insert.c
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/**
* \file
*
* \author Georg Hopp
*
* \copyright
* Copyright © 2014 Georg Hopp
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <pthread.h>
#include "trbase.h"
#include "tr/tree.h"
void *
TR_treeInsert(TR_Tree this, const void * search, TR_TreeComp comp)
{
TR_TreeNode node = this->root;
TR_TreeNode new_node = NULL;
int found;
pthread_mutex_lock(&(this->lock));
/*
* insert the node or return the one in tree if comparison
* succeeds.
*/
if (NULL == node) {
/*
* if the root is NULL we simple add the element and set
* node to it.
*/
this->root = node = new_node = TR_new(TR_TreeNode, search);
} else {
TR_TREE_FIND(node, search, found, comp);
if (found == 0) {
pthread_mutex_unlock(&(this->lock));
// This differs from tsearch, which is the posix equivalent to
// this function in that it will not replace an existing value.
// If there is a value for the given key in the tree it will be
// retured. It is then up to the caller to handle the situation.
// This is used in my http header code to handle multiple value
// per header. There it is more useful to get the already existing
// tree entry and add the new data.
return node->data;
} else {
// not found
if (0 < found) {
node->left = TR_new(TR_TreeNode, search);
node->left->parent = node;
node = new_node = node->left;
} else {
node->right = TR_new(TR_TreeNode, search);
node->right->parent = node;
node = new_node = node->right;
}
}
}
/*
* we expect node not to be NULL and pointing to our
* new node at this point...now rabalance the tree
*/
TR_TREE_BALANCE_INSERT(&(this->root), node);
pthread_mutex_unlock(&(this->lock));
return new_node->data;
}
// vim: set ts=4 sw=4: