ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/deliantra/server/common/shstr.C
(Generate patch)

Comparing deliantra/server/common/shstr.C (file contents):
Revision 1.3 by root, Sun Sep 3 00:18:40 2006 UTC vs.
Revision 1.22 by root, Thu May 17 21:32:08 2007 UTC

1/*
2 * CrossFire, A Multiplayer game
3 *
4 * Copyright (C) 2005, 2006, 2007 Marc Lehmann & Crossfire+ Development Team
5 *
6 * This program 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 2 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, write to the Free Software
18 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19 *
20 * The authors can be reached via e-mail at <crossfire@schmorp.de>
21 */
22
1/* 23/*
2 * shstr.C 24 * shstr.C
3 */ 25 */
4 26
5#include <cstring> 27#include <cstring>
6#include <cstdlib> 28#include <cstdlib>
7 29#include <glib.h>
8#include <tr1/unordered_set> 30#include <tr1/unordered_set>
9 31
10#include "shstr.h" 32#include "global.h"
11 33
12struct hash 34typedef std::tr1::unordered_set <const char *, str_hash, str_equal, slice_allocator<const char *>, true> HT;
13{
14 std::size_t operator ()(const char *s) const
15 {
16 unsigned long hash = 0;
17 unsigned int i = 0;
18
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;
48 35
49static HT ht; 36static HT ht;
37
38static const char *
39makevec (const char *s)
40{
41 int len = strlen (s);
42
43 const char *v = (const char *) (2 + (int *)g_slice_alloc (sizeof (int) * 2 + len + 1));
44
45 shstr::length (v) = len;
46 shstr::refcnt (v) = 1;
47
48 memcpy ((char *) v, s, len + 1);
49
50 return v;
51}
52
53static const char *
54makenull ()
55{
56 const char *s = makevec ("(null)");
57 shstr::length (s) = 0;
58 return s;
59}
60
61const char *shstr::null = makenull ();
50 62
51const char * 63const char *
52shstr::find (const char *s) 64shstr::find (const char *s)
53{ 65{
54 HT::iterator i = ht.find (s); 66 if (!s)
67 return s;
55 68
69 auto (i, ht.find (s));
70
56 return i != ht.end () 71 return i != ht.end ()? *i : 0;
57 ? (char *)*i
58 : 0;
59} 72}
60 73
61const char * 74const char *
62shstr::intern (const char *s) 75shstr::intern (const char *s)
63{ 76{
64 HT::iterator i = ht.find (s); 77 if (!s)
78 return null;
65 79
66 if (i != ht.end ()) 80 if (const char *found = find (s))
67 return (char *)*i; 81 {
82 ++refcnt (found);
83 return found;
84 }
68 85
69 int len = strlen (s); 86 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); 87 ht.insert (s);
81 88 return s;
82 return (char *)v;
83} 89}
84 90
85// TODO: periodically test refcounts == 0 for a few strings (e.g. one hash bucket, 91// periodically test refcounts == 0 for a few strings
86// exploiting the fatc that iterators stay valid for unordered_set). 92// this is the ONLY thing that erases stuff from ht. keep it that way.
87void 93void
88shstr::gc () 94shstr::gc ()
89{ 95{
96 static const char *curpos;
97
98 auto (i, curpos ? ht.find (curpos) : ht.begin ());
99
100 if (i == ht.end ())
101 i = ht.begin ();
102
103 // go through all strings roughly once every 4 minutes
104 int n = ht.size () / 256 + 16;
105
106 for (;;)
107 {
108 if (i == ht.end ())
109 {
110 curpos = 0;
111 return;
112 }
113 else if (!--n)
114 break;
115 else if (!refcnt (*i))
116 {
117 auto (o, i++);
118 const char *s = *o;
119
120 ht.erase (o);
121
122 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
123 g_slice_free1 (sizeof (int) * 2 + length (s) + 1, -2 + (int *) s);
124 }
125 else
126 ++i;
127 }
128
129 curpos = *i;
90} 130}
131
132shstr skill_names[NUM_SKILLS];
133
134// what weird misoptimisation is this again?
135const shstr undead_name ("undead");
136
137//TODO: this should of course not be here
91 138
92/* buf_overflow() - we don't want to exceed the buffer size of 139/* buf_overflow() - we don't want to exceed the buffer size of
93 * buf1 by adding on buf2! Returns true if overflow will occur. 140 * buf1 by adding on buf2! Returns true if overflow will occur.
94 */ 141 */
95
96int 142int
97buf_overflow (const char *buf1, const char *buf2, int bufsize) 143buf_overflow (const char *buf1, const char *buf2, int bufsize)
98{ 144{
99 int len1 = 0, len2 = 0; 145 int len1 = 0, len2 = 0;
100 146
101 if (buf1) 147 if (buf1)
102 len1 = strlen (buf1); 148 len1 = strlen (buf1);
103 if (buf2) 149 if (buf2)
104 len2 = strlen (buf2); 150 len2 = strlen (buf2);
105 if ((len1 + len2) >= bufsize) 151 if ((len1 + len2) >= bufsize)
106 return 1;
107 return 0; 152 return 1;
153
154 return 0;
108} 155}
109

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines