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73 lines
2.1 KiB
C
73 lines
2.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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#ifndef LABWC_ARRAY_H
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#define LABWC_ARRAY_H
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#include <wayland-server-core.h>
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#include "common/mem.h"
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/*
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* Wayland's wl_array API is a bit sparse consisting only of
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* - init
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* - release
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* - add
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* - copy
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* - for_each
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*
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* The purpose of this header is the gather any generic wl_array helpers we
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* create.
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*
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* We take the liberty of using the wl_ suffix here to make it look a bit
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* prettier. If Wayland extend the API in future, we will sort the clash then.
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*/
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/**
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* wl_array_len() - return length of wl_array
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* @array: wl_array for which to calculate length
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* Note: The pointer type might not be 'char' but this is the approach that
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* wl_array_for_each() takes, so we align with their style.
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*/
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static inline size_t
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wl_array_len(struct wl_array *array)
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{
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return array->size / sizeof(const char *);
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}
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/**
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* Iterates in reverse over an array.
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* @pos: pointer that each array element will be assigned to
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* @array: wl_array to iterate over
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*/
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#define wl_array_for_each_reverse(pos, array) \
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for (pos = !(array)->data ? NULL \
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: (void *)((const char *)(array)->data + (array)->size - sizeof(pos)); \
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pos && (const char *)pos >= (const char *)(array)->data; \
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(pos)--)
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/**
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* array_add() - add item to wl_array and exit on allocation error
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* @_arr: wl_array to add the item to
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* @_val: the item to add to the array
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*
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* Let us illustrate the function of this macro by an example:
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*
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* uint32_t value = 5;
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* array_add(array, value);
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*
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* ...is the equivalent of the code below which is how you would
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* otherwise use the wl_array API:
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*
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* uint32_t *elm = wl_array_add(array, sizeof(uint32_t));
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* if (!elm) {
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* perror("failed to allocate memory");
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* exit(EXIT_FAILURE);
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* }
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* *elm = value;
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*/
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#define array_add(_arr, _val) do { \
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__typeof__(_val) *_entry = wl_array_add( \
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(_arr), sizeof(__typeof__(_val))); \
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die_if_null(_entry); \
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*_entry = (_val); \
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} while (0)
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#endif /* LABWC_ARRAY_H */
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