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/cvs/deliantra/server/common/shstr.C
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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 1.15 by root, Tue Sep 12 00:26:16 2006 UTC

1
1/* 2/*
2 * shstr.C 3 * shstr.C
3 */ 4 */
4 5
5#include <cstring> 6#include <cstring>
6#include <cstdlib> 7#include <cstdlib>
7 8
9#include <glib.h>
10
8#include <tr1/unordered_set> 11#include <tr1/unordered_set>
9 12
10#include "shstr.h" 13#include "shstr.h"
14#include "util.h"
11 15
12struct hash 16typedef
17std::tr1::unordered_set < const char *,
18 str_hash,
19 str_equal >
20 HT;
21
22static HT
23 ht;
24
25static const char *
26makevec (const char *s)
13{ 27{
14 std::size_t operator ()(const char *s) const 28 int
15 { 29 len = strlen (s);
16 unsigned long hash = 0;
17 unsigned int i = 0;
18 30
19 /* use the one-at-a-time hash function, which supposedly is 31 const char *
20 * better than the djb2-like one used by perl5.005, but 32 v = (const char *) (2 + (int *) g_slice_alloc (sizeof (int) * 2 + len + 1));
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 33
31 hash += hash << 3; 34 shstr::length (v) = len;
32 hash ^= hash >> 11; 35 shstr::refcnt (v) = 1;
33 hash += hash << 15;
34 36
35 return hash; 37 memcpy ((char *) v, s, len + 1);
36 }
37};
38 38
39struct equal 39 return v;
40{ 40}
41 bool operator ()(const char *a, const char *b) const
42 {
43 return !strcmp (a, b);
44 }
45};
46 41
47typedef std::tr1::unordered_set<const char *, hash, equal> HT; 42const char *
43 shstr::null = makevec ("<nil>");
48 44
49static HT ht; 45// what weird misoptimisation is this again?
46const shstr undead_name ("undead");
47
48shstr skill_names[NUM_SKILLS];
50 49
51const char * 50const char *
52shstr::find (const char *s) 51shstr::find (const char *s)
53{ 52{
53 if (!s)
54 return s;
55
54 HT::iterator i = ht.find (s); 56 HT::iterator i = ht.find (s);
55 57
56 return i != ht.end () 58 return i != ht.end ()? *i : 0;
57 ? (char *)*i
58 : 0;
59} 59}
60 60
61const char * 61const char *
62shstr::intern (const char *s) 62shstr::intern (const char *s)
63{ 63{
64 HT::iterator i = ht.find (s); 64 if (!s)
65 return null;
65 66
66 if (i != ht.end ()) 67 if (const char *found = find (s))
67 return (char *)*i; 68 {
69 ++refcnt (found);
70 return found;
71 }
68 72
69 int len = strlen (s); 73 s = makevec (s);
70
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); 74 ht.insert (s);
81 75 return s;
82 return (char *)v;
83} 76}
84 77
85// TODO: periodically test refcounts == 0 for a few strings (e.g. one hash bucket, 78// periodically test refcounts == 0 for a few strings
86// exploiting the fatc that iterators stay valid for unordered_set). 79// this is the ONLY thing that erases stuff from ht. keep it that way.
87void 80void
88shstr::gc () 81shstr::gc ()
89{ 82{
83return; //D
84//D currently disabled: some datastructures might still store them
85//D but their pointers will become invalidated
86 static const char *curpos;
87
88 HT::iterator i = curpos ? ht.find (curpos) : ht.begin ();
89
90 if (i == ht.end ())
91 i = ht.begin ();
92
93 // go through all strings roughly once every 4 minutes
94 int n = ht.size () / 256 + 16;
95
96 for (;;)
97 {
98 if (i == ht.end ())
99 {
100 curpos = 0;
101 return;
102 }
103 else if (!--n)
104 break;
105 else if (!refcnt (*i))
106 {
107 HT::iterator o = i++;
108 const char *s = *o;
109
110 ht.erase (o);
111
112 //printf ("GC %4d %3d %d >%s<%d\n", (int)ht.size (), n, shstr::refcnt (s), s, shstr::length (s));
113 g_slice_free1 (sizeof (int) * 2 + length (s) + 1, -2 + (int *) s);
114 }
115 else
116 ++i;
117 }
118
119 curpos = *i;
90} 120}
121
122//TODO: this should of course not be here
91 123
92/* buf_overflow() - we don't want to exceed the buffer size of 124/* buf_overflow() - we don't want to exceed the buffer size of
93 * buf1 by adding on buf2! Returns true if overflow will occur. 125 * buf1 by adding on buf2! Returns true if overflow will occur.
94 */ 126 */
95 127
96int 128int
97buf_overflow (const char *buf1, const char *buf2, int bufsize) 129buf_overflow (const char *buf1, const char *buf2, int bufsize)
98{ 130{
99 int len1 = 0, len2 = 0; 131 int len1 = 0, len2 = 0;
100 132
101 if (buf1) 133 if (buf1)
102 len1 = strlen (buf1); 134 len1 = strlen (buf1);
103 if (buf2) 135 if (buf2)
104 len2 = strlen (buf2); 136 len2 = strlen (buf2);
105 if ((len1 + len2) >= bufsize) 137 if ((len1 + len2) >= bufsize)
106 return 1;
107 return 0; 138 return 1;
139 return 0;
108} 140}
109

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