summaryrefslogtreecommitdiff
path: root/libio/strops.c
blob: 0932d4c1b18a6a2c2df2559305ad4af04badf0a4 (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
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
/* Copyright (C) 1993-2016 Free Software Foundation, Inc.
   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or
   modify it under the terms of the GNU Lesser General Public
   License as published by the Free Software Foundation; either
   version 2.1 of the License, or (at your option) any later version.

   The GNU C 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
   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public
   License along with the GNU C Library; if not, see
   <http://www.gnu.org/licenses/>.

   As a special exception, if you link the code in this file with
   files compiled with a GNU compiler to produce an executable,
   that does not cause the resulting executable to be covered by
   the GNU Lesser General Public License.  This exception does not
   however invalidate any other reasons why the executable file
   might be covered by the GNU Lesser General Public License.
   This exception applies to code released by its copyright holders
   in files containing the exception.  */

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

void
_IO_str_init_static_internal (_IO_strfile *sf, char *ptr, _IO_size_t size,
			      char *pstart)
{
  _IO_FILE *fp = &sf->_sbf._f;
  char *end;

  if (size == 0)
    end = __rawmemchr (ptr, '\0');
  else if ((_IO_size_t) ptr + size > (_IO_size_t) ptr)
    end = ptr + size;
  else
    end = (char *) -1;
  _IO_setb (fp, ptr, end, 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 = end;
      fp->_IO_read_end = pstart;
    }
  else
    {
      fp->_IO_write_ptr = ptr;
      fp->_IO_write_end = ptr;
      fp->_IO_read_end = end;
    }
  /* A null _allocate_buffer function flags the strfile as being static. */
  sf->_s._allocate_buffer = (_IO_alloc_type) 0;
}

void
_IO_str_init_static (_IO_strfile *sf, char *ptr, int size, char *pstart)
{
  return _IO_str_init_static_internal (sf, ptr, size < 0 ? -1 : size, pstart);
}

void
_IO_str_init_readonly (_IO_strfile *sf, const char *ptr, int size)
{
  _IO_str_init_static_internal (sf, (char *) ptr, size < 0 ? -1 : size, NULL);
  sf->_sbf._f._IO_file_flags |= _IO_NO_WRITES;
}

int
_IO_str_overflow (_IO_FILE *fp, int c)
{
  int flush_only = c == EOF;
  _IO_size_t pos;
  if (fp->_flags & _IO_NO_WRITES)
      return flush_only ? 0 : EOF;
  if ((fp->_flags & _IO_TIED_PUT_GET) && !(fp->_flags & _IO_CURRENTLY_PUTTING))
    {
      fp->_flags |= _IO_CURRENTLY_PUTTING;
      fp->_IO_write_ptr = fp->_IO_read_ptr;
      fp->_IO_read_ptr = fp->_IO_read_end;
    }
  pos = fp->_IO_write_ptr - fp->_IO_write_base;
  if (pos >= (_IO_size_t) (_IO_blen (fp) + flush_only))
    {
      if (fp->_flags & _IO_USER_BUF) /* not allowed to enlarge */
	return EOF;
      else
	{
	  char *new_buf;
	  char *old_buf = fp->_IO_buf_base;
	  size_t old_blen = _IO_blen (fp);
	  _IO_size_t new_size = 2 * old_blen + 100;
	  if (new_size < old_blen)
	    return EOF;
	  new_buf
	    = (char *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (new_size);
	  if (new_buf == NULL)
	    {
	      /*	  __ferror(fp) = 1; */
	      return EOF;
	    }
	  if (old_buf)
	    {
	      memcpy (new_buf, old_buf, old_blen);
	      (*((_IO_strfile *) fp)->_s._free_buffer) (old_buf);
	      /* Make sure _IO_setb won't try to delete _IO_buf_base. */
	      fp->_IO_buf_base = NULL;
	    }
	  memset (new_buf + old_blen, '\0', new_size - old_blen);

	  _IO_setb (fp, new_buf, new_buf + new_size, 1);
	  fp->_IO_read_base = new_buf + (fp->_IO_read_base - old_buf);
	  fp->_IO_read_ptr = new_buf + (fp->_IO_read_ptr - old_buf);
	  fp->_IO_read_end = new_buf + (fp->_IO_read_end - old_buf);
	  fp->_IO_write_ptr = new_buf + (fp->_IO_write_ptr - old_buf);

	  fp->_IO_write_base = new_buf;
	  fp->_IO_write_end = fp->_IO_buf_end;
	}
    }

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

int
_IO_str_underflow (_IO_FILE *fp)
{
  if (fp->_IO_write_ptr > fp->_IO_read_end)
    fp->_IO_read_end = fp->_IO_write_ptr;
  if ((fp->_flags & _IO_TIED_PUT_GET) && (fp->_flags & _IO_CURRENTLY_PUTTING))
    {
      fp->_flags &= ~_IO_CURRENTLY_PUTTING;
      fp->_IO_read_ptr = fp->_IO_write_ptr;
      fp->_IO_write_ptr = fp->_IO_write_end;
    }
  if (fp->_IO_read_ptr < fp->_IO_read_end)
    return *((unsigned char *) fp->_IO_read_ptr);
  else
    return EOF;
}
libc_hidden_def (_IO_str_underflow)

/* The size of the valid part of the buffer.  */

_IO_ssize_t
_IO_str_count (_IO_FILE *fp)
{
  return ((fp->_IO_write_ptr > fp->_IO_read_end
	   ? fp->_IO_write_ptr : fp->_IO_read_end)
	  - fp->_IO_read_base);
}


static int
enlarge_userbuf (_IO_FILE *fp, _IO_off64_t offset, int reading)
{
  if ((_IO_ssize_t) offset <= _IO_blen (fp))
    return 0;

  _IO_ssize_t oldend = fp->_IO_write_end - fp->_IO_write_base;

  /* Try to enlarge the buffer.  */
  if (fp->_flags & _IO_USER_BUF)
    /* User-provided buffer.  */
    return 1;

  _IO_size_t newsize = offset + 100;
  char *oldbuf = fp->_IO_buf_base;
  char *newbuf
    = (char *) (*((_IO_strfile *) fp)->_s._allocate_buffer) (newsize);
  if (newbuf == NULL)
    return 1;

  if (oldbuf != NULL)
    {
      memcpy (newbuf, oldbuf, _IO_blen (fp));
      (*((_IO_strfile *) fp)->_s._free_buffer) (oldbuf);
      /* Make sure _IO_setb won't try to delete
	 _IO_buf_base. */
      fp->_IO_buf_base = NULL;
    }

  _IO_setb (fp, newbuf, newbuf + newsize, 1);

  if (reading)
    {
      fp->_IO_write_base = newbuf + (fp->_IO_write_base - oldbuf);
      fp->_IO_write_ptr = newbuf + (fp->_IO_write_ptr - oldbuf);
      fp->_IO_write_end = newbuf + (fp->_IO_write_end - oldbuf);
      fp->_IO_read_ptr = newbuf + (fp->_IO_read_ptr - oldbuf);

      fp->_IO_read_base = newbuf;
      fp->_IO_read_end = fp->_IO_buf_end;
    }
  else
    {
      fp->_IO_read_base = newbuf + (fp->_IO_read_base - oldbuf);
      fp->_IO_read_ptr = newbuf + (fp->_IO_read_ptr - oldbuf);
      fp->_IO_read_end = newbuf + (fp->_IO_read_end - oldbuf);
      fp->_IO_write_ptr = newbuf + (fp->_IO_write_ptr - oldbuf);

      fp->_IO_write_base = newbuf;
      fp->_IO_write_end = fp->_IO_buf_end;
    }

  /* Clear the area between the last write position and th
     new position.  */
  assert (offset >= oldend);
  if (reading)
    memset (fp->_IO_read_base + oldend, '\0', offset - oldend);
  else
    memset (fp->_IO_write_base + oldend, '\0', offset - oldend);

  return 0;
}


_IO_off64_t
_IO_str_seekoff (_IO_FILE *fp, _IO_off64_t offset, int dir, int mode)
{
  _IO_off64_t new_pos;

  if (mode == 0 && (fp->_flags & _IO_TIED_PUT_GET))
    mode = (fp->_flags & _IO_CURRENTLY_PUTTING ? _IOS_OUTPUT : _IOS_INPUT);

  if (mode == 0)
    {
      /* Don't move any pointers. But there is no clear indication what
	 mode FP is in. Let's guess. */
      if (fp->_IO_file_flags & _IO_NO_WRITES)
        new_pos = fp->_IO_read_ptr - fp->_IO_read_base;
      else
        new_pos = fp->_IO_write_ptr - fp->_IO_write_base;
    }
  else
    {
      _IO_ssize_t cur_size = _IO_str_count(fp);
      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)
	    return EOF;
	  if ((_IO_ssize_t) offset > cur_size
	      && enlarge_userbuf (fp, offset, 1) != 0)
	    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)
	    return EOF;
	  if ((_IO_ssize_t) offset > cur_size
	      && enlarge_userbuf (fp, offset, 0) != 0)
	    return EOF;
	  fp->_IO_write_ptr = fp->_IO_write_base + offset;
	  new_pos = offset;
	}
    }
  return new_pos;
}
libc_hidden_def (_IO_str_seekoff)

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

void
_IO_str_finish (_IO_FILE *fp, int dummy)
{
  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, 0);
}

const 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),
  JUMP_INIT(showmanyc, _IO_default_showmanyc),
  JUMP_INIT(imbue, _IO_default_imbue)
};