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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 1.39 by root, Mon Oct 12 14:00:57 2009 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 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
41static const char *
42makevec (const char *s)
43{
44 int len = strlen (s);
45 int alloc = sizeof (uint32_t) * 2 + len + 1;
46
47 shstr_alloc += alloc;
48 char *v = (char *)g_slice_alloc (alloc);
49 v += sizeof (uint32_t) * 2;
50
51 shstr::length (v) = len;
52 shstr::refcnt (v) = 1;
53
54 memcpy (v, s, len + 1);
55
56 return v;
57}
58
59shstr_vec<sizeof "(null)"> shstr_tmp::nullvec = { 0, 0xffffffff, "(null)" };
53 60
54const char * 61const char *
55shstr::find (const char *s) 62shstr::find (const char *s)
56{ 63{
57 if (!s) 64 if (!s)
58 return s; 65 return s;
59 66
60 HT::iterator i = ht.find (s); 67 auto (i, ht.find (s));
61 68
62 return i != ht.end () 69 return i != ht.end ()? *i : 0;
63 ? *i
64 : 0;
65} 70}
66 71
67const char * 72const char *
68shstr::intern (const char *s) 73shstr::intern (const char *s)
69{ 74{
70 if (!s) 75 if (!s)
71 return s; 76 return null ();
72 77
73 if (const char *found = find (s)) 78 if (const char *found = find (s))
74 { 79 {
75 ++refcnt (found); 80 ++refcnt (found);
76 return found; 81 return found;
77 } 82 }
78 83
79 int len = strlen (s); 84 --next_gc;
80 85 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); 86 ht.insert (s);
89
90 return v; 87 return s;
91} 88}
92 89
93// periodically test refcounts == 0 for a few strings 90// periodically test refcounts == 0 for a few strings
94// this is the ONLY thing that erases stuff from ht. keep it that way. 91// this is the ONLY thing that erases stuff from ht. keep it that way.
95void 92void
96shstr::gc () 93shstr::gc ()
97{ 94{
95 if (expect_true (next_gc > 0))
96 return;
97
98 static const char *curpos; 98 static const char *curpos;
99 99
100 HT::iterator i = curpos ? ht.find (curpos) : ht.begin (); 100 auto (i, curpos ? ht.find (curpos) : ht.begin ());
101 101
102 if (i == ht.end ()) 102 if (i == ht.end ())
103 i = ht.begin (); 103 i = ht.begin ();
104 104
105 // go through all strings roughly once every 4 minutes
106 int n = ht.size () / 256 + 16; 105 int n = ht.size () / 256 + 16;
106 next_gc += n >> 1;
107 107
108 for (;;) 108 for (;;)
109 { 109 {
110 if (i == ht.end ()) 110 if (i == ht.end ())
111 { 111 {
… …
114 } 114 }
115 else if (!--n) 115 else if (!--n)
116 break; 116 break;
117 else if (!refcnt (*i)) 117 else if (!refcnt (*i))
118 { 118 {
119 HT::iterator o = i++; 119 auto (o, i++);
120 const char *s = *o; 120 const char *s = *o;
121
121 ht.erase (o); 122 ht.erase (o);
122 123
123 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s)); 124 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
124 free (-2 + (int *)s); 125 int alloc = sizeof (uint32_t) * 2 + length (s) + 1;
126 shstr_alloc -= alloc;
127 g_slice_free1 (alloc, (void *)(s - sizeof (uint32_t) * 2));
125 } 128 }
126 else 129 else
127 ++i; 130 ++i;
128 } 131 }
129 132
130 curpos = *i; 133 curpos = *i;
131} 134}
132 135
136// declare these here to get correct initialisation order
137#define def2(id,str) const shstr id (str);
138#define def(id) def2(shstr_ ## id, # id)
139# include "shstrinc.h"
140#undef def
141#undef def2
142
143shstr skill_names[NUM_SKILLS];
144
133//TODO: this should of course not be here 145//TODO: this should of course not be here
146
134/* buf_overflow() - we don't want to exceed the buffer size of 147/* buf_overflow() - we don't want to exceed the buffer size of
135 * buf1 by adding on buf2! Returns true if overflow will occur. 148 * buf1 by adding on buf2! Returns true if overflow will occur.
136 */ 149 */
137
138int 150int
139buf_overflow (const char *buf1, const char *buf2, int bufsize) 151buf_overflow (const char *buf1, const char *buf2, int bufsize)
140{ 152{
141 int len1 = 0, len2 = 0; 153 int len1 = 0, len2 = 0;
142 154
143 if (buf1) 155 if (buf1)
144 len1 = strlen (buf1); 156 len1 = strlen (buf1);
157
145 if (buf2) 158 if (buf2)
146 len2 = strlen (buf2); 159 len2 = strlen (buf2);
160
147 if ((len1 + len2) >= bufsize) 161 if ((len1 + len2) >= bufsize)
148 return 1;
149 return 0; 162 return 1;
163
164 return 0;
150} 165}
151

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