server/include/shstr.h

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008,2009,2010 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 hash;
  uint32_t len;
  uint32_t refcnt;
  // pointer points here
  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 pass 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 &hash (const char *s)
  {
    return *((unsigned int *)s - 3);
  }

  int hash () const
  {
    return hash (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 inline 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:	1.38
Committed:	Fri Mar 26 01:04:44 2010 UTC (14 years, 2 months ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	rel-3_0
Changes since 1.37:	+1 -1 lines
Log Message:	update copyright for up to 2010
#	Content
1	/*
2	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	*
4	* Copyright (©) 2005,2006,2007,2008,2009,2010 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
23	#ifndef SHSTR_H__
24	#define SHSTR_H__
25
26	#include <cstring>
27	#include <sstream>
28
29	#include "traits.h"
30
31	extern size_t shstr_alloc;
32
33	extern int buf_overflow (const char buf1, const char buf2, int bufsize);
34
35	template<int size>
36	struct shstr_vec
37	{
38	uint32_t hash;
39	uint32_t len;
40	uint32_t refcnt;
41	// pointer points here
42	char string [size];
43	};
44
45	// this class is a non-refcounted shared string
46	// it cannot be used to create or store shared strings, but
47	// it can be used to pass shared strings around, i.e. as function arguments
48	// or return values. their lifetime must not span a gc () call, i.e.
49	// they are only valid as temporary values within the same server tick.
50	struct shstr_tmp
51	{
52	static shstr_vec<sizeof ("(null)")> nullvec;
53	static const char *null () { return nullvec.string; } // this is the null pointer value
54
55	const char *s;
56
57	static unsigned int &hash (const char *s)
58	{
59	return ((unsigned int )s - 3);
60	}
61
62	int hash () const
63	{
64	return hash (s);
65	}
66
67	static unsigned int &length (const char *s)
68	{
69	return ((unsigned int )s - 2);
70	}
71
72	int length () const
73	{
74	return length (s);
75	}
76
77	// returns whether this shared string begins with the given prefix,
78	// used mainly for searches when users give only the start of a name.
79	bool starts_with (const char *prefix) const
80	{
81	int plen = strlen (prefix);
82
83	return length () >= plen && !strncasecmp (s, prefix, plen);
84	}
85
86	// returns true if the substring is contained in the shstr
87	// if the shstr is 0, then this always returns false.
88	// the shstr is (theoretically) treated as a comma/colon/space etc. separated list.
89	bool contains (const char *substring) const
90	{
91	return s != null () && strstr (s, substring);
92	}
93
94	//TODO: case sensitive should be eradicated
95	bool eq_nc (const char *otherstring) const
96	{
97	return !strcasecmp (s, otherstring);
98	}
99
100	shstr_tmp ()
101	: s (null ())
102	{
103	}
104
105	shstr_tmp (const shstr_tmp &sh)
106	: s (sh.s)
107	{
108	}
109
110	shstr_tmp operator =(const shstr_tmp &sh)
111	{
112	s = sh.s;
113
114	return *this;
115	}
116
117	// this is used for informational messages and the like
118	const char *operator &() const { return s; }
119
120	operator const char *() const { return s == null () ? 0 : s; }
121
122	protected:
123	// dummy is there so it isn't used as type converter accidentally
124	shstr_tmp (int dummy, const char *s)
125	: s(s)
126	{
127	}
128	};
129
130	inline bool operator ==(const shstr_tmp &a, const shstr_tmp &b)
131	{
132	return a.s == b.s;
133	}
134
135	inline bool operator !=(const shstr_tmp &a, const shstr_tmp &b)
136	{
137	return a.s != b.s;
138	}
139
140	inline int strlen (shstr_tmp sh)
141	{
142	return sh.length ();
143	}
144
145	static inline std::ostream &operator <<(std::ostream &o, shstr_tmp sh)
146	{
147	o.write (sh.s, sh.length ());
148
149	return o;
150	}
151
152	struct shstr : shstr_tmp
153	{
154	static unsigned int &refcnt (const char *s)
155	{
156	return ((unsigned int )s - 1);
157	}
158
159	unsigned int &refcnt () const
160	{
161	return refcnt (s);
162	}
163
164	shstr ()
165	{
166	}
167
168	static const char find (const char s);
169	static const char intern (const char s);
170
171	static void gc (); // garbage collect a few strings
172
173	shstr (const shstr &sh)
174	: shstr_tmp (sh)
175	{
176	++refcnt ();
177	}
178
179	shstr (const shstr_tmp &sh)
180	: shstr_tmp (sh)
181	{
182	++refcnt ();
183	}
184
185	explicit shstr (const char *str)
186	: shstr_tmp (0, is_constant (str) && !str ? null () : intern (str))
187	{
188	}
189
190	~shstr ()
191	{
192	--refcnt ();
193	}
194
195	using shstr_tmp::operator &;
196	using shstr_tmp::operator const char *;
197
198	// (note: not the copy constructor)
199	shstr &operator =(const shstr_tmp &sh)
200	{
201	--refcnt ();
202	s = sh.s;
203	++refcnt ();
204
205	return *this;
206	}
207
208	// here it comes
209	shstr &operator =(const shstr &sh)
210	{
211	return (*this) = (shstr_tmp)sh;
212	}
213
214	// shstr_tmp doesn't have this one
215	shstr &operator =(const char *str)
216	{
217	--refcnt ();
218	s = is_constant (str) && !str ? null () : intern (str);
219
220	return *this;
221	}
222	};
223
224	// only good for mass comparisons to shstr objects, or very
225	// temporary passing, basically a non-refcounted shstr
226	struct shstr_cmp
227	{
228	const char *s;
229
230	// initialies to the non-matching string (as opposed to the null string)
231	shstr_cmp ()
232	{
233	s = 0;
234	}
235
236	shstr_cmp (const char *str)
237	: s (shstr::find (str))
238	{
239	}
240
241	shstr_cmp (shstr_tmp sh)
242	: s (sh.s)
243	{
244	}
245
246	// this is used for informational messages and the like
247	const char *operator &() const { return s; }
248
249	operator const char *() const { return s; }
250	};
251
252	inline bool operator ==(const shstr_cmp &a, const shstr_tmp &b)
253	{
254	return a.s == b.s;
255	}
256
257	inline bool operator ==(const shstr_tmp &a, const shstr_cmp &b)
258	{
259	return a.s == b.s;
260	}
261
262	#define def2(id,str) extern const shstr id;
263	#define def(id) def2(shstr_ ## id, # id)
264	# include "shstrinc.h"
265	#undef def
266	#undef def2
267
268	// undefined external reference to catch people using str* functions when they shouldn't
269	//template<class any> void strcmp (const shstr_tmp &a, any b);
270	template<class any> void strstr (const shstr_tmp &a, any b);
271
272	#endif
273