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DEFINITIONS
This source file includes following definitions.
- compare_dirent
- free_dirsort_privates
- open_and_sort_dir
- dirsort_opendir
- dirsort_readdir
- dirsort_seekdir
- dirsort_telldir
- dirsort_rewinddir
- vfs_dirsort_init
1 /*
2 * VFS module to provide a sorted directory list.
3 *
4 * Copyright (C) Andy Kelk (andy@mopoke.co.uk), 2009
5 *
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 3 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, see <http://www.gnu.org/licenses/>.
19 */
20
21 #include "includes.h"
22
23 static int compare_dirent (const void *a, const void *b) {
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24 const SMB_STRUCT_DIRENT *da = (const SMB_STRUCT_DIRENT *) a;
25 const SMB_STRUCT_DIRENT *db = (const SMB_STRUCT_DIRENT *) b;
26 return StrCaseCmp(da->d_name, db->d_name);
27 }
28
29 struct dirsort_privates {
30 long pos;
31 SMB_STRUCT_DIRENT *directory_list;
32 long number_of_entries;
33 time_t mtime;
34 SMB_STRUCT_DIR *source_directory;
35 int fd;
36 };
37
38 static void free_dirsort_privates(void **datap) {
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39 struct dirsort_privates *data = (struct dirsort_privates *) *datap;
40 SAFE_FREE(data->directory_list);
41 SAFE_FREE(data);
42 *datap = NULL;
43
44 return;
45 }
46
47 static void open_and_sort_dir (vfs_handle_struct *handle)
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48 {
49 SMB_STRUCT_DIRENT *dp;
50 struct stat dir_stat;
51 long current_pos;
52 struct dirsort_privates *data = NULL;
53
54 SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
55
56 data->number_of_entries = 0;
57
58 if (fstat(data->fd, &dir_stat) == 0) {
59 data->mtime = dir_stat.st_mtime;
60 }
61
62 while (SMB_VFS_NEXT_READDIR(handle, data->source_directory, NULL)
63 != NULL) {
64 data->number_of_entries++;
65 }
66
67 /* Open the underlying directory and count the number of entries
68 Skip back to the beginning as we'll read it again */
69 SMB_VFS_NEXT_REWINDDIR(handle, data->source_directory);
70
71 /* Set up an array and read the directory entries into it */
72 SAFE_FREE(data->directory_list); /* destroy previous cache if needed */
73 data->directory_list = (SMB_STRUCT_DIRENT *)SMB_MALLOC(
74 data->number_of_entries * sizeof(SMB_STRUCT_DIRENT));
75 current_pos = data->pos;
76 data->pos = 0;
77 while ((dp = SMB_VFS_NEXT_READDIR(handle, data->source_directory,
78 NULL)) != NULL) {
79 data->directory_list[data->pos++] = *dp;
80 }
81
82 /* Sort the directory entries by name */
83 data->pos = current_pos;
84 qsort(data->directory_list, data->number_of_entries,
85 sizeof(SMB_STRUCT_DIRENT), compare_dirent);
86 }
87
88 static SMB_STRUCT_DIR *dirsort_opendir(vfs_handle_struct *handle,
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89 const char *fname, const char *mask,
90 uint32 attr)
91 {
92 struct dirsort_privates *data = NULL;
93
94 /* set up our private data about this directory */
95 data = (struct dirsort_privates *)SMB_MALLOC(
96 sizeof(struct dirsort_privates));
97
98 data->directory_list = NULL;
99 data->pos = 0;
100
101 /* Open the underlying directory and count the number of entries */
102 data->source_directory = SMB_VFS_NEXT_OPENDIR(handle, fname, mask,
103 attr);
104
105 data->fd = dirfd(data->source_directory);
106
107 SMB_VFS_HANDLE_SET_DATA(handle, data, free_dirsort_privates,
108 struct dirsort_privates, return NULL);
109
110 open_and_sort_dir(handle);
111
112 return data->source_directory;
113 }
114
115 static SMB_STRUCT_DIRENT *dirsort_readdir(vfs_handle_struct *handle,
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116 SMB_STRUCT_DIR *dirp)
117 {
118 struct dirsort_privates *data = NULL;
119 time_t current_mtime;
120 struct stat dir_stat;
121
122 SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
123 return NULL);
124
125 if (fstat(data->fd, &dir_stat) == -1) {
126 return NULL;
127 }
128
129 current_mtime = dir_stat.st_mtime;
130
131 /* throw away cache and re-read the directory if we've changed */
132 if (current_mtime > data->mtime) {
133 open_and_sort_dir(handle);
134 }
135
136 if (data->pos >= data->number_of_entries) {
137 return NULL;
138 }
139
140 return &data->directory_list[data->pos++];
141 }
142
143 static void dirsort_seekdir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp,
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144 long offset)
145 {
146 struct dirsort_privates *data = NULL;
147 SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
148
149 data->pos = offset;
150 }
151
152 static long dirsort_telldir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
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153 {
154 struct dirsort_privates *data = NULL;
155 SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates,
156 return -1);
157
158 return data->pos;
159 }
160
161 static void dirsort_rewinddir(vfs_handle_struct *handle, SMB_STRUCT_DIR *dirp)
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162 {
163 struct dirsort_privates *data = NULL;
164 SMB_VFS_HANDLE_GET_DATA(handle, data, struct dirsort_privates, return);
165
166 data->pos = 0;
167 }
168
169 /* VFS operations structure */
170
171 static vfs_op_tuple dirsort_op_tuples[] = {
172
173 /* Directory operations */
174
175 {SMB_VFS_OP(dirsort_opendir), SMB_VFS_OP_OPENDIR,
176 SMB_VFS_LAYER_TRANSPARENT},
177 {SMB_VFS_OP(dirsort_readdir), SMB_VFS_OP_READDIR,
178 SMB_VFS_LAYER_TRANSPARENT},
179 {SMB_VFS_OP(dirsort_seekdir), SMB_VFS_OP_SEEKDIR,
180 SMB_VFS_LAYER_TRANSPARENT},
181 {SMB_VFS_OP(dirsort_telldir), SMB_VFS_OP_TELLDIR,
182 SMB_VFS_LAYER_TRANSPARENT},
183 {SMB_VFS_OP(dirsort_rewinddir), SMB_VFS_OP_REWINDDIR,
184 SMB_VFS_LAYER_TRANSPARENT},
185
186 {NULL, SMB_VFS_OP_NOOP,
187 SMB_VFS_LAYER_NOOP}
188 };
189
190 NTSTATUS vfs_dirsort_init(void)
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191 {
192 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, "dirsort",
193 dirsort_op_tuples);
194 }