server/include/shstr.h

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 * 
 * Copyright (©) 2005,2006,2007,2008,2009,2010,2011 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;

  //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:	1.40
Committed:	Sat Apr 23 04:56:50 2011 UTC (13 years, 1 month ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.39:	+1 -1 lines
Log Message:	update copyright to 2011
#	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	1.40	* Copyright (©) 2005,2006,2007,2008,2009,2010,2011 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	root	1.36	uint32_t hash;
39	root	1.25	uint32_t len;
40			uint32_t refcnt;
41	root	1.36	// pointer points here
42			char string [size];
43	root	1.25	};
44
45	root	1.24	// this class is a non-refcounted shared string
46			// it cannot be used to create or store shared strings, but
47	root	1.37	// it can be used to pass shared strings around, i.e. as function arguments
48	root	1.24	// 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	root	1.5	{
52	root	1.25	static shstr_vec<sizeof ("(null)")> nullvec;
53			static const char *null () { return nullvec.string; } // this is the null pointer value
54	root	1.8
55	root	1.5	const char *s;
56	root	1.4
57	root	1.36	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	root	1.24	static unsigned int &length (const char *s)
68	root	1.5	{
69	root	1.24	return ((unsigned int )s - 2);
70	root	1.5	}
71
72	root	1.24	int length () const
73	root	1.7	{
74	root	1.24	return length (s);
75	root	1.7	}
76
77	root	1.24	// 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	root	1.7	{
81	root	1.24	int plen = strlen (prefix);
82
83			return length () >= plen && !strncasecmp (s, prefix, plen);
84	root	1.7	}
85
86	root	1.32	// 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	root	1.39	bool contains (const char *substring) const;
90	root	1.7
91	root	1.28	//TODO: case sensitive should be eradicated
92			bool eq_nc (const char *otherstring) const
93			{
94			return !strcasecmp (s, otherstring);
95			}
96
97	root	1.24	shstr_tmp ()
98	root	1.25	: s (null ())
99	root	1.24	{
100			}
101
102			shstr_tmp (const shstr_tmp &sh)
103			: s (sh.s)
104	root	1.15	{
105			}
106
107	root	1.24	shstr_tmp operator =(const shstr_tmp &sh)
108			{
109			s = sh.s;
110	root	1.5
111	root	1.24	return *this;
112			}
113	root	1.5
114	root	1.6	// this is used for informational messages and the like
115	root	1.8	const char *operator &() const { return s; }
116	root	1.5
117	root	1.25	operator const char *() const { return s == null () ? 0 : s; }
118	root	1.26
119			protected:
120			// dummy is there so it isn't used as type converter accidentally
121			shstr_tmp (int dummy, const char *s)
122			: s(s)
123			{
124			}
125	root	1.24	};
126
127			inline bool operator ==(const shstr_tmp &a, const shstr_tmp &b)
128			{
129			return a.s == b.s;
130			}
131
132			inline bool operator !=(const shstr_tmp &a, const shstr_tmp &b)
133			{
134			return a.s != b.s;
135			}
136
137	root	1.31	inline int strlen (shstr_tmp sh)
138	root	1.24	{
139			return sh.length ();
140			}
141
142	root	1.35	static inline std::ostream &operator <<(std::ostream &o, shstr_tmp sh)
143	root	1.24	{
144			o.write (sh.s, sh.length ());
145
146			return o;
147			}
148
149			struct shstr : shstr_tmp
150			{
151			static unsigned int &refcnt (const char *s)
152			{
153			return ((unsigned int )s - 1);
154			}
155
156			unsigned int &refcnt () const
157			{
158			return refcnt (s);
159			}
160	root	1.5
161			shstr ()
162			{
163			}
164
165	root	1.24	static const char find (const char s);
166			static const char intern (const char s);
167
168			static void gc (); // garbage collect a few strings
169
170	root	1.6	shstr (const shstr &sh)
171	root	1.24	: shstr_tmp (sh)
172			{
173			++refcnt ();
174			}
175
176			shstr (const shstr_tmp &sh)
177			: shstr_tmp (sh)
178	root	1.5	{
179	root	1.8	++refcnt ();
180	root	1.5	}
181
182	root	1.24	explicit shstr (const char *str)
183	root	1.26	: shstr_tmp (0, is_constant (str) && !str ? null () : intern (str))
184	root	1.5	{
185			}
186
187			~shstr ()
188			{
189	root	1.8	--refcnt ();
190	root	1.5	}
191
192	root	1.24	using shstr_tmp::operator &;
193			using shstr_tmp::operator const char *;
194
195			// (note: not the copy constructor)
196			shstr &operator =(const shstr_tmp &sh)
197	root	1.5	{
198	root	1.8	--refcnt ();
199	root	1.5	s = sh.s;
200	root	1.8	++refcnt ();
201	root	1.5
202			return *this;
203			}
204
205	root	1.24	// here it comes
206			shstr &operator =(const shstr &sh)
207			{
208			return (*this) = (shstr_tmp)sh;
209			}
210
211			// shstr_tmp doesn't have this one
212			shstr &operator =(const char *str)
213	root	1.5	{
214	root	1.8	--refcnt ();
215	root	1.25	s = is_constant (str) && !str ? null () : intern (str);
216	root	1.1
217	root	1.5	return *this;
218			}
219			};
220	root	1.1
221	root	1.24	// only good for mass comparisons to shstr objects, or very
222			// temporary passing, basically a non-refcounted shstr
223	root	1.10	struct shstr_cmp
224			{
225			const char *s;
226
227	root	1.28	// initialies to the non-matching string (as opposed to the null string)
228			shstr_cmp ()
229			{
230			s = 0;
231			}
232
233			shstr_cmp (const char *str)
234	root	1.24	: s (shstr::find (str))
235	root	1.10	{
236			}
237
238	root	1.25	shstr_cmp (shstr_tmp sh)
239	root	1.23	: s (sh.s)
240			{
241			}
242
243			// this is used for informational messages and the like
244			const char *operator &() const { return s; }
245
246	root	1.10	operator const char *() const { return s; }
247			};
248
249	root	1.24	inline bool operator ==(const shstr_cmp &a, const shstr_tmp &b)
250	root	1.5	{
251			return a.s == b.s;
252			}
253	root	1.4
254	root	1.24	inline bool operator ==(const shstr_tmp &a, const shstr_cmp &b)
255	root	1.4	{
256	root	1.24	return a.s == b.s;
257	root	1.5	}
258	root	1.4
259	root	1.30	#define def2(id,str) extern const shstr id;
260			#define def(id) def2(shstr_ ## id, # id)
261	root	1.18	# include "shstrinc.h"
262			#undef def
263	root	1.28	#undef def2
264
265			// undefined external reference to catch people using str* functions when they shouldn't
266			//template<class any> void strcmp (const shstr_tmp &a, any b);
267	root	1.29	template<class any> void strstr (const shstr_tmp &a, any b);
268	root	1.9
269	root	1.2	#endif
270