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, 8 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
#	Content
1	#ifndef SHSTR_H__
2	#define SHSTR_H__
3
4	#include "util.h"
5
6	extern int buf_overflow (const char buf1, const char buf2, int bufsize);
7
8	struct shstr
9	{
10	static const char *null;
11
12	const char *s;
13
14	static int &refcnt (const char *s)
15	{
16	return ((int )s - 1);
17	}
18
19	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	return length (s);
32	}
33
34	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	// this is used for informational messages and the like
40	const char *operator &() const { return s; }
41
42	const char &operator [](int i) const { return s[i]; }
43	operator const char *() const { return s == null ? 0 : s; }
44
45	shstr ()
46	: s (null)
47	{
48	}
49
50	shstr (const shstr &sh)
51	: s (sh.s)
52	{
53	++refcnt ();
54	}
55
56	explicit shstr (const char *s)
57	: s (intern (s))
58	{
59	}
60
61	~shstr ()
62	{
63	--refcnt ();
64	}
65
66	const shstr &operator =(const shstr &sh)
67	{
68	--refcnt ();
69	s = sh.s;
70	++refcnt ();
71
72	return *this;
73	}
74
75	const shstr &operator =(const char *str)
76	{
77	--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
87	return *this;
88	}
89	};
90
91	inline int strlen (const shstr &sh)
92	{
93	return sh.length ();
94	}
95
96	inline bool operator ==(const shstr &a, const shstr &b)
97	{
98	return a.s == b.s;
99	}
100
101	inline bool operator !=(const shstr &a, const shstr &b)
102	{
103	return !(a == b);
104	}
105
106	#endif
107