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Comparing deliantra/server/common/shstr.C (file contents):
Revision 1.5 by root, Sun Sep 3 09:00:05 2006 UTC vs.
Revision 1.43 by root, Fri Mar 26 01:04:44 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
12// NOTE: even with lots of stuff loaded, we do not usually have >>20000 strings. 34size_t shstr_alloc;
13// maybe refcounting is just overhead?
14 35
15struct hash
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; 36typedef std::tr1::unordered_set <const char *, str_hash, str_equal, slice_allocator<const char *> > HT;
51 37
52static 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)" };
53 63
54const char * 64const char *
55shstr::find (const char *s) 65shstr::find (const char *s)
56{ 66{
57 if (!s) 67 if (!s)
58 return s; 68 return s;
59 69
60 HT::iterator i = ht.find (s); 70 auto (i, ht.find (s));
61 71
62 return i != ht.end () 72 return i != ht.end ()? *i : 0;
63 ? *i
64 : 0;
65} 73}
66 74
67const char * 75const char *
68shstr::intern (const char *s) 76shstr::intern (const char *s)
69{ 77{
70 if (!s) 78 if (!s)
71 return s; 79 return null ();
72 80
73 if (const char *found = find (s)) 81 if (const char *found = find (s))
74 { 82 {
75 ++refcnt (found); 83 ++refcnt (found);
76 return found; 84 return found;
77 } 85 }
78 86
79 int len = strlen (s); 87 --next_gc;
80 88 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); 89 ht.insert (s);
89
90 return v; 90 return s;
91} 91}
92 92
93// periodically test refcounts == 0 for a few strings 93// periodically test refcounts == 0 for a few strings
94// this is the ONLY thing that erases stuff from ht. keep it that way. 94// this is the ONLY thing that erases stuff from ht. keep it that way.
95void 95void
96shstr::gc () 96shstr::gc ()
97{ 97{
98 if (expect_true (next_gc > 0))
99 return;
100
98 static const char *curpos; 101 static const char *curpos;
99 102
100 HT::iterator i = curpos ? ht.find (curpos) : ht.begin (); 103 auto (i, curpos ? ht.find (curpos) : ht.begin ());
101 104
102 if (i == ht.end ()) 105 if (i == ht.end ())
103 i = ht.begin (); 106 i = ht.begin ();
104 107
105 // go through all strings roughly once every 4 minutes
106 for (int n = ht.size () / 256 + 16; --n; ) 108 int n = ht.size () / 256 + 16;
109 next_gc += n >> 1;
110
111 for (;;)
107 { 112 {
108 if (i == ht.end ()) 113 if (i == ht.end ())
109 { 114 {
110 curpos = 0; 115 curpos = 0;
111 return; 116 return;
112 } 117 }
118 else if (!--n)
119 break;
120 else if (!refcnt (*i))
121 {
122 auto (o, i++);
123 const char *s = *o;
113 124
114 if (!refcnt (*i))
115 {
116 HT::iterator o = i++;
117 const char *s = *o;
118 ht.erase (o); 125 ht.erase (o);
119 126
120 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s)); 127 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
121 free (-2 + (int *)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));
122 } 131 }
123 else 132 else
124 ++i; 133 ++i;
125 } 134 }
126 135
127 curpos = *i; 136 curpos = *i;
128} 137}
129 138
130//TODO: this should of course not be here 139// declare these here to get correct initialisation order
131/* buf_overflow() - we don't want to exceed the buffer size of 140#define def2(id,str) const shstr id (str);
132 * buf1 by adding on buf2! Returns true if overflow will occur. 141#define def(id) def2(shstr_ ## id, # id)
133 */ 142# include "shstrinc.h"
143#undef def
144#undef def2
134 145
135int 146shstr skill_names[NUM_SKILLS];
136buf_overflow (const char *buf1, const char *buf2, int bufsize) 147materialtype_t material_null;
137{
138 int len1 = 0, len2 = 0;
139 148
140 if (buf1)
141 len1 = strlen (buf1);
142 if (buf2)
143 len2 = strlen (buf2);
144 if ((len1 + len2) >= bufsize)
145 return 1;
146 return 0;
147}
148

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