Permalink
Cannot retrieve contributors at this time
198 lines (168 sloc)
6.16 KB
#ifndef RUBY_DARRAY_H | |
#define RUBY_DARRAY_H | |
#include <stdint.h> | |
#include <stddef.h> | |
#include <stdlib.h> | |
// Type for a dynamic array. Use to declare a dynamic array. | |
// It is a pointer so it fits in st_table nicely. Designed | |
// to be fairly type-safe. | |
// | |
// NULL is a valid empty dynamic array. | |
// | |
// Example: | |
// rb_darray(char) char_array = NULL; | |
// if (!rb_darray_append(&char_array, 'e')) abort(); | |
// printf("pushed %c\n", *rb_darray_ref(char_array, 0)); | |
// rb_darray_free(char_array); | |
// | |
#define rb_darray(T) struct { rb_darray_meta_t meta; T data[]; } * | |
// Copy an element out of the array. Warning: not bounds checked. | |
// | |
// T rb_darray_get(rb_darray(T) ary, int32_t idx); | |
// | |
#define rb_darray_get(ary, idx) ((ary)->data[(idx)]) | |
// Assign to an element. Warning: not bounds checked. | |
// | |
// void rb_darray_set(rb_darray(T) ary, int32_t idx, T element); | |
// | |
#define rb_darray_set(ary, idx, element) ((ary)->data[(idx)] = (element)) | |
// Get a pointer to an element. Warning: not bounds checked. | |
// | |
// T *rb_darray_ref(rb_darray(T) ary, int32_t idx); | |
// | |
#define rb_darray_ref(ary, idx) (&((ary)->data[(idx)])) | |
// Copy a new element into the array. Return 1 on success and 0 on failure. | |
// ptr_to_ary is evaluated multiple times. | |
// | |
// bool rb_darray_append(rb_darray(T) *ptr_to_ary, T element); | |
// | |
#define rb_darray_append(ptr_to_ary, element) ( \ | |
rb_darray_ensure_space((ptr_to_ary), sizeof(**(ptr_to_ary)), sizeof((*(ptr_to_ary))->data[0])) ? ( \ | |
rb_darray_set(*(ptr_to_ary), \ | |
(*(ptr_to_ary))->meta.size, \ | |
(element)), \ | |
++((*(ptr_to_ary))->meta.size), \ | |
1 \ | |
) : 0) | |
// Last element of the array | |
// | |
#define rb_darray_back(ary) ((ary)->data[(ary)->meta.size - 1]) | |
// Remove the last element of the array. | |
// | |
#define rb_darray_pop_back(ary) ((ary)->meta.size--) | |
// Remove element at idx and replace it by the last element | |
#define rb_darray_remove_unordered(ary, idx) do { \ | |
rb_darray_set(ary, idx, rb_darray_back(ary)); \ | |
rb_darray_pop_back(ary); \ | |
} while (0); | |
// Iterate over items of the array in a for loop | |
// | |
#define rb_darray_foreach(ary, idx_name, elem_ptr_var) \ | |
for (int idx_name = 0; idx_name < rb_darray_size(ary) && ((elem_ptr_var) = rb_darray_ref(ary, idx_name)); ++idx_name) | |
// Iterate over valid indicies in the array in a for loop | |
// | |
#define rb_darray_for(ary, idx_name) \ | |
for (int idx_name = 0; idx_name < rb_darray_size(ary); ++idx_name) | |
// Make a dynamic array of a certain size. All bytes backing the elements are set to zero. | |
// Return 1 on success and 0 on failure. | |
// | |
// Note that NULL is a valid empty dynamic array. | |
// | |
// bool rb_darray_make(rb_darray(T) *ptr_to_ary, int32_t size); | |
// | |
#define rb_darray_make(ptr_to_ary, size) rb_darray_make_impl((ptr_to_ary), size, sizeof(**(ptr_to_ary)), sizeof((*(ptr_to_ary))->data[0])) | |
// Set the size of the array to zero without freeing the backing memory. | |
// Allows reusing the same array. | |
// | |
#define rb_darray_clear(ary) (ary->meta.size = 0) | |
typedef struct rb_darray_meta { | |
int32_t size; | |
int32_t capa; | |
} rb_darray_meta_t; | |
// Get the size of the dynamic array. | |
// | |
static inline int32_t | |
rb_darray_size(const void *ary) | |
{ | |
const rb_darray_meta_t *meta = ary; | |
return meta ? meta->size : 0; | |
} | |
// Get the capacity of the dynamic array. | |
// | |
static inline int32_t | |
rb_darray_capa(const void *ary) | |
{ | |
const rb_darray_meta_t *meta = ary; | |
return meta ? meta->capa : 0; | |
} | |
// Free the dynamic array. | |
// | |
static inline void | |
rb_darray_free(void *ary) | |
{ | |
free(ary); | |
} | |
// Internal function. Calculate buffer size on malloc heap. | |
static inline size_t | |
rb_darray_buffer_size(int32_t capacity, size_t header_size, size_t element_size) | |
{ | |
if (capacity == 0) return 0; | |
return header_size + (size_t)capacity * element_size; | |
} | |
// Internal function | |
// Ensure there is space for one more element. Return 1 on success and 0 on failure. | |
// Note: header_size can be bigger than sizeof(rb_darray_meta_t) when T is __int128_t, for example. | |
static inline int | |
rb_darray_ensure_space(void *ptr_to_ary, size_t header_size, size_t element_size) | |
{ | |
rb_darray_meta_t **ptr_to_ptr_to_meta = ptr_to_ary; | |
rb_darray_meta_t *meta = *ptr_to_ptr_to_meta; | |
int32_t current_capa = rb_darray_capa(meta); | |
if (rb_darray_size(meta) < current_capa) return 1; | |
int32_t new_capa; | |
// Calculate new capacity | |
if (current_capa == 0) { | |
new_capa = 1; | |
} | |
else { | |
int64_t doubled = 2 * (int64_t)current_capa; | |
new_capa = (int32_t)doubled; | |
if (new_capa != doubled) return 0; | |
} | |
// Calculate new buffer size | |
size_t current_buffer_size = rb_darray_buffer_size(current_capa, header_size, element_size); | |
size_t new_buffer_size = rb_darray_buffer_size(new_capa, header_size, element_size); | |
if (new_buffer_size <= current_buffer_size) return 0; | |
rb_darray_meta_t *doubled_ary = realloc(meta, new_buffer_size); | |
if (!doubled_ary) return 0; | |
if (meta == NULL) { | |
// First allocation. Initialize size. On subsequence allocations | |
// realloc takes care of carrying over the size. | |
doubled_ary->size = 0; | |
} | |
doubled_ary->capa = new_capa; | |
// We don't have access to the type of the dynamic array in function context. | |
// Write out result with memcpy to avoid strict aliasing issue. | |
memcpy(ptr_to_ary, &doubled_ary, sizeof(doubled_ary)); | |
return 1; | |
} | |
static inline int | |
rb_darray_make_impl(void *ptr_to_ary, int32_t array_size, size_t header_size, size_t element_size) | |
{ | |
rb_darray_meta_t **ptr_to_ptr_to_meta = ptr_to_ary; | |
if (array_size < 0) return 0; | |
if (array_size == 0) { | |
*ptr_to_ptr_to_meta = NULL; | |
return 1; | |
} | |
size_t buffer_size = rb_darray_buffer_size(array_size, header_size, element_size); | |
rb_darray_meta_t *meta = calloc(buffer_size, 1); | |
if (!meta) return 0; | |
meta->size = array_size; | |
meta->capa = array_size; | |
// We don't have access to the type of the dynamic array in function context. | |
// Write out result with memcpy to avoid strict aliasing issue. | |
memcpy(ptr_to_ary, &meta, sizeof(meta)); | |
return 1; | |
} | |
#endif /* RUBY_DARRAY_H */ |