server/include/dynbuf.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
 * Copyright (©) 2002 Mark Wedel & Crossfire Development Team
 * Copyright (©) 1992 Frank Tore Johansen
 *
 * 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 DYNBUF_H__
#define DYNBUF_H__

#include <cstring>
#include <cassert>

#include "ecb.h"
#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 _size;

  int extend, cextend;
  chunk *first, *last;

  void reserve (int size);
  void init (int initial);  // allocate sinitial chunk
  void free_chain (chunk *&chain); // free chain of chunks
  char *_linearise (int extra = 0);
  void finalise ();

public:
  
  // initial - the size of the initial chunk to be allocated
  // extend  - first incremental step when buffer size exceeded
  dynbuf (int initial = 4096 - 64, int extend = 16384 - 64)
  : extend (extend)
  {
    init (initial);
  }

  ~dynbuf ()
  {
    free (first);
  }

  // resets the dynbuf, but does not free the first chunk
  // which is either of size "initial" or the size of the last
  // linearise
  void clear ();

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

  void linearise (void *data);
  char *linearise () // does not 0-terminate(!)
  {
    return first->next ? _linearise () : first->data;
  }

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

  // make sure we have "size" extra room
  char *force (int size)
  {
    if (ecb_expect_false (ptr + size > end))
      reserve (size);

    ecb_assume (ptr + size <= end);

    return ptr;
  }

  // used for force + alloc combo
  void alloc (char *p)
  {
    ptr = p;
  }

  // allocate size bytes and return pointer to them (caller must force())
  char *falloc (int size)
  {
    char *res = ptr;
    ptr += size;
    return res;
  }

  // allocate size bytes and return pointer to them
  char *alloc (int size)
  {
    force (size);
    return falloc (size);
  }

  void fadd (char c) { *ptr++ = c; }
  void fadd (unsigned char c) { fadd (char (c)); }
  void fadd (const void *p, int len)
  {
    memcpy (falloc (len), p, len);
  }

  void add (const void *p, int len)
  {
    force (len);
    fadd (p, len);
  }

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

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

  void add (shstr_tmp s)
  {
    add (s.s, s.length ());
  }

  // rather inefficient
  void splice (int offset, int olen, const char *s, int slen);
  void splice (int offset, int olen) { splice (offset, olen, "", 0); }

  //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 << (shstr_tmp 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;
  void add (sint32 i);
  void add (sint64 i);

  //TODO: should optimise the case printf "(name %+d)" as it comes up extremely often

  //using dynbuf::operator <<; // doesn't work, sometimes C++ just suxx
  // instead we use an ugly template function
  template<typename T>
  dynbuf_text &operator << (T c) { *(dynbuf *)this << c; return *this; }

  dynbuf_text &operator << (sint16 i) { add (sint32 (i)); return *this; }
  dynbuf_text &operator << (uint16 i) { add (sint32 (i)); return *this; }
  dynbuf_text &operator << (sint32 i) { add (sint32 (i)); return *this; }
  dynbuf_text &operator << (sint64 i) { add (sint64 (i)); return *this; }
  dynbuf_text &operator << (uint32 i) { add (sint64 (i)); return *this; }
  dynbuf_text &operator << (uint64 i) { add (sint64 (i)); return *this; }

  void printf (const char *format, ...) ecb_attribute ((format (printf, 2, 3)));
  void vprintf (const char *format, va_list ap);

  void add_abilities (const char *name, uint32 abilities);
  void add_paths     (const char *name, uint32 paths);

  // we need to redefine, to keep the API :/
  using dynbuf::splice;
  void splice (int offset, int olen, const char *s)
  {
    dynbuf::splice (offset, olen, s, strlen (s));
  }

  // returns the string, linearised and with trailing \0
  operator char *();
};

#endif

Revision:	1.41
Committed:	Fri Jun 20 14:06:35 2025 UTC (15 months, 3 weeks ago) by root
Content type:	text/plain
Branch:	MAIN
CVS Tags:	HEAD
Changes since 1.40:	+2 -2 lines
Log Message:	* empty log message *
#	Content
1	/*
2	* This file is part of Deliantra, the Roguelike Realtime MMORPG.
3	*
4	* Copyright (©) 2017,2018 Marc Alexander Lehmann / the Deliantra team
5	* Copyright (©) 2005,2006,2007,2008,2009,2010,2011,2012,2013,2014,2015,2016 Marc Alexander Lehmann / Robin Redeker / the Deliantra team
6	* Copyright (©) 2002 Mark Wedel & Crossfire Development Team
7	* Copyright (©) 1992 Frank Tore Johansen
8	*
9	* Deliantra is free software: you can redistribute it and/or modify it under
10	* the terms of the Affero GNU General Public License as published by the
11	* Free Software Foundation, either version 3 of the License, or (at your
12	* option) any later version.
13	*
14	* This program is distributed in the hope that it will be useful,
15	* but WITHOUT ANY WARRANTY; without even the implied warranty of
16	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17	* GNU General Public License for more details.
18	*
19	* You should have received a copy of the Affero GNU General Public License
20	* and the GNU General Public License along with this program. If not, see
21	* <http://www.gnu.org/licenses/>.
22	*
23	* The authors can be reached via e-mail to <support@deliantra.net>
24	*/
25
26	#ifndef DYNBUF_H__
27	#define DYNBUF_H__
28
29	#include <cstring>
30	#include <cassert>
31
32	#include "ecb.h"
33	#include "util.h"
34	#include "shstr.h"
35
36	// this is a "buffer" that can grow fast
37	// and is still somewhat space-efficient.
38	// unlike obstacks or other data structures,
39	// it never moves data around. basically,
40	// this is a fast strstream without the overhead.
41
42	struct dynbuf
43	{
44	protected:
45	struct chunk
46	{
47	chunk *next;
48	int alloc;
49	int size;
50	char data[0];
51	};
52
53	char ptr, end;
54	int _size;
55
56	int extend, cextend;
57	chunk first, last;
58
59	void reserve (int size);
60	void init (int initial); // allocate sinitial chunk
61	void free_chain (chunk *&chain); // free chain of chunks
62	char *_linearise (int extra = 0);
63	void finalise ();
64
65	public:
66
67	// initial - the size of the initial chunk to be allocated
68	// extend - first incremental step when buffer size exceeded
69	dynbuf (int initial = 4096 - 64, int extend = 16384 - 64)
70	: extend (extend)
71	{
72	init (initial);
73	}
74
75	~dynbuf ()
76	{
77	free (first);
78	}
79
80	// resets the dynbuf, but does not free the first chunk
81	// which is either of size "initial" or the size of the last
82	// linearise
83	void clear ();
84
85	int size () const { return _size + (ptr - last->data); }
86	bool empty () const { return !size (); }
87
88	void linearise (void *data);
89	char *linearise () // does not 0-terminate(!)
90	{
91	return first->next ? _linearise () : first->data;
92	}
93
94	int room () const { return end - ptr; }
95
96	// make sure we have "size" extra room
97	char *force (int size)
98	{
99	if (ecb_expect_false (ptr + size > end))
100	reserve (size);
101
102	ecb_assume (ptr + size <= end);
103
104	return ptr;
105	}
106
107	// used for force + alloc combo
108	void alloc (char *p)
109	{
110	ptr = p;
111	}
112
113	// allocate size bytes and return pointer to them (caller must force())
114	char *falloc (int size)
115	{
116	char *res = ptr;
117	ptr += size;
118	return res;
119	}
120
121	// allocate size bytes and return pointer to them
122	char *alloc (int size)
123	{
124	force (size);
125	return falloc (size);
126	}
127
128	void fadd (char c) { *ptr++ = c; }
129	void fadd (unsigned char c) { fadd (char (c)); }
130	void fadd (const void *p, int len)
131	{
132	memcpy (falloc (len), p, len);
133	}
134
135	void add (const void *p, int len)
136	{
137	force (len);
138	fadd (p, len);
139	}
140
141	void add (char c)
142	{
143	alloc (1)[0] = c;
144	}
145
146	void add (const char *s)
147	{
148	add (s, strlen (s));
149	}
150
151	void add (shstr_tmp s)
152	{
153	add (s.s, s.length ());
154	}
155
156	// rather inefficient
157	void splice (int offset, int olen, const char *s, int slen);
158	void splice (int offset, int olen) { splice (offset, olen, "", 0); }
159
160	//TODO
161	//void add_destructive (dynbuf &buf);
162
163	dynbuf &operator << (char c) { add (c); return *this; }
164	dynbuf &operator << (unsigned char c) { return *this << char (c); }
165	dynbuf &operator << (const char s) { add (s); return this; }
166	dynbuf &operator << (shstr_tmp s) { add (s); return *this; }
167	dynbuf &operator << (const std::string &s) { add (s.data(), s.size ()); return *this; }
168
169	operator std::string ();
170	};
171
172	struct dynbuf_text : dynbuf
173	{
174	dynbuf_text (int initial = 4096, int extend = 16384)
175	: dynbuf (initial, extend)
176	{ }
177
178	using dynbuf::add;
179	void add (sint32 i);
180	void add (sint64 i);
181
182	//TODO: should optimise the case printf "(name %+d)" as it comes up extremely often
183
184	//using dynbuf::operator <<; // doesn't work, sometimes C++ just suxx
185	// instead we use an ugly template function
186	template<typename T>
187	dynbuf_text &operator << (T c) { (dynbuf )this << c; return *this; }
188
189	dynbuf_text &operator << (sint16 i) { add (sint32 (i)); return *this; }
190	dynbuf_text &operator << (uint16 i) { add (sint32 (i)); return *this; }
191	dynbuf_text &operator << (sint32 i) { add (sint32 (i)); return *this; }
192	dynbuf_text &operator << (sint64 i) { add (sint64 (i)); return *this; }
193	dynbuf_text &operator << (uint32 i) { add (sint64 (i)); return *this; }
194	dynbuf_text &operator << (uint64 i) { add (sint64 (i)); return *this; }
195
196	void printf (const char *format, ...) ecb_attribute ((format (printf, 2, 3)));
197	void vprintf (const char *format, va_list ap);
198
199	void add_abilities (const char *name, uint32 abilities);
200	void add_paths (const char *name, uint32 paths);
201
202	// we need to redefine, to keep the API :/
203	using dynbuf::splice;
204	void splice (int offset, int olen, const char *s)
205	{
206	dynbuf::splice (offset, olen, s, strlen (s));
207	}
208
209	// returns the string, linearised and with trailing \0
210	operator char *();
211	};
212
213	#endif
214