xref: /openbsd/lib/libfuse/tree.c (revision f6aab3d8)
1 /*	$OpenBSD: tree.c,v 1.2 2014/02/05 20:13:58 syl Exp $	*/
2 
3 /*
4  * Copyright (c) 2012 Eric Faurot <eric@openbsd.org>
5  *
6  * Permission to use, copy, modify, and distribute this software for any
7  * purpose with or without fee is hereby granted, provided that the above
8  * copyright notice and this permission notice appear in all copies.
9  *
10  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
11  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
12  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
13  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
14  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
15  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
16  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
17  */
18 
19 #include <stdlib.h>
20 #include <errno.h>
21 
22 #include "fuse_private.h"
23 
24 struct treeentry {
25 	SPLAY_ENTRY(treeentry)	 entry;
26 	uint64_t		 id;
27 	void			*data;
28 };
29 
30 static int treeentry_cmp(struct treeentry *, struct treeentry *);
31 
32 SPLAY_PROTOTYPE(tree, treeentry, entry, treeentry_cmp);
33 
34 int
35 tree_check(struct tree *t, uint64_t id)
36 {
37 	struct treeentry	key;
38 
39 	key.id = id;
40 	return (SPLAY_FIND(tree, t, &key) != NULL);
41 }
42 
43 void *
44 tree_set(struct tree *t, uint64_t id, void *data)
45 {
46 	struct treeentry	*entry, key;
47 
48 	key.id = id;
49 	if ((entry = SPLAY_FIND(tree, t, &key)) == NULL) {
50 		entry = malloc(sizeof *entry);
51 		if (entry == NULL)
52 			return (NULL);
53 		entry->id = id;
54 		SPLAY_INSERT(tree, t, entry);
55 	}
56 
57 	entry->data = data;
58 
59 	return (entry);
60 }
61 
62 void *
63 tree_get(struct tree *t, uint64_t id)
64 {
65 	struct treeentry	key, *entry;
66 
67 	key.id = id;
68 	if ((entry = SPLAY_FIND(tree, t, &key)) == NULL) {
69 		errno = ENOENT;
70 		return (NULL);
71 	}
72 
73 	return (entry->data);
74 }
75 
76 void *
77 tree_pop(struct tree *t, uint64_t id)
78 {
79 	struct treeentry	key, *entry;
80 	void			*data;
81 
82 	key.id = id;
83 	if ((entry = SPLAY_FIND(tree, t, &key)) == NULL)
84 		return (NULL);
85 
86 	data = entry->data;
87 	SPLAY_REMOVE(tree, t, entry);
88 	free(entry);
89 
90 	return (data);
91 }
92 
93 static int
94 treeentry_cmp(struct treeentry *a, struct treeentry *b)
95 {
96 	if (a->id < b->id)
97 		return (-1);
98 	if (a->id > b->id)
99 		return (1);
100 	return (0);
101 }
102 
103 SPLAY_GENERATE(tree, treeentry, entry, treeentry_cmp);
104