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Improve plist_dict_set_item performance for large dictionaries with hash table

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This commit is contained in:
Nikias Bassen
2016-11-18 03:22:25 +01:00
parent f1f2bcebc8
commit 582c59bf7d
5 changed files with 119 additions and 18 deletions
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src/bplist.c
+1 -1
View File
@@ -1156,7 +1156,7 @@ PLIST_API void plist_to_bin(plist_t plist, char **plist_bin, uint32_t * length)
//list of objects
objects = ptr_array_new(256);
//hashtable to write only once same nodes
ref_table = hash_table_new(plist_data_hash, plist_data_compare);
ref_table = hash_table_new(plist_data_hash, plist_data_compare, free);
//serialize plist
ser_s.objects = objects;
src/hashtable.c
+37 -3
View File
@@ -2,7 +2,7 @@
* hashtable.c
* really simple hash table implementation
*
* Copyright (c) 2011 Nikias Bassen, All Rights Reserved.
* Copyright (c) 2011-2016 Nikias Bassen, All Rights Reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -20,7 +20,7 @@
*/
#include "hashtable.h"
hashtable_t* hash_table_new(hash_func_t hash_func, compare_func_t compare_func)
hashtable_t* hash_table_new(hash_func_t hash_func, compare_func_t compare_func, free_func_t free_func)
{
hashtable_t* ht = (hashtable_t*)malloc(sizeof(hashtable_t));
int i;
@@ -30,6 +30,7 @@ hashtable_t* hash_table_new(hash_func_t hash_func, compare_func_t compare_func)
ht->count = 0;
ht->hash_func = hash_func;
ht->compare_func = compare_func;
ht->free_func = free_func;
return ht;
}
@@ -42,7 +43,9 @@ void hash_table_destroy(hashtable_t *ht)
if (ht->entries[i]) {
hashentry_t* e = ht->entries[i];
while (e) {
free(e->value);
if (ht->free_func) {
ht->free_func(e->value);
}
hashentry_t* old = e;
e = e->next;
free(old);
@@ -104,3 +107,34 @@ void* hash_table_lookup(hashtable_t* ht, void *key)
}
return NULL;
}
void hash_table_remove(hashtable_t* ht, void *key)
{
if (!ht || !key) return;
unsigned int hash = ht->hash_func(key);
int idx0 = hash & 0xFFF;
// get the idx0 list
hashentry_t* e = ht->entries[idx0];
hashentry_t* last = e;
while (e) {
if (ht->compare_func(e->key, key)) {
// found element, remove it from the list
hashentry_t* old = e;
if (e == ht->entries[idx0]) {
ht->entries[idx0] = e->next;
} else {
last->next = e->next;
}
if (ht->free_func) {
ht->free_func(old->value);
}
free(old);
return;
}
last = e;
e = e->next;
}
}
src/hashtable.h
+5 -2
View File
@@ -2,7 +2,7 @@
* hashtable.h
* header file for really simple hash table implementation
*
* Copyright (c) 2011 Nikias Bassen, All Rights Reserved.
* Copyright (c) 2011-2016 Nikias Bassen, All Rights Reserved.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
@@ -30,18 +30,21 @@ typedef struct hashentry_t {
typedef unsigned int(*hash_func_t)(const void* key);
typedef int (*compare_func_t)(const void *a, const void *b);
typedef void (*free_func_t)(void *ptr);
typedef struct hashtable_t {
hashentry_t *entries[4096];
size_t count;
hash_func_t hash_func;
compare_func_t compare_func;
free_func_t free_func;
} hashtable_t;
hashtable_t* hash_table_new(hash_func_t hash_func, compare_func_t compare_func);
hashtable_t* hash_table_new(hash_func_t hash_func, compare_func_t compare_func, free_func_t free_func);
void hash_table_destroy(hashtable_t *ht);
void hash_table_insert(hashtable_t* ht, void *key, void *value);
void* hash_table_lookup(hashtable_t* ht, void *key);
void hash_table_remove(hashtable_t* ht, void *key);
#endif
src/plist.c
+75 -12
View File
@@ -37,6 +37,7 @@
#include <node.h>
#include <node_iterator.h>
#include <hashtable.h>
extern void plist_xml_init(void);
extern void plist_xml_deinit(void);
@@ -148,6 +149,31 @@ plist_data_t plist_new_plist_data(void)
return data;
}
static unsigned int dict_key_hash(const void *data)
{
plist_data_t keydata = (plist_data_t)data;
unsigned int hash = 5381;
size_t i;
char *str = keydata->strval;
for (i = 0; i < keydata->length; str++, i++) {
hash = ((hash << 5) + hash) + *str;
}
return hash;
}
static int dict_key_compare(const void* a, const void* b)
{
plist_data_t data_a = (plist_data_t)a;
plist_data_t data_b = (plist_data_t)b;
if (data_a->strval == NULL || data_b->strval == NULL) {
return FALSE;
}
if (data_a->length != data_b->length) {
return FALSE;
}
return (strcmp(data_a->strval, data_b->strval) == 0) ? TRUE : FALSE;
}
void plist_free_data(plist_data_t data)
{
if (data)
@@ -161,6 +187,9 @@ void plist_free_data(plist_data_t data)
case PLIST_DATA:
free(data->buff);
break;
case PLIST_DICT:
hash_table_destroy(data->hashtable);
break;
default:
break;
}
@@ -483,20 +512,27 @@ PLIST_API plist_t plist_dict_get_item(plist_t node, const char* key)
if (node && PLIST_DICT == plist_get_node_type(node))
{
plist_t current = NULL;
for (current = (plist_t)node_first_child(node);
plist_data_t data = plist_get_data(node);
hashtable_t *ht = (hashtable_t*)data->hashtable;
if (ht) {
struct plist_data_s sdata;
sdata.strval = (char*)key;
sdata.length = strlen(key);
ret = (plist_t)hash_table_lookup(ht, &sdata);
} else {
plist_t current = NULL;
for (current = (plist_t)node_first_child(node);
current;
current = (plist_t)node_next_sibling(node_next_sibling(current)))
{
plist_data_t data = plist_get_data(current);
assert( PLIST_KEY == plist_get_node_type(current) );
if (data && !strcmp(key, data->strval))
{
ret = (plist_t)node_next_sibling(current);
break;
data = plist_get_data(current);
assert( PLIST_KEY == plist_get_node_type(current) );
if (data && !strcmp(key, data->strval))
{
ret = (plist_t)node_next_sibling(current);
break;
}
}
}
}
@@ -507,6 +543,7 @@ PLIST_API void plist_dict_set_item(plist_t node, const char* key, plist_t item)
{
if (node && PLIST_DICT == plist_get_node_type(node)) {
node_t* old_item = plist_dict_get_item(node, key);
plist_t key_node = NULL;
if (old_item) {
int idx = plist_free_node(old_item);
if (idx < 0) {
@@ -514,10 +551,32 @@ PLIST_API void plist_dict_set_item(plist_t node, const char* key, plist_t item)
} else {
node_insert(node, idx, item);
}
key_node = node_prev_sibling(item);
} else {
node_attach(node, plist_new_key(key));
key_node = plist_new_key(key);
node_attach(node, key_node);
node_attach(node, item);
}
hashtable_t *ht = ((plist_data_t)((node_t*)node)->data)->hashtable;
if (ht) {
/* store pointer to item in hash table */
hash_table_insert(ht, (plist_data_t)((node_t*)key_node)->data, item);
} else {
if (((node_t*)node)->count > 500) {
/* make new hash table */
ht = hash_table_new(dict_key_hash, dict_key_compare, NULL);
/* calculate the hashes for all entries we have so far */
plist_t current = NULL;
for (current = (plist_t)node_first_child(node);
ht && current;
current = (plist_t)node_next_sibling(node_next_sibling(current)))
{
hash_table_insert(ht, ((node_t*)current)->data, node_next_sibling(current));
}
((plist_data_t)((node_t*)node)->data)->hashtable = ht;
}
}
}
return;
}
@@ -535,6 +594,10 @@ PLIST_API void plist_dict_remove_item(plist_t node, const char* key)
if (old_item)
{
plist_t key_node = node_prev_sibling(old_item);
hashtable_t* ht = ((plist_data_t)((node_t*)node)->data)->hashtable;
if (ht) {
hash_table_remove(ht, ((node_t*)key_node)->data);
}
plist_free(key_node);
plist_free(old_item);
}
src/plist.h
+1
View File
@@ -56,6 +56,7 @@ struct plist_data_s
double realval;
char *strval;
uint8_t *buff;
void *hashtable;
};
uint64_t length;
plist_type type;