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/cvs/deliantra/server/include/util.h
Revision: 1.112
Committed: Tue Jul 6 20:15:13 2010 UTC (13 years, 10 months ago) by root
Content type: text/plain
Branch: MAIN
Changes since 1.111: +2 -1 lines
Log Message:
try better mixing for fnv1a

File Contents

# Content
1 /*
2 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
3 *
4 * Copyright (©) 2005,2006,2007,2008,2009,2010 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5 *
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
8 * Free Software Foundation, either version 3 of the License, or (at your
9 * option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
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
18 * <http://www.gnu.org/licenses/>.
19 *
20 * The authors can be reached via e-mail to <support@deliantra.net>
21 */
22
23 #ifndef UTIL_H__
24 #define UTIL_H__
25
26 #include <compiler.h>
27
28 #define DEBUG_POISON 0x00 // poison memory before freeing it if != 0
29 #define DEBUG_SALLOC 0 // add a debug wrapper around all sallocs
30 #define PREFER_MALLOC 0 // use malloc and not the slice allocator
31
32 #include <pthread.h>
33
34 #include <cstddef>
35 #include <cmath>
36 #include <new>
37 #include <vector>
38
39 #include <glib.h>
40
41 #include <shstr.h>
42 #include <traits.h>
43
44 #if DEBUG_SALLOC
45 # define g_slice_alloc0(s) debug_slice_alloc0(s)
46 # define g_slice_alloc(s) debug_slice_alloc(s)
47 # define g_slice_free1(s,p) debug_slice_free1(s,p)
48 void *g_slice_alloc (unsigned long size);
49 void *g_slice_alloc0 (unsigned long size);
50 void g_slice_free1 (unsigned long size, void *ptr);
51 #elif PREFER_MALLOC
52 # define g_slice_alloc0(s) calloc (1, (s))
53 # define g_slice_alloc(s) malloc ((s))
54 # define g_slice_free1(s,p) free ((p))
55 #endif
56
57 // use C0X decltype for auto declarations until ISO C++ sanctifies them (if ever)
58 #define auto(var,expr) decltype(expr) var = (expr)
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)
62 template<typename T, int N>
63 static 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
71 // very ugly macro that basically declares and initialises a variable
72 // that is in scope for the next statement only
73 // works only for stuff that can be assigned 0 and converts to false
74 // (note: works great for pointers)
75 // most ugly macro I ever wrote
76 #define statementvar(type, name, value) if (type name = 0) { } else if (((name) = (value)), 1)
77
78 // in range including end
79 #define IN_RANGE_INC(val,beg,end) \
80 ((unsigned int)(val) - (unsigned int)(beg) <= (unsigned int)(end) - (unsigned int)(beg))
81
82 // in range excluding end
83 #define IN_RANGE_EXC(val,beg,end) \
84 ((unsigned int)(val) - (unsigned int)(beg) < (unsigned int)(end) - (unsigned int)(beg))
85
86 void cleanup (const char *cause, bool make_core = false);
87 void fork_abort (const char *msg);
88
89 // rationale for using (U) not (T) is to reduce signed/unsigned issues,
90 // as a is often a constant while b is the variable. it is still a bug, though.
91 template<typename T, typename U> static inline T min (T a, U b) { return (U)a < b ? (U)a : b; }
92 template<typename T, typename U> static inline T max (T a, U b) { return (U)a > b ? (U)a : b; }
93 template<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; }
94
95 template<typename T, typename U> static inline void min_it (T &v, U m) { v = min (v, (T)m); }
96 template<typename T, typename U> static inline void max_it (T &v, U m) { v = max (v, (T)m); }
97 template<typename T, typename U, typename V> static inline void clamp_it (T &v, U a, V b) { v = clamp (v, (T)a, (T)b); }
98
99 template<typename T, typename U> static inline void swap (T& a, U& b) { T t=a; a=(T)b; b=(U)t; }
100
101 template<typename T, typename U, typename V> static inline T min (T a, U b, V c) { return min (a, min (b, c)); }
102 template<typename T, typename U, typename V> static inline T max (T a, U b, V c) { return max (a, max (b, c)); }
103
104 // sign returns -1 or +1
105 template<typename T>
106 static inline T sign (T v) { return v < 0 ? -1 : +1; }
107 // relies on 2c representation
108 template<>
109 inline sint8 sign (sint8 v) { return 1 - (sint8 (uint8 (v) >> 7) * 2); }
110 template<>
111 inline sint16 sign (sint16 v) { return 1 - (sint16 (uint16 (v) >> 15) * 2); }
112 template<>
113 inline sint32 sign (sint32 v) { return 1 - (sint32 (uint32 (v) >> 31) * 2); }
114
115 // sign0 returns -1, 0 or +1
116 template<typename T>
117 static inline T sign0 (T v) { return v ? sign (v) : 0; }
118
119 template<typename T, typename U>
120 static inline T copysign (T a, U b) { return a > 0 ? b : -b; }
121
122 // div* only work correctly for div > 0
123 // div, with correct rounding (< 0.5 downwards, >=0.5 upwards)
124 template<typename T> static inline T div (T val, T div)
125 {
126 return expect_false (val < 0) ? - ((-val + (div - 1) / 2) / div) : (val + div / 2) / div;
127 }
128
129 template<> inline float div (float val, float div) { return val / div; }
130 template<> inline double div (double val, double div) { return val / div; }
131
132 // div, round-up
133 template<typename T> static inline T div_ru (T val, T div)
134 {
135 return expect_false (val < 0) ? - ((-val ) / div) : (val + div - 1) / div;
136 }
137 // div, round-down
138 template<typename T> static inline T div_rd (T val, T div)
139 {
140 return expect_false (val < 0) ? - ((-val + (div - 1) ) / div) : (val ) / div;
141 }
142
143 // lerp* only work correctly for min_in < max_in
144 // Linear intERPolate, scales val from min_in..max_in to min_out..max_out
145 template<typename T>
146 static inline T
147 lerp (T val, T min_in, T max_in, T min_out, T max_out)
148 {
149 return min_out + div <T> ((val - min_in) * (max_out - min_out), max_in - min_in);
150 }
151
152 // lerp, round-down
153 template<typename T>
154 static inline T
155 lerp_rd (T val, T min_in, T max_in, T min_out, T max_out)
156 {
157 return min_out + div_rd<T> ((val - min_in) * (max_out - min_out), max_in - min_in);
158 }
159
160 // lerp, round-up
161 template<typename T>
162 static inline T
163 lerp_ru (T val, T min_in, T max_in, T min_out, T max_out)
164 {
165 return min_out + div_ru<T> ((val - min_in) * (max_out - min_out), max_in - min_in);
166 }
167
168 // lots of stuff taken from FXT
169
170 /* Rotate right. This is used in various places for checksumming */
171 //TODO: that sucks, use a better checksum algo
172 static inline uint32_t
173 rotate_right (uint32_t c, uint32_t count = 1)
174 {
175 return (c << (32 - count)) | (c >> count);
176 }
177
178 static inline uint32_t
179 rotate_left (uint32_t c, uint32_t count = 1)
180 {
181 return (c >> (32 - count)) | (c << count);
182 }
183
184 // Return abs(a-b)
185 // Both a and b must not have the most significant bit set
186 static inline uint32_t
187 upos_abs_diff (uint32_t a, uint32_t b)
188 {
189 long d1 = b - a;
190 long d2 = (d1 & (d1 >> 31)) << 1;
191
192 return d1 - d2; // == (b - d) - (a + d);
193 }
194
195 // Both a and b must not have the most significant bit set
196 static inline uint32_t
197 upos_min (uint32_t a, uint32_t b)
198 {
199 int32_t d = b - a;
200 d &= d >> 31;
201 return a + d;
202 }
203
204 // Both a and b must not have the most significant bit set
205 static inline uint32_t
206 upos_max (uint32_t a, uint32_t b)
207 {
208 int32_t d = b - a;
209 d &= d >> 31;
210 return b - d;
211 }
212
213 // this is much faster than crossfire's original algorithm
214 // on modern cpus
215 inline int
216 isqrt (int n)
217 {
218 return (int)sqrtf ((float)n);
219 }
220
221 // this is kind of like the ^^ operator, if it would exist, without sequence point.
222 // more handy than it looks like, due to the implicit !! done on its arguments
223 inline bool
224 logical_xor (bool a, bool b)
225 {
226 return a != b;
227 }
228
229 inline bool
230 logical_implies (bool a, bool b)
231 {
232 return a <= b;
233 }
234
235 // this is only twice as fast as naive sqrtf (dx*dy+dy*dy)
236 #if 0
237 // and has a max. error of 6 in the range -100..+100.
238 #else
239 // and has a max. error of 9 in the range -100..+100.
240 #endif
241 inline int
242 idistance (int dx, int dy)
243 {
244 unsigned int dx_ = abs (dx);
245 unsigned int dy_ = abs (dy);
246
247 #if 0
248 return dx_ > dy_
249 ? (dx_ * 61685 + dy_ * 26870) >> 16
250 : (dy_ * 61685 + dx_ * 26870) >> 16;
251 #else
252 return dx_ + dy_ - min (dx_, dy_) * 5 / 8;
253 #endif
254 }
255
256 /*
257 * absdir(int): Returns a number between 1 and 8, which represent
258 * the "absolute" direction of a number (it actually takes care of
259 * "overflow" in previous calculations of a direction).
260 */
261 inline int
262 absdir (int d)
263 {
264 return ((d - 1) & 7) + 1;
265 }
266
267 // avoid ctz name because netbsd or freebsd spams it's namespace with it
268 #if GCC_VERSION(3,4)
269 static inline int least_significant_bit (uint32_t x)
270 {
271 return __builtin_ctz (x);
272 }
273 #else
274 int 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
281 extern ssize_t slice_alloc; // statistics
282
283 void *salloc_ (int n) throw (std::bad_alloc);
284 void *salloc_ (int n, void *src) throw (std::bad_alloc);
285
286 // strictly the same as g_slice_alloc, but never returns 0
287 template<typename T>
288 inline T *salloc (int n = 1) throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T)); }
289
290 // also copies src into the new area, like "memdup"
291 // if src is 0, clears the memory
292 template<typename T>
293 inline T *salloc (int n, T *src) throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T), (void *)src); }
294
295 // clears the memory
296 template<typename T>
297 inline T *salloc0(int n = 1) throw (std::bad_alloc) { return (T *)salloc_ (n * sizeof (T), 0); }
298
299 // for symmetry
300 template<typename T>
301 inline void sfree (T *ptr, int n = 1) throw ()
302 {
303 if (expect_true (ptr))
304 {
305 slice_alloc -= n * sizeof (T);
306 if (DEBUG_POISON) memset (ptr, DEBUG_POISON, n * sizeof (T));
307 g_slice_free1 (n * sizeof (T), (void *)ptr);
308 assert (slice_alloc >= 0);//D
309 }
310 }
311
312 // nulls the pointer
313 template<typename T>
314 inline void sfree0 (T *&ptr, int n = 1) throw ()
315 {
316 sfree<T> (ptr, n);
317 ptr = 0;
318 }
319
320 // makes dynamically allocated objects zero-initialised
321 struct zero_initialised
322 {
323 void *operator new (size_t s, void *p)
324 {
325 memset (p, 0, s);
326 return p;
327 }
328
329 void *operator new (size_t s)
330 {
331 return salloc0<char> (s);
332 }
333
334 void *operator new[] (size_t s)
335 {
336 return salloc0<char> (s);
337 }
338
339 void operator delete (void *p, size_t s)
340 {
341 sfree ((char *)p, s);
342 }
343
344 void operator delete[] (void *p, size_t s)
345 {
346 sfree ((char *)p, s);
347 }
348 };
349
350 // makes dynamically allocated objects zero-initialised
351 struct slice_allocated
352 {
353 void *operator new (size_t s, void *p)
354 {
355 return p;
356 }
357
358 void *operator new (size_t s)
359 {
360 return salloc<char> (s);
361 }
362
363 void *operator new[] (size_t s)
364 {
365 return salloc<char> (s);
366 }
367
368 void operator delete (void *p, size_t s)
369 {
370 sfree ((char *)p, s);
371 }
372
373 void operator delete[] (void *p, size_t s)
374 {
375 sfree ((char *)p, s);
376 }
377 };
378
379 // a STL-compatible allocator that uses g_slice
380 // boy, this is verbose
381 template<typename Tp>
382 struct slice_allocator
383 {
384 typedef size_t size_type;
385 typedef ptrdiff_t difference_type;
386 typedef Tp *pointer;
387 typedef const Tp *const_pointer;
388 typedef Tp &reference;
389 typedef const Tp &const_reference;
390 typedef Tp value_type;
391
392 template <class U>
393 struct rebind
394 {
395 typedef slice_allocator<U> other;
396 };
397
398 slice_allocator () throw () { }
399 slice_allocator (const slice_allocator &) throw () { }
400 template<typename Tp2>
401 slice_allocator (const slice_allocator<Tp2> &) throw () { }
402
403 ~slice_allocator () { }
404
405 pointer address (reference x) const { return &x; }
406 const_pointer address (const_reference x) const { return &x; }
407
408 pointer allocate (size_type n, const_pointer = 0)
409 {
410 return salloc<Tp> (n);
411 }
412
413 void deallocate (pointer p, size_type n)
414 {
415 sfree<Tp> (p, n);
416 }
417
418 size_type max_size () const throw ()
419 {
420 return size_t (-1) / sizeof (Tp);
421 }
422
423 void construct (pointer p, const Tp &val)
424 {
425 ::new (p) Tp (val);
426 }
427
428 void destroy (pointer p)
429 {
430 p->~Tp ();
431 }
432 };
433
434 INTERFACE_CLASS (attachable)
435 struct refcnt_base
436 {
437 typedef int refcnt_t;
438 mutable refcnt_t ACC (RW, refcnt);
439
440 MTH void refcnt_inc () const { ++refcnt; }
441 MTH void refcnt_dec () const { --refcnt; }
442
443 refcnt_base () : refcnt (0) { }
444 };
445
446 // to avoid branches with more advanced compilers
447 extern refcnt_base::refcnt_t refcnt_dummy;
448
449 template<class T>
450 struct refptr
451 {
452 // p if not null
453 refcnt_base::refcnt_t *refcnt_ref () { return p ? &p->refcnt : &refcnt_dummy; }
454
455 void refcnt_dec ()
456 {
457 if (!is_constant (p))
458 --*refcnt_ref ();
459 else if (p)
460 --p->refcnt;
461 }
462
463 void refcnt_inc ()
464 {
465 if (!is_constant (p))
466 ++*refcnt_ref ();
467 else if (p)
468 ++p->refcnt;
469 }
470
471 T *p;
472
473 refptr () : p(0) { }
474 refptr (const refptr<T> &p) : p(p.p) { refcnt_inc (); }
475 refptr (T *p) : p(p) { refcnt_inc (); }
476 ~refptr () { refcnt_dec (); }
477
478 const refptr<T> &operator =(T *o)
479 {
480 // if decrementing ever destroys we need to reverse the order here
481 refcnt_dec ();
482 p = o;
483 refcnt_inc ();
484 return *this;
485 }
486
487 const refptr<T> &operator =(const refptr<T> &o)
488 {
489 *this = o.p;
490 return *this;
491 }
492
493 T &operator * () const { return *p; }
494 T *operator ->() const { return p; }
495
496 operator T *() const { return p; }
497 };
498
499 typedef refptr<maptile> maptile_ptr;
500 typedef refptr<object> object_ptr;
501 typedef refptr<archetype> arch_ptr;
502 typedef refptr<client> client_ptr;
503 typedef refptr<player> player_ptr;
504 typedef refptr<region> region_ptr;
505
506 #define STRHSH_NULL 2166136261
507
508 static inline uint32_t
509 strhsh (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
525 static inline uint32_t
526 memhsh (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 }
535
536 struct str_hash
537 {
538 std::size_t operator ()(const char *s) const
539 {
540 return strhsh (s);
541 }
542
543 std::size_t operator ()(const shstr &s) const
544 {
545 return strhsh (s);
546 }
547 };
548
549 struct str_equal
550 {
551 bool operator ()(const char *a, const char *b) const
552 {
553 return !strcmp (a, b);
554 }
555 };
556
557 // Mostly the same as std::vector, but insert/erase can reorder
558 // the elements, making append(=insert)/remove O(1) instead of O(n).
559 //
560 // NOTE: only some forms of erase are available
561 template<class T>
562 struct unordered_vector : std::vector<T, slice_allocator<T> >
563 {
564 typedef typename unordered_vector::iterator iterator;
565
566 void erase (unsigned int pos)
567 {
568 if (pos < this->size () - 1)
569 (*this)[pos] = (*this)[this->size () - 1];
570
571 this->pop_back ();
572 }
573
574 void erase (iterator i)
575 {
576 erase ((unsigned int )(i - this->begin ()));
577 }
578 };
579
580 // This container blends advantages of linked lists
581 // (efficiency) with vectors (random access) by
582 // by using an unordered vector and storing the vector
583 // index inside the object.
584 //
585 // + memory-efficient on most 64 bit archs
586 // + O(1) insert/remove
587 // + free unique (but varying) id for inserted objects
588 // + cache-friendly iteration
589 // - only works for pointers to structs
590 //
591 // NOTE: only some forms of erase/insert are available
592 typedef int object_vector_index;
593
594 template<class T, object_vector_index T::*indexmember>
595 struct object_vector : std::vector<T *, slice_allocator<T *> >
596 {
597 typedef typename object_vector::iterator iterator;
598
599 bool contains (const T *obj) const
600 {
601 return obj->*indexmember;
602 }
603
604 iterator find (const T *obj)
605 {
606 return obj->*indexmember
607 ? this->begin () + obj->*indexmember - 1
608 : this->end ();
609 }
610
611 void push_back (T *obj)
612 {
613 std::vector<T *, slice_allocator<T *> >::push_back (obj);
614 obj->*indexmember = this->size ();
615 }
616
617 void insert (T *obj)
618 {
619 push_back (obj);
620 }
621
622 void insert (T &obj)
623 {
624 insert (&obj);
625 }
626
627 void erase (T *obj)
628 {
629 unsigned int pos = obj->*indexmember;
630 obj->*indexmember = 0;
631
632 if (pos < this->size ())
633 {
634 (*this)[pos - 1] = (*this)[this->size () - 1];
635 (*this)[pos - 1]->*indexmember = pos;
636 }
637
638 this->pop_back ();
639 }
640
641 void erase (T &obj)
642 {
643 erase (&obj);
644 }
645 };
646
647 /////////////////////////////////////////////////////////////////////////////
648
649 // something like a vector or stack, but without
650 // out of bounds checking
651 template<typename T>
652 struct 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
715 // basically does what strncpy should do, but appends "..." to strings exceeding length
716 // returns the number of bytes actually used (including \0)
717 int assign (char *dst, const char *src, int maxsize);
718
719 // type-safe version of assign
720 template<int N>
721 inline int assign (char (&dst)[N], const char *src)
722 {
723 return assign ((char *)&dst, src, N);
724 }
725
726 typedef double tstamp;
727
728 // return current time as timestamp
729 tstamp now ();
730
731 int similar_direction (int a, int b);
732
733 // like v?sprintf, but returns a "static" buffer
734 char *vformat (const char *format, va_list ap);
735 char *format (const char *format, ...) attribute ((format (printf, 1, 2)));
736
737 // safety-check player input which will become object->msg
738 bool msg_is_safe (const char *msg);
739
740 /////////////////////////////////////////////////////////////////////////////
741 // threads, very very thin wrappers around pthreads
742
743 struct thread
744 {
745 pthread_t id;
746
747 void start (void *(*start_routine)(void *), void *arg = 0);
748
749 void cancel ()
750 {
751 pthread_cancel (id);
752 }
753
754 void *join ()
755 {
756 void *ret;
757
758 if (pthread_join (id, &ret))
759 cleanup ("pthread_join failed", 1);
760
761 return ret;
762 }
763 };
764
765 // note that mutexes are not classes
766 typedef pthread_mutex_t smutex;
767
768 #if __linux && defined (PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP)
769 #define SMUTEX_INITIALISER PTHREAD_ADAPTIVE_MUTEX_INITIALIZER_NP
770 #else
771 #define SMUTEX_INITIALISER PTHREAD_MUTEX_INITIALIZER
772 #endif
773
774 #define SMUTEX(name) smutex name = SMUTEX_INITIALISER
775 #define SMUTEX_LOCK(name) pthread_mutex_lock (&(name))
776 #define SMUTEX_UNLOCK(name) pthread_mutex_unlock (&(name))
777
778 typedef pthread_cond_t scond;
779
780 #define SCOND(name) scond name = PTHREAD_COND_INITIALIZER
781 #define SCOND_SIGNAL(name) pthread_cond_signal (&(name))
782 #define SCOND_BROADCAST(name) pthread_cond_broadcast (&(name))
783 #define SCOND_WAIT(name,mutex) pthread_cond_wait (&(name), &(mutex))
784
785 #endif
786