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91b6eb11 | 1 | /* Increase the size of a dynamic array in preparation of an emplace operation. |
6d7e8eda | 2 | Copyright (C) 2017-2023 Free Software Foundation, Inc. |
91b6eb11 FW |
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 | |
5a82c748 | 17 | <https://www.gnu.org/licenses/>. */ |
91b6eb11 FW |
18 | |
19 | #include <dynarray.h> | |
5898f454 | 20 | #include <errno.h> |
de0e1b45 | 21 | #include <intprops.h> |
91b6eb11 FW |
22 | #include <stdlib.h> |
23 | #include <string.h> | |
24 | ||
25 | bool | |
26 | __libc_dynarray_emplace_enlarge (struct dynarray_header *list, | |
27 | void *scratch, size_t element_size) | |
28 | { | |
29 | size_t new_allocated; | |
30 | if (list->allocated == 0) | |
31 | { | |
32 | /* No scratch buffer provided. Choose a reasonable default | |
33 | size. */ | |
34 | if (element_size < 4) | |
35 | new_allocated = 16; | |
ab5ac271 | 36 | else if (element_size < 8) |
91b6eb11 FW |
37 | new_allocated = 8; |
38 | else | |
39 | new_allocated = 4; | |
40 | } | |
41 | else | |
42 | /* Increase the allocated size, using an exponential growth | |
43 | policy. */ | |
44 | { | |
45 | new_allocated = list->allocated + list->allocated / 2 + 1; | |
46 | if (new_allocated <= list->allocated) | |
5898f454 FW |
47 | { |
48 | /* Overflow. */ | |
49 | __set_errno (ENOMEM); | |
50 | return false; | |
51 | } | |
91b6eb11 FW |
52 | } |
53 | ||
54 | size_t new_size; | |
de0e1b45 | 55 | if (INT_MULTIPLY_WRAPV (new_allocated, element_size, &new_size)) |
91b6eb11 FW |
56 | return false; |
57 | void *new_array; | |
58 | if (list->array == scratch) | |
59 | { | |
60 | /* The previous array was not heap-allocated. */ | |
61 | new_array = malloc (new_size); | |
62 | if (new_array != NULL && list->array != NULL) | |
63 | memcpy (new_array, list->array, list->used * element_size); | |
64 | } | |
65 | else | |
66 | new_array = realloc (list->array, new_size); | |
67 | if (new_array == NULL) | |
68 | return false; | |
69 | list->array = new_array; | |
70 | list->allocated = new_allocated; | |
71 | return true; | |
72 | } | |
73 | libc_hidden_def (__libc_dynarray_emplace_enlarge) |