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 1.44 by root, Thu Apr 15 00:36:51 2010 UTC

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
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 34size_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 35
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; 36typedef std::tr1::unordered_set <const char *, str_hash, str_equal, slice_allocator<const char *> > HT;
48 37
49static HT ht; 38static HT ht;
39static int next_gc;
40
41#define NUM_INT 3
42
43static const char *
44makevec (const char *s)
45{
46 int len = strlen (s);
47 int alloc = sizeof (uint32_t) * NUM_INT + len + 1;
48
49 shstr_alloc += alloc;
50 char *v = (char *)g_slice_alloc (alloc);
51 v += sizeof (uint32_t) * NUM_INT;
52
53 shstr::hash (v) = strhsh (s);
54 shstr::length (v) = len;
55 shstr::refcnt (v) = 1;
56
57 memcpy (v, s, len + 1);
58
59 return v;
60}
61
62shstr_vec<sizeof "(null)"> shstr_tmp::nullvec = { STRHSH_NULL, 0, 0xffffffff, "(null)" };
50 63
51const char * 64const char *
52shstr::find (const char *s) 65shstr::find (const char *s)
53{ 66{
54 HT::iterator i = ht.find (s); 67 if (!s)
68 return s;
55 69
70 auto (i, ht.find (s));
71
56 return i != ht.end () 72 return i != ht.end ()? *i : 0;
57 ? (char *)*i
58 : 0;
59} 73}
60 74
61const char * 75const char *
62shstr::intern (const char *s) 76shstr::intern (const char *s)
63{ 77{
64 HT::iterator i = ht.find (s); 78 if (!s)
79 return null ();
65 80
66 if (i != ht.end ()) 81 if (const char *found = find (s))
67 return (char *)*i; 82 {
83 ++refcnt (found);
84 return found;
85 }
68 86
69 int len = strlen (s); 87 --next_gc;
70 88 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); 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 if (expect_true (next_gc > 0))
99 return;
100
101 static const char *curpos;
102
103 auto (i, curpos ? ht.find (curpos) : ht.begin ());
104
105 if (i == ht.end ())
106 i = ht.begin ();
107
108 int n = ht.size () / 256 + 16;
109 next_gc += n >> 1;
110
111 for (;;)
112 {
113 if (i == ht.end ())
114 {
115 curpos = 0;
116 return;
117 }
118 else if (!--n)
119 break;
120 else if (!refcnt (*i))
121 {
122 auto (o, i++);
123 const char *s = *o;
124
125 ht.erase (o);
126
127 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
128 int alloc = sizeof (uint32_t) * NUM_INT + length (s) + 1;
129 shstr_alloc -= alloc;
130 g_slice_free1 (alloc, (void *)(s - sizeof (uint32_t) * NUM_INT));
131 }
132 else
133 ++i;
134 }
135
136 curpos = *i;
90} 137}
91 138
92/* buf_overflow() - we don't want to exceed the buffer size of 139// declare these here to get correct initialisation order
93 * buf1 by adding on buf2! Returns true if overflow will occur. 140#define def2(id,str) const shstr id (str);
94 */ 141#define def(id) def2(shstr_ ## id, # id)
142# include "shstrinc.h"
143#undef def
144#undef def2
95 145
96int 146materialtype_t material_null;
97buf_overflow (const char *buf1, const char *buf2, int bufsize)
98{
99 int len1 = 0, len2 = 0;
100 147
101 if (buf1)
102 len1 = strlen (buf1);
103 if (buf2)
104 len2 = strlen (buf2);
105 if ((len1 + len2) >= bufsize)
106 return 1;
107 return 0;
108}
109

Diff Legend

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