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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 1.37 by root, Thu Jan 1 16:05:12 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
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
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; 35typedef std::tr1::unordered_set <const char *, str_hash, str_equal, slice_allocator<const char *> > 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 (uint32_t) * 2 + len + 1;
46 const char *v = (const char *) (2 + (int *)g_slice_alloc (sizeof (uint32_t) * 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
56shstr_vec<sizeof "(null)"> shstr_tmp::nullvec = { 0, 0xffffffff, "(null)" };
53 57
54const char * 58const char *
55shstr::find (const char *s) 59shstr::find (const char *s)
56{ 60{
57 if (!s) 61 if (!s)
58 return s; 62 return s;
59 63
60 HT::iterator i = ht.find (s); 64 auto (i, ht.find (s));
61 65
62 return i != ht.end () 66 return i != ht.end ()? *i : 0;
63 ? *i
64 : 0;
65} 67}
66 68
67const char * 69const char *
68shstr::intern (const char *s) 70shstr::intern (const char *s)
69{ 71{
70 if (!s) 72 if (!s)
71 return s; 73 return null ();
72 74
73 if (const char *found = find (s)) 75 if (const char *found = find (s))
74 { 76 {
75 ++refcnt (found); 77 ++refcnt (found);
76 return found; 78 return found;
77 } 79 }
78 80
79 int len = strlen (s); 81 --next_gc;
80 82 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); 83 ht.insert (s);
89
90 return v; 84 return s;
91} 85}
92 86
93// periodically test refcounts == 0 for a few strings 87// periodically test refcounts == 0 for a few strings
94// this is the ONLY thing that erases stuff from ht. keep it that way. 88// this is the ONLY thing that erases stuff from ht. keep it that way.
95void 89void
96shstr::gc () 90shstr::gc ()
97{ 91{
92 if (expect_true (next_gc > 0))
93 return;
94
98 static const char *curpos; 95 static const char *curpos;
99 96
100 HT::iterator i = curpos ? ht.find (curpos) : ht.begin (); 97 auto (i, curpos ? ht.find (curpos) : ht.begin ());
101 98
102 if (i == ht.end ()) 99 if (i == ht.end ())
103 i = ht.begin (); 100 i = ht.begin ();
104 101
105 // go through all strings roughly once every 4 minutes
106 int n = ht.size () / 256 + 16; 102 int n = ht.size () / 256 + 16;
103 next_gc += n >> 1;
107 104
108 for (;;) 105 for (;;)
109 { 106 {
110 if (i == ht.end ()) 107 if (i == ht.end ())
111 { 108 {
… …
114 } 111 }
115 else if (!--n) 112 else if (!--n)
116 break; 113 break;
117 else if (!refcnt (*i)) 114 else if (!refcnt (*i))
118 { 115 {
119 HT::iterator o = i++; 116 auto (o, i++);
120 const char *s = *o; 117 const char *s = *o;
118
121 ht.erase (o); 119 ht.erase (o);
122 120
123 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s)); 121 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
124 free (-2 + (int *)s); 122 shstr_alloc -= sizeof (uint32_t) * 2 + length (s) + 1;
123 g_slice_free1 (sizeof (uint32_t) * 2 + length (s) + 1, -2 + (int *) s);
125 } 124 }
126 else 125 else
127 ++i; 126 ++i;
128 } 127 }
129 128
130 curpos = *i; 129 curpos = *i;
131} 130}
132 131
132// declare these here to get correct initialisation order
133#define def2(id,str) const shstr id (str);
134#define def(id) def2(shstr_ ## id, # id)
135# include "shstrinc.h"
136#undef def
137#undef def2
138
139shstr skill_names[NUM_SKILLS];
140
133//TODO: this should of course not be here 141//TODO: this should of course not be here
142
134/* buf_overflow() - we don't want to exceed the buffer size of 143/* buf_overflow() - we don't want to exceed the buffer size of
135 * buf1 by adding on buf2! Returns true if overflow will occur. 144 * buf1 by adding on buf2! Returns true if overflow will occur.
136 */ 145 */
137
138int 146int
139buf_overflow (const char *buf1, const char *buf2, int bufsize) 147buf_overflow (const char *buf1, const char *buf2, int bufsize)
140{ 148{
141 int len1 = 0, len2 = 0; 149 int len1 = 0, len2 = 0;
142 150
143 if (buf1) 151 if (buf1)
144 len1 = strlen (buf1); 152 len1 = strlen (buf1);
153
145 if (buf2) 154 if (buf2)
146 len2 = strlen (buf2); 155 len2 = strlen (buf2);
156
147 if ((len1 + len2) >= bufsize) 157 if ((len1 + len2) >= bufsize)
148 return 1;
149 return 0; 158 return 1;
159
160 return 0;
150} 161}
151

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