1/* Variable-sized buffer with on-stack default allocation.
2 Copyright (C) 2015-2017 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 <http://www.gnu.org/licenses/>. */
18
19#include <scratch_buffer.h>
20#include <errno.h>
21
22bool
23__libc_scratch_buffer_grow (struct scratch_buffer *buffer)
24{
25 void *new_ptr;
26 size_t new_length = buffer->length * 2;
27
28 /* Discard old buffer. */
29 scratch_buffer_free (buffer);
30
31 /* Check for overflow. */
32 if (__glibc_likely (new_length >= buffer->length))
33 new_ptr = malloc (new_length);
34 else
35 {
36 __set_errno (ENOMEM);
37 new_ptr = NULL;
38 }
39
40 if (__glibc_unlikely (new_ptr == NULL))
41 {
42 /* Buffer must remain valid to free. */
43 scratch_buffer_init (buffer);
44 return false;
45 }
46
47 /* Install new heap-based buffer. */
48 buffer->data = new_ptr;
49 buffer->length = new_length;
50 return true;
51}
52libc_hidden_def (__libc_scratch_buffer_grow);
53