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Comparing deliantra/server/include/util.h (file contents):
Revision 1.102 by root, Thu Apr 29 12:24:04 2010 UTC vs.
Revision 1.120 by root, Mon Oct 29 23:55:54 2012 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 (©) 2005,2006,2007,2008,2009,2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team 4 * Copyright (©) 2005,2006,2007,2008,2009,2010,2011,2012 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.
10 * 10 *
11 * This program is distributed in the hope that it will be useful, 11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details. 14 * GNU General Public License for more details.
15 * 15 *
16 * You should have received a copy of the Affero GNU General Public License 16 * You should have received a copy of the Affero GNU General Public License
17 * and the GNU General Public License along with this program. If not, see 17 * and the GNU General Public License along with this program. If not, see
18 * <http://www.gnu.org/licenses/>. 18 * <http://www.gnu.org/licenses/>.
19 * 19 *
20 * The authors can be reached via e-mail to <support@deliantra.net> 20 * The authors can be reached via e-mail to <support@deliantra.net>
21 */ 21 */
22 22
23#ifndef UTIL_H__ 23#ifndef UTIL_H__
24#define UTIL_H__ 24#define UTIL_H__
… …
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)
… …
84void cleanup (const char *cause, bool make_core = false); 86void cleanup (const char *cause, bool make_core = false);
85void fork_abort (const char *msg); 87void fork_abort (const char *msg);
86 88
87// rationale for using (U) not (T) is to reduce signed/unsigned issues, 89// rationale for using (U) not (T) is to reduce signed/unsigned issues,
88// as a is often a constant while b is the variable. it is still a bug, though. 90// as a is often a constant while b is the variable. it is still a bug, though.
89template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; } 91template<typename T, typename U> static inline T min (T a, U b) { return a < (T)b ? a : (T)b; }
90template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; } 92template<typename T, typename U> static inline T max (T a, U b) { return a > (T)b ? a : (T)b; }
91template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? (T)a : v >(T)b ? (T)b : v; } 93template<typename T, typename U, typename V> static inline T clamp (T v, U a, V b) { return v < (T)a ? (T)a : v >(T)b ? (T)b : v; }
92 94
93template<typename T, typename U> static inline void min_it (T &v, U m) { v = min (v, (T)m); } 95template<typename T, typename U> static inline void min_it (T &v, U m) { v = min (v, (T)m); }
94template<typename T, typename U> static inline void max_it (T &v, U m) { v = max (v, (T)m); } 96template<typename T, typename U> static inline void max_it (T &v, U m) { v = max (v, (T)m); }
95template<typename T, typename U, typename V> static inline void clamp_it (T &v, U a, V b) { v = clamp (v, (T)a, (T)b); } 97template<typename T, typename U, typename V> static inline void clamp_it (T &v, U a, V b) { v = clamp (v, (T)a, (T)b); }
… …
102// sign returns -1 or +1 104// sign returns -1 or +1
103template<typename T> 105template<typename T>
104static inline T sign (T v) { return v < 0 ? -1 : +1; } 106static inline T sign (T v) { return v < 0 ? -1 : +1; }
105// relies on 2c representation 107// relies on 2c representation
106template<> 108template<>
107inline 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); }
108 114
109// sign0 returns -1, 0 or +1 115// sign0 returns -1, 0 or +1
110template<typename T> 116template<typename T>
111static inline T sign0 (T v) { return v ? sign (v) : 0; } 117static inline T sign0 (T v) { return v ? sign (v) : 0; }
112 118
119//clashes with C++0x
113template<typename T, typename U> 120template<typename T, typename U>
114static inline T copysign (T a, U b) { return a > 0 ? b : -b; } 121static inline T copysign (T a, U b) { return a > 0 ? b : -b; }
115 122
116// div* only work correctly for div > 0 123// div* only work correctly for div > 0
117// div, with correct rounding (< 0.5 downwards, >=0.5 upwards) 124// div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
118template<typename T> static inline T div (T val, T div) 125template<typename T> static inline T div (T val, T div)
119{ 126{
120 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;
121} 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
122// div, round-up 133// div, round-up
123template<typename T> static inline T div_ru (T val, T div) 134template<typename T> static inline T div_ru (T val, T div)
124{ 135{
125 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div; 136 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div;
126} 137}
… …
241#else 252#else
242 return dx_ + dy_ - min (dx_, dy_) * 5 / 8; 253 return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
243#endif 254#endif
244} 255}
245 256
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
246/* 277/*
247 * absdir(int): Returns a number between 1 and 8, which represent 278 * absdir(int): Returns a number between 1 and 8, which represent
248 * the "absolute" direction of a number (it actually takes care of 279 * the "absolute" direction of a number (it actually takes care of
249 * "overflow" in previous calculations of a direction). 280 * "overflow" in previous calculations of a direction).
250 */ 281 */
… …
293 if (expect_true (ptr)) 324 if (expect_true (ptr))
294 { 325 {
295 slice_alloc -= n * sizeof (T); 326 slice_alloc -= n * sizeof (T);
296 if (DEBUG_POISON) memset (ptr, DEBUG_POISON, n * sizeof (T)); 327 if (DEBUG_POISON) memset (ptr, DEBUG_POISON, n * sizeof (T));
297 g_slice_free1 (n * sizeof (T), (void *)ptr); 328 g_slice_free1 (n * sizeof (T), (void *)ptr);
298 assert (slice_alloc >= 0);//D
299 } 329 }
300} 330}
301 331
302// nulls the pointer 332// nulls the pointer
303template<typename T> 333template<typename T>
… …
419 { 449 {
420 p->~Tp (); 450 p->~Tp ();
421 } 451 }
422}; 452};
423 453
424// P. L'Ecuyer, “Maximally Equidistributed Combined Tausworthe Generators”, Mathematics of Computation, 65, 213 (1996), 203–213. 454// basically a memory area, but refcounted
425// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme.ps 455struct refcnt_buf
426// http://www.iro.umontreal.ca/~lecuyer/myftp/papers/tausme2.ps
427struct tausworthe_random_generator
428{ 456{
429 uint32_t state [4]; 457 char *data;
430 458
431 void operator =(const tausworthe_random_generator &src) 459 refcnt_buf (size_t size = 0);
432 { 460 refcnt_buf (void *data, size_t size);
433 state [0] = src.state [0];
434 state [1] = src.state [1];
435 state [2] = src.state [2];
436 state [3] = src.state [3];
437 }
438 461
439 void seed (uint32_t seed); 462 refcnt_buf (const refcnt_buf &src)
440 uint32_t next ();
441};
442
443// Xorshift RNGs, George Marsaglia
444// http://www.jstatsoft.org/v08/i14/paper
445// this one is about 40% faster than the tausworthe one above (i.e. not much),
446// despite the inlining, and has the issue of only creating 2**32-1 numbers.
447// see also http://www.iro.umontreal.ca/~lecuyer/myftp/papers/xorshift.pdf
448struct xorshift_random_generator
449{
450 uint32_t x, y;
451
452 void operator =(const xorshift_random_generator &src)
453 { 463 {
454 x = src.x; 464 data = src.data;
455 y = src.y; 465 ++_refcnt ();
456 } 466 }
457 467
458 void seed (uint32_t seed) 468 ~refcnt_buf ();
459 {
460 x = seed;
461 y = seed * 69069U;
462 }
463 469
464 uint32_t next () 470 refcnt_buf &operator =(const refcnt_buf &src);
471
472 operator char *()
465 { 473 {
466 uint32_t t = x ^ (x << 10);
467 x = y;
468 y = y ^ (y >> 13) ^ t ^ (t >> 10);
469 return y; 474 return data;
470 } 475 }
471};
472 476
473template<class generator> 477 size_t size () const
474struct random_number_generator : generator
475{
476 // uniform distribution, 0 .. max (0, num - 1)
477 uint32_t operator ()(uint32_t num)
478 { 478 {
479 return !is_constant (num) ? get_range (num) // non-constant 479 return _size ();
480 : num & (num - 1) ? (this->next () * (uint64_t)num) >> 32U // constant, non-power-of-two
481 : this->next () & (num - 1); // constant, power-of-two
482 }
483
484 // return a number within the closed interval [min .. max]
485 int operator () (int r_min, int r_max)
486 {
487 return is_constant (r_min) && is_constant (r_max) && r_min <= r_max
488 ? r_min + operator ()(r_max - r_min + 1)
489 : get_range (r_min, r_max);
490 }
491
492 // return a number within the closed interval [0..1]
493 double operator ()()
494 {
495 return this->next () / (double)0xFFFFFFFFU;
496 } 480 }
497 481
498protected: 482protected:
499 uint32_t get_range (uint32_t r_max); 483 enum {
500 int get_range (int r_min, int r_max); 484 overhead = sizeof (unsigned int) * 2
501}; 485 };
502 486
503typedef random_number_generator<tausworthe_random_generator> rand_gen; 487 unsigned int &_size () const
488 {
489 return ((unsigned int *)data)[-2];
490 }
504 491
505extern rand_gen rndm, rmg_rndm; 492 unsigned int &_refcnt () const
493 {
494 return ((unsigned int *)data)[-1];
495 }
496
497 void _alloc (unsigned int size)
498 {
499 data = ((char *)salloc<char> (size + overhead)) + overhead;
500 _size () = size;
501 _refcnt () = 1;
502 }
503
504 void dec ()
505 {
506 if (!--_refcnt ())
507 sfree<char> (data - overhead, size () + overhead);
508 }
509};
506 510
507INTERFACE_CLASS (attachable) 511INTERFACE_CLASS (attachable)
508struct refcnt_base 512struct refcnt_base
509{ 513{
510 typedef int refcnt_t; 514 typedef int refcnt_t;
… …
584 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/) 588 // use FNV-1a hash (http://isthe.com/chongo/tech/comp/fnv/)
585 // it is about twice as fast as the one-at-a-time one, 589 // it is about twice as fast as the one-at-a-time one,
586 // with good distribution. 590 // with good distribution.
587 // FNV-1a is faster on many cpus because the multiplication 591 // FNV-1a is faster on many cpus because the multiplication
588 // runs concurrently with the looping logic. 592 // runs concurrently with the looping logic.
593 // we modify the hash a bit to improve its distribution
589 uint32_t hash = STRHSH_NULL; 594 uint32_t hash = STRHSH_NULL;
590 595
591 while (*s) 596 while (*s)
592 hash = (hash ^ *s++) * 16777619U; 597 hash = (hash ^ *s++) * 16777619U;
593 598
594 return hash; 599 return hash ^ (hash >> 16);
595} 600}
596 601
597static inline uint32_t 602static inline uint32_t
598memhsh (const char *s, size_t len) 603memhsh (const char *s, size_t len)
599{ 604{
… …
649 } 654 }
650}; 655};
651 656
652// This container blends advantages of linked lists 657// This container blends advantages of linked lists
653// (efficiency) with vectors (random access) by 658// (efficiency) with vectors (random access) by
654// by using an unordered vector and storing the vector 659// using an unordered vector and storing the vector
655// index inside the object. 660// index inside the object.
656// 661//
657// + memory-efficient on most 64 bit archs 662// + memory-efficient on most 64 bit archs
658// + O(1) insert/remove 663// + O(1) insert/remove
659// + free unique (but varying) id for inserted objects 664// + free unique (but varying) id for inserted objects
… …
696 insert (&obj); 701 insert (&obj);
697 } 702 }
698 703
699 void erase (T *obj) 704 void erase (T *obj)
700 { 705 {
701 unsigned int pos = obj->*indexmember; 706 object_vector_index pos = obj->*indexmember;
702 obj->*indexmember = 0; 707 obj->*indexmember = 0;
703 708
704 if (pos < this->size ()) 709 if (pos < this->size ())
705 { 710 {
706 (*this)[pos - 1] = (*this)[this->size () - 1]; 711 (*this)[pos - 1] = (*this)[this->size () - 1];
… …
714 { 719 {
715 erase (&obj); 720 erase (&obj);
716 } 721 }
717}; 722};
718 723
724/////////////////////////////////////////////////////////////////////////////
725
726// something like a vector or stack, but without
727// out of bounds checking
728template<typename T>
729struct fixed_stack
730{
731 T *data;
732 int size;
733 int max;
734
735 fixed_stack ()
736 : size (0), data (0)
737 {
738 }
739
740 fixed_stack (int max)
741 : size (0), max (max)
742 {
743 data = salloc<T> (max);
744 }
745
746 void reset (int new_max)
747 {
748 sfree (data, max);
749 size = 0;
750 max = new_max;
751 data = salloc<T> (max);
752 }
753
754 void free ()
755 {
756 sfree (data, max);
757 data = 0;
758 }
759
760 ~fixed_stack ()
761 {
762 sfree (data, max);
763 }
764
765 T &operator[](int idx)
766 {
767 return data [idx];
768 }
769
770 void push (T v)
771 {
772 data [size++] = v;
773 }
774
775 T &pop ()
776 {
777 return data [--size];
778 }
779
780 T remove (int idx)
781 {
782 T v = data [idx];
783
784 data [idx] = data [--size];
785
786 return v;
787 }
788};
789
790/////////////////////////////////////////////////////////////////////////////
791
719// basically does what strncpy should do, but appends "..." to strings exceeding length 792// basically does what strncpy should do, but appends "..." to strings exceeding length
720// returns the number of bytes actually used (including \0) 793// returns the number of bytes actually used (including \0)
721int assign (char *dst, const char *src, int maxsize); 794int assign (char *dst, const char *src, int maxsize);
722 795
723// type-safe version of assign 796// type-safe version of assign

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