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/cvs/deliantra/server/include/util.h
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.

File Contents

# 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 # define expect(expr,value) __builtin_expect ((expr),(value))
9 # define prefetch(addr,rw,locality) __builtin_prefetch (addr, rw, locality)
10 #else
11 # define is_constant(c) 0
12 # define expect(expr,value) (expr)
13 # define prefetch(addr,rw,locality)
14 #endif
15
16 // 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 #include <cstddef>
23 #include <cmath>
24 #include <new>
25 #include <vector>
26
27 #include <glib.h>
28
29 #include <shstr.h>
30 #include <traits.h>
31
32 // use a gcc extension for auto declarations until ISO C++ sanctifies them
33 #define auto(var,expr) typeof(expr) var = (expr)
34
35 // 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 // 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 void fork_abort (const char *msg);
51
52 // 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
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 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 // lots of stuff taken from FXT
68
69 /* Rotate right. This is used in various places for checksumming */
70 //TODO: that sucks, use a better checksum algo
71 static inline uint32_t
72 rotate_right (uint32_t c, uint32_t count = 1)
73 {
74 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 }
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 // 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 (dx*dy+dy*dy)
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 return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
138 #endif
139 }
140
141 /*
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
152 // makes dynamically allocated objects zero-initialised
153 struct zero_initialised
154 {
155 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 void *salloc_ (int n) throw (std::bad_alloc);
183 void *salloc_ (int n, void *src) throw (std::bad_alloc);
184
185 // strictly the same as g_slice_alloc, but never returns 0
186 template<typename T>
187 inline T *salloc (int n = 1) throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T)); }
188
189 // also copies src into the new area, like "memdup"
190 // if src is 0, clears the memory
191 template<typename T>
192 inline T *salloc (int n, T *src) throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T), (void *)src); }
193
194 // 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 // for symmetry
199 template<typename T>
200 inline void sfree (T *ptr, int n = 1) throw ()
201 {
202 #ifdef PREFER_MALLOC
203 free (ptr);
204 #else
205 g_slice_free1 (n * sizeof (T), (void *)ptr);
206 #endif
207 }
208
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 return salloc<Tp> (n);
241 }
242
243 void deallocate (pointer p, size_type n)
244 {
245 sfree<Tp> (p, n);
246 }
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 };
263
264 // 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 // generator
270 uint32_t state [4];
271
272 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 uint32_t next ();
282
283 // uniform distribution
284 uint32_t operator ()(uint32_t num)
285 {
286 return is_constant (num)
287 ? (next () * (uint64_t)num) >> 32U
288 : get_range (num);
289 }
290
291 // return a number within (min .. max)
292 int operator () (int r_min, int r_max)
293 {
294 return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
295 ? r_min + operator ()(r_max - r_min + 1)
296 : get_range (r_min, r_max);
297 }
298
299 double operator ()()
300 {
301 return this->next () / (double)0xFFFFFFFFU;
302 }
303
304 protected:
305 uint32_t get_range (uint32_t r_max);
306 int get_range (int r_min, int r_max);
307 };
308
309 typedef tausworthe_random_generator rand_gen;
310
311 extern rand_gen rndm;
312
313 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 typedef refptr<maptile> maptile_ptr;
345 typedef refptr<object> object_ptr;
346 typedef refptr<archetype> arch_ptr;
347 typedef refptr<client> client_ptr;
348 typedef refptr<player> player_ptr;
349
350 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 template<class T>
385 struct unordered_vector : std::vector<T, slice_allocator<T> >
386 {
387 typedef typename unordered_vector::iterator iterator;
388
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 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 unsigned int pos = obj->*index;
422 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 // 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 template<int N>
444 inline void assign (char (&dst)[N], const char *src)
445 {
446 assign ((char *)&dst, src, N);
447 }
448
449 typedef double tstamp;
450
451 // return current time as timestampe
452 tstamp now ();
453
454 int similar_direction (int a, int b);
455
456 // like printf, but returns a std::string
457 const std::string format (const char *format, ...);
458
459 #endif
460