snapraid/tommyds/tommyhashdyn.c

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/*
* Copyright (c) 2010, Andrea Mazzoleni. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
#include "tommyhashdyn.h"
#include "tommylist.h"
/******************************************************************************/
/* hashdyn */
void tommy_hashdyn_init(tommy_hashdyn* hashdyn)
{
/* fixed initial size */
hashdyn->bucket_bit = TOMMY_HASHDYN_BIT;
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hashdyn->bucket_max = (tommy_size_t)1 << hashdyn->bucket_bit;
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hashdyn->bucket_mask = hashdyn->bucket_max - 1;
hashdyn->bucket = tommy_cast(tommy_hashdyn_node**, tommy_calloc(hashdyn->bucket_max, sizeof(tommy_hashdyn_node*)));
hashdyn->count = 0;
}
void tommy_hashdyn_done(tommy_hashdyn* hashdyn)
{
tommy_free(hashdyn->bucket);
}
/**
* Resize the bucket vector.
*/
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static void tommy_hashdyn_resize(tommy_hashdyn* hashdyn, tommy_size_t new_bucket_bit)
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{
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tommy_size_t bucket_bit;
tommy_size_t bucket_max;
tommy_size_t new_bucket_max;
tommy_size_t new_bucket_mask;
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tommy_hashdyn_node** new_bucket;
bucket_bit = hashdyn->bucket_bit;
bucket_max = hashdyn->bucket_max;
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new_bucket_max = (tommy_size_t)1 << new_bucket_bit;
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new_bucket_mask = new_bucket_max - 1;
/* allocate the new vector using malloc() and not calloc() */
/* because data is fully initialized in the update process */
new_bucket = tommy_cast(tommy_hashdyn_node**, tommy_malloc(new_bucket_max * sizeof(tommy_hashdyn_node*)));
/* reinsert all the elements */
if (new_bucket_bit > bucket_bit) {
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tommy_size_t i;
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/* grow */
for (i = 0; i < bucket_max; ++i) {
tommy_hashdyn_node* j;
/* setup the new two buckets */
new_bucket[i] = 0;
new_bucket[i + bucket_max] = 0;
/* reinsert the bucket */
j = hashdyn->bucket[i];
while (j) {
tommy_hashdyn_node* j_next = j->next;
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tommy_size_t pos = j->index & new_bucket_mask;
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if (new_bucket[pos])
tommy_list_insert_tail_not_empty(new_bucket[pos], j);
else
tommy_list_insert_first(&new_bucket[pos], j);
j = j_next;
}
}
} else {
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tommy_size_t i;
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/* shrink */
for (i = 0; i < new_bucket_max; ++i) {
/* setup the new bucket with the lower bucket*/
new_bucket[i] = hashdyn->bucket[i];
/* concat the upper bucket */
tommy_list_concat(&new_bucket[i], &hashdyn->bucket[i + new_bucket_max]);
}
}
tommy_free(hashdyn->bucket);
/* setup */
hashdyn->bucket_bit = new_bucket_bit;
hashdyn->bucket_max = new_bucket_max;
hashdyn->bucket_mask = new_bucket_mask;
hashdyn->bucket = new_bucket;
}
/**
* Grow.
*/
tommy_inline void hashdyn_grow_step(tommy_hashdyn* hashdyn)
{
/* grow if more than 50% full */
if (hashdyn->count >= hashdyn->bucket_max / 2)
tommy_hashdyn_resize(hashdyn, hashdyn->bucket_bit + 1);
}
/**
* Shrink.
*/
tommy_inline void hashdyn_shrink_step(tommy_hashdyn* hashdyn)
{
/* shrink if less than 12.5% full */
if (hashdyn->count <= hashdyn->bucket_max / 8 && hashdyn->bucket_bit > TOMMY_HASHDYN_BIT)
tommy_hashdyn_resize(hashdyn, hashdyn->bucket_bit - 1);
}
void tommy_hashdyn_insert(tommy_hashdyn* hashdyn, tommy_hashdyn_node* node, void* data, tommy_hash_t hash)
{
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tommy_size_t pos = hash & hashdyn->bucket_mask;
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tommy_list_insert_tail(&hashdyn->bucket[pos], node, data);
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node->index = hash;
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++hashdyn->count;
hashdyn_grow_step(hashdyn);
}
void* tommy_hashdyn_remove_existing(tommy_hashdyn* hashdyn, tommy_hashdyn_node* node)
{
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tommy_size_t pos = node->index & hashdyn->bucket_mask;
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tommy_list_remove_existing(&hashdyn->bucket[pos], node);
--hashdyn->count;
hashdyn_shrink_step(hashdyn);
return node->data;
}
void* tommy_hashdyn_remove(tommy_hashdyn* hashdyn, tommy_search_func* cmp, const void* cmp_arg, tommy_hash_t hash)
{
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tommy_size_t pos = hash & hashdyn->bucket_mask;
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tommy_hashdyn_node* node = hashdyn->bucket[pos];
while (node) {
/* we first check if the hash matches, as in the same bucket we may have multiples hash values */
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if (node->index == hash && cmp(cmp_arg, node->data) == 0) {
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tommy_list_remove_existing(&hashdyn->bucket[pos], node);
--hashdyn->count;
hashdyn_shrink_step(hashdyn);
return node->data;
}
node = node->next;
}
return 0;
}
void tommy_hashdyn_foreach(tommy_hashdyn* hashdyn, tommy_foreach_func* func)
{
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tommy_size_t bucket_max = hashdyn->bucket_max;
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tommy_hashdyn_node** bucket = hashdyn->bucket;
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tommy_size_t pos;
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for (pos = 0; pos < bucket_max; ++pos) {
tommy_hashdyn_node* node = bucket[pos];
while (node) {
void* data = node->data;
node = node->next;
func(data);
}
}
}
void tommy_hashdyn_foreach_arg(tommy_hashdyn* hashdyn, tommy_foreach_arg_func* func, void* arg)
{
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tommy_size_t bucket_max = hashdyn->bucket_max;
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tommy_hashdyn_node** bucket = hashdyn->bucket;
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tommy_size_t pos;
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for (pos = 0; pos < bucket_max; ++pos) {
tommy_hashdyn_node* node = bucket[pos];
while (node) {
void* data = node->data;
node = node->next;
func(arg, data);
}
}
}
tommy_size_t tommy_hashdyn_memory_usage(tommy_hashdyn* hashdyn)
{
return hashdyn->bucket_max * (tommy_size_t)sizeof(hashdyn->bucket[0])
+ tommy_hashdyn_count(hashdyn) * (tommy_size_t)sizeof(tommy_hashdyn_node);
}