server/include/shstr.h

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
 * 
 * Deliantra is free software: you can redistribute it and/or modify it under
 * the terms of the Affero GNU General Public License as published by the
 * Free Software Foundation, either version 3 of the License, or (at your
 * option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the Affero GNU General Public License
 * and the GNU General Public License along with this program. If not, see
 * <http://www.gnu.org/licenses/>.
 * 
 * The authors can be reached via e-mail to <support@deliantra.net>
 */

#ifndef SHSTR_H__
#define SHSTR_H__

#include <cstring>
#include <sstream>

#include "traits.h"

extern size_t shstr_alloc;

extern int buf_overflow (const char *buf1, const char *buf2, int bufsize);

template<int size>
struct shstr_vec
{
  uint32_t len;
  uint32_t refcnt;
  char string[size];
};

// this class is a non-refcounted shared string
// it cannot be used to create or store shared strings, but
// it can be used to apss shared strings around, i.e. as function arguments
// or return values. their lifetime must not span a gc () call, i.e.
// they are only valid as temporary values within the same server tick.
struct shstr_tmp
{
  static shstr_vec<sizeof ("(null)")> nullvec;
  static const char *null () { return nullvec.string; } // this is the null pointer value

  const char *s;

  static unsigned int &length (const char *s)
  {
    return *((unsigned int *)s - 2);
  }

  int length () const
  {
    return length (s);
  }

  // returns whether this shared string begins with the given prefix,
  // used mainly for searches when users give only the start of a name.
  bool starts_with (const char *prefix) const
  {
    int plen = strlen (prefix);

    return length () >= plen && !strncasecmp (s, prefix, plen);
  }

  // returns true if the substring is contained in the shstr
  // if the shstr is 0, then this always returns false.
  // the shstr is (theoretically) treated as a comma/colon/space etc. separated list.
  bool contains (const char *substring) const
  {
    return s != null () && strstr (s, substring);
  }

  //TODO: case sensitive should be eradicated
  bool eq_nc (const char *otherstring) const
  {
    return !strcasecmp (s, otherstring);
  }

  shstr_tmp ()
  : s (null ())
  {
  }

  shstr_tmp (const shstr_tmp &sh)
  : s (sh.s)
  {
  }

  shstr_tmp operator =(const shstr_tmp &sh)
  {
    s = sh.s;

    return *this;
  }

  // this is used for informational messages and the like
  const char *operator &() const { return s; }

  operator const char *() const { return s == null () ? 0 : s; }

protected:
  // dummy is there so it isn't used as type converter accidentally
  shstr_tmp (int dummy, const char *s)
  : s(s)
  {
  }
};

inline bool operator ==(const shstr_tmp &a, const shstr_tmp &b)
{
  return a.s == b.s;
}

inline bool operator !=(const shstr_tmp &a, const shstr_tmp &b)
{
  return a.s != b.s;
}

inline int strlen (shstr_tmp sh)
{
  return sh.length ();
}

static std::ostream &operator <<(std::ostream &o, shstr_tmp sh)
{
  o.write (sh.s, sh.length ());

  return o;
}

struct shstr : shstr_tmp
{
  static unsigned int &refcnt (const char *s)
  {
    return *((unsigned int *)s - 1);
  }

  unsigned int &refcnt () const
  {
    return refcnt (s);
  }

  shstr ()
  {
  }

  static const char *find (const char *s);
  static const char *intern (const char *s);

  static void gc (); // garbage collect a few strings

  shstr (const shstr &sh)
  : shstr_tmp (sh)
  {
    ++refcnt ();
  }

  shstr (const shstr_tmp &sh)
  : shstr_tmp (sh)
  {
    ++refcnt ();
  }

  explicit shstr (const char *str)
  : shstr_tmp (0, is_constant (str) && !str ? null () : intern (str))
  {
  }

  ~shstr ()
  {
    --refcnt ();
  }

  using shstr_tmp::operator &;
  using shstr_tmp::operator const char *;

  // (note: not the copy constructor)
  shstr &operator =(const shstr_tmp &sh)
  {
    --refcnt ();
    s = sh.s;
    ++refcnt ();

    return *this;
  }

  // here it comes
  shstr &operator =(const shstr &sh)
  {
    return (*this) = (shstr_tmp)sh;
  }

  // shstr_tmp doesn't have this one
  shstr &operator =(const char *str)
  {
    --refcnt ();
    s = is_constant (str) && !str ? null () : intern (str);

    return *this;
  }
};

// only good for mass comparisons to shstr objects, or very
// temporary passing, basically a non-refcounted shstr
struct shstr_cmp
{
  const char *s;

  // initialies to the non-matching string (as opposed to the null string)
  shstr_cmp ()
  {
    s = 0;
  }

  shstr_cmp (const char *str)
  : s (shstr::find (str))
  {
  }

  shstr_cmp (shstr_tmp sh)
  : s (sh.s)
  {
  }

  // this is used for informational messages and the like
  const char *operator &() const { return s; }

  operator const char *() const { return s; }
};

inline bool operator ==(const shstr_cmp &a, const shstr_tmp &b)
{
  return a.s == b.s;
}

inline bool operator ==(const shstr_tmp &a, const shstr_cmp &b)
{
  return a.s == b.s;
}

#define def2(id,str) extern const shstr id;
#define def(id)      def2(shstr_ ## id, # id)
# include "shstrinc.h"
#undef def
#undef def2

// undefined external reference to catch people using str* functions when they shouldn't
//template<class any> void strcmp (const shstr_tmp &a, any b);
template<class any> void strstr (const shstr_tmp &a, any b);

#endif

Revision:	1.33
Committed:	Mon Oct 12 14:00:58 2009 UTC (14 years, 7 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-2_82, rel-2_81
Changes since 1.32:	+7 -6 lines
Log Message:	clarify license
#	User	Rev	Content
1	root	1.16	/*
2	root	1.20	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	root	1.16	*
4	root	1.22	* Copyright (©) 2005,2006,2007,2008 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
5	root	1.16	*
6	root	1.33	* 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	root	1.16	*
11	root	1.17	* 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	root	1.16	*
16	root	1.33	* 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	root	1.16	*
20	root	1.20	* The authors can be reached via e-mail to <support@deliantra.net>
21	root	1.16	*/
22
23	root	1.2	#ifndef SHSTR_H__
24			#define SHSTR_H__
25
26	root	1.24	#include <cstring>
27	root	1.13	#include <sstream>
28
29	root	1.25	#include "traits.h"
30	root	1.8
31	root	1.19	extern size_t shstr_alloc;
32
33	root	1.8	extern int buf_overflow (const char buf1, const char buf2, int bufsize);
34	root	1.5
35	root	1.25	template<int size>
36			struct shstr_vec
37			{
38			uint32_t len;
39			uint32_t refcnt;
40			char string[size];
41			};
42
43	root	1.24	// this class is a non-refcounted shared string
44			// it cannot be used to create or store shared strings, but
45			// it can be used to apss shared strings around, i.e. as function arguments
46			// or return values. their lifetime must not span a gc () call, i.e.
47			// they are only valid as temporary values within the same server tick.
48			struct shstr_tmp
49	root	1.5	{
50	root	1.25	static shstr_vec<sizeof ("(null)")> nullvec;
51			static const char *null () { return nullvec.string; } // this is the null pointer value
52	root	1.8
53	root	1.5	const char *s;
54	root	1.4
55	root	1.24	static unsigned int &length (const char *s)
56	root	1.5	{
57	root	1.24	return ((unsigned int )s - 2);
58	root	1.5	}
59
60	root	1.24	int length () const
61	root	1.7	{
62	root	1.24	return length (s);
63	root	1.7	}
64
65	root	1.24	// returns whether this shared string begins with the given prefix,
66			// used mainly for searches when users give only the start of a name.
67			bool starts_with (const char *prefix) const
68	root	1.7	{
69	root	1.24	int plen = strlen (prefix);
70
71			return length () >= plen && !strncasecmp (s, prefix, plen);
72	root	1.7	}
73
74	root	1.32	// returns true if the substring is contained in the shstr
75			// if the shstr is 0, then this always returns false.
76			// the shstr is (theoretically) treated as a comma/colon/space etc. separated list.
77	root	1.24	bool contains (const char *substring) const
78	root	1.7	{
79	root	1.29	return s != null () && strstr (s, substring);
80	root	1.7	}
81
82	root	1.28	//TODO: case sensitive should be eradicated
83			bool eq_nc (const char *otherstring) const
84			{
85			return !strcasecmp (s, otherstring);
86			}
87
88	root	1.24	shstr_tmp ()
89	root	1.25	: s (null ())
90	root	1.24	{
91			}
92
93			shstr_tmp (const shstr_tmp &sh)
94			: s (sh.s)
95	root	1.15	{
96			}
97
98	root	1.24	shstr_tmp operator =(const shstr_tmp &sh)
99			{
100			s = sh.s;
101	root	1.5
102	root	1.24	return *this;
103			}
104	root	1.5
105	root	1.6	// this is used for informational messages and the like
106	root	1.8	const char *operator &() const { return s; }
107	root	1.5
108	root	1.25	operator const char *() const { return s == null () ? 0 : s; }
109	root	1.26
110			protected:
111			// dummy is there so it isn't used as type converter accidentally
112			shstr_tmp (int dummy, const char *s)
113			: s(s)
114			{
115			}
116	root	1.24	};
117
118			inline bool operator ==(const shstr_tmp &a, const shstr_tmp &b)
119			{
120			return a.s == b.s;
121			}
122
123			inline bool operator !=(const shstr_tmp &a, const shstr_tmp &b)
124			{
125			return a.s != b.s;
126			}
127
128	root	1.31	inline int strlen (shstr_tmp sh)
129	root	1.24	{
130			return sh.length ();
131			}
132
133			static std::ostream &operator <<(std::ostream &o, shstr_tmp sh)
134			{
135			o.write (sh.s, sh.length ());
136
137			return o;
138			}
139
140			struct shstr : shstr_tmp
141			{
142			static unsigned int &refcnt (const char *s)
143			{
144			return ((unsigned int )s - 1);
145			}
146
147			unsigned int &refcnt () const
148			{
149			return refcnt (s);
150			}
151	root	1.5
152			shstr ()
153			{
154			}
155
156	root	1.24	static const char find (const char s);
157			static const char intern (const char s);
158
159			static void gc (); // garbage collect a few strings
160
161	root	1.6	shstr (const shstr &sh)
162	root	1.24	: shstr_tmp (sh)
163			{
164			++refcnt ();
165			}
166
167			shstr (const shstr_tmp &sh)
168			: shstr_tmp (sh)
169	root	1.5	{
170	root	1.8	++refcnt ();
171	root	1.5	}
172
173	root	1.24	explicit shstr (const char *str)
174	root	1.26	: shstr_tmp (0, is_constant (str) && !str ? null () : intern (str))
175	root	1.5	{
176			}
177
178			~shstr ()
179			{
180	root	1.8	--refcnt ();
181	root	1.5	}
182
183	root	1.24	using shstr_tmp::operator &;
184			using shstr_tmp::operator const char *;
185
186			// (note: not the copy constructor)
187			shstr &operator =(const shstr_tmp &sh)
188	root	1.5	{
189	root	1.8	--refcnt ();
190	root	1.5	s = sh.s;
191	root	1.8	++refcnt ();
192	root	1.5
193			return *this;
194			}
195
196	root	1.24	// here it comes
197			shstr &operator =(const shstr &sh)
198			{
199			return (*this) = (shstr_tmp)sh;
200			}
201
202			// shstr_tmp doesn't have this one
203			shstr &operator =(const char *str)
204	root	1.5	{
205	root	1.8	--refcnt ();
206	root	1.25	s = is_constant (str) && !str ? null () : intern (str);
207	root	1.1
208	root	1.5	return *this;
209			}
210			};
211	root	1.1
212	root	1.24	// only good for mass comparisons to shstr objects, or very
213			// temporary passing, basically a non-refcounted shstr
214	root	1.10	struct shstr_cmp
215			{
216			const char *s;
217
218	root	1.28	// initialies to the non-matching string (as opposed to the null string)
219			shstr_cmp ()
220			{
221			s = 0;
222			}
223
224			shstr_cmp (const char *str)
225	root	1.24	: s (shstr::find (str))
226	root	1.10	{
227			}
228
229	root	1.25	shstr_cmp (shstr_tmp sh)
230	root	1.23	: s (sh.s)
231			{
232			}
233
234			// this is used for informational messages and the like
235			const char *operator &() const { return s; }
236
237	root	1.10	operator const char *() const { return s; }
238			};
239
240	root	1.24	inline bool operator ==(const shstr_cmp &a, const shstr_tmp &b)
241	root	1.5	{
242			return a.s == b.s;
243			}
244	root	1.4
245	root	1.24	inline bool operator ==(const shstr_tmp &a, const shstr_cmp &b)
246	root	1.4	{
247	root	1.24	return a.s == b.s;
248	root	1.5	}
249	root	1.4
250	root	1.30	#define def2(id,str) extern const shstr id;
251			#define def(id) def2(shstr_ ## id, # id)
252	root	1.18	# include "shstrinc.h"
253			#undef def
254	root	1.28	#undef def2
255
256			// undefined external reference to catch people using str* functions when they shouldn't
257			//template<class any> void strcmp (const shstr_tmp &a, any b);
258	root	1.29	template<class any> void strstr (const shstr_tmp &a, any b);
259	root	1.9
260	root	1.2	#endif
261