,beg,end) \
44			((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
45
46			// in range excluding end
47			#define IN_RANGE_EXC(val,beg,end) \
48			((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
49
50	root	1.31	void fork_abort (const char *msg);
51
52	root	1.35	// rationale for using (U) not (T) is to reduce signed/unsigned issues,
53			// as a is often a constant while b is the variable. it is still a bug, though.
54			template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
55			template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
56			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; }
57	root	1.32
58			template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
59
60	root	1.44	template<typename T>
61			static inline T
62			lerp (T val, T min_in, T max_in, T min_out, T max_out)
63			{
64			return (val - min_in) * (max_out - min_out) / (max_in - min_in) + min_out;
65			}
66
67	root	1.37	// lots of stuff taken from FXT
68
69			/* Rotate right. This is used in various places for checksumming */
70	root	1.38	//TODO: that sucks, use a better checksum algo
71	root	1.37	static inline uint32_t
72	root	1.38	rotate_right (uint32_t c, uint32_t count = 1)
73	root	1.37	{
74	root	1.38	return (c << (32 - count)) \| (c >> count);
75			}
76
77			static inline uint32_t
78			rotate_left (uint32_t c, uint32_t count = 1)
79			{
80			return (c >> (32 - count)) \| (c << count);
81	root	1.37	}
82
83			// Return abs(a-b)
84			// Both a and b must not have the most significant bit set
85			static inline uint32_t
86			upos_abs_diff (uint32_t a, uint32_t b)
87			{
88			long d1 = b - a;
89			long d2 = (d1 & (d1 >> 31)) << 1;
90
91			return d1 - d2; // == (b - d) - (a + d);
92			}
93
94			// Both a and b must not have the most significant bit set
95			static inline uint32_t
96			upos_min (uint32_t a, uint32_t b)
97			{
98			int32_t d = b - a;
99			d &= d >> 31;
100			return a + d;
101			}
102
103			// Both a and b must not have the most significant bit set
104			static inline uint32_t
105			upos_max (uint32_t a, uint32_t b)
106			{
107			int32_t d = b - a;
108			d &= d >> 31;
109			return b - d;
110			}
111
112	root	1.28	// this is much faster than crossfires original algorithm
113			// on modern cpus
114			inline int
115			isqrt (int n)
116			{
117			return (int)sqrtf ((float)n);
118			}
119
120			// this is only twice as fast as naive sqrtf (dxdy+dydy)
121			#if 0
122			// and has a max. error of 6 in the range -100..+100.
123			#else
124			// and has a max. error of 9 in the range -100..+100.
125			#endif
126			inline int
127			idistance (int dx, int dy)
128			{
129			unsigned int dx_ = abs (dx);
130			unsigned int dy_ = abs (dy);
131
132			#if 0
133			return dx_ > dy_
134			? (dx_ * 61685 + dy_ * 26870) >> 16
135			: (dy_ * 61685 + dx_ * 26870) >> 16;
136			#else
137	root	1.30	return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
138	root	1.28	#endif
139			}
140
141	root	1.29	/*
142			* absdir(int): Returns a number between 1 and 8, which represent
143			* the "absolute" direction of a number (it actually takes care of
144			* "overflow" in previous calculations of a direction).
145			*/
146			inline int
147			absdir (int d)
148			{
149			return ((d - 1) & 7) + 1;
150			}
151	root	1.28
152	root	1.1	// makes dynamically allocated objects zero-initialised
153			struct zero_initialised
154			{
155	root	1.11	void operator new (size_t s, void p)
156			{
157			memset (p, 0, s);
158			return p;
159			}
160
161			void *operator new (size_t s)
162			{
163			return g_slice_alloc0 (s);
164			}
165
166			void *operator new[] (size_t s)
167			{
168			return g_slice_alloc0 (s);
169			}
170
171			void operator delete (void *p, size_t s)
172			{
173			g_slice_free1 (s, p);
174			}
175
176			void operator delete[] (void *p, size_t s)
177			{
178			g_slice_free1 (s, p);
179			}
180			};
181
182	root	1.20	void *salloc_ (int n) throw (std::bad_alloc);
183			void salloc_ (int n, void src) throw (std::bad_alloc);
184
185	root	1.12	// strictly the same as g_slice_alloc, but never returns 0
186	root	1.20	template<typename T>
187			inline T salloc (int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T)); }
188
189	root	1.17	// also copies src into the new area, like "memdup"
190	root	1.18	// if src is 0, clears the memory
191			template<typename T>
192	root	1.20	inline T salloc (int n, T src) throw (std::bad_alloc) { return (T )salloc_ (n sizeof (T), (void *)src); }
193	root	1.18
194	root	1.21	// clears the memory
195			template<typename T>
196			inline T salloc0(int n = 1) throw (std::bad_alloc) { return (T )salloc_ (n * sizeof (T), 0); }
197
198	root	1.12	// for symmetry
199	root	1.18	template<typename T>
200	root	1.20	inline void sfree (T *ptr, int n = 1) throw ()
201	root	1.12	{
202	root	1.36	#ifdef PREFER_MALLOC
203			free (ptr);
204			#else
205	root	1.20	g_slice_free1 (n * sizeof (T), (void *)ptr);
206	root	1.36	#endif
207	root	1.12	}
208	root	1.11
209			// a STL-compatible allocator that uses g_slice
210			// boy, this is verbose
211			template<typename Tp>
212			struct slice_allocator
213			{
214			typedef size_t size_type;
215			typedef ptrdiff_t difference_type;
216			typedef Tp *pointer;
217			typedef const Tp *const_pointer;
218			typedef Tp &reference;
219			typedef const Tp &const_reference;
220			typedef Tp value_type;
221
222			template <class U>
223			struct rebind
224			{
225			typedef slice_allocator<U> other;
226			};
227
228			slice_allocator () throw () { }
229			slice_allocator (const slice_allocator &o) throw () { }
230			template<typename Tp2>
231			slice_allocator (const slice_allocator<Tp2> &) throw () { }
232
233			~slice_allocator () { }
234
235			pointer address (reference x) const { return &x; }
236			const_pointer address (const_reference x) const { return &x; }
237
238			pointer allocate (size_type n, const_pointer = 0)
239			{
240	root	1.18	return salloc<Tp> (n);
241	root	1.11	}
242
243			void deallocate (pointer p, size_type n)
244			{
245	root	1.19	sfree<Tp> (p, n);
246	root	1.11	}
247
248			size_type max_size ()const throw ()
249			{
250			return size_t (-1) / sizeof (Tp);
251			}
252
253			void construct (pointer p, const Tp &val)
254			{
255			::new (p) Tp (val);
256			}
257
258			void destroy (pointer p)
259			{
260			p->~Tp ();
261			}
262	root	1.1	};
263
264	root	1.32	// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
265			// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
266			// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
267			struct tausworthe_random_generator
268			{
269	root	1.34	// generator
270	root	1.32	uint32_t state [4];
271
272	root	1.34	void operator =(const tausworthe_random_generator &src)
273			{
274			state [0] = src.state [0];
275			state [1] = src.state [1];
276			state [2] = src.state [2];
277			state [3] = src.state [3];
278			}
279
280			void seed (uint32_t seed);
281	root	1.32	uint32_t next ();
282
283	root	1.34	// uniform distribution
284	root	1.42	uint32_t operator ()(uint32_t num)
285	root	1.32	{
286	root	1.42	return is_constant (num)
287			? (next () * (uint64_t)num) >> 32U
288			: get_range (num);
289	root	1.32	}
290
291			// return a number within (min .. max)
292			int operator () (int r_min, int r_max)
293			{
294	root	1.42	return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
295			? r_min + operator ()(r_max - r_min + 1)
296	root	1.34	: get_range (r_min, r_max);
297	root	1.32	}
298
299			double operator ()()
300			{
301	root	1.34	return this->next () / (double)0xFFFFFFFFU;
302	root	1.32	}
303	root	1.34
304			protected:
305			uint32_t get_range (uint32_t r_max);
306			int get_range (int r_min, int r_max);
307	root	1.32	};
308
309			typedef tausworthe_random_generator rand_gen;
310
311			extern rand_gen rndm;
312
313	root	1.7	template<class T>
314			struct refptr
315			{
316			T *p;
317
318			refptr () : p(0) { }
319			refptr (const refptr<T> &p) : p(p.p) { if (p) p->refcnt_inc (); }
320			refptr (T *p) : p(p) { if (p) p->refcnt_inc (); }
321			~refptr () { if (p) p->refcnt_dec (); }
322
323			const refptr<T> &operator =(T *o)
324			{
325			if (p) p->refcnt_dec ();
326			p = o;
327			if (p) p->refcnt_inc ();
328
329			return *this;
330			}
331
332			const refptr<T> &operator =(const refptr<T> o)
333			{
334			*this = o.p;
335			return *this;
336			}
337
338			T &operator * () const { return *p; }
339			T *operator ->() const { return p; }
340
341			operator T *() const { return p; }
342			};
343
344	root	1.24	typedef refptr<maptile> maptile_ptr;
345	root	1.22	typedef refptr<object> object_ptr;
346			typedef refptr<archetype> arch_ptr;
347	root	1.24	typedef refptr<client> client_ptr;
348			typedef refptr<player> player_ptr;
349	root	1.22
350	root	1.4	struct str_hash
351			{
352			std::size_t operator ()(const char *s) const
353			{
354			unsigned long hash = 0;
355
356			/* use the one-at-a-time hash function, which supposedly is
357			* better than the djb2-like one used by perl5.005, but
358			* certainly is better then the bug used here before.
359			* see http://burtleburtle.net/bob/hash/doobs.html
360			*/
361			while (*s)
362			{
363			hash += *s++;
364			hash += hash << 10;
365			hash ^= hash >> 6;
366			}
367
368			hash += hash << 3;
369			hash ^= hash >> 11;
370			hash += hash << 15;
371
372			return hash;
373			}
374			};
375
376			struct str_equal
377			{
378			bool operator ()(const char a, const char b) const
379			{
380			return !strcmp (a, b);
381			}
382			};
383
384	root	1.26	template<class T>
385			struct unordered_vector : std::vector<T, slice_allocator<T> >
386	root	1.6	{
387	root	1.11	typedef typename unordered_vector::iterator iterator;
388	root	1.6
389			void erase (unsigned int pos)
390			{
391			if (pos < this->size () - 1)
392			(this)[pos] = (this)[this->size () - 1];
393
394			this->pop_back ();
395			}
396
397			void erase (iterator i)
398			{
399			erase ((unsigned int )(i - this->begin ()));
400			}
401			};
402
403	root	1.26	template<class T, int T::* index>
404			struct object_vector : std::vector<T , slice_allocator<T > >
405			{
406			void insert (T *obj)
407			{
408			assert (!(obj->*index));
409			push_back (obj);
410			obj->*index = this->size ();
411			}
412
413			void insert (T &obj)
414			{
415			insert (&obj);
416			}
417
418			void erase (T *obj)
419			{
420			assert (obj->*index);
421	pippijn	1.39	unsigned int pos = obj->*index;
422	root	1.26	obj->*index = 0;
423
424			if (pos < this->size ())
425			{
426			(this)[pos - 1] = (this)[this->size () - 1];
427			(this)[pos - 1]->index = pos;
428			}
429
430			this->pop_back ();
431			}
432
433			void erase (T &obj)
434			{
435			errase (&obj);
436			}
437			};
438
439	root	1.10	// basically does what strncpy should do, but appends "..." to strings exceeding length
440			void assign (char dst, const char src, int maxlen);
441
442			// type-safe version of assign
443	root	1.9	template<int N>
444			inline void assign (char (&dst)[N], const char *src)
445			{
446	root	1.10	assign ((char *)&dst, src, N);
447	root	1.9	}
448
449	root	1.17	typedef double tstamp;
450
451			// return current time as timestampe
452			tstamp now ();
453
454	root	1.25	int similar_direction (int a, int b);
455
456	root	1.43	// like printf, but returns a std::string
457			const std::string format (const char *format, ...);
458
459	root	1.1	#endif
460