stdio-common/tst-memstream-string.c

   1 /* Test writing differently sized strings to a memstream.
   2    Copyright (C) 2022-2024 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <stdio.h>
  20 #include <stdlib.h>
  21 #include <string.h>
  22 #include <support/check.h>
  23 #include <support/support.h>
  24 #include <support/xmemstream.h>
  25
  26 /* Returns a printable ASCII character based on INDEX.   */
  27 static inline char
  28 char_from_index (unsigned int index)
  29 {
  30   return ' ' + (index % 95);
  31 }
  32
  33 enum { result_size = 25000 };
  34
  35 static void
  36 run_one_size (unsigned int chunk_size)
  37 {
  38   char *chunk = xmalloc (chunk_size + 1);
  39
  40   struct xmemstream mem;
  41   xopen_memstream (&mem);
  42   unsigned int written = 0;
  43   for (unsigned int i = 0; i < result_size; )
  44     {
  45       unsigned int to_print = result_size - i;
  46       if (to_print > chunk_size)
  47         to_print = chunk_size;
  48       for (unsigned int j = 0; j < to_print; ++j)
  49         chunk[j] = char_from_index(i + j);
  50       chunk[to_print] = '\0';
  51       fprintf (mem.out, "%s", chunk); /* Needs -fno-builtin-fprintf.  */
  52       i += to_print;
  53       written += strlen(chunk);
  54     }
  55   xfclose_memstream (&mem);
  56
  57   TEST_COMPARE (written, result_size);
  58   TEST_COMPARE (mem.length, result_size);
  59   TEST_COMPARE (strlen (mem.buffer), result_size);
  60
  61   for (unsigned int i = 0; i < result_size; ++i)
  62     TEST_COMPARE (mem.buffer[i], char_from_index (i));
  63
  64   free (mem.buffer);
  65   free (chunk);
  66 }
  67
  68 static int
  69 do_test (void)
  70 {
  71   for (unsigned int chunk_size = 1; chunk_size <= 30; ++ chunk_size)
  72     run_one_size (chunk_size);
  73
  74   return 0;
  75 }
  76
  77 #include <support/test-driver.c>