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 1.93 by root, Sat Nov 7 18:30:05 2009 UTC vs.
Revision 1.101 by root, Wed Apr 28 19:49:50 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// could use the sizeof (arr) /( sizeof (arr [0]) here, but C++ is
61// much more obfuscated... :)
62
63template<typename T, int N>
64inline int array_length (const T (&arr)[N])
65{
66 return N;
67}
68
60// very ugly macro that basically declares and initialises a variable 69// very ugly macro that basically declares and initialises a variable
61// that is in scope for the next statement only 70// that is in scope for the next statement only
62// works only for stuff that can be assigned 0 and converts to false 71// works only for stuff that can be assigned 0 and converts to false
63// (note: works great for pointers) 72// (note: works great for pointers)
64// most ugly macro I ever wrote 73// most ugly macro I ever wrote
… …
99 108
100// sign0 returns -1, 0 or +1 109// sign0 returns -1, 0 or +1
101template<typename T> 110template<typename T>
102static inline T sign0 (T v) { return v ? sign (v) : 0; } 111static inline T sign0 (T v) { return v ? sign (v) : 0; }
103 112
113template<typename T, typename U>
114static inline T copysign (T a, U b) { return a > 0 ? b : -b; }
115
104// div* only work correctly for div > 0 116// div* only work correctly for div > 0
105// div, with correct rounding (< 0.5 downwards, >=0.5 upwards) 117// div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
106template<typename T> static inline T div (T val, T div) 118template<typename T> static inline T div (T val, T div)
107{ 119{
108 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div; 120 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div;
… …
186 int32_t d = b - a; 198 int32_t d = b - a;
187 d &= d >> 31; 199 d &= d >> 31;
188 return b - d; 200 return b - d;
189} 201}
190 202
191// this is much faster than crossfires original algorithm 203// this is much faster than crossfire's original algorithm
192// on modern cpus 204// on modern cpus
193inline int 205inline int
194isqrt (int n) 206isqrt (int n)
195{ 207{
196 return (int)sqrtf ((float)n); 208 return (int)sqrtf ((float)n);
… …
240absdir (int d) 252absdir (int d)
241{ 253{
242 return ((d - 1) & 7) + 1; 254 return ((d - 1) & 7) + 1;
243} 255}
244 256
257// avoid ctz name because netbsd or freebsd spams it's namespace with it
258#if GCC_VERSION(3,4)
259static inline int least_significant_bit (uint32_t x)
260{
261 return __builtin_ctz (x);
262}
263#else
264int least_significant_bit (uint32_t x);
265#endif
266
267#define for_all_bits_sparse_32(mask, idxvar) \
268 for (uint32_t idxvar, mask_ = mask; \
269 mask_ && ((idxvar = least_significant_bit (mask_)), mask_ &= ~(1 << idxvar), 1);)
270
245extern ssize_t slice_alloc; // statistics 271extern ssize_t slice_alloc; // statistics
246 272
247void *salloc_ (int n) throw (std::bad_alloc); 273void *salloc_ (int n) throw (std::bad_alloc);
248void *salloc_ (int n, void *src) throw (std::bad_alloc); 274void *salloc_ (int n, void *src) throw (std::bad_alloc);
249 275
… …
453 return !is_constant (num) ? get_range (num) // non-constant 479 return !is_constant (num) ? get_range (num) // non-constant
454 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two 480 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two
455 : this->next () & (num - 1); // constant, power-of-two 481 : this->next () & (num - 1); // constant, power-of-two
456 } 482 }
457 483
458 // return a number within (min .. max) 484 // return a number within the closed interval [min .. max]
459 int operator () (int r_min, int r_max) 485 int operator () (int r_min, int r_max)
460 { 486 {
461 return is_constant (r_min) && is_constant (r_max) && r_min <= r_max 487 return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
462 ? r_min + operator ()(r_max - r_min + 1) 488 ? r_min + operator ()(r_max - r_min + 1)
463 : get_range (r_min, r_max); 489 : get_range (r_min, r_max);
464 } 490 }
465 491
492 // return a number within the closed interval [0..1]
466 double operator ()() 493 double operator ()()
467 { 494 {
468 return this->next () / (double)0xFFFFFFFFU; 495 return this->next () / (double)0xFFFFFFFFU;
469 } 496 }
470 497
… …
546typedef refptr<object> object_ptr; 573typedef refptr<object> object_ptr;
547typedef refptr<archetype> arch_ptr; 574typedef refptr<archetype> arch_ptr;
548typedef refptr<client> client_ptr; 575typedef refptr<client> client_ptr;
549typedef refptr<player> player_ptr; 576typedef refptr<player> player_ptr;
550 577
578#define STRHSH_NULL 2166136261
579
580static inline uint32_t
581strhsh (const char *s)
582{
583 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
584 // it is about twice as fast as the one-at-a-time one,
585 // with good distribution.
586 // FNV-1a is faster on many cpus because the multiplication
587 // runs concurrently with the looping logic.
588 uint32_t hash = STRHSH_NULL;
589
590 while (*s)
591 hash = (hash ^ *s++) * 16777619U;
592
593 return hash;
594}
595
596static inline uint32_t
597memhsh (const char *s, size_t len)
598{
599 uint32_t hash = STRHSH_NULL;
600
601 while (len--)
602 hash = (hash ^ *s++) * 16777619U;
603
604 return hash;
605}
606
551struct str_hash 607struct str_hash
552{ 608{
553 std::size_t operator ()(const char *s) const 609 std::size_t operator ()(const char *s) const
554 { 610 {
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; 611 return strhsh (s);
612 }
613
614 std::size_t operator ()(const shstr &s) const
615 {
616 return strhsh (s);
586 } 617 }
587}; 618};
588 619
589struct str_equal 620struct str_equal
590{ 621{

Diff Legend

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