use prev pointer when array do adding (#430)

* use prev pointer when array do adding
This commit is contained in:
xiaomianhehe 2020-02-18 11:54:23 +08:00 committed by GitHub
parent 2955fe5ec4
commit e8077d0150
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 29 additions and 10 deletions

37
cJSON.c
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@ -1871,22 +1871,34 @@ static cJSON_bool add_item_to_array(cJSON *array, cJSON *item)
}
child = array->child;
/*
* To find the last item int array quickly, we use prev in array
*/
if (child == NULL)
{
/* list is empty, start new one */
array->child = item;
item->prev = item;
item->next = NULL;
}
else
{
/* append to the end */
while (child->next)
if (child->prev)
{
child = child->next;
suffix_object(child->prev, item);
array->child->prev = item;
}
else
{
while (child->next)
{
child = child->next;
}
suffix_object(child, item);
array->child->prev = item;
}
suffix_object(child, item);
}
return true;
}
@ -2206,14 +2218,21 @@ CJSON_PUBLIC(cJSON_bool) cJSON_ReplaceItemViaPointer(cJSON * const parent, cJSON
{
replacement->next->prev = replacement;
}
if (replacement->prev != NULL)
{
replacement->prev->next = replacement;
}
if (parent->child == item)
{
parent->child = replacement;
}
else
{ /*
* To find the last item int array quickly, we use prev in array.
* We can't modify the last item's next pointer where this item was the parent's child
*/
if (replacement->prev != NULL)
{
replacement->prev->next = replacement;
}
}
item->next = NULL;
item->prev = NULL;

View File

@ -306,7 +306,7 @@ static void cjson_replace_item_via_pointer_should_replace_items(void)
/* replace beginning */
TEST_ASSERT_TRUE(cJSON_ReplaceItemViaPointer(array, beginning, &(replacements[0])));
TEST_ASSERT_NULL(replacements[0].prev);
TEST_ASSERT_TRUE(replacements[0].prev == end);
TEST_ASSERT_TRUE(replacements[0].next == middle);
TEST_ASSERT_TRUE(middle->prev == &(replacements[0]));
TEST_ASSERT_TRUE(array->child == &(replacements[0]));