#include "stack.h"

#include "buffer.h"

#include <stdlib.h>

#include <string.h>

#include <assert.h>

void

hoedown_stack_init(hoedown_stack *st, size_t initial_size)

{

  assert(st);

  st->item = NULL;

  st->size = st->asize = 0;

  if (!initial_size)

    initial_size = 8;

  hoedown_stack_grow(st, initial_size);

}

void

hoedown_stack_uninit(hoedown_stack *st)

{

  assert(st);

  free(st->item);

}

void

hoedown_stack_grow(hoedown_stack *st, size_t neosz)

{

  assert(st);

  if (st->asize >= neosz)

    return;

  st->item = hoedown_realloc(st->item, neosz * sizeof(void *));

  memset(st->item + st->asize, 0x0, (neosz - st->asize) * sizeof(void *));

  st->asize = neosz;

  if (st->size > neosz)

    st->size = neosz;

}

void

hoedown_stack_push(hoedown_stack *st, void *item)

{

  assert(st);

  if (st->size >= st->asize)

    hoedown_stack_grow(st, st->size * 2);

  st->item[st->size++] = item;

}

void *

hoedown_stack_pop(hoedown_stack *st)

{

  assert(st);

  if (!st->size)

    return NULL;

  return st->item[--st->size];

}

void *

hoedown_stack_top(const hoedown_stack *st)

{

  assert(st);

  if (!st->size)

    return NULL;

  return st->item[st->size - 1];

}