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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 1.37 by root, Thu Jan 1 16:05:12 2009 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 (uint32_t) * 2 + len + 1;
46 const char *v = (const char *) (2 + (int *)g_slice_alloc (sizeof (uint32_t) * 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
56shstr_vec<sizeof "(null)"> shstr_tmp::nullvec = { 0, 0xffffffff, "(null)" };
50 57
51const char * 58const char *
52shstr::find (const char *s) 59shstr::find (const char *s)
53{ 60{
54 HT::iterator i = ht.find (s); 61 if (!s)
62 return s;
55 63
64 auto (i, ht.find (s));
65
56 return i != ht.end () 66 return i != ht.end ()? *i : 0;
57 ? (char *)*i
58 : 0;
59} 67}
60 68
61const char * 69const char *
62shstr::intern (const char *s) 70shstr::intern (const char *s)
63{ 71{
64 HT::iterator i = ht.find (s); 72 if (!s)
73 return null ();
65 74
66 if (i != ht.end ()) 75 if (const char *found = find (s))
67 return (char *)*i; 76 {
77 ++refcnt (found);
78 return found;
79 }
68 80
69 int len = strlen (s); 81 --next_gc;
70 82 s = makevec (s);
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); 83 ht.insert (s);
81 84 return s;
82 return (char *)v;
83} 85}
84 86
85// TODO: periodically test refcounts == 0 for a few strings (e.g. one hash bucket, 87// periodically test refcounts == 0 for a few strings
86// exploiting the fatc that iterators stay valid for unordered_set). 88// this is the ONLY thing that erases stuff from ht. keep it that way.
87void 89void
88shstr::gc () 90shstr::gc ()
89{ 91{
92 if (expect_true (next_gc > 0))
93 return;
94
95 static const char *curpos;
96
97 auto (i, curpos ? ht.find (curpos) : ht.begin ());
98
99 if (i == ht.end ())
100 i = ht.begin ();
101
102 int n = ht.size () / 256 + 16;
103 next_gc += n >> 1;
104
105 for (;;)
106 {
107 if (i == ht.end ())
108 {
109 curpos = 0;
110 return;
111 }
112 else if (!--n)
113 break;
114 else if (!refcnt (*i))
115 {
116 auto (o, i++);
117 const char *s = *o;
118
119 ht.erase (o);
120
121 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
122 shstr_alloc -= sizeof (uint32_t) * 2 + length (s) + 1;
123 g_slice_free1 (sizeof (uint32_t) * 2 + length (s) + 1, -2 + (int *) s);
124 }
125 else
126 ++i;
127 }
128
129 curpos = *i;
90} 130}
131
132// declare these here to get correct initialisation order
133#define def2(id,str) const shstr id (str);
134#define def(id) def2(shstr_ ## id, # id)
135# include "shstrinc.h"
136#undef def
137#undef def2
138
139shstr skill_names[NUM_SKILLS];
140
141//TODO: this should of course not be here
91 142
92/* buf_overflow() - we don't want to exceed the buffer size of 143/* buf_overflow() - we don't want to exceed the buffer size of
93 * buf1 by adding on buf2! Returns true if overflow will occur. 144 * buf1 by adding on buf2! Returns true if overflow will occur.
94 */ 145 */
95
96int 146int
97buf_overflow (const char *buf1, const char *buf2, int bufsize) 147buf_overflow (const char *buf1, const char *buf2, int bufsize)
98{ 148{
99 int len1 = 0, len2 = 0; 149 int len1 = 0, len2 = 0;
100 150
101 if (buf1) 151 if (buf1)
102 len1 = strlen (buf1); 152 len1 = strlen (buf1);
153
103 if (buf2) 154 if (buf2)
104 len2 = strlen (buf2); 155 len2 = strlen (buf2);
156
105 if ((len1 + len2) >= bufsize) 157 if ((len1 + len2) >= bufsize)
106 return 1;
107 return 0; 158 return 1;
159
160 return 0;
108} 161}
109

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