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2bd0ea18 | 1 | /* |
0d3e0b37 | 2 | * Copyright (c) 2000-2001 Silicon Graphics, Inc. All Rights Reserved. |
2bd0ea18 NS |
3 | * |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of version 2 of the GNU General Public License as | |
6 | * published by the Free Software Foundation. | |
7 | * | |
8 | * This program is distributed in the hope that it would be useful, but | |
9 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
10 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. | |
11 | * | |
12 | * Further, this software is distributed without any warranty that it is | |
13 | * free of the rightful claim of any third person regarding infringement | |
14 | * or the like. Any license provided herein, whether implied or | |
15 | * otherwise, applies only to this software file. Patent licenses, if | |
16 | * any, provided herein do not apply to combinations of this program with | |
17 | * other software, or any other product whatsoever. | |
18 | * | |
19 | * You should have received a copy of the GNU General Public License along | |
20 | * with this program; if not, write the Free Software Foundation, Inc., 59 | |
21 | * Temple Place - Suite 330, Boston MA 02111-1307, USA. | |
22 | * | |
23 | * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy, | |
24 | * Mountain View, CA 94043, or: | |
25 | * | |
26 | * http://www.sgi.com | |
27 | * | |
28 | * For further information regarding this notice, see: | |
29 | * | |
30 | * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/ | |
31 | */ | |
32 | ||
33 | #include <libxfs.h> | |
34 | #include "dir_stack.h" | |
35 | #include "err_protos.h" | |
36 | ||
37 | /* | |
38 | * a directory stack for holding directories while | |
39 | * we traverse filesystem hierarchy subtrees. | |
40 | * names are kind of misleading as this is really | |
41 | * implemented as an inode stack. so sue me... | |
42 | */ | |
43 | ||
44 | static dir_stack_t dirstack_freelist; | |
45 | static int dirstack_init = 0; | |
46 | ||
47 | void | |
48 | dir_stack_init(dir_stack_t *stack) | |
49 | { | |
50 | stack->cnt = 0; | |
51 | stack->head = NULL; | |
52 | ||
53 | if (dirstack_init == 0) { | |
54 | dirstack_init = 1; | |
55 | dir_stack_init(&dirstack_freelist); | |
56 | } | |
57 | ||
58 | stack->cnt = 0; | |
59 | stack->head = NULL; | |
60 | ||
61 | return; | |
62 | } | |
63 | ||
64 | static void | |
65 | dir_stack_push(dir_stack_t *stack, dir_stack_elem_t *elem) | |
66 | { | |
27527004 | 67 | ASSERT(stack->cnt > 0 || (stack->cnt == 0 && stack->head == NULL)); |
2bd0ea18 NS |
68 | |
69 | elem->next = stack->head; | |
70 | stack->head = elem; | |
71 | stack->cnt++; | |
72 | ||
73 | return; | |
74 | } | |
75 | ||
76 | static dir_stack_elem_t * | |
77 | dir_stack_pop(dir_stack_t *stack) | |
78 | { | |
79 | dir_stack_elem_t *elem; | |
80 | ||
81 | if (stack->cnt == 0) { | |
82 | ASSERT(stack->head == NULL); | |
83 | return(NULL); | |
84 | } | |
85 | ||
86 | elem = stack->head; | |
87 | ||
88 | ASSERT(elem != NULL); | |
89 | ||
90 | stack->head = elem->next; | |
91 | elem->next = NULL; | |
92 | stack->cnt--; | |
93 | ||
94 | return(elem); | |
95 | } | |
96 | ||
97 | void | |
98 | push_dir(dir_stack_t *stack, xfs_ino_t ino) | |
99 | { | |
100 | dir_stack_elem_t *elem; | |
101 | ||
102 | if (dirstack_freelist.cnt == 0) { | |
103 | if ((elem = malloc(sizeof(dir_stack_elem_t))) == NULL) { | |
104 | do_error( | |
105 | "couldn't malloc dir stack element, try more swap\n"); | |
106 | exit(1); | |
107 | } | |
108 | } else { | |
109 | elem = dir_stack_pop(&dirstack_freelist); | |
110 | } | |
111 | ||
112 | elem->ino = ino; | |
113 | ||
114 | dir_stack_push(stack, elem); | |
115 | ||
116 | return; | |
117 | } | |
118 | ||
119 | xfs_ino_t | |
120 | pop_dir(dir_stack_t *stack) | |
121 | { | |
122 | dir_stack_elem_t *elem; | |
123 | xfs_ino_t ino; | |
124 | ||
125 | elem = dir_stack_pop(stack); | |
126 | ||
127 | if (elem == NULL) | |
128 | return(NULLFSINO); | |
129 | ||
130 | ino = elem->ino; | |
131 | elem->ino = NULLFSINO; | |
132 | ||
133 | dir_stack_push(&dirstack_freelist, elem); | |
134 | ||
135 | return(ino); | |
136 | } |