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authorRiccardo Spagni <ric@spagni.net>2014-10-05 23:44:31 +0200
committerRiccardo Spagni <ric@spagni.net>2014-10-05 23:44:31 +0200
commit9ef094b356b4da7542c3cab898dac7e135b76903 (patch)
tree99b5876712b0b1551fc042fe75447b998e4b0fc1 /external/unbound/util/rbtree.h
parentsplit mnemonic printout over 3 lines (diff)
downloadmonero-9ef094b356b4da7542c3cab898dac7e135b76903.tar.xz
added unbound to external deps
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+/*
+ * rbtree.h -- generic red-black tree
+ *
+ * Copyright (c) 2001-2007, NLnet Labs. All rights reserved.
+ *
+ * This software is open source.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ *
+ * 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.
+ *
+ * Neither the name of the NLNET LABS nor the names of its contributors may
+ * be used to endorse or promote products derived from this software without
+ * specific prior written permission.
+ *
+ * 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
+ * HOLDER 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.
+ *
+ */
+
+/**
+ * \file
+ * Red black tree. Implementation taken from NSD 3.0.5, adjusted for use
+ * in unbound (memory allocation, logging and so on).
+ */
+
+#ifndef UTIL_RBTREE_H_
+#define UTIL_RBTREE_H_
+
+/**
+ * This structure must be the first member of the data structure in
+ * the rbtree. This allows easy casting between an rbnode_t and the
+ * user data (poor man's inheritance).
+ */
+typedef struct rbnode_t rbnode_t;
+/**
+ * The rbnode_t struct definition.
+ */
+struct rbnode_t {
+ /** parent in rbtree, RBTREE_NULL for root */
+ rbnode_t *parent;
+ /** left node (smaller items) */
+ rbnode_t *left;
+ /** right node (larger items) */
+ rbnode_t *right;
+ /** pointer to sorting key */
+ const void *key;
+ /** colour of this node */
+ uint8_t color;
+};
+
+/** The nullpointer, points to empty node */
+#define RBTREE_NULL &rbtree_null_node
+/** the global empty node */
+extern rbnode_t rbtree_null_node;
+
+/** An entire red black tree */
+typedef struct rbtree_t rbtree_t;
+/** definition for tree struct */
+struct rbtree_t {
+ /** The root of the red-black tree */
+ rbnode_t *root;
+
+ /** The number of the nodes in the tree */
+ size_t count;
+
+ /**
+ * Key compare function. <0,0,>0 like strcmp.
+ * Return 0 on two NULL ptrs.
+ */
+ int (*cmp) (const void *, const void *);
+};
+
+/**
+ * Create new tree (malloced) with given key compare function.
+ * @param cmpf: compare function (like strcmp) takes pointers to two keys.
+ * @return: new tree, empty.
+ */
+rbtree_t *rbtree_create(int (*cmpf)(const void *, const void *));
+
+/**
+ * Init a new tree (malloced by caller) with given key compare function.
+ * @param rbtree: uninitialised memory for new tree, returned empty.
+ * @param cmpf: compare function (like strcmp) takes pointers to two keys.
+ */
+void rbtree_init(rbtree_t *rbtree, int (*cmpf)(const void *, const void *));
+
+/**
+ * Insert data into the tree.
+ * @param rbtree: tree to insert to.
+ * @param data: element to insert.
+ * @return: data ptr or NULL if key already present.
+ */
+rbnode_t *rbtree_insert(rbtree_t *rbtree, rbnode_t *data);
+
+/**
+ * Delete element from tree.
+ * @param rbtree: tree to delete from.
+ * @param key: key of item to delete.
+ * @return: node that is now unlinked from the tree. User to delete it.
+ * returns 0 if node not present
+ */
+rbnode_t *rbtree_delete(rbtree_t *rbtree, const void *key);
+
+/**
+ * Find key in tree. Returns NULL if not found.
+ * @param rbtree: tree to find in.
+ * @param key: key that must match.
+ * @return: node that fits or NULL.
+ */
+rbnode_t *rbtree_search(rbtree_t *rbtree, const void *key);
+
+/**
+ * Find, but match does not have to be exact.
+ * @param rbtree: tree to find in.
+ * @param key: key to find position of.
+ * @param result: set to the exact node if present, otherwise to element that
+ * precedes the position of key in the tree. NULL if no smaller element.
+ * @return: true if exact match in result. Else result points to <= element,
+ * or NULL if key is smaller than the smallest key.
+ */
+int rbtree_find_less_equal(rbtree_t *rbtree, const void *key,
+ rbnode_t **result);
+
+/**
+ * Returns first (smallest) node in the tree
+ * @param rbtree: tree
+ * @return: smallest element or NULL if tree empty.
+ */
+rbnode_t *rbtree_first(rbtree_t *rbtree);
+
+/**
+ * Returns last (largest) node in the tree
+ * @param rbtree: tree
+ * @return: largest element or NULL if tree empty.
+ */
+rbnode_t *rbtree_last(rbtree_t *rbtree);
+
+/**
+ * Returns next larger node in the tree
+ * @param rbtree: tree
+ * @return: next larger element or NULL if no larger in tree.
+ */
+rbnode_t *rbtree_next(rbnode_t *rbtree);
+
+/**
+ * Returns previous smaller node in the tree
+ * @param rbtree: tree
+ * @return: previous smaller element or NULL if no previous in tree.
+ */
+rbnode_t *rbtree_previous(rbnode_t *rbtree);
+
+/**
+ * Call with node=variable of struct* with rbnode_t as first element.
+ * with type is the type of a pointer to that struct.
+ */
+#define RBTREE_FOR(node, type, rbtree) \
+ for(node=(type)rbtree_first(rbtree); \
+ (rbnode_t*)node != RBTREE_NULL; \
+ node = (type)rbtree_next((rbnode_t*)node))
+
+/**
+ * Call function for all elements in the redblack tree, such that
+ * leaf elements are called before parent elements. So that all
+ * elements can be safely free()d.
+ * Note that your function must not remove the nodes from the tree.
+ * Since that may trigger rebalances of the rbtree.
+ * @param tree: the tree
+ * @param func: function called with element and user arg.
+ * The function must not alter the rbtree.
+ * @param arg: user argument.
+ */
+void traverse_postorder(rbtree_t* tree, void (*func)(rbnode_t*, void*),
+ void* arg);
+
+#endif /* UTIL_RBTREE_H_ */