| 1 | /* Increase the size of a dynamic array in preparation of an emplace operation.
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| 2 | Copyright (C) 2017-2021 Free Software Foundation, Inc.
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| 3 | This file is part of the GNU C Library.
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| 4 |
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| 5 | The GNU C Library is free software; you can redistribute it and/or
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| 6 | modify it under the terms of the GNU Lesser General Public
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| 7 | License as published by the Free Software Foundation; either
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| 8 | version 2.1 of the License, or (at your option) any later version.
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| 9 |
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| 10 | The GNU C Library is distributed in the hope that it will be useful,
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| 11 | but WITHOUT ANY WARRANTY; without even the implied warranty of
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| 12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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| 13 | Lesser General Public License for more details.
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| 14 |
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| 15 | You should have received a copy of the GNU Lesser General Public
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| 16 | License along with the GNU C Library; if not, see
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| 17 | <https://www.gnu.org/licenses/>. */
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| 18 |
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| 19 | #ifndef _LIBC
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| 20 | # include <libc-config.h>
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| 21 | #endif
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| 22 |
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| 23 | #include <dynarray.h>
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| 24 | #include <errno.h>
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| 25 | #include <intprops.h>
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| 26 | #include <stdlib.h>
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| 27 | #include <string.h>
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| 28 |
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| 29 | bool
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| 30 | __libc_dynarray_emplace_enlarge (struct dynarray_header *list,
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| 31 | void *scratch, size_t element_size)
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| 32 | {
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| 33 | size_t new_allocated;
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| 34 | if (list->allocated == 0)
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| 35 | {
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| 36 | /* No scratch buffer provided. Choose a reasonable default
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| 37 | size. */
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| 38 | if (element_size < 4)
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| 39 | new_allocated = 16;
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| 40 | else if (element_size < 8)
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| 41 | new_allocated = 8;
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| 42 | else
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| 43 | new_allocated = 4;
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| 44 | }
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| 45 | else
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| 46 | /* Increase the allocated size, using an exponential growth
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| 47 | policy. */
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| 48 | {
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| 49 | new_allocated = list->allocated + list->allocated / 2 + 1;
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| 50 | if (new_allocated <= list->allocated)
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| 51 | {
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| 52 | /* Overflow. */
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| 53 | __set_errno (ENOMEM);
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| 54 | return false;
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| 55 | }
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| 56 | }
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| 57 |
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| 58 | size_t new_size;
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| 59 | if (INT_MULTIPLY_WRAPV (new_allocated, element_size, &new_size))
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| 60 | return false;
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| 61 | void *new_array;
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| 62 | if (list->array == scratch)
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| 63 | {
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| 64 | /* The previous array was not heap-allocated. */
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| 65 | new_array = malloc (new_size);
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| 66 | if (new_array != NULL && list->array != NULL)
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| 67 | memcpy (new_array, list->array, list->used * element_size);
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| 68 | }
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| 69 | else
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| 70 | new_array = realloc (list->array, new_size);
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| 71 | if (new_array == NULL)
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| 72 | return false;
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| 73 | list->array = new_array;
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| 74 | list->allocated = new_allocated;
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| 75 | return true;
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| 76 | }
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| 77 | libc_hidden_def (__libc_dynarray_emplace_enlarge)
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