server/include/shstr.h

#ifndef SHSTR_H__
#define SHSTR_H__

#include "util.h"

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

struct shstr
{
  static const char *null;

  const char *s;

  static int &refcnt (const char *s)
  {
    return *((int *)s - 1);
  }

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

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

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

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

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

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

  const char &operator [](int i) const { return s[i]; }
  operator const char *() const { return s == null ? 0 : s; }

  shstr ()
  : s (null)
  {
  }

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

  explicit shstr (const char *s)
  : s (intern (s))
  {
  }

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

  const shstr &operator =(const shstr &sh)
  {
    --refcnt ();
    s = sh.s;
    ++refcnt ();

    return *this;
  }

  const shstr &operator =(const char *str)
  {
    --refcnt ();

#if 0
    // this optimises the important case of str == constant 0
    if (is_constant (str))
      s = str ? intern (str) : null;
    else
#endif
      s = intern (str);

    return *this;
  }
};

inline int strlen (const shstr &sh)
{
  return sh.length ();
}

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

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

#endif

Revision:	1.8
Committed:	Sun Sep 3 23:33:01 2006 UTC (17 years, 9 months ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.7:	+22 -11 lines
Log Message:	use alternative shstr representation, might or might not be faster, but does save code
#	User	Rev	Content
1	root	1.2	#ifndef SHSTR_H__
2			#define SHSTR_H__
3
4	root	1.8	#include "util.h"
5
6			extern int buf_overflow (const char buf1, const char buf2, int bufsize);
7	root	1.5
8			struct shstr
9			{
10	root	1.8	static const char *null;
11
12	root	1.5	const char *s;
13	root	1.4
14	root	1.7	static int &refcnt (const char *s)
15	root	1.5	{
16			return ((int )s - 1);
17			}
18
19	root	1.7	static int &length (const char *s)
20			{
21			return ((int )s - 2);
22			}
23
24			int &refcnt () const
25			{
26			return refcnt (s);
27			}
28
29			int length () const
30			{
31	root	1.8	return length (s);
32	root	1.7	}
33
34	root	1.5	static const char find (const char s);
35			static const char intern (const char s);
36
37			static void gc (); // garbage collect a few strings
38
39	root	1.6	// this is used for informational messages and the like
40	root	1.8	const char *operator &() const { return s; }
41	root	1.5
42	root	1.6	const char &operator [](int i) const { return s[i]; }
43	root	1.8	operator const char *() const { return s == null ? 0 : s; }
44	root	1.5
45			shstr ()
46	root	1.8	: s (null)
47	root	1.5	{
48			}
49
50	root	1.6	shstr (const shstr &sh)
51	root	1.5	: s (sh.s)
52			{
53	root	1.8	++refcnt ();
54	root	1.5	}
55
56			explicit shstr (const char *s)
57			: s (intern (s))
58			{
59			}
60
61			~shstr ()
62			{
63	root	1.8	--refcnt ();
64	root	1.5	}
65
66			const shstr &operator =(const shstr &sh)
67			{
68	root	1.8	--refcnt ();
69	root	1.5	s = sh.s;
70	root	1.8	++refcnt ();
71	root	1.5
72			return *this;
73			}
74
75			const shstr &operator =(const char *str)
76			{
77	root	1.8	--refcnt ();
78
79			#if 0
80			// this optimises the important case of str == constant 0
81			if (is_constant (str))
82			s = str ? intern (str) : null;
83			else
84			#endif
85			s = intern (str);
86	root	1.1
87	root	1.5	return *this;
88			}
89			};
90	root	1.1
91	root	1.5	inline int strlen (const shstr &sh)
92			{
93			return sh.length ();
94			}
95	root	1.2
96	root	1.5	inline bool operator ==(const shstr &a, const shstr &b)
97			{
98			return a.s == b.s;
99			}
100	root	1.4
101	root	1.5	inline bool operator !=(const shstr &a, const shstr &b)
102	root	1.4	{
103	root	1.5	return !(a == b);
104			}
105	root	1.4
106	root	1.2	#endif
107