1 /* Test writing differently sized strings to a memstream.
2    Copyright (C) 2022 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
char_from_index(unsigned int index)28 char_from_index (unsigned int index)
29 {
30   return ' ' + (index % 95);
31 }
32 
33 enum { result_size = 25000 };
34 
35 static void
run_one_size(unsigned int chunk_size)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
do_test(void)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>
78