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Comparing deliantra/server/include/util.h (file contents):
Revision 1.104 by root, Thu Apr 29 21:21:34 2010 UTC vs.
Revision 1.112 by root, Tue Jul 6 20:15:13 2010 UTC

… …
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// could use the sizeof (arr) /( sizeof (arr [0]) here, but C++ is 60#if cplusplus_does_not_suck
61// much more obfuscated... :) 61// does not work for local types (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2657.htm)
62
63template<typename T, int N> 62template<typename T, int N>
64inline int array_length (const T (&arr)[N]) 63static inline int array_length (const T (&arr)[N])
65{ 64{
66 return N; 65 return N;
67} 66}
67#else
68#define array_length(name) (sizeof (name) / sizeof (name [0]))
69#endif
68 70
69// very ugly macro that basically declares and initialises a variable 71// very ugly macro that basically declares and initialises a variable
70// that is in scope for the next statement only 72// that is in scope for the next statement only
71// 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
72// (note: works great for pointers) 74// (note: works great for pointers)
… …
121// div, with correct rounding (< 0.5 downwards, >=0.5 upwards) 123// div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
122template<typename T> static inline T div (T val, T div) 124template<typename T> static inline T div (T val, T div)
123{ 125{
124 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;
125} 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
126// div, round-up 132// div, round-up
127template<typename T> static inline T div_ru (T val, T div) 133template<typename T> static inline T div_ru (T val, T div)
128{ 134{
129 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div; 135 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div;
130} 136}
… …
423 { 429 {
424 p->~Tp (); 430 p->~Tp ();
425 } 431 }
426}; 432};
427 433
428// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213.
429// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps
430// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
431struct tausworthe_random_generator
432{
433 uint32_t state [4];
434
435 void operator =(const tausworthe_random_generator &src)
436 {
437 state [0] = src.state [0];
438 state [1] = src.state [1];
439 state [2] = src.state [2];
440 state [3] = src.state [3];
441 }
442
443 void seed (uint32_t seed);
444 uint32_t next ();
445};
446
447// Xorshift RNGs, George Marsaglia
448// http://www.jstatsoft.org/v08/i14/paper
449// this one is about 40% faster than the tausworthe one above (i.e. not much),
450// despite the inlining, and has the issue of only creating 2**32-1 numbers.
451// see also http://www.iro.umontreal.ca/~lecuyer/myftp/papers/xorshift.pdf
452struct xorshift_random_generator
453{
454 uint32_t x, y;
455
456 void operator =(const xorshift_random_generator &src)
457 {
458 x = src.x;
459 y = src.y;
460 }
461
462 void seed (uint32_t seed)
463 {
464 x = seed;
465 y = seed * 69069U;
466 }
467
468 uint32_t next ()
469 {
470 uint32_t t = x ^ (x << 10);
471 x = y;
472 y = y ^ (y >> 13) ^ t ^ (t >> 10);
473 return y;
474 }
475};
476
477template<class generator>
478struct random_number_generator : generator
479{
480 // uniform distribution, 0 .. max (0, num - 1)
481 uint32_t operator ()(uint32_t num)
482 {
483 return !is_constant (num) ? get_range (num) // non-constant
484 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two
485 : this->next () & (num - 1); // constant, power-of-two
486 }
487
488 // return a number within the closed interval [min .. max]
489 int operator () (int r_min, int r_max)
490 {
491 return is_constant (r_min <= r_max) && r_min <= r_max
492 ? r_min + operator ()(r_max - r_min + 1)
493 : get_range (r_min, r_max);
494 }
495
496 // return a number within the closed interval [0..1]
497 double operator ()()
498 {
499 return this->next () / (double)0xFFFFFFFFU;
500 }
501
502protected:
503 uint32_t get_range (uint32_t r_max);
504 int get_range (int r_min, int r_max);
505};
506
507typedef random_number_generator<tausworthe_random_generator> rand_gen;
508
509extern rand_gen rndm, rmg_rndm;
510
511INTERFACE_CLASS (attachable) 434INTERFACE_CLASS (attachable)
512struct refcnt_base 435struct refcnt_base
513{ 436{
514 typedef int refcnt_t; 437 typedef int refcnt_t;
515 mutable refcnt_t ACC (RW, refcnt); 438 mutable refcnt_t ACC (RW, refcnt);
… …
588 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/) 511 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
589 // it is about twice as fast as the one-at-a-time one, 512 // it is about twice as fast as the one-at-a-time one,
590 // with good distribution. 513 // with good distribution.
591 // FNV-1a is faster on many cpus because the multiplication 514 // FNV-1a is faster on many cpus because the multiplication
592 // runs concurrently with the looping logic. 515 // runs concurrently with the looping logic.
516 // we modify the hash a bit to improve its distribution
593 uint32_t hash = STRHSH_NULL; 517 uint32_t hash = STRHSH_NULL;
594 518
595 while (*s) 519 while (*s)
596 hash = (hash ^ *s++) * 16777619U; 520 hash = (hash ^ *s++) * 16777619U;
597 521
598 return hash; 522 return hash ^ (hash >> 16);
599} 523}
600 524
601static inline uint32_t 525static inline uint32_t
602memhsh (const char *s, size_t len) 526memhsh (const char *s, size_t len)
603{ 527{
… …
718 { 642 {
719 erase (&obj); 643 erase (&obj);
720 } 644 }
721}; 645};
722 646
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
723// 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
724// returns the number of bytes actually used (including \0) 716// returns the number of bytes actually used (including \0)
725int assign (char *dst, const char *src, int maxsize); 717int assign (char *dst, const char *src, int maxsize);
726 718
727// type-safe version of assign 719// type-safe version of assign

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