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Comparing deliantra/server/include/shstr.h (file contents):
Revision 1.7 by root, Sun Sep 3 09:00:09 2006 UTC vs.
Revision 1.27 by root, Wed Dec 31 18:29:44 2008 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#ifndef SHSTR_H__ 22#ifndef SHSTR_H__
2#define SHSTR_H__ 23#define SHSTR_H__
3 24
25#include <cstring>
26#include <sstream>
27
28#include "traits.h"
29
30extern size_t shstr_alloc;
31
4extern int buf_overflow(const char *buf1, const char *buf2, int bufsize); 32extern int buf_overflow (const char *buf1, const char *buf2, int bufsize);
5 33
34template<int size>
6struct shstr 35struct shstr_vec
7{ 36{
37 uint32_t len;
38 uint32_t refcnt;
39 char string[size];
40};
41
42// this class is a non-refcounted shared string
43// it cannot be used to create or store shared strings, but
44// it can be used to apss shared strings around, i.e. as function arguments
45// or return values. their lifetime must not span a gc () call, i.e.
46// they are only valid as temporary values within the same server tick.
47struct shstr_tmp
48{
49 static shstr_vec<sizeof ("(null)")> nullvec;
50 static const char *null () { return nullvec.string; } // this is the null pointer value
51
8 const char *s; 52 const char *s;
9 53
10 static int &refcnt (const char *s)
11 {
12 return *((int *)s - 1);
13 }
14
15 static int &length (const char *s) 54 static unsigned int &length (const char *s)
16 { 55 {
17 return *((int *)s - 2); 56 return *((unsigned int *)s - 2);
18 } 57 }
19 58
20 int &refcnt () const 59 int length () const
60 {
61 return length (s);
62 }
63
64 // returns whether this shared string begins with the given prefix,
65 // used mainly for searches when users give only the start of a name.
66 bool starts_with (const char *prefix) const
67 {
68 int plen = strlen (prefix);
69
70 return length () >= plen && !strncasecmp (s, prefix, plen);
71 }
72
73 bool contains (const char *substring) const
74 {
75 return strstr (s, substring);
76 }
77
78 shstr_tmp ()
79 : s (null ())
80 {
81 }
82
83 shstr_tmp (const shstr_tmp &sh)
84 : s (sh.s)
85 {
86 }
87
88 shstr_tmp operator =(const shstr_tmp &sh)
89 {
90 s = sh.s;
91
92 return *this;
93 }
94
95 // this is used for informational messages and the like
96 const char *operator &() const { return s; }
97
98 operator const char *() const { return s == null () ? 0 : s; }
99
100protected:
101 // dummy is there so it isn't used as type converter accidentally
102 shstr_tmp (int dummy, const char *s)
103 : s(s)
104 {
105 }
106};
107
108inline bool operator ==(const shstr_tmp &a, const shstr_tmp &b)
109{
110 return a.s == b.s;
111}
112
113inline bool operator !=(const shstr_tmp &a, const shstr_tmp &b)
114{
115 return a.s != b.s;
116}
117
118inline int strlen (const shstr_tmp &sh)
119{
120 return sh.length ();
121}
122
123// undefined external reference to catch people using strcmp when they shouldn't
124int strcmp (const shstr_tmp &a, const shstr_tmp &b);
125
126static std::ostream &operator <<(std::ostream &o, shstr_tmp sh)
127{
128 o.write (sh.s, sh.length ());
129
130 return o;
131}
132
133struct shstr : shstr_tmp
134{
135 static unsigned int &refcnt (const char *s)
136 {
137 return *((unsigned int *)s - 1);
138 }
139
140 unsigned int &refcnt () const
21 { 141 {
22 return refcnt (s); 142 return refcnt (s);
23 } 143 }
24 144
25 int length () const 145 shstr ()
26 { 146 {
27 return s ? length (s) : 0;
28 } 147 }
29 148
30 static const char *find (const char *s); 149 static const char *find (const char *s);
31 static const char *intern (const char *s); 150 static const char *intern (const char *s);
32 151
33 static void gc (); // garbage collect a few strings 152 static void gc (); // garbage collect a few strings
34 153
154 shstr (const shstr &sh)
155 : shstr_tmp (sh)
156 {
157 ++refcnt ();
158 }
159
160 shstr (const shstr_tmp &sh)
161 : shstr_tmp (sh)
162 {
163 ++refcnt ();
164 }
165
166 explicit shstr (const char *str)
167 : shstr_tmp (0, is_constant (str) && !str ? null () : intern (str))
168 {
169 }
170
171 ~shstr ()
172 {
173 --refcnt ();
174 }
175
176 using shstr_tmp::operator &;
177 using shstr_tmp::operator const char *;
178
179 // (note: not the copy constructor)
180 shstr &operator =(const shstr_tmp &sh)
181 {
182 --refcnt ();
183 s = sh.s;
184 ++refcnt ();
185
186 return *this;
187 }
188
189 // here it comes
190 shstr &operator =(const shstr &sh)
191 {
192 return (*this) = (shstr_tmp)sh;
193 }
194
195 // shstr_tmp doesn't have this one
196 shstr &operator =(const char *str)
197 {
198 --refcnt ();
199 s = is_constant (str) && !str ? null () : intern (str);
200
201 return *this;
202 }
203};
204
205// only good for mass comparisons to shstr objects, or very
206// temporary passing, basically a non-refcounted shstr
207struct shstr_cmp
208{
209 const char *s;
210
211 explicit shstr_cmp (const char *str)
212 : s (shstr::find (str))
213 {
214 }
215
216 shstr_cmp (shstr_tmp sh)
217 : s (sh.s)
218 {
219 }
220
35 // this is used for informational messages and the like 221 // this is used for informational messages and the like
36 const char *operator &() const { return s ? s : "<nil>"; }
37
38 const char &operator [](int i) const { return s[i]; } 222 const char *operator &() const { return s; }
223
39 operator const char *() const { return s; } 224 operator const char *() const { return s; }
40
41 shstr ()
42 : s (0)
43 {
44 }
45
46 shstr (const shstr &sh)
47 : s (sh.s)
48 {
49 if (s) ++refcnt ();
50 }
51
52 explicit shstr (const char *s)
53 : s (intern (s))
54 {
55 }
56
57 ~shstr ()
58 {
59 if (s) --refcnt ();
60 }
61
62 const shstr &operator =(const shstr &sh)
63 {
64 if (s) --refcnt ();
65 s = sh.s;
66 if (s) ++refcnt ();
67
68 return *this;
69 }
70
71 const shstr &operator =(const char *str)
72 {
73 if (s) --refcnt ();
74 s = intern (str);
75
76 return *this;
77 }
78}; 225};
79 226
80inline int strlen (const shstr &sh)
81{
82 return sh.length ();
83}
84
85inline bool operator ==(const shstr &a, const shstr &b) 227inline bool operator ==(const shstr_cmp &a, const shstr_tmp &b)
86{ 228{
87 return a.s == b.s; 229 return a.s == b.s;
88} 230}
89 231
90inline bool operator !=(const shstr &a, const shstr &b) 232inline bool operator ==(const shstr_tmp &a, const shstr_cmp &b)
91{ 233{
92 return !(a == b); 234 return a.s == b.s;
93} 235}
236
237#define def(str) extern const shstr shstr_ ## str;
238# include "shstrinc.h"
239#undef def
94 240
95#endif 241#endif
96 242

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