server/include/shstr.h

/*
 * This file is part of Deliantra, the Roguelike Realtime MMORPG.
 *
 * Copyright (©) 2017,2018 Marc Alexander Lehmann / the Deliantra team
 * Copyright (©) 2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016 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_tmp &sh)
  : shstr_tmp (sh)
  {
    ++refcnt ();
  }

  explicit shstr (const char *str)
  : shstr_tmp (0, ecb_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 = ecb_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:	1.46
Committed:	Tue Nov 27 18:47:35 2018 UTC (5 years, 6 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.45:	+0 -6 lines
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.16	/*
2	root	1.20	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	root	1.42	*
4	root	1.45	* Copyright (©) 2017,2018 Marc Alexander Lehmann / the Deliantra team
5	root	1.43	* Copyright (©) 2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
6	root	1.42	*
7	root	1.33	* Deliantra is free software: you can redistribute it and/or modify it under
8			* the terms of the Affero GNU General Public License as published by the
9			* Free Software Foundation, either version 3 of the License, or (at your
10			* option) any later version.
11	root	1.42	*
12	root	1.17	* This program is distributed in the hope that it will be useful,
13			* but WITHOUT ANY WARRANTY; without even the implied warranty of
14			* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15			* GNU General Public License for more details.
16	root	1.42	*
17	root	1.33	* You should have received a copy of the Affero GNU General Public License
18			* and the GNU General Public License along with this program. If not, see
19			* <http://www.gnu.org/licenses/>.
20	root	1.42	*
21	root	1.20	* The authors can be reached via e-mail to <support@deliantra.net>
22	root	1.16	*/
23
24	root	1.2	#ifndef SHSTR_H__
25			#define SHSTR_H__
26
27	root	1.24	#include <cstring>
28	root	1.13	#include <sstream>
29
30	root	1.25	#include "traits.h"
31	root	1.8
32	root	1.19	extern size_t shstr_alloc;
33
34	root	1.8	extern int buf_overflow (const char buf1, const char buf2, int bufsize);
35	root	1.5
36	root	1.25	template<int size>
37			struct shstr_vec
38			{
39	root	1.36	uint32_t hash;
40	root	1.25	uint32_t len;
41			uint32_t refcnt;
42	root	1.36	// pointer points here
43			char string [size];
44	root	1.25	};
45
46	root	1.24	// this class is a non-refcounted shared string
47			// it cannot be used to create or store shared strings, but
48	root	1.37	// it can be used to pass shared strings around, i.e. as function arguments
49	root	1.24	// or return values. their lifetime must not span a gc () call, i.e.
50			// they are only valid as temporary values within the same server tick.
51			struct shstr_tmp
52	root	1.5	{
53	root	1.25	static shstr_vec<sizeof ("(null)")> nullvec;
54			static const char *null () { return nullvec.string; } // this is the null pointer value
55	root	1.8
56	root	1.5	const char *s;
57	root	1.4
58	root	1.36	static unsigned int &hash (const char *s)
59			{
60			return ((unsigned int )s - 3);
61			}
62
63			int hash () const
64			{
65			return hash (s);
66			}
67
68	root	1.24	static unsigned int &length (const char *s)
69	root	1.5	{
70	root	1.24	return ((unsigned int )s - 2);
71	root	1.5	}
72
73	root	1.24	int length () const
74	root	1.7	{
75	root	1.24	return length (s);
76	root	1.7	}
77
78	root	1.24	// returns whether this shared string begins with the given prefix,
79			// used mainly for searches when users give only the start of a name.
80			bool starts_with (const char *prefix) const
81	root	1.7	{
82	root	1.24	int plen = strlen (prefix);
83
84			return length () >= plen && !strncasecmp (s, prefix, plen);
85	root	1.7	}
86
87	root	1.32	// returns true if the substring is contained in the shstr
88			// if the shstr is 0, then this always returns false.
89			// the shstr is (theoretically) treated as a comma/colon/space etc. separated list.
90	root	1.39	bool contains (const char *substring) const;
91	root	1.7
92	root	1.28	//TODO: case sensitive should be eradicated
93			bool eq_nc (const char *otherstring) const
94			{
95			return !strcasecmp (s, otherstring);
96			}
97
98	root	1.24	shstr_tmp ()
99	root	1.25	: s (null ())
100	root	1.24	{
101			}
102
103			shstr_tmp (const shstr_tmp &sh)
104			: s (sh.s)
105	root	1.15	{
106			}
107
108	root	1.24	shstr_tmp operator =(const shstr_tmp &sh)
109			{
110			s = sh.s;
111	root	1.5
112	root	1.24	return *this;
113			}
114	root	1.5
115	root	1.6	// this is used for informational messages and the like
116	root	1.8	const char *operator &() const { return s; }
117	root	1.5
118	root	1.25	operator const char *() const { return s == null () ? 0 : s; }
119	root	1.26
120			protected:
121			// dummy is there so it isn't used as type converter accidentally
122			shstr_tmp (int dummy, const char *s)
123			: s(s)
124			{
125			}
126	root	1.24	};
127
128			inline bool operator ==(const shstr_tmp &a, const shstr_tmp &b)
129			{
130			return a.s == b.s;
131			}
132
133			inline bool operator !=(const shstr_tmp &a, const shstr_tmp &b)
134			{
135			return a.s != b.s;
136			}
137
138	root	1.31	inline int strlen (shstr_tmp sh)
139	root	1.24	{
140			return sh.length ();
141			}
142
143	root	1.35	static inline std::ostream &operator <<(std::ostream &o, shstr_tmp sh)
144	root	1.24	{
145			o.write (sh.s, sh.length ());
146
147			return o;
148			}
149
150			struct shstr : shstr_tmp
151			{
152			static unsigned int &refcnt (const char *s)
153			{
154			return ((unsigned int )s - 1);
155			}
156
157			unsigned int &refcnt () const
158			{
159			return refcnt (s);
160			}
161	root	1.5
162			shstr ()
163			{
164			}
165
166	root	1.24	static const char find (const char s);
167			static const char intern (const char s);
168
169			static void gc (); // garbage collect a few strings
170
171			shstr (const shstr_tmp &sh)
172			: shstr_tmp (sh)
173	root	1.5	{
174	root	1.8	++refcnt ();
175	root	1.5	}
176
177	root	1.24	explicit shstr (const char *str)
178	root	1.44	: shstr_tmp (0, ecb_is_constant (str) && !str ? null () : intern (str))
179	root	1.5	{
180			}
181
182			~shstr ()
183			{
184	root	1.8	--refcnt ();
185	root	1.5	}
186
187	root	1.24	using shstr_tmp::operator &;
188			using shstr_tmp::operator const char *;
189
190			// (note: not the copy constructor)
191			shstr &operator =(const shstr_tmp &sh)
192	root	1.5	{
193	root	1.8	--refcnt ();
194	root	1.5	s = sh.s;
195	root	1.8	++refcnt ();
196	root	1.5
197			return *this;
198			}
199
200	root	1.24	// here it comes
201			shstr &operator =(const shstr &sh)
202			{
203			return (*this) = (shstr_tmp)sh;
204			}
205
206			// shstr_tmp doesn't have this one
207			shstr &operator =(const char *str)
208	root	1.5	{
209	root	1.8	--refcnt ();
210	root	1.44	s = ecb_is_constant (str) && !str ? null () : intern (str);
211	root	1.1
212	root	1.5	return *this;
213			}
214			};
215	root	1.1
216	root	1.24	// only good for mass comparisons to shstr objects, or very
217			// temporary passing, basically a non-refcounted shstr
218	root	1.10	struct shstr_cmp
219			{
220			const char *s;
221
222	root	1.28	// initialies to the non-matching string (as opposed to the null string)
223			shstr_cmp ()
224			{
225			s = 0;
226			}
227
228			shstr_cmp (const char *str)
229	root	1.24	: s (shstr::find (str))
230	root	1.10	{
231			}
232
233	root	1.25	shstr_cmp (shstr_tmp sh)
234	root	1.23	: s (sh.s)
235			{
236			}
237
238			// this is used for informational messages and the like
239			const char *operator &() const { return s; }
240
241	root	1.10	operator const char *() const { return s; }
242			};
243
244	root	1.24	inline bool operator ==(const shstr_cmp &a, const shstr_tmp &b)
245	root	1.5	{
246			return a.s == b.s;
247			}
248	root	1.4
249	root	1.24	inline bool operator ==(const shstr_tmp &a, const shstr_cmp &b)
250	root	1.4	{
251	root	1.24	return a.s == b.s;
252	root	1.5	}
253	root	1.4
254	root	1.30	#define def2(id,str) extern const shstr id;
255			#define def(id) def2(shstr_ ## id, # id)
256	root	1.18	# include "shstrinc.h"
257			#undef def
258	root	1.28	#undef def2
259
260			// undefined external reference to catch people using str* functions when they shouldn't
261			//template<class any> void strcmp (const shstr_tmp &a, any b);
262	root	1.29	template<class any> void strstr (const shstr_tmp &a, any b);
263	root	1.9
264	root	1.2	#endif
265