htable2.h

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/*
 * This file is part of the Sofia-SIP package
 *
 * Copyright (C) 2005 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 HTABLE2_H
#define HTABLE2_H

 
typedef unsigned long hash_value_t;

#define HTABLE2_MIN_SIZE 31

#define HTABLE2_DECLARE2(type, sname, pr, entrytype, sizetype)  \
typedef struct sname { \
  sizetype pr##size; \
  sizetype pr##used; \
  entrytype *pr##table; \
} type
 
#define HTABLE2_DECLARE(sname, prefix, pr, entrytype)   \
  HTABLE2_DECLARE2(prefix##t, sname, pr, entrytype, unsigned)
 
#ifndef HTABLE2_SCOPE
#define HTABLE2_SCOPE su_inline
#endif

#define HTABLE2_PROTOS2(type, prefix, pr, entrytype, sizetype)      \
HTABLE2_SCOPE int prefix##_resize(void *a, type *, sizetype); \
HTABLE2_SCOPE int prefix##_is_full(type const *); \
HTABLE2_SCOPE entrytype *prefix##_hash(type const *, hash_value_t); \
HTABLE2_SCOPE entrytype *prefix##_next(type const *, entrytype *); \
HTABLE2_SCOPE entrytype *prefix##_append(type *, entrytype); \
HTABLE2_SCOPE entrytype *prefix##_insert(type *, entrytype); \
HTABLE2_SCOPE int prefix##_remove(type *, entrytype const)
 
#define HTABLE2_PROTOS(type, prefix, pr, entrytype) \
  HTABLE2_PROTOS2(type, prefix, pr, entrytype, unsigned)

#define HTABLE2_BODIES2(type, prefix, pr, entrytype, sizetype,      \
                hfun, is_used, reclaim, is_equal, halloc)   \
 \
HTABLE2_SCOPE \
int prefix##_resize(void *realloc_arg, \
                    type pr[1], \
            sizetype new_size) \
{ \
  entrytype *new_hash; \
  entrytype *old_hash = pr->pr##table; \
  sizetype old_size; \
  sizetype i, j, i0; \
  sizetype again = 0, used = 0, collisions = 0; \
\
  (void)realloc_arg; \
\
  if (new_size == 0) \
    new_size = 2 * pr->pr##size + 1; \
  if (new_size < HTABLE2_MIN_SIZE) \
    new_size = HTABLE2_MIN_SIZE; \
  if (new_size < 5 * pr->pr##used / 4) \
    new_size = 5 * pr->pr##used / 4; \
\
  if (!(new_hash = halloc(realloc_arg, NULL, sizeof(*new_hash) * new_size))) \
    return -1; \
\
  for (i = 0; i < new_size; i++) { \
    (reclaim(&new_hash[i])); \
  } \
  old_size = pr->pr##size; \
\
  do for (j = 0; j < old_size; j++) { \
    if (!is_used(old_hash[j])) \
      continue; \
\
    if (again < 2 && hfun(old_hash[j]) % old_size > j) { \
      /* Wrapped, leave entry for second pass */ \
      again = 1; continue; \
    } \
\
    i0 = hfun(old_hash[j]) % new_size; \
\
    for (i = i0; is_used(new_hash[i]); \
         i = (i + 1) % new_size, assert(i != i0)) \
      collisions++; \
\
    new_hash[i] = old_hash[j]; reclaim(&old_hash[j]); \
    used++; \
  } \
  while (again++ == 1); \
\
  pr->pr##table = new_hash, pr->pr##size = new_size; \
\
  if (old_hash) old_hash = halloc(realloc_arg, old_hash, 0);    \
\
  assert(pr->pr##used == used);\
\
  return 0; \
} \
\
HTABLE2_SCOPE \
int prefix##_is_full(type const *pr) \
{ \
  return pr->pr##table == NULL || 3 * pr->pr##used > 2 * pr->pr##size; \
} \
\
HTABLE2_SCOPE \
entrytype *prefix##_hash(type const *pr, hash_value_t hv) \
{ \
  return pr->pr##table + hv % pr->pr##size; \
} \
\
HTABLE2_SCOPE \
entrytype *prefix##_next(type const *pr, entrytype *ee) \
{ \
  if (++ee < pr->pr##table + pr->pr##size && ee >= pr->pr##table) \
    return ee; \
  else \
    return pr->pr##table; \
}  \
\
HTABLE2_SCOPE \
entrytype *prefix##_append(type *pr, entrytype e) \
{ \
  entrytype *ee; \
\
  assert(pr->pr##used < pr->pr##size); \
  if (pr->pr##used == pr->pr##size) \
    return (entrytype *)0; \
\
  pr->pr##used++; \
  for (ee = prefix##_hash(pr, hfun(e)); \
       is_used(*ee); \
       ee = prefix##_next(pr, ee)) \
   ; \
  *ee = e; \
\
  return ee; \
} \
\
HTABLE2_SCOPE \
entrytype *prefix##_insert(type *pr, entrytype e) \
{ \
  entrytype e0; \
  entrytype *ee; \
\
  assert(pr->pr##used < pr->pr##size); \
  if (pr->pr##used == pr->pr##size) \
    return (entrytype *)0; \
\
  pr->pr##used++; \
  /* Insert entry into hash table (before other entries with same hash) */ \
  for (ee = prefix##_hash(pr, hfun(e));  \
       is_used((*ee)); \
       ee = prefix##_next(pr, ee)) \
    *ee = e, e = e0; \
  *ee = e; \
\
  return ee; \
} \
\
HTABLE2_SCOPE \
int prefix##_remove(type *pr, entrytype const e) \
{ \
  sizetype i, j, k, size = pr->pr##size; \
  entrytype *htable = pr->pr##table; \
\
  /* Search for entry */ \
  for (i = hfun(e) % size; is_used(htable[i]); i = (i + 1) % size) \
    if (is_equal(e, htable[i])) \
      break; \
\
  if (!is_used(htable[i])) return -1; \
\
  /* Move table entries towards their primary place  */ \
  for (j = (i + 1) % size; is_used(htable[j]); j = (j + 1) % size) { \
    /* k is primary place for entry */ \
    k = hfun(htable[j]) % size; \
    if (k == j)         /* entry is in its primary place? */ \
      continue; \
    /* primary place is between i and j - do not move this to i */ \
    if (j > i ? (i < k && k < j) : (i < k || k < j)) \
      continue; \
\
    htable[i] = htable[j], i = j; \
  } \
\
  pr->pr##used--; \
\
  reclaim(&htable[i]); \
\
  return 0; \
} \
extern int const prefix##_dummy
 
#define HTABLE2_BODIES(type, prefix, pr, entrytype, \
                hfun, is_used, reclaim, is_equal, halloc) \
  HTABLE2_BODIES2(type, prefix, pr, entrytype, unsigned, \
                hfun, is_used, reclaim, is_equal, halloc)
 
 
#endif