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nagios4/skiplist.h

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+/************************************************************************
+ *
+ * SKIPLIST.H - Skiplist data structures and functions
+ *
+ *
+ * License:
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ ************************************************************************/
+
+#ifndef LIBNAGIOS_skiplist_h__
+#define LIBNAGIOS_skiplist_h__
+#include "lnag-utils.h"
+
+/**
+ * @file skiplist.h
+ * @brief Skiplist library functions
+ *
+ * http://en.wikipedia.org/wiki/Skiplist
+ *
+ * @{
+ */
+
+#define SKIPLIST_OK              0 /**< A ok */
+#define SKIPLIST_ERROR_ARGS      1 /**< Bad arguments */
+#define SKIPLIST_ERROR_MEMORY    2 /**< Memory error */
+#define SKIPLIST_ERROR_DUPLICATE 3 /**< Trying to insert non-unique item */
+
+NAGIOS_BEGIN_DECL
+
+struct skiplist_struct;
+typedef struct skiplist_struct skiplist;
+
+/**
+ * Return number of items currently in the skiplist
+ * @param list The list to investigate
+ * @return number of items in list
+ */
+unsigned long skiplist_num_items(skiplist *list);
+
+/**
+ * Create a new skiplist
+ * @param max_levels Number of "ups" we have.
+ * This Should be kept close to lg2 of the number of items to store.
+ * @param level_probability Ignored
+ * @param allow_duplicates Allow duplicates in this list
+ * @param append_duplicates Append rather than prepend duplicates
+ * @param compare_function Comparison function for data entries
+ * @return pointer to a new skiplist on success, NULL on errors
+ */
+skiplist *skiplist_new(int max_levels, float level_probability, int allow_duplicates, int append_duplicates, int (*compare_function)(void *, void *));
+
+/**
+ * Insert an item into a skiplist
+ * @param list The list to insert to
+ * @param data The data to insert
+ * @return SKIPLIST_OK on success, or an error code
+ */
+int skiplist_insert(skiplist *list, void *data);
+
+/**
+ * Empty the skiplist of all data
+ * @param list The list to empty
+ * @return ERROR on failures. OK on success
+ */
+int skiplist_empty(skiplist *list);
+
+/**
+ * Free all nodes (but not all data) in a skiplist
+ * This is similar to skiplist_empty(), but also free()'s the head node
+ * @param list The list to free
+ * @return OK on success, ERROR on failures
+ */
+int skiplist_free(skiplist **list);
+
+/**
+ * Get the first item in the skiplist
+ * @param list The list to peek into
+ * @return The first item, or NULL if there is none
+ */
+void *skiplist_peek(skiplist *list);
+
+/**
+ * Pop the first item from the skiplist
+ * @param list The list to pop from
+ */
+void *skiplist_pop(skiplist *list);
+
+/**
+ * Get first node of skiplist
+ * @param list The list to search
+ * @param[out] node_ptr State variable for skiplist_get_next()
+ * @return The data-item of the first node on success, NULL on errors
+ */
+void *skiplist_get_first(skiplist *list, void **node_ptr);
+
+/**
+ * Get next item from node_ptr
+ * @param[out] node_ptr State variable primed from an earlier call to
+ * skiplist_get_first() or skiplist_get_next()
+ * @return The next data-item matching node_ptr on success, NULL on errors
+ */
+void *skiplist_get_next(void **node_ptr);
+
+/**
+ * Find first entry in skiplist matching data
+ * @param list The list to search
+ * @param data Comparison object used to search
+ * @param[out] node_ptr State variable for future lookups with
+ * skiplist_find_next()
+ * @return The first found data-item, of NULL if none could be found
+ */
+void *skiplist_find_first(skiplist *list, void *data, void **node_ptr);
+
+/**
+ * Find next entry in skiplist matching data
+ * @param list The list to search
+ * @param data The data to compare against
+ * @param[out] node_ptr State var primed from earlier call to
+ * skiplist_find_next() or skiplist_find_first()
+ * @return The next found data-item, or NULL if none could be found
+ */
+void *skiplist_find_next(skiplist *list, void *data, void **node_ptr);
+
+/**
+ * Delete all items matching 'data' from skiplist
+ * @param list The list to delete from
+ * @param data Comparison object used to find the real node
+ * @return OK on success, ERROR on errors
+ */
+int skiplist_delete(skiplist *list, void *data);
+
+/**
+ * Delete first item matching 'data' from skiplist
+ * @param list The list to delete from
+ * @param data Comparison object used to search the list
+ * @return OK on success, ERROR on errors.
+ */
+int skiplist_delete_first(skiplist *list, void *data);
+
+/**
+ * Delete a particular node from the skiplist
+ * @param list The list to search
+ * @param node_ptr The node to delete
+ * @return OK on success, ERROR on errors.
+ */
+int skiplist_delete_node(skiplist *list, void *node_ptr);
+
+NAGIOS_END_DECL
+/* @} */
+#endif