container_multihashmap32.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2008 GNUnet e.V.
 
     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     or (at your option) any later version.
 
     GNUnet 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
     Affero General Public License for more details.
 
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
     SPDX-License-Identifier: AGPL3.0-or-later
 */
#include "platform.h"
#include "gnunet_util_lib.h"
 
#define LOG(kind, ...) \
  GNUNET_log_from (kind, "util-container-multihashmap32", __VA_ARGS__)
 
 
#define NEXT_CACHE_SIZE 16
 
struct MapEntry
{
  uint32_t key;
 
  void *value;
 
  struct MapEntry *next;
};
 
struct GNUNET_CONTAINER_MultiHashMap32
{
  struct MapEntry **map;
 
  unsigned int size;
 
  unsigned int map_length;
 
  unsigned int modification_counter;
 
  struct MapEntry *next_cache[NEXT_CACHE_SIZE];
 
  unsigned int next_cache_off;
};
 
 
struct GNUNET_CONTAINER_MultiHashMap32Iterator
{
  struct MapEntry *me;
 
  unsigned int idx;
 
  unsigned int modification_counter;
 
  const struct GNUNET_CONTAINER_MultiHashMap32 *map;
};
 
 
struct GNUNET_CONTAINER_MultiHashMap32 *
GNUNET_CONTAINER_multihashmap32_create (unsigned int len)
{
  struct GNUNET_CONTAINER_MultiHashMap32 *ret;
 
  GNUNET_assert (len > 0);
  ret = GNUNET_new (struct GNUNET_CONTAINER_MultiHashMap32);
  ret->map = GNUNET_malloc_large (len * sizeof(struct MapEntry *));
  if (NULL == ret->map)
  {
    GNUNET_free (ret);
    return NULL;
  }
  ret->map_length = len;
  return ret;
}
 
 
void
GNUNET_CONTAINER_multihashmap32_destroy (
  struct GNUNET_CONTAINER_MultiHashMap32 *map)
{
  struct MapEntry *e;
 
  for (unsigned int i = 0; i < map->map_length; i++)
  {
    while (NULL != (e = map->map[i]))
    {
      map->map[i] = e->next;
      GNUNET_free (e);
    }
  }
  GNUNET_free (map->map);
  GNUNET_free (map);
}
 
 
static unsigned int
idx_of (const struct GNUNET_CONTAINER_MultiHashMap32 *m, const uint32_t key)
{
  GNUNET_assert (NULL != m);
  return ((unsigned int) key) % m->map_length;
}
 
 
unsigned int
GNUNET_CONTAINER_multihashmap32_size (
  const struct GNUNET_CONTAINER_MultiHashMap32 *map)
{
  return map->size;
}
 
 
void *
GNUNET_CONTAINER_multihashmap32_get (
  const struct GNUNET_CONTAINER_MultiHashMap32 *map,
  uint32_t key)
{
  struct MapEntry *e;
 
  e = map->map[idx_of (map, key)];
  while (NULL != e)
  {
    if (key == e->key)
      return e->value;
    e = e->next;
  }
  return NULL;
}
 
 
int
GNUNET_CONTAINER_multihashmap32_iterate (
  struct GNUNET_CONTAINER_MultiHashMap32 *map,
  GNUNET_CONTAINER_MultiHashMapIterator32Callback it,
  void *it_cls)
{
  int count;
  struct MapEntry **ce;
 
  count = 0;
  GNUNET_assert (NULL != map);
  ce = &map->next_cache[map->next_cache_off];
  GNUNET_assert (++map->next_cache_off < NEXT_CACHE_SIZE);
  for (unsigned int i = 0; i < map->map_length; i++)
  {
    struct MapEntry *e;
 
    *ce = map->map[i];
    while (NULL != (e = *ce))
    {
      *ce = e->next;
      if (NULL != it)
      {
        if (GNUNET_OK != it (it_cls, e->key, e->value))
        {
          GNUNET_assert (--map->next_cache_off < NEXT_CACHE_SIZE);
          return GNUNET_SYSERR;
        }
      }
      count++;
    }
  }
  GNUNET_assert (--map->next_cache_off < NEXT_CACHE_SIZE);
  return count;
}
 
 
static void
update_next_cache (struct GNUNET_CONTAINER_MultiHashMap32 *map,
                   const struct MapEntry *me)
{
  for (unsigned int i = 0; i < map->next_cache_off; i++)
    if (map->next_cache[i] == me)
      map->next_cache[i] = me->next;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_CONTAINER_multihashmap32_remove (
  struct GNUNET_CONTAINER_MultiHashMap32 *map,
  uint32_t key,
  const void *value)
{
  struct MapEntry *e;
  struct MapEntry *p;
  unsigned int i;
 
  map->modification_counter++;
 
  i = idx_of (map, key);
  p = NULL;
  e = map->map[i];
  while (e != NULL)
  {
    if ((key == e->key) && (value == e->value))
    {
      if (p == NULL)
        map->map[i] = e->next;
      else
        p->next = e->next;
      update_next_cache (map, e);
      GNUNET_free (e);
      map->size--;
      return GNUNET_YES;
    }
    p = e;
    e = e->next;
  }
  return GNUNET_NO;
}
 
 
int
GNUNET_CONTAINER_multihashmap32_remove_all (
  struct GNUNET_CONTAINER_MultiHashMap32 *map,
  uint32_t key)
{
  struct MapEntry *e;
  struct MapEntry *p;
  unsigned int i;
  int ret;
 
  map->modification_counter++;
 
  ret = 0;
  i = idx_of (map, key);
  p = NULL;
  e = map->map[i];
  while (e != NULL)
  {
    if (key == e->key)
    {
      if (p == NULL)
        map->map[i] = e->next;
      else
        p->next = e->next;
      update_next_cache (map, e);
      GNUNET_free (e);
      map->size--;
      if (p == NULL)
        e = map->map[i];
      else
        e = p->next;
      ret++;
    }
    else
    {
      p = e;
      e = e->next;
    }
  }
  return ret;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_CONTAINER_multihashmap32_contains (
  const struct GNUNET_CONTAINER_MultiHashMap32 *map,
  uint32_t key)
{
  struct MapEntry *e;
 
  e = map->map[idx_of (map, key)];
  while (e != NULL)
  {
    if (key == e->key)
      return GNUNET_YES;
    e = e->next;
  }
  return GNUNET_NO;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_CONTAINER_multihashmap32_contains_value (
  const struct GNUNET_CONTAINER_MultiHashMap32 *map,
  uint32_t key,
  const void *value)
{
  struct MapEntry *e;
 
  e = map->map[idx_of (map, key)];
  while (e != NULL)
  {
    if ((key == e->key) && (e->value == value))
      return GNUNET_YES;
    e = e->next;
  }
  return GNUNET_NO;
}
 
 
static void
grow (struct GNUNET_CONTAINER_MultiHashMap32 *map)
{
  struct MapEntry **old_map;
  struct MapEntry **new_map;
  struct MapEntry *e;
  unsigned int old_len;
  unsigned int new_len;
  unsigned int idx;
 
  old_map = map->map;
  old_len = map->map_length;
  new_len = old_len * 2;
  if (0 == new_len) /* 2^31 * 2 == 0 */
    new_len = old_len; /* never use 0 */
  if (new_len == old_len)
    return; /* nothing changed */
  new_map = GNUNET_malloc_large (new_len * sizeof(struct MapEntry *));
  if (NULL == new_map)
    return; /* grow not possible */
  map->modification_counter++;
  map->map_length = new_len;
  map->map = new_map;
  for (unsigned int i = 0; i < old_len; i++)
  {
    while (NULL != (e = old_map[i]))
    {
      old_map[i] = e->next;
      idx = idx_of (map, e->key);
      e->next = new_map[idx];
      new_map[idx] = e;
    }
  }
  GNUNET_free (old_map);
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_CONTAINER_multihashmap32_put (
  struct GNUNET_CONTAINER_MultiHashMap32 *map,
  uint32_t key,
  void *value,
  enum GNUNET_CONTAINER_MultiHashMapOption opt)
{
  struct MapEntry *e;
  unsigned int i;
 
  i = idx_of (map, key);
  if ((opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE) &&
      (opt != GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_FAST))
  {
    e = map->map[i];
    while (e != NULL)
    {
      if (key == e->key)
      {
        if (opt == GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY)
          return GNUNET_SYSERR;
        e->value = value;
        return GNUNET_NO;
      }
      e = e->next;
    }
  }
  if (map->size / 3 >= map->map_length / 4)
  {
    grow (map);
    i = idx_of (map, key);
  }
  e = GNUNET_new (struct MapEntry);
  e->key = key;
  e->value = value;
  e->next = map->map[i];
  map->map[i] = e;
  map->size++;
  return GNUNET_OK;
}
 
 
int
GNUNET_CONTAINER_multihashmap32_get_multiple (
  struct GNUNET_CONTAINER_MultiHashMap32 *map,
  uint32_t key,
  GNUNET_CONTAINER_MultiHashMapIterator32Callback it,
  void *it_cls)
{
  int count;
  struct MapEntry *e;
  struct MapEntry **ce;
 
  count = 0;
  ce = &map->next_cache[map->next_cache_off];
  GNUNET_assert (++map->next_cache_off < NEXT_CACHE_SIZE);
 
  *ce = map->map[idx_of (map, key)];
  while (NULL != (e = *ce))
  {
    *ce = e->next;
    if (key != e->key)
      continue;
    if ((NULL != it) && (GNUNET_OK != it (it_cls, key, e->value)))
    {
      GNUNET_assert (--map->next_cache_off < NEXT_CACHE_SIZE);
      return GNUNET_SYSERR;
    }
    count++;
  }
  GNUNET_assert (--map->next_cache_off < NEXT_CACHE_SIZE);
  return count;
}
 
 
struct GNUNET_CONTAINER_MultiHashMap32Iterator *
GNUNET_CONTAINER_multihashmap32_iterator_create (
  const struct GNUNET_CONTAINER_MultiHashMap32 *map)
{
  struct GNUNET_CONTAINER_MultiHashMap32Iterator *iter;
 
  iter = GNUNET_new (struct GNUNET_CONTAINER_MultiHashMap32Iterator);
  iter->map = map;
  iter->modification_counter = map->modification_counter;
  iter->me = map->map[0];
  return iter;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_CONTAINER_multihashmap32_iterator_next (
  struct GNUNET_CONTAINER_MultiHashMap32Iterator *iter,
  uint32_t *key,
  const void **value)
{
  /* make sure the map has not been modified */
  GNUNET_assert (iter->modification_counter == iter->map->modification_counter);
 
  /* look for the next entry, skipping empty buckets */
  while (1)
  {
    if (iter->idx >= iter->map->map_length)
      return GNUNET_NO;
    if (NULL != iter->me)
    {
      if (NULL != key)
        *key = iter->me->key;
      if (NULL != value)
        *value = iter->me->value;
      iter->me = iter->me->next;
      return GNUNET_YES;
    }
    iter->idx += 1;
    if (iter->idx < iter->map->map_length)
      iter->me = iter->map->map[iter->idx];
  }
}
 
 
void
GNUNET_CONTAINER_multihashmap32_iterator_destroy (
  struct GNUNET_CONTAINER_MultiHashMapIterator *iter)
{
  GNUNET_free (iter);
}
 
 
/* end of container_multihashmap.c */