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Comparing deliantra/server/common/shstr.C (file contents):
Revision 1.6 by root, Sun Sep 3 11:37:25 2006 UTC vs.
Revision 1.29 by root, Fri Apr 11 21:09:52 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
12// NOTE: even with lots of stuff loaded, we do not usually have >>20000 strings. 33size_t shstr_alloc;
13// maybe refcounting is just overhead?
14 34
15struct hash 35typedef std::tr1::unordered_set <const char *, str_hash, str_equal, slice_allocator<const char *>, true> HT;
16{
17 std::size_t operator ()(const char *s) const
18 {
19 unsigned long hash = 0;
20 unsigned int i = 0;
21
22 /* use the one-at-a-time hash function, which supposedly is
23 * better than the djb2-like one used by perl5.005, but
24 * certainly is better then the bug used here before.
25 * see http://burtleburtle.net/bob/hash/doobs.html
26 */
27 while (*s)
28 {
29 hash += *s++;
30 hash += hash << 10;
31 hash ^= hash >> 6;
32 }
33
34 hash += hash << 3;
35 hash ^= hash >> 11;
36 hash += hash << 15;
37
38 return hash;
39 }
40};
41
42struct equal
43{
44 bool operator ()(const char *a, const char *b) const
45 {
46 return !strcmp (a, b);
47 }
48};
49
50typedef std::tr1::unordered_set<const char *, hash, equal> HT;
51 36
52static 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 ();
53 65
54const char * 66const char *
55shstr::find (const char *s) 67shstr::find (const char *s)
56{ 68{
57 if (!s) 69 if (!s)
58 return s; 70 return s;
59 71
60 HT::iterator i = ht.find (s); 72 auto (i, ht.find (s));
61 73
62 return i != ht.end () 74 return i != ht.end ()? *i : 0;
63 ? *i
64 : 0;
65} 75}
66 76
67const char * 77const char *
68shstr::intern (const char *s) 78shstr::intern (const char *s)
69{ 79{
70 if (!s) 80 if (!s)
71 return s; 81 return null;
72 82
73 if (const char *found = find (s)) 83 if (const char *found = find (s))
74 { 84 {
75 ++refcnt (found); 85 ++refcnt (found);
76 return found; 86 return found;
77 } 87 }
78 88
79 int len = strlen (s); 89 --next_gc;
80 90 s = makevec (s);
81 const char *v = (const char *)(2 + (int *)malloc (sizeof (int) * 2 + len + 1));
82
83 length (v) = len;
84 refcnt (v) = 1;
85
86 memcpy ((char *)v, s, len + 1);
87
88 ht.insert (v); 91 ht.insert (s);
89
90 return v; 92 return s;
91} 93}
92 94
93// periodically test refcounts == 0 for a few strings 95// periodically test refcounts == 0 for a few strings
94// this is the ONLY thing that erases stuff from ht. keep it that way. 96// this is the ONLY thing that erases stuff from ht. keep it that way.
95void 97void
96shstr::gc () 98shstr::gc ()
97{ 99{
100 if (expect_true (next_gc > 0))
101 return;
102
98 static const char *curpos; 103 static const char *curpos;
99 104
100 HT::iterator i = curpos ? ht.find (curpos) : ht.begin (); 105 auto (i, curpos ? ht.find (curpos) : ht.begin ());
101 106
102 if (i == ht.end ()) 107 if (i == ht.end ())
103 i = ht.begin (); 108 i = ht.begin ();
104 109
105 // go through all strings roughly once every 4 minutes
106 int n = ht.size () / 256 + 16; 110 int n = ht.size () / 256 + 16;
111 next_gc += n >> 1;
107 112
108 for (;;) 113 for (;;)
109 { 114 {
110 if (i == ht.end ()) 115 if (i == ht.end ())
111 { 116 {
… …
114 } 119 }
115 else if (!--n) 120 else if (!--n)
116 break; 121 break;
117 else if (!refcnt (*i)) 122 else if (!refcnt (*i))
118 { 123 {
119 HT::iterator o = i++; 124 auto (o, i++);
120 const char *s = *o; 125 const char *s = *o;
126
121 ht.erase (o); 127 ht.erase (o);
122 128
123 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s)); 129 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
124 free (-2 + (int *)s); 130 shstr_alloc -= sizeof (int) * 2 + length (s) + 1;
131 g_slice_free1 (sizeof (int) * 2 + length (s) + 1, -2 + (int *) s);
125 } 132 }
126 else 133 else
127 ++i; 134 ++i;
128 } 135 }
129 136
130 curpos = *i; 137 curpos = *i;
131} 138}
132 139
140// declare these here to get correct initialisation order
141#define def(str) const shstr shstr_ ## str (# str);
142# include "shstrinc.h"
143#undef def
144
145shstr skill_names[NUM_SKILLS];
146
133//TODO: this should of course not be here 147//TODO: this should of course not be here
148
134/* buf_overflow() - we don't want to exceed the buffer size of 149/* buf_overflow() - we don't want to exceed the buffer size of
135 * buf1 by adding on buf2! Returns true if overflow will occur. 150 * buf1 by adding on buf2! Returns true if overflow will occur.
136 */ 151 */
137
138int 152int
139buf_overflow (const char *buf1, const char *buf2, int bufsize) 153buf_overflow (const char *buf1, const char *buf2, int bufsize)
140{ 154{
141 int len1 = 0, len2 = 0; 155 int len1 = 0, len2 = 0;
142 156
143 if (buf1) 157 if (buf1)
144 len1 = strlen (buf1); 158 len1 = strlen (buf1);
159
145 if (buf2) 160 if (buf2)
146 len2 = strlen (buf2); 161 len2 = strlen (buf2);
162
147 if ((len1 + len2) >= bufsize) 163 if ((len1 + len2) >= bufsize)
148 return 1;
149 return 0; 164 return 1;
165
166 return 0;
150} 167}
151

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