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https://github.com/kdave/btrfs-progs
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a5d95a73f9
API for extensible array of pointers for covenience. A simple wrapper around a (void *) array with length. Signed-off-by: David Sterba <dsterba@suse.com>
100 lines
2.5 KiB
C
100 lines
2.5 KiB
C
/*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License v2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#define _GNU_SOURCE 1
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include "common/array.h"
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/*
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* Extensible array of pointers. Length is the number of user defined pointers,
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* capacity is the whole allocated size. Pointers are potentially unstable after
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* an append operation. Array initialized to all zeros is valid and can be extended.
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*/
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static const int alloc_increment = 32;
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/* Initialize new array, preallocate @capacity elemennts. */
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int array_init(struct array *arr, unsigned int capacity)
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{
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void *tmp;
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arr->data = NULL;
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arr->length = 0;
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arr->capacity = capacity;
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if (arr->capacity == 0)
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arr->capacity = alloc_increment;
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tmp = calloc(arr->capacity, sizeof(void *));
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if (!tmp)
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return -1;
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arr->data = tmp;
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return 0;
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}
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/* Free internal data array. */
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void array_free(struct array *arr)
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{
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free(arr->data);
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arr->length = 0;
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arr->capacity = 0;
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arr->data = NULL;
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}
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/* Free all elements up to length. */
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void array_free_elements(struct array *arr)
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{
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unsigned int i;
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for (i = 0; i < arr->length; i++) {
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free(arr->data[i]);
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arr->data[i] = NULL;
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}
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arr->length = 0;
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}
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/* Reset all elements to NULL up to capacity. */
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void array_clear(struct array *arr)
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{
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for (unsigned int i = 0; i < arr->capacity; i++)
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arr->data[i] = NULL;
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}
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/* Use the whole capacity for elements. */
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void array_use_capacity(struct array *arr)
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{
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arr->length = arr->capacity;
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}
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/* Append a new element (increas length), extend the array if needed. */
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int array_append(struct array *arr, void *element)
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{
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if (arr->length == arr->capacity) {
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void **tmp;
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tmp = realloc(arr->data, (arr->capacity + alloc_increment) * sizeof(void *));
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if (!tmp)
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return -1;
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arr->data = tmp;
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memset(&arr->data[arr->capacity], 0, alloc_increment * sizeof(void *));
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arr->capacity += alloc_increment;
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}
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arr->data[arr->length] = element;
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arr->length++;
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return 0;
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}
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