aboutsummaryrefslogtreecommitdiff
path: root/libio/strops.c
blob: 98c5b263d5ee3ca01adffe09ea1f9cc9950a15f8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
/* 
Copyright (C) 1993 Free Software Foundation

This file is part of the GNU IO Library.  This library is free
software; you can redistribute it and/or modify it under the
terms of the GNU General Public License as published by the
Free Software Foundation; either version 2, or (at your option)
any later version.

This library 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 GNU General Public License
along with this library; see the file COPYING.  If not, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

As a special exception, if you link this library with files
compiled with a GNU compiler to produce an executable, this does not cause
the resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why
the executable file might be covered by the GNU General Public License. */

#include "strfile.h"
#include "libioP.h"
#include <string.h>

#define LEN(fp) (((_IO_strfile*)(fp))->_s._len)

#ifdef TODO
/* An "unbounded buffer" is when a buffer is supplied, but with no
   specified length.  An example is the buffer argument to sprintf.
   */
#endif

void
DEFUN(_IO_str_init_static, (fp, ptr, size, pstart),
      _IO_FILE *fp AND char *ptr AND int size AND char *pstart)
{
  if (size == 0)
    size = strlen(ptr);
  else if (size < 0)
    {
      /* If size is negative 'the characters are assumed to
	 continue indefinitely.'  This is kind of messy ... */
#if 1
      int s;
      size = 512;
      /* Try increasing powers of 2, as long as we don't wrap around.
	 This can lose in pathological cases (ptr near the end
	 of the address space).  A better solution might be to
	 adjust the size on underflow/overflow.  FIXME. */
      for ( ; s = 2*size, s > 0 && ptr + s > ptr && s < 0x4000000L; )
	size = s;
      size = s;
#else
      /* The following semi-portable kludge assumes that
	 sizeof(unsigned long) == sizeof(char*). Hence,
	 (unsigned long)(-1) should be the largest possible address. */
      unsigned long highest = (unsigned long)(-1);
      /* Pointers are signed on some brain-damaged systems, in
	 which case we divide by two to get the maximum signed address. */
      if  ((char*)highest < ptr)
	highest >>= 1;
      size = (char*)highest - ptr;
#endif
    }
  _IO_setb(fp, ptr, ptr+size, 0);

  fp->_IO_write_base = ptr;
  fp->_IO_read_base = ptr;
  fp->_IO_read_ptr = ptr;
  if (pstart)
    {
      fp->_IO_write_ptr = pstart;
      fp->_IO_write_end = ptr+size;
      fp->_IO_read_end = pstart;
    }
  else
    {
      fp->_IO_write_ptr = ptr;
      fp->_IO_write_end = ptr;
      fp->_IO_read_end = ptr+size;
    }
  LEN(fp) = size;
  /* A null _allocate_buffer function flags the strfile as being static. */
  (((_IO_strfile*)(fp))->_s._allocate_buffer) =  (_IO_alloc_type)0;
}

void
DEFUN(_IO_str_init_readonly, (fp, ptr, size),
      _IO_FILE *fp AND const char *ptr AND int size)
{
  _IO_str_init_static (fp, (char*)ptr, size, NULL);
  fp->_IO_file_flags |= _IO_NO_WRITES;
}

int
DEFUN(_IO_str_overflow, (fp, c),
      register _IO_FILE* fp AND int c)
{
  int flush_only = c == EOF;
  _IO_size_t pos = fp->_IO_write_ptr - fp->_IO_write_base;
  _IO_size_t get_pos = fp->_IO_read_ptr - fp->_IO_read_base;
  if (fp->_flags & _IO_NO_WRITES)
      return flush_only ? 0 : EOF;
  if (pos > LEN(fp)) LEN(fp) = pos;
  if ((fp->_flags & _IO_TIED_PUT_GET) && !(fp->_flags & _IO_CURRENTLY_PUTTING))
    {
      pos = get_pos;
      fp->_flags |= _IO_CURRENTLY_PUTTING;
      get_pos = LEN(fp);
    }
  if (pos >= _IO_blen(fp) + flush_only)
    {
      if (fp->_flags & _IO_USER_BUF) /* not allowed to enlarge */
	{
#ifdef TODO
	  if (indefinite size)
	    {
	      fp->_IO_buf_end += 512;
	    }
	  else
#endif
	  return EOF;
	}
      else
	{
	  char *new_buf;
	  _IO_size_t new_size = 2 * _IO_blen(fp);
	  new_buf
	    = (char*)(*((_IO_strfile*)fp)->_s._allocate_buffer)(new_size);
	  if (new_buf == NULL)
	    {
	      /*	  __ferror(fp) = 1; */
	      return EOF;
	    }
	  memcpy(new_buf, fp->_IO_buf_base, _IO_blen(fp));
#if 0
	  if (lenp == &LEN(fp)) /* use '\0'-filling */
	      memset(new_buf + pos, 0, blen() - pos);
#endif
	  if (fp->_IO_buf_base)
	    {
	      (*((_IO_strfile*)fp)->_s._free_buffer)(fp->_IO_buf_base);
	      /* Make sure _IO_setb won't try to delete _IO_buf_base. */
	      fp->_IO_buf_base = NULL;
	    }
	  _IO_setb(fp, new_buf, new_buf + new_size, 1);
	  fp->_IO_write_base = new_buf;
	}
      fp->_IO_write_end = fp->_IO_buf_end;
    }

  fp->_IO_write_ptr = fp->_IO_buf_base + pos;

  fp->_IO_read_base = fp->_IO_buf_base;
  fp->_IO_read_ptr = fp->_IO_buf_base + get_pos;
  fp->_IO_read_end = fp->_IO_buf_base + LEN(fp);

  if (!flush_only)
    *fp->_IO_write_ptr++ = (unsigned char) c;
  return c;
}

int
DEFUN(_IO_str_underflow, (fp),
      register _IO_FILE* fp)
{
  _IO_size_t ppos = fp->_IO_write_ptr - fp->_IO_write_base;
  if (ppos > LEN(fp)) LEN(fp) = ppos;
  if ((fp->_flags & _IO_TIED_PUT_GET) && (fp->_flags & _IO_CURRENTLY_PUTTING))
    {
      fp->_flags &= ~_IO_CURRENTLY_PUTTING;
      fp->_IO_write_ptr = fp->_IO_write_end;
    }
  fp->_IO_read_end = fp->_IO_read_base + LEN(fp);
  if (fp->_IO_read_ptr < fp->_IO_read_end)
    return *fp->_IO_read_ptr;
  else
    return EOF;
}

_IO_ssize_t
DEFUN(_IO_str_count, (fp),
      register _IO_FILE *fp)
{
  _IO_ssize_t put_len = fp->_IO_write_ptr - fp->_IO_write_base;
  if (put_len < LEN(fp))
    put_len = LEN(fp);
  return put_len;
}     

_IO_pos_t
DEFUN(_IO_str_seekoff, (fp, offset, dir, mode),
      register _IO_FILE *fp AND _IO_off_t offset AND int dir AND int mode)
{
  _IO_ssize_t cur_size = _IO_str_count(fp);
  _IO_pos_t new_pos = EOF;

  /* Move the get pointer, if requested. */
  if (mode & _IOS_INPUT)
    {
      switch (dir)
	{
	case _IO_seek_end:
	  offset += cur_size;
	  break;
	case _IO_seek_cur:
	  offset += fp->_IO_read_ptr - fp->_IO_read_base;
	  break;
	default: /* case _IO_seek_set: */
	  break;
	}
      if (offset < 0 || (_IO_size_t)offset > cur_size)
	return EOF;
      fp->_IO_read_ptr = fp->_IO_read_base + offset;
      fp->_IO_read_end = fp->_IO_read_base + cur_size;
      new_pos = offset;
    }

  /* Move the put pointer, if requested. */
  if (mode & _IOS_OUTPUT)
    {
      switch (dir)
	{
	case _IO_seek_end:
	  offset += cur_size;
	  break;
	case _IO_seek_cur:
	  offset += fp->_IO_write_ptr - fp->_IO_write_base;
	  break;
	default: /* case _IO_seek_set: */
	  break;
	}
      if (offset < 0 || (_IO_size_t)offset > cur_size)
	return EOF;
      LEN(fp) = cur_size;
      fp->_IO_write_ptr = fp->_IO_write_base + offset;
      new_pos = offset;
    }
  return new_pos;
}

int
DEFUN(_IO_str_pbackfail, (fp, c),
      register _IO_FILE *fp AND int c)
{
  if ((fp->_flags & _IO_NO_WRITES) && c != EOF)
    return EOF;
  return _IO_default_pbackfail(fp, c);
}

void
DEFUN (_IO_str_finish, (fp),
      register _IO_FILE* fp)
{
  if (fp->_IO_buf_base && !(fp->_flags & _IO_USER_BUF))
    (((_IO_strfile*)fp)->_s._free_buffer)(fp->_IO_buf_base);
  fp->_IO_buf_base = NULL;

  _IO_default_finish(fp);
}

struct _IO_jump_t _IO_str_jumps = {
  JUMP_INIT_DUMMY,
  JUMP_INIT(finish, _IO_str_finish),
  JUMP_INIT(overflow, _IO_str_overflow),
  JUMP_INIT(underflow, _IO_str_underflow),
  JUMP_INIT(uflow, _IO_default_uflow),
  JUMP_INIT(pbackfail, _IO_str_pbackfail),
  JUMP_INIT(xsputn, _IO_default_xsputn),
  JUMP_INIT(xsgetn, _IO_default_xsgetn),
  JUMP_INIT(seekoff, _IO_str_seekoff),
  JUMP_INIT(seekpos, _IO_default_seekpos),
  JUMP_INIT(setbuf, _IO_default_setbuf),
  JUMP_INIT(sync, _IO_default_sync),
  JUMP_INIT(doallocate, _IO_default_doallocate),
  JUMP_INIT(read, _IO_default_read),
  JUMP_INIT(write, _IO_default_write),
  JUMP_INIT(seek, _IO_default_seek),
  JUMP_INIT(close, _IO_default_close),
  JUMP_INIT(stat, _IO_default_stat)
};