topaz/core/vector.h

55 lines
1.5 KiB
C

// SPDX-License-Identifier: BSD-3-Clause
#ifndef VECTOR_H
#define VECTOR_H
#include <stdlib.h>
#include "../types.h"
/* The vector is a dynamically growing array
* that can be operated as a regular array
* by accessing its `data` member and as a
* stack using `vector_push()` and `vector_pop()`.
*/
struct vector {
usize length, size;
void *data;
};
/*
* Create a new vector with starting capacity of `size`
* where each element has size `element_size`.
*/
struct vector *vector_init(usize size, usize element_size);
void vector_deinit(struct vector *vector);
/*
* This function reduces the lenth of the vector thus
* removing the last element. If the used memory (length)
* is less than 1/3 of the allocated memory (size) the
* memory is reallocated to fit 1.5x the new length.
* Consider using the `vector_pop()` macro instead.
*/
void *vector_shrink(struct vector *vector, usize element_size);
/*
* Push `value` on the vector. If there isn't enough
* allocated memory, reallocate the internal array
* to be 1.5x the current size and copy all the elements
* to the new allocated memory.
*/
#define vector_push(vec, T, value) do {\
if (vec->length + 1 >= vec->size) {\
vec->size += vec->size/2;\
vec->data = realloc(vec->data, vec->size * sizeof(T));\
}\
((T *)vec->data)[vec->length] = value;\
vec->length += 1;\
} while (0)
/*
* Return the last element of the vector and calls
* `vector_shrink()`. Check out that function description.
*/
#define vector_pop(vector, T) (((T*)vector_shrink((vector), sizeof(T)))[vector->length])
#endif