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Comparing deliantra/server/common/shstr.C (file contents):
Revision 1.3 by root, Sun Sep 3 00:18:40 2006 UTC vs.
Revision 1.26 by root, Tue Oct 16 05:34:24 2007 UTC

1/*
2 * This file is part of Crossfire TRT, the Roguelike Realtime MORPG.
3 *
4 * Copyright (©) 2005,2006,2007 Marc Alexander Lehmann / Robin Redeker / the Crossfire TRT team
5 *
6 * Crossfire TRT is free software: you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation, either version 3 of the License, or
9 * (at your 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 GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
18 *
19 * The authors can be reached via e-mail to <crossfire@schmorp.de>
20 */
21
1/* 22/*
2 * shstr.C 23 * shstr.C
3 */ 24 */
4 25
5#include <cstring> 26#include <cstring>
6#include <cstdlib> 27#include <cstdlib>
7 28#include <glib.h>
8#include <tr1/unordered_set> 29#include <tr1/unordered_set>
9 30
10#include "shstr.h" 31#include "global.h"
11 32
12struct hash 33size_t shstr_alloc;
13{
14 std::size_t operator ()(const char *s) const
15 {
16 unsigned long hash = 0;
17 unsigned int i = 0;
18 34
19 /* use the one-at-a-time hash function, which supposedly is 35typedef std::tr1::unordered_set <const char *, str_hash, str_equal, slice_allocator<const char *>, true> HT;
20 * better than the djb2-like one used by perl5.005, but
21 * certainly is better then the bug used here before.
22 * see http://burtleburtle.net/bob/hash/doobs.html
23 */
24 while (*s)
25 {
26 hash += *s++;
27 hash += hash << 10;
28 hash ^= hash >> 6;
29 }
30
31 hash += hash << 3;
32 hash ^= hash >> 11;
33 hash += hash << 15;
34
35 return hash;
36 }
37};
38
39struct equal
40{
41 bool operator ()(const char *a, const char *b) const
42 {
43 return !strcmp (a, b);
44 }
45};
46
47typedef std::tr1::unordered_set<const char *, hash, equal> HT;
48 36
49static HT ht; 37static HT ht;
38
39static const char *
40makevec (const char *s)
41{
42 int len = strlen (s);
43
44 shstr_alloc += sizeof (int) * 2 + len + 1;
45 const char *v = (const char *) (2 + (int *)g_slice_alloc (sizeof (int) * 2 + len + 1));
46
47 shstr::length (v) = len;
48 shstr::refcnt (v) = 1;
49
50 memcpy ((char *) v, s, len + 1);
51
52 return v;
53}
54
55static const char *
56makenull ()
57{
58 const char *s = makevec ("(null)");
59 shstr::length (s) = 0;
60 return s;
61}
62
63const char *shstr::null = makenull ();
50 64
51const char * 65const char *
52shstr::find (const char *s) 66shstr::find (const char *s)
53{ 67{
54 HT::iterator i = ht.find (s); 68 if (!s)
69 return s;
55 70
71 auto (i, ht.find (s));
72
56 return i != ht.end () 73 return i != ht.end ()? *i : 0;
57 ? (char *)*i
58 : 0;
59} 74}
60 75
61const char * 76const char *
62shstr::intern (const char *s) 77shstr::intern (const char *s)
63{ 78{
64 HT::iterator i = ht.find (s); 79 if (!s)
80 return null;
65 81
66 if (i != ht.end ()) 82 if (const char *found = find (s))
67 return (char *)*i; 83 {
84 ++refcnt (found);
85 return found;
86 }
68 87
69 int len = strlen (s); 88 s = makevec (s);
70
71 int *v = (int *)malloc (sizeof (int) * 2 + len + 1);
72
73 v [0] = len;
74 v [1] = 0;
75
76 v += 2;
77
78 memcpy (v, s, len + 1);
79
80 ht.insert ((char *)v); 89 ht.insert (s);
81 90 return s;
82 return (char *)v;
83} 91}
84 92
85// TODO: periodically test refcounts == 0 for a few strings (e.g. one hash bucket, 93// periodically test refcounts == 0 for a few strings
86// exploiting the fatc that iterators stay valid for unordered_set). 94// this is the ONLY thing that erases stuff from ht. keep it that way.
87void 95void
88shstr::gc () 96shstr::gc ()
89{ 97{
98 static const char *curpos;
99
100 auto (i, curpos ? ht.find (curpos) : ht.begin ());
101
102 if (i == ht.end ())
103 i = ht.begin ();
104
105 // go through all strings roughly once every 4 minutes
106 int n = ht.size () / 256 + 16;
107
108 for (;;)
109 {
110 if (i == ht.end ())
111 {
112 curpos = 0;
113 return;
114 }
115 else if (!--n)
116 break;
117 else if (!refcnt (*i))
118 {
119 auto (o, i++);
120 const char *s = *o;
121
122 ht.erase (o);
123
124 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
125 shstr_alloc -= sizeof (int) * 2 + length (s) + 1;
126 g_slice_free1 (sizeof (int) * 2 + length (s) + 1, -2 + (int *) s);
127 }
128 else
129 ++i;
130 }
131
132 curpos = *i;
90} 133}
134
135// declare these here to get correct initialisation order
136#define def(str) const shstr shstr_ ## str (# str);
137# include "shstrinc.h"
138#undef def
139
140shstr skill_names[NUM_SKILLS];
141
142//TODO: this should of course not be here
91 143
92/* buf_overflow() - we don't want to exceed the buffer size of 144/* buf_overflow() - we don't want to exceed the buffer size of
93 * buf1 by adding on buf2! Returns true if overflow will occur. 145 * buf1 by adding on buf2! Returns true if overflow will occur.
94 */ 146 */
95
96int 147int
97buf_overflow (const char *buf1, const char *buf2, int bufsize) 148buf_overflow (const char *buf1, const char *buf2, int bufsize)
98{ 149{
99 int len1 = 0, len2 = 0; 150 int len1 = 0, len2 = 0;
100 151
101 if (buf1) 152 if (buf1)
102 len1 = strlen (buf1); 153 len1 = strlen (buf1);
154
103 if (buf2) 155 if (buf2)
104 len2 = strlen (buf2); 156 len2 = strlen (buf2);
157
105 if ((len1 + len2) >= bufsize) 158 if ((len1 + len2) >= bufsize)
106 return 1;
107 return 0; 159 return 1;
160
161 return 0;
108} 162}
109

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