Callbacks

Every collection can have an optional callback node. In this node there are five functions:

Callback	Description
`create`	Is called when an element was successfully added to the collection
`read`	Is called when the collection was successfully queried about an element
`update`	Is called when an element in the collection was successfully updated
`delete`	Is called when an element was successfully removed from the collection
`resize`	Is called when the collection was full and successfully resized

Check the documentation for each collection to see which functions call which callbacks.

cmc_callbacks

Every collection has a pointer to this struct. If it is NULL then the collection has no callbacks. Also, individual callbacks can be optional if set to NULL.

struct cmc_callbacks
{
    void (*create)(void);
    void (*read)(void);
    void (*update)(void);
    void (*delete)(void);
    void (*resize)(void);
};

Example

#include "cmc/heap.h"
#include "utl/futils.h" // cmc_i32_cmp

// Generate a heap of integers
CMC_GENERATE_HEAP(i32h, i32heap, int)

void heap_on_create(void)
{
    printf("An element was added to the heap\n");
}

int main(void)
{
    // create() is set but the other callbacks are not
    struct cmc_callbacks my_callbacks = { .create = heap_on_create, NULL };

    // Create a max heap with the callbacks
    struct i32heap *heap = i32h_new_custom(
        100, cmc_max_heap, &(struct i32heap_fval){ .cmp = cmc_i32_cmp }, NULL,
        &my_callbacks);

    i32h_insert(heap, 10);
    i32h_insert(heap, 11);
    i32h_insert(heap, 12);

    i32h_free(heap);
}