server/include/dynbuf.h

#ifndef DYNBUF_H__
#define DYNBUF_H__

#include <cstring>
#include <cassert>

#include "util.h"
#include "shstr.h"

// this is a "buffer" that can grow fast
// and is still somewhat space-efficient.
// unlike obstacks or other data structures,
// it never moves data around. basically,
// this is a fast strstream without the overhead.

struct dynbuf
{
protected:
  struct chunk
  {
    chunk *next;
    int alloc;
    int size;
    char data[0];
  };

  char *ptr, *end;
  int ext;
  int _size;

  chunk *first, *last;

  void _reserve (int size);
  void _clear ();
  void clear ();
  void finish ();

public:
  
  dynbuf (int initial = 4096, int extend = 16384);
  ~dynbuf ();

  int  size  () const { return _size + (ptr - last->data); }
  bool empty () const { return !size (); }

  void linearise (void *data);
  char *linearise (); // does not 0-terminate(!)

  int room () const { return end - ptr; }

  char *force (int size)
  {
    if (expect_false (ptr + size >= end))
      _reserve (size);

    return ptr;
  }

  char *alloc (int size)
  {
    char *res = force (size);
    ptr += size;
    return res;
  }

  void fadd (char c) { *ptr++ = c; }
  void fadd (unsigned char c) { fadd (char (c)); }

  void add (const void *p, int len)
  {
    memcpy (alloc (len), p, len);
  }

  void add (char c)
  {
    alloc (1)[0] = c;
  }

  void add (const char *s)
  {
     add (s, strlen (s));
  }

  void add (const shstr &s)
  {
    add (s.s, s.length ());
  }

  //TODO
  //void add_destructive (dynbuf &buf);

  dynbuf &operator << (char c) { add (c); return *this; }
  dynbuf &operator << (unsigned char c) { return *this << char (c); }
  dynbuf &operator << (const char *s) { add (s); return *this; }
  dynbuf &operator << (const shstr &s) { add (s); return *this; }
  dynbuf &operator << (const std::string &s) { add (s.data(), s.size ()); return *this; }

  operator std::string ();
};

struct dynbuf_text : dynbuf
{
  dynbuf_text (int initial = 4096, int extend = 16384)
  : dynbuf (initial, extend)
  { }

  using dynbuf::add;

  static const int max_sint32_size = 11;
  static const int max_sint64_size = 20;

  void add (sint32 i);
  void add (sint64 i);

  void printf (const char *format, ...);
};

#endif

Revision:	1.9
Committed:	Sun May 27 23:22:29 2007 UTC (17 years ago) by root
Content type:	text/plain
Branch:	MAIN
Changes since 1.8:	+1 -1 lines
Log Message:	minor cleanups/optimisations
#	User	Rev	Content
1	root	1.1	#ifndef DYNBUF_H__
2			#define DYNBUF_H__
3
4			#include <cstring>
5			#include <cassert>
6
7	root	1.8	#include "util.h"
8	root	1.4	#include "shstr.h"
9
10	root	1.1	// this is a "buffer" that can grow fast
11			// and is still somewhat space-efficient.
12			// unlike obstacks or other data structures,
13			// it never moves data around. basically,
14			// this is a fast strstream without the overhead.
15
16	root	1.4	struct dynbuf
17	root	1.1	{
18	root	1.4	protected:
19	root	1.1	struct chunk
20			{
21			chunk *next;
22	root	1.5	int alloc;
23	root	1.1	int size;
24			char data[0];
25			};
26
27	root	1.6	char ptr, end;
28	root	1.1	int ext;
29			int _size;
30
31			chunk first, last;
32
33			void _reserve (int size);
34	root	1.7	void _clear ();
35	root	1.1	void clear ();
36			void finish ();
37
38			public:
39
40	root	1.2	dynbuf (int initial = 4096, int extend = 16384);
41	root	1.1	~dynbuf ();
42
43	root	1.6	int size () const { return _size + (ptr - last->data); }
44			bool empty () const { return !size (); }
45	root	1.1
46			void linearise (void *data);
47	root	1.6	char *linearise (); // does not 0-terminate(!)
48
49			int room () const { return end - ptr; }
50	root	1.1
51			char *force (int size)
52			{
53	root	1.8	if (expect_false (ptr + size >= end))
54	root	1.1	_reserve (size);
55
56			return ptr;
57			}
58
59			char *alloc (int size)
60			{
61			char *res = force (size);
62	root	1.9	ptr += size;
63	root	1.1	return res;
64			}
65
66	root	1.6	void fadd (char c) { *ptr++ = c; }
67	root	1.2	void fadd (unsigned char c) { fadd (char (c)); }
68	root	1.1
69			void add (const void *p, int len)
70			{
71			memcpy (alloc (len), p, len);
72			}
73
74			void add (char c)
75			{
76	root	1.3	alloc (1)[0] = c;
77	root	1.1	}
78
79			void add (const char *s)
80			{
81			add (s, strlen (s));
82			}
83
84	root	1.4	void add (const shstr &s)
85			{
86			add (s.s, s.length ());
87			}
88	root	1.1
89			//TODO
90			//void add_destructive (dynbuf &buf);
91
92			dynbuf &operator << (char c) { add (c); return *this; }
93			dynbuf &operator << (unsigned char c) { return *this << char (c); }
94			dynbuf &operator << (const char s) { add (s); return this; }
95	root	1.6	dynbuf &operator << (const shstr &s) { add (s); return *this; }
96	root	1.4	dynbuf &operator << (const std::string &s) { add (s.data(), s.size ()); return *this; }
97
98			operator std::string ();
99			};
100
101			struct dynbuf_text : dynbuf
102			{
103			dynbuf_text (int initial = 4096, int extend = 16384)
104			: dynbuf (initial, extend)
105			{ }
106
107			using dynbuf::add;
108
109			static const int max_sint32_size = 11;
110			static const int max_sint64_size = 20;
111
112			void add (sint32 i);
113			void add (sint64 i);
114
115			void printf (const char *format, ...);
116	root	1.1	};
117
118			#endif
119	root	1.6