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Comparing deliantra/server/include/util.h (file contents):
Revision 1.93 by root, Sat Nov 7 18:30:05 2009 UTC vs.
Revision 1.115 by root, Tue Apr 26 14:41:36 2011 UTC

1/* 1/*
2 * This file is part of Deliantra, the Roguelike Realtime MMORPG. 2 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
3 * 3 *
4 * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team 4 * Copyright (©) 2005,2006,2007,2008,2009,2010,2011 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5 * 5 *
6 * Deliantra is free software: you can redistribute it and/or modify it under 6 * Deliantra is free software: you can redistribute it and/or modify it under
7 * the terms of the Affero GNU General Public License as published by the 7 * the terms of the Affero GNU General Public License as published by the
8 * Free Software Foundation, either version 3 of the License, or (at your 8 * Free Software Foundation, either version 3 of the License, or (at your
9 * option) any later version. 9 * option) any later version.
… …
55#endif 55#endif
56 56
57// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever) 57// use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever)
58#define auto(var,expr) decltype(expr) var = (expr) 58#define auto(var,expr) decltype(expr) var = (expr)
59 59
60#if cplusplus_does_not_suck
61// does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
62template<typename T, int N>
63static inline int array_length (const T (&arr)[N])
64{
65 return N;
66}
67#else
68#define array_length(name) (sizeof (name) / sizeof (name [0]))
69#endif
70
60// very ugly macro that basically declares and initialises a variable 71// very ugly macro that basically declares and initialises a variable
61// that is in scope for the next statement only 72// that is in scope for the next statement only
62// works only for stuff that can be assigned 0 and converts to false 73// works only for stuff that can be assigned 0 and converts to false
63// (note: works great for pointers) 74// (note: works great for pointers)
64// most ugly macro I ever wrote 75// most ugly macro I ever wrote
… …
93// sign returns -1 or +1 104// sign returns -1 or +1
94template<typename T> 105template<typename T>
95static inline T sign (T v) { return v < 0 ? -1 : +1; } 106static inline T sign (T v) { return v < 0 ? -1 : +1; }
96// relies on 2c representation 107// relies on 2c representation
97template<> 108template<>
98inline sint8 sign (sint8 v) { return 1 - (sint8 (uint8 (v) >> 7) * 2); } 109inline sint8 sign (sint8 v) { return 1 - (sint8 (uint8 (v) >> 7) * 2); }
110template<>
111inline sint16 sign (sint16 v) { return 1 - (sint16 (uint16 (v) >> 15) * 2); }
112template<>
113inline sint32 sign (sint32 v) { return 1 - (sint32 (uint32 (v) >> 31) * 2); }
99 114
100// sign0 returns -1, 0 or +1 115// sign0 returns -1, 0 or +1
101template<typename T> 116template<typename T>
102static inline T sign0 (T v) { return v ? sign (v) : 0; } 117static inline T sign0 (T v) { return v ? sign (v) : 0; }
118
119//clashes with C++0x
120template<typename T, typename U>
121static inline T copysign (T a, U b) { return a > 0 ? b : -b; }
103 122
104// div* only work correctly for div > 0 123// div* only work correctly for div > 0
105// div, with correct rounding (< 0.5 downwards, >=0.5 upwards) 124// div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
106template<typename T> static inline T div (T val, T div) 125template<typename T> static inline T div (T val, T div)
107{ 126{
108 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div; 127 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div;
109} 128}
129
130template<> inline float div (float val, float div) { return val / div; }
131template<> inline double div (double val, double div) { return val / div; }
132
110// div, round-up 133// div, round-up
111template<typename T> static inline T div_ru (T val, T div) 134template<typename T> static inline T div_ru (T val, T div)
112{ 135{
113 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div; 136 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div;
114} 137}
… …
186 int32_t d = b - a; 209 int32_t d = b - a;
187 d &= d >> 31; 210 d &= d >> 31;
188 return b - d; 211 return b - d;
189} 212}
190 213
191// this is much faster than crossfires original algorithm 214// this is much faster than crossfire's original algorithm
192// on modern cpus 215// on modern cpus
193inline int 216inline int
194isqrt (int n) 217isqrt (int n)
195{ 218{
196 return (int)sqrtf ((float)n); 219 return (int)sqrtf ((float)n);
… …
229#else 252#else
230 return dx_ + dy_ - min (dx_, dy_) * 5 / 8; 253 return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
231#endif 254#endif
232} 255}
233 256
257// can be substantially faster than floor, if your value range allows for it
258template<typename T>
259inline T
260fastfloor (T x)
261{
262 return std::floor (x);
263}
264
265inline float
266fastfloor (float x)
267{
268 return sint32(x) - (x < 0);
269}
270
271inline double
272fastfloor (double x)
273{
274 return sint64(x) - (x < 0);
275}
276
234/* 277/*
235 * absdir(int): Returns a number between 1 and 8, which represent 278 * absdir(int): Returns a number between 1 and 8, which represent
236 * the "absolute" direction of a number (it actually takes care of 279 * the "absolute" direction of a number (it actually takes care of
237 * "overflow" in previous calculations of a direction). 280 * "overflow" in previous calculations of a direction).
238 */ 281 */
… …
240absdir (int d) 283absdir (int d)
241{ 284{
242 return ((d - 1) & 7) + 1; 285 return ((d - 1) & 7) + 1;
243} 286}
244 287
288// avoid ctz name because netbsd or freebsd spams it's namespace with it
289#if GCC_VERSION(3,4)
290static inline int least_significant_bit (uint32_t x)
291{
292 return __builtin_ctz (x);
293}
294#else
295int least_significant_bit (uint32_t x);
296#endif
297
298#define for_all_bits_sparse_32(mask, idxvar) \
299 for (uint32_t idxvar, mask_ = mask; \
300 mask_ && ((idxvar = least_significant_bit (mask_)), mask_ &= ~(1 << idxvar), 1);)
301
245extern ssize_t slice_alloc; // statistics 302extern ssize_t slice_alloc; // statistics
246 303
247void *salloc_ (int n) throw (std::bad_alloc); 304void *salloc_ (int n) throw (std::bad_alloc);
248void *salloc_ (int n, void *src) throw (std::bad_alloc); 305void *salloc_ (int n, void *src) throw (std::bad_alloc);
249 306
… …
393 { 450 {
394 p->~Tp (); 451 p->~Tp ();
395 } 452 }
396}; 453};
397 454
398// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
399// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
400// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
401struct tausworthe_random_generator
402{
403 uint32_t state [4];
404
405 void operator =(const tausworthe_random_generator &src)
406 {
407 state [0] = src.state [0];
408 state [1] = src.state [1];
409 state [2] = src.state [2];
410 state [3] = src.state [3];
411 }
412
413 void seed (uint32_t seed);
414 uint32_t next ();
415};
416
417// Xorshift RNGs, George Marsaglia
418// http://www.jstatsoft.org/v08/i14/paper
419// this one is about 40% faster than the tausworthe one above (i.e. not much),
420// despite the inlining, and has the issue of only creating 2**32-1 numbers.
421// see also http://www.iro.umontreal.ca/~lecuyer/myftp/papers/xorshift.pdf
422struct xorshift_random_generator
423{
424 uint32_t x, y;
425
426 void operator =(const xorshift_random_generator &src)
427 {
428 x = src.x;
429 y = src.y;
430 }
431
432 void seed (uint32_t seed)
433 {
434 x = seed;
435 y = seed * 69069U;
436 }
437
438 uint32_t next ()
439 {
440 uint32_t t = x ^ (x << 10);
441 x = y;
442 y = y ^ (y >> 13) ^ t ^ (t >> 10);
443 return y;
444 }
445};
446
447template<class generator>
448struct random_number_generator : generator
449{
450 // uniform distribution, 0 .. max (0, num - 1)
451 uint32_t operator ()(uint32_t num)
452 {
453 return !is_constant (num) ? get_range (num) // non-constant
454 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two
455 : this->next () & (num - 1); // constant, power-of-two
456 }
457
458 // return a number within (min .. max)
459 int operator () (int r_min, int r_max)
460 {
461 return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
462 ? r_min + operator ()(r_max - r_min + 1)
463 : get_range (r_min, r_max);
464 }
465
466 double operator ()()
467 {
468 return this->next () / (double)0xFFFFFFFFU;
469 }
470
471protected:
472 uint32_t get_range (uint32_t r_max);
473 int get_range (int r_min, int r_max);
474};
475
476typedef random_number_generator<tausworthe_random_generator> rand_gen;
477
478extern rand_gen rndm, rmg_rndm;
479
480INTERFACE_CLASS (attachable) 455INTERFACE_CLASS (attachable)
481struct refcnt_base 456struct refcnt_base
482{ 457{
483 typedef int refcnt_t; 458 typedef int refcnt_t;
484 mutable refcnt_t ACC (RW, refcnt); 459 mutable refcnt_t ACC (RW, refcnt);
… …
545typedef refptr<maptile> maptile_ptr; 520typedef refptr<maptile> maptile_ptr;
546typedef refptr<object> object_ptr; 521typedef refptr<object> object_ptr;
547typedef refptr<archetype> arch_ptr; 522typedef refptr<archetype> arch_ptr;
548typedef refptr<client> client_ptr; 523typedef refptr<client> client_ptr;
549typedef refptr<player> player_ptr; 524typedef refptr<player> player_ptr;
525typedef refptr<region> region_ptr;
526
527#define STRHSH_NULL 2166136261
528
529static inline uint32_t
530strhsh (const char *s)
531{
532 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
533 // it is about twice as fast as the one-at-a-time one,
534 // with good distribution.
535 // FNV-1a is faster on many cpus because the multiplication
536 // runs concurrently with the looping logic.
537 // we modify the hash a bit to improve its distribution
538 uint32_t hash = STRHSH_NULL;
539
540 while (*s)
541 hash = (hash ^ *s++) * 16777619U;
542
543 return hash ^ (hash >> 16);
544}
545
546static inline uint32_t
547memhsh (const char *s, size_t len)
548{
549 uint32_t hash = STRHSH_NULL;
550
551 while (len--)
552 hash = (hash ^ *s++) * 16777619U;
553
554 return hash;
555}
550 556
551struct str_hash 557struct str_hash
552{ 558{
553 std::size_t operator ()(const char *s) const 559 std::size_t operator ()(const char *s) const
554 { 560 {
555#if 0
556 uint32_t hash = 0;
557
558 /* use the one-at-a-time hash function, which supposedly is
559 * better than the djb2-like one used by perl5.005, but
560 * certainly is better then the bug used here before.
561 * see http://burtleburtle.net/bob/hash/doobs.html
562 */
563 while (*s)
564 {
565 hash += *s++;
566 hash += hash << 10;
567 hash ^= hash >> 6;
568 }
569
570 hash += hash << 3;
571 hash ^= hash >> 11;
572 hash += hash << 15;
573#else
574 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
575 // it is about twice as fast as the one-at-a-time one,
576 // with good distribution.
577 // FNV-1a is faster on many cpus because the multiplication
578 // runs concurrent with the looping logic.
579 uint32_t hash = 2166136261;
580
581 while (*s)
582 hash = (hash ^ *s++) * 16777619;
583#endif
584
585 return hash; 561 return strhsh (s);
562 }
563
564 std::size_t operator ()(const shstr &s) const
565 {
566 return strhsh (s);
586 } 567 }
587}; 568};
588 569
589struct str_equal 570struct str_equal
590{ 571{
… …
682 { 663 {
683 erase (&obj); 664 erase (&obj);
684 } 665 }
685}; 666};
686 667
668/////////////////////////////////////////////////////////////////////////////
669
670// something like a vector or stack, but without
671// out of bounds checking
672template<typename T>
673struct fixed_stack
674{
675 T *data;
676 int size;
677 int max;
678
679 fixed_stack ()
680 : size (0), data (0)
681 {
682 }
683
684 fixed_stack (int max)
685 : size (0), max (max)
686 {
687 data = salloc<T> (max);
688 }
689
690 void reset (int new_max)
691 {
692 sfree (data, max);
693 size = 0;
694 max = new_max;
695 data = salloc<T> (max);
696 }
697
698 void free ()
699 {
700 sfree (data, max);
701 data = 0;
702 }
703
704 ~fixed_stack ()
705 {
706 sfree (data, max);
707 }
708
709 T &operator[](int idx)
710 {
711 return data [idx];
712 }
713
714 void push (T v)
715 {
716 data [size++] = v;
717 }
718
719 T &pop ()
720 {
721 return data [--size];
722 }
723
724 T remove (int idx)
725 {
726 T v = data [idx];
727
728 data [idx] = data [--size];
729
730 return v;
731 }
732};
733
734/////////////////////////////////////////////////////////////////////////////
735
687// basically does what strncpy should do, but appends "..." to strings exceeding length 736// basically does what strncpy should do, but appends "..." to strings exceeding length
688// returns the number of bytes actually used (including \0) 737// returns the number of bytes actually used (including \0)
689int assign (char *dst, const char *src, int maxsize); 738int assign (char *dst, const char *src, int maxsize);
690 739
691// type-safe version of assign 740// type-safe version of assign

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