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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 1.112 by root, Tue Jul 6 20:15:13 2010 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 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
119template<typename T, typename U>
120static inline T copysign (T a, U b) { return a > 0 ? b : -b; }
103 121
104// div* only work correctly for div > 0 122// div* only work correctly for div > 0
105// div, with correct rounding (< 0.5 downwards, >=0.5 upwards) 123// div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
106template<typename T> static inline T div (T val, T div) 124template<typename T> static inline T div (T val, T div)
107{ 125{
108 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div; 126 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div;
109} 127}
128
129template<> inline float div (float val, float div) { return val / div; }
130template<> inline double div (double val, double div) { return val / div; }
131
110// div, round-up 132// div, round-up
111template<typename T> static inline T div_ru (T val, T div) 133template<typename T> static inline T div_ru (T val, T div)
112{ 134{
113 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div; 135 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div;
114} 136}
… …
186 int32_t d = b - a; 208 int32_t d = b - a;
187 d &= d >> 31; 209 d &= d >> 31;
188 return b - d; 210 return b - d;
189} 211}
190 212
191// this is much faster than crossfires original algorithm 213// this is much faster than crossfire's original algorithm
192// on modern cpus 214// on modern cpus
193inline int 215inline int
194isqrt (int n) 216isqrt (int n)
195{ 217{
196 return (int)sqrtf ((float)n); 218 return (int)sqrtf ((float)n);
… …
240absdir (int d) 262absdir (int d)
241{ 263{
242 return ((d - 1) & 7) + 1; 264 return ((d - 1) & 7) + 1;
243} 265}
244 266
267// avoid ctz name because netbsd or freebsd spams it's namespace with it
268#if GCC_VERSION(3,4)
269static inline int least_significant_bit (uint32_t x)
270{
271 return __builtin_ctz (x);
272}
273#else
274int least_significant_bit (uint32_t x);
275#endif
276
277#define for_all_bits_sparse_32(mask, idxvar) \
278 for (uint32_t idxvar, mask_ = mask; \
279 mask_ && ((idxvar = least_significant_bit (mask_)), mask_ &= ~(1 << idxvar), 1);)
280
245extern ssize_t slice_alloc; // statistics 281extern ssize_t slice_alloc; // statistics
246 282
247void *salloc_ (int n) throw (std::bad_alloc); 283void *salloc_ (int n) throw (std::bad_alloc);
248void *salloc_ (int n, void *src) throw (std::bad_alloc); 284void *salloc_ (int n, void *src) throw (std::bad_alloc);
249 285
… …
393 { 429 {
394 p->~Tp (); 430 p->~Tp ();
395 } 431 }
396}; 432};
397 433
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) 434INTERFACE_CLASS (attachable)
481struct refcnt_base 435struct refcnt_base
482{ 436{
483 typedef int refcnt_t; 437 typedef int refcnt_t;
484 mutable refcnt_t ACC (RW, refcnt); 438 mutable refcnt_t ACC (RW, refcnt);
… …
545typedef refptr<maptile> maptile_ptr; 499typedef refptr<maptile> maptile_ptr;
546typedef refptr<object> object_ptr; 500typedef refptr<object> object_ptr;
547typedef refptr<archetype> arch_ptr; 501typedef refptr<archetype> arch_ptr;
548typedef refptr<client> client_ptr; 502typedef refptr<client> client_ptr;
549typedef refptr<player> player_ptr; 503typedef refptr<player> player_ptr;
504typedef refptr<region> region_ptr;
505
506#define STRHSH_NULL 2166136261
507
508static inline uint32_t
509strhsh (const char *s)
510{
511 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
512 // it is about twice as fast as the one-at-a-time one,
513 // with good distribution.
514 // FNV-1a is faster on many cpus because the multiplication
515 // runs concurrently with the looping logic.
516 // we modify the hash a bit to improve its distribution
517 uint32_t hash = STRHSH_NULL;
518
519 while (*s)
520 hash = (hash ^ *s++) * 16777619U;
521
522 return hash ^ (hash >> 16);
523}
524
525static inline uint32_t
526memhsh (const char *s, size_t len)
527{
528 uint32_t hash = STRHSH_NULL;
529
530 while (len--)
531 hash = (hash ^ *s++) * 16777619U;
532
533 return hash;
534}
550 535
551struct str_hash 536struct str_hash
552{ 537{
553 std::size_t operator ()(const char *s) const 538 std::size_t operator ()(const char *s) const
554 { 539 {
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; 540 return strhsh (s);
541 }
542
543 std::size_t operator ()(const shstr &s) const
544 {
545 return strhsh (s);
586 } 546 }
587}; 547};
588 548
589struct str_equal 549struct str_equal
590{ 550{
… …
682 { 642 {
683 erase (&obj); 643 erase (&obj);
684 } 644 }
685}; 645};
686 646
647/////////////////////////////////////////////////////////////////////////////
648
649// something like a vector or stack, but without
650// out of bounds checking
651template<typename T>
652struct fixed_stack
653{
654 T *data;
655 int size;
656 int max;
657
658 fixed_stack ()
659 : size (0), data (0)
660 {
661 }
662
663 fixed_stack (int max)
664 : size (0), max (max)
665 {
666 data = salloc<T> (max);
667 }
668
669 void reset (int new_max)
670 {
671 sfree (data, max);
672 size = 0;
673 max = new_max;
674 data = salloc<T> (max);
675 }
676
677 void free ()
678 {
679 sfree (data, max);
680 data = 0;
681 }
682
683 ~fixed_stack ()
684 {
685 sfree (data, max);
686 }
687
688 T &operator[](int idx)
689 {
690 return data [idx];
691 }
692
693 void push (T v)
694 {
695 data [size++] = v;
696 }
697
698 T &pop ()
699 {
700 return data [--size];
701 }
702
703 T remove (int idx)
704 {
705 T v = data [idx];
706
707 data [idx] = data [--size];
708
709 return v;
710 }
711};
712
713/////////////////////////////////////////////////////////////////////////////
714
687// basically does what strncpy should do, but appends "..." to strings exceeding length 715// basically does what strncpy should do, but appends "..." to strings exceeding length
688// returns the number of bytes actually used (including \0) 716// returns the number of bytes actually used (including \0)
689int assign (char *dst, const char *src, int maxsize); 717int assign (char *dst, const char *src, int maxsize);
690 718
691// type-safe version of assign 719// type-safe version of assign

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