1 /* Stack implementation using a vector to store the elements */ 2 3 #include "stack.h" 4 5 #include <stdio.h> 6 #include <string.h> 7 8 void stack_new(Stack **S, size_t mem_width) { 9 (*S) = malloc(sizeof(Stack)); 10 (*S)->vector = malloc(sizeof(Stack *) * STACK_INITIAL_ALLOC); 11 (*S)->mem_width = mem_width; 12 (*S)->mem_alloc = STACK_INITIAL_ALLOC; 13 (*S)->len = 0; 14 } 15 16 /* generates a copy of the element an push it into stack 17 * does not check if elem is valid type */ 18 void stack_push(Stack *S, const void *elem) { 19 if(S->mem_alloc == S->len) 20 S->vector = realloc(S->vector, 21 (S->mem_alloc *= STACK_GROWTH_FACTOR) * sizeof(Stack *)); 22 23 S->vector[S->len] = malloc(S->mem_width); 24 memcpy(S->vector[S->len++], elem, S->mem_width); 25 } 26 27 void stack_peek(const Stack *S, void *data) { 28 data = S->len ? S->vector[S->len - 1] : NULL; 29 } 30 31 void stack_pop(Stack *S, void *data) { 32 if(S->len) { 33 memcpy(data, S->vector[--S->len], S->mem_width); 34 free(S->vector[S->len]); 35 } 36 } 37 38 void stack_destroy(Stack *S) { 39 free(S->vector); 40 free(S); 41 } 42
