sofia-sip/heap.h

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/*
 * This file is part of the Sofia-SIP package
 *
 * Copyright (C) 2007 Nokia Corporation.
 *
 * Contact: Pekka Pessi <pekka.pessi@nokia-email.address.hidden>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public License
 * as published by the Free Software Foundation; either version 2.1 of
 * the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
 * 02110-1301 USA
 *
 */

#ifndef SOFIA_SIP_HEAP_H

#define SOFIA_SIP_HEAP_H

#define HEAP_MIN_SIZE 31

#define HEAP_TYPE struct { void *private; }

#define HEAP_DECLARE(scope, heaptype, prefix, type) \
scope int prefix##resize(void *, heaptype *, size_t); \
scope int prefix##free(void *, heaptype *); \
scope int prefix##is_full(heaptype const); \
scope size_t prefix##size(heaptype const); \
scope size_t prefix##used(heaptype const); \
scope void prefix##sort(heaptype); \
scope int prefix##add(heaptype, type); \
scope type prefix##remove(heaptype, size_t); \
scope type prefix##get(heaptype, size_t)

#define HEAP_BODIES(scope, heaptype, prefix, type, less, set, alloc, null) \
scope int prefix##resize(void *realloc_arg, heaptype h[1], size_t new_size) \
{ \
  struct prefix##priv { size_t _size, _used; type _heap[2]; }; \
  struct prefix##priv *_priv; \
  size_t _offset = \
    (offsetof(struct prefix##priv, _heap[1]) - 1) / sizeof (type); \
  size_t _min_size = 32 - _offset; \
  size_t _bytes; \
  size_t _used = 0; \
 \
  _priv = *(void **)h; \
 \
  if (_priv) { \
    if (new_size == 0) \
      new_size = 2 * _priv->_size + _offset + 1; \
    _used = _priv->_used; \
    if (new_size < _used) \
      new_size = _used; \
  } \
 \
  if (new_size < _min_size) \
    new_size = _min_size; \
 \
  _bytes = (_offset + 1 + new_size) * sizeof (type); \
 \
  (void)realloc_arg; /* avoid warning */ \
  _priv = alloc(realloc_arg, *(struct prefix##priv **)h, _bytes); \
  if (!_priv) \
    return -1; \
 \
  *(struct prefix##priv **)h = _priv; \
  _priv->_size = new_size; \
  _priv->_used = _used; \
 \
  return 0; \
} \
 \
 \
scope int prefix##free(void *realloc_arg, heaptype h[1]) \
{ \
  (void)realloc_arg; \
  *(void **)h = alloc(realloc_arg, *(void **)h, 0); \
  return 0; \
} \
 \
 \
scope int prefix##is_full(heaptype h) \
{ \
  struct prefix##priv { size_t _size, _used; type _heap[1];}; \
  struct prefix##priv *_priv = *(void **)&h; \
 \
  return _priv == NULL || _priv->_used >= _priv->_size; \
} \
 \
 \
scope int prefix##add(heaptype h, type e) \
{ \
  struct prefix##priv { size_t _size, _used; type _heap[1];};   \
  struct prefix##priv *_priv = *(void **)&h; \
  type *heap = _priv->_heap - 1; \
  size_t i, parent; \
 \
  if (_priv == NULL || _priv->_used >= _priv->_size) \
    return -1; \
 \
  for (i = ++_priv->_used; i > 1; i = parent) { \
    parent = i / 2; \
    if (!less(e, heap[parent])) \
      break; \
    set(heap, i, heap[parent]); \
  } \
 \
  set(heap, i, e); \
 \
  return 0; \
} \
 \
 \
scope type prefix##remove(heaptype h, size_t index) \
{ \
  struct prefix##priv { size_t _size, _used; type _heap[1];}; \
  struct prefix##priv *_priv = *(void **)&h; \
  type *heap = _priv->_heap - 1; \
  type retval[1]; \
  type e; \
 \
  size_t top, left, right, move; \
 \
  if (index - 1 >= _priv->_used) \
    return (null); \
 \
  move = _priv->_used--; \
  set(retval, 0, heap[index]); \
 \
  for (top = index;;index = top) { \
    left = 2 * top; \
    right = 2 * top + 1; \
 \
    if (left >= move) \
      break; \
    if (right < move && less(heap[right], heap[left])) \
      top = right; \
    else \
      top = left; \
    set(heap, index, heap[top]); \
  } \
 \
  if (index == move) \
    return *retval; \
 \
  e = heap[move]; \
  for (; index > 1; index = top) { \
    top = index / 2; \
    if (!less(e, heap[top])) \
      break; \
    set(heap, index, heap[top]); \
  } \
 \
  set(heap, index, e); \
 \
  return *retval; \
} \
 \
scope \
type prefix##get(heaptype h, size_t index) \
{ \
  struct prefix##priv { size_t _size, _used; type _heap[1];}; \
  struct prefix##priv *_priv = *(void **)&h; \
 \
  if (--index >= _priv->_used) \
    return (null); \
 \
  return _priv->_heap[index]; \
} \
 \
scope \
size_t prefix##size(heaptype const h) \
{ \
  struct prefix##priv { size_t _size, _used; type _heap[1];}; \
  struct prefix##priv *_priv = *(void **)&h; \
  return _priv ? _priv->_size : 0; \
} \
 \
scope \
size_t prefix##used(heaptype const h) \
{ \
  struct prefix##priv { size_t _size, _used; type _heap[1];}; \
  struct prefix##priv *_priv = *(void **)&h; \
  return _priv ? _priv->_used : 0; \
} \
static int prefix##_less(void *h, size_t a, size_t b) \
{ \
  type *_heap = h; return less(_heap[a], _heap[b]);     \
} \
static void prefix##_swap(void *h, size_t a, size_t b) \
{ \
  type *_heap = h; type _swap = _heap[a]; \
  set(_heap, a, _heap[b]); set(_heap, b, _swap); \
} \
scope void prefix##sort(heaptype h) \
{ \
  struct prefix##priv { size_t _size, _used; type _heap[1];}; \
  struct prefix##priv *_priv = *(void **)&h; \
  if (_priv) \
    su_smoothsort(_priv->_heap - 1, 1, _priv->_used, prefix##_less, prefix##_swap); \
} \
extern int const prefix##dummy_heap

#include <sofia-sip/su_types.h>

SOFIA_BEGIN_DECLS

SOFIAPUBFUN void su_smoothsort(void *base, size_t r0, size_t N,
                               int (*less)(void *base, size_t a, size_t b),
                               void (*swap)(void *base, size_t a, size_t b));

SOFIA_END_DECLS

#endif