X-Git-Url: https://git.octo.it/?a=blobdiff_plain;f=src%2Futils_avltree.h;h=37af5e482dc1cc700f74ffe03b7d865d95835960;hb=e00f829437e24dfc52f2aeeced75fd36467da7a2;hp=7875e0b2674802df844901e1b5f42fed644ab437;hpb=f4c3e684850315991f0760e90f5d845af4615d5f;p=collectd.git

diff --git a/src/utils_avltree.h b/src/utils_avltree.h
index 7875e0b2..37af5e48 100644
--- a/src/utils_avltree.h
+++ b/src/utils_avltree.h
@@ -1,3 +1,25 @@
+/**
+ * collectd - src/utils_avltree.h
+ * Copyright (C) 2006,2007  Florian octo Forster
+ *
+ * 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 2 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, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
+ *
+ * Authors:
+ *   Florian octo Forster <octo at verplant.org>
+ **/
+
 #ifndef UTILS_AVLTREE_H
 #define UTILS_AVLTREE_H 1
 
@@ -7,23 +29,119 @@ typedef struct avl_tree_s avl_tree_t;
 struct avl_iterator_s;
 typedef struct avl_iterator_s avl_iterator_t;
 
-struct avl_keyval_s
-{
-	void *key;
-	void *value;
-};
-
+/*
+ * NAME
+ *   avl_create
+ *
+ * DESCRIPTION
+ *   Allocates a new AVL-tree.
+ *
+ * PARAMETERS
+ *   `compare'  The function-pointer `compare' is used to compare two keys. It
+ *              has to return less than zero if it's first argument is smaller
+ *              then the second argument, more than zero if the first argument
+ *              is bigger than the second argument and zero if they are equal.
+ *              If your keys are char-pointers, you can use the `strcmp'
+ *              function from the libc here.
+ *
+ * RETURN VALUE
+ *   A avl_tree_t-pointer upon success or NULL upon failure.
+ */
 avl_tree_t *avl_create (int (*compare) (const void *, const void *));
+
+
+/*
+ * NAME
+ *   avl_destroy
+ *
+ * DESCRIPTION
+ *   Deallocates an AVL-tree. Stored value- and key-pointer are lost, but of
+ *   course not freed.
+ */
 void avl_destroy (avl_tree_t *t);
 
+/*
+ * NAME
+ *   avl_insert
+ *
+ * DESCRIPTION
+ *   Stores the key-value-pair in the AVL-tree pointed to by `t'.
+ *
+ * PARAMETERS
+ *   `t'        AVL-tree to store the data in.
+ *   `key'      Key used to store the value under. This is used to get back to
+ *              the value again.
+ *   `value'    Value to be stored.
+ *
+ * RETURN VALUE
+ *   Zero upon success and non-zero upon failure and if the key is already
+ *   stored in the tree.
+ */
 int avl_insert (avl_tree_t *t, void *key, void *value);
+
+/*
+ * NAME
+ *   avl_remove
+ *
+ * DESCRIPTION
+ *   Removes a key-value-pair from the tree t. The stored key and value may be
+ *   returned in `rkey' and `rvalue'.
+ *
+ * PARAMETERS
+ *   `t'	AVL-tree to remove key-value-pair from.
+ *   `key'      Key to identify the entry.
+ *   `rkey'     Pointer to a pointer in which to store the key. May be NULL.
+ *   `rvalue'   Pointer to a pointer in which to store the value. May be NULL.
+ *
+ * RETURN VALUE
+ *   Zero upon success or non-zero if the key isn't found in the tree.
+ */
 int avl_remove (avl_tree_t *t, void *key, void **rkey, void **rvalue);
 
+/*
+ * NAME
+ *   avl_get
+ *
+ * DESCRIPTION
+ *   Retrieve the `value' belonging to `key'.
+ *
+ * PARAMETERS
+ *   `t'	AVL-tree to get the value from.
+ *   `key'      Key to identify the entry.
+ *   `value'    Pointer to a pointer in which to store the value. May be NULL.
+ *
+ * RETURN VALUE
+ *   Zero upon success or non-zero if the key isn't found in the tree.
+ */
 int avl_get (avl_tree_t *t, const void *key, void **value);
 
+/*
+ * NAME
+ *   avl_pick
+ *
+ * DESCRIPTION
+ *   Remove a (pseudo-)random element from the tree and return it's `key' and
+ *   `value'. Entries are not returned in any particular order. This function
+ *   is intended for cache-flushes that don't care about the order but simply
+ *   want to remove all elements, one at a time.
+ *
+ * PARAMETERS
+ *   `t'	AVL-tree to get the value from.
+ *   `key'      Pointer to a pointer in which to store the key.
+ *   `value'    Pointer to a pointer in which to store the value.
+ *
+ * RETURN VALUE
+ *   Zero upon success or non-zero if the tree is empty or key or value is
+ *   NULL.
+ */
+int avl_pick (avl_tree_t *t, void **key, void **value);
+
+#if 0
+/* This code disabled until a need arises. */
 avl_iterator_t *avl_get_iterator (avl_tree_t *t);
 void *avl_iterator_next (avl_iterator_t *iter);
 void *avl_iterator_prev (avl_iterator_t *iter);
 void avl_iterator_destroy (avl_iterator_t *iter);
+#endif
 
 #endif /* UTILS_AVLTREE_H */