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Comparing deliantra/server/common/shstr.C (file contents):
Revision 1.4 by root, Sun Sep 3 08:05:39 2006 UTC vs.
Revision 1.31 by root, Tue Jul 29 02:00:55 2008 UTC

1/*
2 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
3 *
4 * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5 *
6 * Deliantra 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 <support@deliantra.net>
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
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; 35typedef std::tr1::unordered_set <const char *, str_hash, str_equal, slice_allocator<const char *> > HT;
48 36
49static HT ht; 37static HT ht;
38static int next_gc;
39
40static const char *
41makevec (const char *s)
42{
43 int len = strlen (s);
44
45 shstr_alloc += sizeof (int) * 2 + len + 1;
46 const char *v = (const char *) (2 + (int *)g_slice_alloc (sizeof (int) * 2 + len + 1));
47
48 shstr::length (v) = len;
49 shstr::refcnt (v) = 1;
50
51 memcpy ((char *) v, s, len + 1);
52
53 return v;
54}
55
56static const char *
57makenull ()
58{
59 const char *s = makevec ("(null)");
60 shstr::length (s) = 0;
61 return s;
62}
63
64const char *shstr::null = makenull ();
50 65
51const char * 66const char *
52shstr::find (const char *s) 67shstr::find (const char *s)
53{ 68{
54 if (!s) 69 if (!s)
55 return s; 70 return s;
56 71
57 HT::iterator i = ht.find (s); 72 auto (i, ht.find (s));
58 73
59 return i != ht.end () 74 return i != ht.end ()? *i : 0;
60 ? (char *)*i
61 : 0;
62} 75}
63 76
64const char * 77const char *
65shstr::intern (const char *s) 78shstr::intern (const char *s)
66{ 79{
67 if (!s) 80 if (!s)
68 return s; 81 return null;
69 82
70 if (const char *found = find (s)) 83 if (const char *found = find (s))
84 {
85 ++refcnt (found);
71 return found; 86 return found;
87 }
72 88
73 int len = strlen (s); 89 --next_gc;
74 90 s = makevec (s);
75 int *v = (int *)malloc (sizeof (int) * 2 + len + 1);
76
77 v [0] = len;
78 v [1] = 0;
79
80 v += 2;
81
82 memcpy (v, s, len + 1);
83
84 ht.insert ((char *)v); 91 ht.insert (s);
85 92 return s;
86 return (char *)v;
87} 93}
88 94
89// TODO: periodically test refcounts == 0 for a few strings (e.g. one hash bucket, 95// periodically test refcounts == 0 for a few strings
90// exploiting the fatc that iterators stay valid for unordered_set). 96// this is the ONLY thing that erases stuff from ht. keep it that way.
91void 97void
92shstr::gc () 98shstr::gc ()
93{ 99{
100 if (expect_true (next_gc > 0))
101 return;
102
103 static const char *curpos;
104
105 auto (i, curpos ? ht.find (curpos) : ht.begin ());
106
107 if (i == ht.end ())
108 i = ht.begin ();
109
110 int n = ht.size () / 256 + 16;
111 next_gc += n >> 1;
112
113 for (;;)
114 {
115 if (i == ht.end ())
116 {
117 curpos = 0;
118 return;
119 }
120 else if (!--n)
121 break;
122 else if (!refcnt (*i))
123 {
124 auto (o, i++);
125 const char *s = *o;
126
127 ht.erase (o);
128
129 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
130 shstr_alloc -= sizeof (int) * 2 + length (s) + 1;
131 g_slice_free1 (sizeof (int) * 2 + length (s) + 1, -2 + (int *) s);
132 }
133 else
134 ++i;
135 }
136
137 curpos = *i;
94} 138}
139
140const shstr shstr_null;
141
142// declare these here to get correct initialisation order
143#define def(str) const shstr shstr_ ## str (# str);
144# include "shstrinc.h"
145#undef def
146
147shstr skill_names[NUM_SKILLS];
148
149//TODO: this should of course not be here
95 150
96/* buf_overflow() - we don't want to exceed the buffer size of 151/* buf_overflow() - we don't want to exceed the buffer size of
97 * buf1 by adding on buf2! Returns true if overflow will occur. 152 * buf1 by adding on buf2! Returns true if overflow will occur.
98 */ 153 */
99
100int 154int
101buf_overflow (const char *buf1, const char *buf2, int bufsize) 155buf_overflow (const char *buf1, const char *buf2, int bufsize)
102{ 156{
103 int len1 = 0, len2 = 0; 157 int len1 = 0, len2 = 0;
104 158
105 if (buf1) 159 if (buf1)
106 len1 = strlen (buf1); 160 len1 = strlen (buf1);
161
107 if (buf2) 162 if (buf2)
108 len2 = strlen (buf2); 163 len2 = strlen (buf2);
164
109 if ((len1 + len2) >= bufsize) 165 if ((len1 + len2) >= bufsize)
110 return 1;
111 return 0; 166 return 1;
167
168 return 0;
112} 169}
113

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