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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 1.47 by elmex, Fri Jun 3 08:36:45 2011 UTC

1/*
2 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
3 *
4 * Copyright (©) 2005,2006,2007,2008,2009,2010,2011 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)" };
63
64bool
65shstr_tmp::contains (const char *substring) const
66{
67 //TODO: this is supposed to check for comma-seperation...
68 return s != null ()
69 && substring
70 && strstr (s, substring);
71}
50 72
51const char * 73const char *
52shstr::find (const char *s) 74shstr::find (const char *s)
53{ 75{
54 HT::iterator i = ht.find (s); 76 if (!s)
77 return s;
55 78
79 auto (i, ht.find (s));
80
56 return i != ht.end () 81 return i != ht.end ()? *i : 0;
57 ? (char *)*i
58 : 0;
59} 82}
60 83
61const char * 84const char *
62shstr::intern (const char *s) 85shstr::intern (const char *s)
63{ 86{
64 HT::iterator i = ht.find (s); 87 if (!s)
88 return null ();
65 89
66 if (i != ht.end ()) 90 if (const char *found = find (s))
67 return (char *)*i; 91 {
92 ++refcnt (found);
93 return found;
94 }
68 95
69 int len = strlen (s); 96 --next_gc;
70 97 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); 98 ht.insert (s);
81 99 return s;
82 return (char *)v;
83} 100}
84 101
85// TODO: periodically test refcounts == 0 for a few strings (e.g. one hash bucket, 102// periodically test refcounts == 0 for a few strings
86// exploiting the fatc that iterators stay valid for unordered_set). 103// this is the ONLY thing that erases stuff from ht. keep it that way.
87void 104void
88shstr::gc () 105shstr::gc ()
89{ 106{
107 if (expect_true (next_gc > 0))
108 return;
109
110 static const char *curpos;
111
112 auto (i, curpos ? ht.find (curpos) : ht.begin ());
113
114 if (i == ht.end ())
115 i = ht.begin ();
116
117 int n = ht.size () / 256 + 16;
118 next_gc += n >> 1;
119
120 for (;;)
121 {
122 if (i == ht.end ())
123 {
124 curpos = 0;
125 return;
126 }
127 else if (!--n)
128 break;
129 else if (!refcnt (*i))
130 {
131 auto (o, i++);
132 const char *s = *o;
133
134 ht.erase (o);
135
136 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
137 int alloc = sizeof (uint32_t) * NUM_INT + length (s) + 1;
138 shstr_alloc -= alloc;
139 g_slice_free1 (alloc, (void *)(s - sizeof (uint32_t) * NUM_INT));
140 }
141 else
142 ++i;
143 }
144
145 curpos = *i;
90} 146}
91 147
92/* buf_overflow() - we don't want to exceed the buffer size of 148// declare these here to get correct initialisation order
93 * buf1 by adding on buf2! Returns true if overflow will occur. 149#define def2(id,str) const shstr id (str);
94 */ 150#define def(id) def2(shstr_ ## id, # id)
151# include "shstrinc.h"
152#undef def
153#undef def2
95 154
96int 155materialtype_t material_null;
97buf_overflow (const char *buf1, const char *buf2, int bufsize)
98{
99 int len1 = 0, len2 = 0;
100 156
101 if (buf1) 157struct freed_map freed_map;
102 len1 = strlen (buf1);
103 if (buf2)
104 len2 = strlen (buf2);
105 if ((len1 + len2) >= bufsize)
106 return 1;
107 return 0;
108}
109

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