ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/deliantra/server/include/util.h
(Generate patch)

Comparing deliantra/server/include/util.h (file contents):
Revision 1.96 by root, Wed Nov 11 03:52:44 2009 UTC vs.
Revision 1.113 by root, Fri Apr 22 02:03:11 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 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}
… …
407 { 430 {
408 p->~Tp (); 431 p->~Tp ();
409 } 432 }
410}; 433};
411 434
412// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
413// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
414// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
415struct tausworthe_random_generator
416{
417 uint32_t state [4];
418
419 void operator =(const tausworthe_random_generator &src)
420 {
421 state [0] = src.state [0];
422 state [1] = src.state [1];
423 state [2] = src.state [2];
424 state [3] = src.state [3];
425 }
426
427 void seed (uint32_t seed);
428 uint32_t next ();
429};
430
431// Xorshift RNGs, George Marsaglia
432// http://www.jstatsoft.org/v08/i14/paper
433// this one is about 40% faster than the tausworthe one above (i.e. not much),
434// despite the inlining, and has the issue of only creating 2**32-1 numbers.
435// see also http://www.iro.umontreal.ca/~lecuyer/myftp/papers/xorshift.pdf
436struct xorshift_random_generator
437{
438 uint32_t x, y;
439
440 void operator =(const xorshift_random_generator &src)
441 {
442 x = src.x;
443 y = src.y;
444 }
445
446 void seed (uint32_t seed)
447 {
448 x = seed;
449 y = seed * 69069U;
450 }
451
452 uint32_t next ()
453 {
454 uint32_t t = x ^ (x << 10);
455 x = y;
456 y = y ^ (y >> 13) ^ t ^ (t >> 10);
457 return y;
458 }
459};
460
461template<class generator>
462struct random_number_generator : generator
463{
464 // uniform distribution, 0 .. max (0, num - 1)
465 uint32_t operator ()(uint32_t num)
466 {
467 return !is_constant (num) ? get_range (num) // non-constant
468 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two
469 : this->next () & (num - 1); // constant, power-of-two
470 }
471
472 // return a number within (min .. max)
473 int operator () (int r_min, int r_max)
474 {
475 return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
476 ? r_min + operator ()(r_max - r_min + 1)
477 : get_range (r_min, r_max);
478 }
479
480 double operator ()()
481 {
482 return this->next () / (double)0xFFFFFFFFU;
483 }
484
485protected:
486 uint32_t get_range (uint32_t r_max);
487 int get_range (int r_min, int r_max);
488};
489
490typedef random_number_generator<tausworthe_random_generator> rand_gen;
491
492extern rand_gen rndm, rmg_rndm;
493
494INTERFACE_CLASS (attachable) 435INTERFACE_CLASS (attachable)
495struct refcnt_base 436struct refcnt_base
496{ 437{
497 typedef int refcnt_t; 438 typedef int refcnt_t;
498 mutable refcnt_t ACC (RW, refcnt); 439 mutable refcnt_t ACC (RW, refcnt);
… …
559typedef refptr<maptile> maptile_ptr; 500typedef refptr<maptile> maptile_ptr;
560typedef refptr<object> object_ptr; 501typedef refptr<object> object_ptr;
561typedef refptr<archetype> arch_ptr; 502typedef refptr<archetype> arch_ptr;
562typedef refptr<client> client_ptr; 503typedef refptr<client> client_ptr;
563typedef refptr<player> player_ptr; 504typedef refptr<player> player_ptr;
505typedef refptr<region> region_ptr;
564 506
565#define STRHSH_NULL 2166136261 507#define STRHSH_NULL 2166136261
566 508
567static inline uint32_t 509static inline uint32_t
568strhsh (const char *s) 510strhsh (const char *s)
… …
570 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/) 512 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
571 // it is about twice as fast as the one-at-a-time one, 513 // it is about twice as fast as the one-at-a-time one,
572 // with good distribution. 514 // with good distribution.
573 // FNV-1a is faster on many cpus because the multiplication 515 // FNV-1a is faster on many cpus because the multiplication
574 // runs concurrently with the looping logic. 516 // runs concurrently with the looping logic.
517 // we modify the hash a bit to improve its distribution
575 uint32_t hash = STRHSH_NULL; 518 uint32_t hash = STRHSH_NULL;
576 519
577 while (*s) 520 while (*s)
578 hash = (hash ^ *s++) * 16777619; 521 hash = (hash ^ *s++) * 16777619U;
579 522
580 return hash; 523 return hash ^ (hash >> 16);
581} 524}
582 525
583static inline uint32_t 526static inline uint32_t
584memhsh (const char *s, size_t len) 527memhsh (const char *s, size_t len)
585{ 528{
586 uint32_t hash = STRHSH_NULL; 529 uint32_t hash = STRHSH_NULL;
587 530
588 while (len--) 531 while (len--)
589 hash = (hash ^ *s++) * 16777619; 532 hash = (hash ^ *s++) * 16777619U;
590 533
591 return hash; 534 return hash;
592} 535}
593 536
594struct str_hash 537struct str_hash
… …
700 { 643 {
701 erase (&obj); 644 erase (&obj);
702 } 645 }
703}; 646};
704 647
648/////////////////////////////////////////////////////////////////////////////
649
650// something like a vector or stack, but without
651// out of bounds checking
652template<typename T>
653struct fixed_stack
654{
655 T *data;
656 int size;
657 int max;
658
659 fixed_stack ()
660 : size (0), data (0)
661 {
662 }
663
664 fixed_stack (int max)
665 : size (0), max (max)
666 {
667 data = salloc<T> (max);
668 }
669
670 void reset (int new_max)
671 {
672 sfree (data, max);
673 size = 0;
674 max = new_max;
675 data = salloc<T> (max);
676 }
677
678 void free ()
679 {
680 sfree (data, max);
681 data = 0;
682 }
683
684 ~fixed_stack ()
685 {
686 sfree (data, max);
687 }
688
689 T &operator[](int idx)
690 {
691 return data [idx];
692 }
693
694 void push (T v)
695 {
696 data [size++] = v;
697 }
698
699 T &pop ()
700 {
701 return data [--size];
702 }
703
704 T remove (int idx)
705 {
706 T v = data [idx];
707
708 data [idx] = data [--size];
709
710 return v;
711 }
712};
713
714/////////////////////////////////////////////////////////////////////////////
715
705// basically does what strncpy should do, but appends "..." to strings exceeding length 716// basically does what strncpy should do, but appends "..." to strings exceeding length
706// returns the number of bytes actually used (including \0) 717// returns the number of bytes actually used (including \0)
707int assign (char *dst, const char *src, int maxsize); 718int assign (char *dst, const char *src, int maxsize);
708 719
709// type-safe version of assign 720// type-safe version of assign

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines