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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 "tommytrieinp.h"
+
+#include <assert.h> /* for assert */
+
+/******************************************************************************/
+/* trie_inplace */
+
+/**
+ * Mask for the inner branches.
+ */
+#define TOMMY_TRIE_INPLACE_TREE_MASK (TOMMY_TRIE_INPLACE_TREE_MAX - 1)
+
+/**
+ * Shift for the first level of branches.
+ */
+#define TOMMY_TRIE_INPLACE_BUCKET_SHIFT (TOMMY_KEY_BIT - TOMMY_TRIE_INPLACE_BUCKET_BIT)
+
+/**
+ * Create a new list with a single element.
+ */
+tommy_inline tommy_trie_inplace_node* tommy_trie_inplace_list_insert_first(tommy_trie_inplace_node* node)
+{
+ /* one element "circular" prev list */
+ node->prev = node;
+
+ /* one element "0 terminated" next list */
+ node->next = 0;
+
+ return node;
+}
+
+/**
+ * Add an element to an existing list.
+ * \note The element is inserted at the end of the list.
+ */
+tommy_inline void tommy_trie_inplace_list_insert_tail_not_empty(tommy_trie_inplace_node* head, tommy_trie_inplace_node* node)
+{
+ /* insert in the list in the last position */
+
+ /* insert in the "circular" prev list */
+ node->prev = head->prev;
+ head->prev = node;
+
+ /* insert in the "0 terminated" next list */
+ node->next = 0;
+ node->prev->next = node;
+}
+
+/**
+ * Remove an element from the list.
+ */
+tommy_inline void tommy_trie_inplace_list_remove(tommy_trie_inplace_node** let_ptr, tommy_trie_inplace_node* node)
+{
+ tommy_trie_inplace_node* head = *let_ptr;
+
+ /* remove from the "circular" prev list */
+ if (node->next)
+ node->next->prev = node->prev;
+ else
+ head->prev = node->prev; /* the last */
+
+ /* remove from the "0 terminated" next list */
+ if (head == node)
+ *let_ptr = node->next; /* the new first */
+ else
+ node->prev->next = node->next;
+}
+
+void tommy_trie_inplace_init(tommy_trie_inplace* trie_inplace)
+{
+ tommy_uint_t i;
+
+ for (i = 0; i < TOMMY_TRIE_INPLACE_BUCKET_MAX; ++i)
+ trie_inplace->bucket[i] = 0;
+
+ trie_inplace->count = 0;
+}
+
+static void trie_inplace_bucket_insert(tommy_uint_t shift, tommy_trie_inplace_node** let_ptr, tommy_trie_inplace_node* insert, tommy_key_t key)
+{
+ tommy_trie_inplace_node* node;
+
+ node = *let_ptr;
+ while (node && node->key != key) {
+ let_ptr = &node->map[(key >> shift) & TOMMY_TRIE_INPLACE_TREE_MASK];
+ node = *let_ptr;
+ shift -= TOMMY_TRIE_INPLACE_TREE_BIT;
+ }
+
+ /* if null, just insert the node */
+ if (!node) {
+ /* setup the node as a list */
+ *let_ptr = tommy_trie_inplace_list_insert_first(insert);
+ } else {
+ /* if it's the same key, insert in the list */
+ tommy_trie_inplace_list_insert_tail_not_empty(node, insert);
+ }
+}
+
+void tommy_trie_inplace_insert(tommy_trie_inplace* trie_inplace, tommy_trie_inplace_node* node, void* data, tommy_key_t key)
+{
+ tommy_trie_inplace_node** let_ptr;
+ tommy_uint_t i;
+
+ node->data = data;
+ node->key = key;
+ /* clear the child pointers */
+ for (i = 0; i < TOMMY_TRIE_INPLACE_TREE_MAX; ++i)
+ node->map[i] = 0;
+
+ let_ptr = &trie_inplace->bucket[key >> TOMMY_TRIE_INPLACE_BUCKET_SHIFT];
+
+ trie_inplace_bucket_insert(TOMMY_TRIE_INPLACE_BUCKET_SHIFT, let_ptr, node, key);
+
+ ++trie_inplace->count;
+}
+
+static tommy_trie_inplace_node* trie_inplace_bucket_remove(tommy_uint_t shift, tommy_trie_inplace_node** let_ptr, tommy_trie_inplace_node* remove, tommy_key_t key)
+{
+ tommy_trie_inplace_node* node;
+ int i;
+ tommy_trie_inplace_node** leaf_let_ptr;
+ tommy_trie_inplace_node* leaf;
+
+ node = *let_ptr;
+ while (node && node->key != key) {
+ let_ptr = &node->map[(key >> shift) & TOMMY_TRIE_INPLACE_TREE_MASK];
+ node = *let_ptr;
+ shift -= TOMMY_TRIE_INPLACE_TREE_BIT;
+ }
+
+ if (!node)
+ return 0;
+
+ /* if the node to remove is not specified */
+ if (!remove)
+ remove = node; /* remove the first */
+
+ tommy_trie_inplace_list_remove(let_ptr, remove);
+
+ /* if not change in the node, nothing more to do */
+ if (*let_ptr == node)
+ return remove;
+
+ /* if we have a substitute */
+ if (*let_ptr != 0) {
+ /* copy the child pointers to the new one */
+ node = *let_ptr;
+ for (i = 0; i < TOMMY_TRIE_INPLACE_TREE_MAX; ++i)
+ node->map[i] = remove->map[i];
+
+ return remove;
+ }
+
+ /* find a leaf */
+ leaf_let_ptr = 0;
+ leaf = remove;
+
+ /* search backward, statistically we have more zeros than ones */
+ i = TOMMY_TRIE_INPLACE_TREE_MAX - 1;
+ while (i >= 0) {
+ if (leaf->map[i]) {
+ leaf_let_ptr = &leaf->map[i];
+ leaf = *leaf_let_ptr;
+ i = TOMMY_TRIE_INPLACE_TREE_MAX - 1;
+ continue;
+ }
+ --i;
+ }
+
+ /* if it's itself a leaf */
+ if (!leaf_let_ptr)
+ return remove;
+
+ /* remove the leaf */
+ *leaf_let_ptr = 0;
+
+ /* copy the child pointers */
+ for (i = 0; i < TOMMY_TRIE_INPLACE_TREE_MAX; ++i)
+ leaf->map[i] = remove->map[i];
+
+ /* put it in place */
+ *let_ptr = leaf;
+
+ return remove;
+}
+
+void* tommy_trie_inplace_remove(tommy_trie_inplace* trie_inplace, tommy_key_t key)
+{
+ tommy_trie_inplace_node* ret;
+ tommy_trie_inplace_node** let_ptr;
+
+ let_ptr = &trie_inplace->bucket[key >> TOMMY_TRIE_INPLACE_BUCKET_SHIFT];
+
+ ret = trie_inplace_bucket_remove(TOMMY_TRIE_INPLACE_BUCKET_SHIFT, let_ptr, 0, key);
+
+ if (!ret)
+ return 0;
+
+ --trie_inplace->count;
+
+ return ret->data;
+}
+
+void* tommy_trie_inplace_remove_existing(tommy_trie_inplace* trie_inplace, tommy_trie_inplace_node* node)
+{
+ tommy_trie_inplace_node* ret;
+ tommy_key_t key = node->key;
+ tommy_trie_inplace_node** let_ptr;
+
+ let_ptr = &trie_inplace->bucket[key >> TOMMY_TRIE_INPLACE_BUCKET_SHIFT];
+
+ ret = trie_inplace_bucket_remove(TOMMY_TRIE_INPLACE_BUCKET_SHIFT, let_ptr, node, key);
+
+ /* the element removed must match the one passed */
+ assert(ret == node);
+
+ --trie_inplace->count;
+
+ return ret->data;
+}
+
+tommy_trie_inplace_node* tommy_trie_inplace_bucket(tommy_trie_inplace* trie_inplace, tommy_key_t key)
+{
+ tommy_trie_inplace_node* node;
+ tommy_uint_t shift;
+
+ node = trie_inplace->bucket[key >> TOMMY_TRIE_INPLACE_BUCKET_SHIFT];
+ shift = TOMMY_TRIE_INPLACE_BUCKET_SHIFT;
+
+ while (node && node->key != key) {
+ node = node->map[(key >> shift) & TOMMY_TRIE_INPLACE_TREE_MASK];
+ shift -= TOMMY_TRIE_INPLACE_TREE_BIT;
+ }
+
+ return node;
+}
+
+tommy_size_t tommy_trie_inplace_memory_usage(tommy_trie_inplace* trie_inplace)
+{
+ return tommy_trie_inplace_count(trie_inplace) * (tommy_size_t)sizeof(tommy_trie_inplace_node);
+}
+