Sync with maint
[git] / dir-iterator.c
1 #include "cache.h"
2 #include "dir.h"
3 #include "iterator.h"
4 #include "dir-iterator.h"
5
6 struct dir_iterator_level {
7         DIR *dir;
8
9         /*
10          * The length of the directory part of path at this level
11          * (including a trailing '/'):
12          */
13         size_t prefix_len;
14 };
15
16 /*
17  * The full data structure used to manage the internal directory
18  * iteration state. It includes members that are not part of the
19  * public interface.
20  */
21 struct dir_iterator_int {
22         struct dir_iterator base;
23
24         /*
25          * The number of levels currently on the stack. After the first
26          * call to dir_iterator_begin(), if it succeeds to open the
27          * first level's dir, this will always be at least 1. Then,
28          * when it comes to zero the iteration is ended and this
29          * struct is freed.
30          */
31         size_t levels_nr;
32
33         /* The number of levels that have been allocated on the stack */
34         size_t levels_alloc;
35
36         /*
37          * A stack of levels. levels[0] is the uppermost directory
38          * that will be included in this iteration.
39          */
40         struct dir_iterator_level *levels;
41
42         /* Combination of flags for this dir-iterator */
43         unsigned int flags;
44 };
45
46 /*
47  * Push a level in the iter stack and initialize it with information from
48  * the directory pointed by iter->base->path. It is assumed that this
49  * strbuf points to a valid directory path. Return 0 on success and -1
50  * otherwise, setting errno accordingly and leaving the stack unchanged.
51  */
52 static int push_level(struct dir_iterator_int *iter)
53 {
54         struct dir_iterator_level *level;
55
56         ALLOC_GROW(iter->levels, iter->levels_nr + 1, iter->levels_alloc);
57         level = &iter->levels[iter->levels_nr++];
58
59         if (!is_dir_sep(iter->base.path.buf[iter->base.path.len - 1]))
60                 strbuf_addch(&iter->base.path, '/');
61         level->prefix_len = iter->base.path.len;
62
63         level->dir = opendir(iter->base.path.buf);
64         if (!level->dir) {
65                 int saved_errno = errno;
66                 if (errno != ENOENT) {
67                         warning_errno("error opening directory '%s'",
68                                       iter->base.path.buf);
69                 }
70                 iter->levels_nr--;
71                 errno = saved_errno;
72                 return -1;
73         }
74
75         return 0;
76 }
77
78 /*
79  * Pop the top level on the iter stack, releasing any resources associated
80  * with it. Return the new value of iter->levels_nr.
81  */
82 static int pop_level(struct dir_iterator_int *iter)
83 {
84         struct dir_iterator_level *level =
85                 &iter->levels[iter->levels_nr - 1];
86
87         if (level->dir && closedir(level->dir))
88                 warning_errno("error closing directory '%s'",
89                               iter->base.path.buf);
90         level->dir = NULL;
91
92         return --iter->levels_nr;
93 }
94
95 /*
96  * Populate iter->base with the necessary information on the next iteration
97  * entry, represented by the given dirent de. Return 0 on success and -1
98  * otherwise, setting errno accordingly.
99  */
100 static int prepare_next_entry_data(struct dir_iterator_int *iter,
101                                    struct dirent *de)
102 {
103         int err, saved_errno;
104
105         strbuf_addstr(&iter->base.path, de->d_name);
106         /*
107          * We have to reset these because the path strbuf might have
108          * been realloc()ed at the previous strbuf_addstr().
109          */
110         iter->base.relative_path = iter->base.path.buf +
111                                    iter->levels[0].prefix_len;
112         iter->base.basename = iter->base.path.buf +
113                               iter->levels[iter->levels_nr - 1].prefix_len;
114
115         if (iter->flags & DIR_ITERATOR_FOLLOW_SYMLINKS)
116                 err = stat(iter->base.path.buf, &iter->base.st);
117         else
118                 err = lstat(iter->base.path.buf, &iter->base.st);
119
120         saved_errno = errno;
121         if (err && errno != ENOENT)
122                 warning_errno("failed to stat '%s'", iter->base.path.buf);
123
124         errno = saved_errno;
125         return err;
126 }
127
128 int dir_iterator_advance(struct dir_iterator *dir_iterator)
129 {
130         struct dir_iterator_int *iter =
131                 (struct dir_iterator_int *)dir_iterator;
132
133         if (S_ISDIR(iter->base.st.st_mode) && push_level(iter)) {
134                 if (errno != ENOENT && iter->flags & DIR_ITERATOR_PEDANTIC)
135                         goto error_out;
136                 if (iter->levels_nr == 0)
137                         goto error_out;
138         }
139
140         /* Loop until we find an entry that we can give back to the caller. */
141         while (1) {
142                 struct dirent *de;
143                 struct dir_iterator_level *level =
144                         &iter->levels[iter->levels_nr - 1];
145
146                 strbuf_setlen(&iter->base.path, level->prefix_len);
147                 errno = 0;
148                 de = readdir(level->dir);
149
150                 if (!de) {
151                         if (errno) {
152                                 warning_errno("error reading directory '%s'",
153                                               iter->base.path.buf);
154                                 if (iter->flags & DIR_ITERATOR_PEDANTIC)
155                                         goto error_out;
156                         } else if (pop_level(iter) == 0) {
157                                 return dir_iterator_abort(dir_iterator);
158                         }
159                         continue;
160                 }
161
162                 if (is_dot_or_dotdot(de->d_name))
163                         continue;
164
165                 if (prepare_next_entry_data(iter, de)) {
166                         if (errno != ENOENT && iter->flags & DIR_ITERATOR_PEDANTIC)
167                                 goto error_out;
168                         continue;
169                 }
170
171                 return ITER_OK;
172         }
173
174 error_out:
175         dir_iterator_abort(dir_iterator);
176         return ITER_ERROR;
177 }
178
179 int dir_iterator_abort(struct dir_iterator *dir_iterator)
180 {
181         struct dir_iterator_int *iter = (struct dir_iterator_int *)dir_iterator;
182
183         for (; iter->levels_nr; iter->levels_nr--) {
184                 struct dir_iterator_level *level =
185                         &iter->levels[iter->levels_nr - 1];
186
187                 if (level->dir && closedir(level->dir)) {
188                         int saved_errno = errno;
189                         strbuf_setlen(&iter->base.path, level->prefix_len);
190                         errno = saved_errno;
191                         warning_errno("error closing directory '%s'",
192                                       iter->base.path.buf);
193                 }
194         }
195
196         free(iter->levels);
197         strbuf_release(&iter->base.path);
198         free(iter);
199         return ITER_DONE;
200 }
201
202 struct dir_iterator *dir_iterator_begin(const char *path, unsigned int flags)
203 {
204         struct dir_iterator_int *iter = xcalloc(1, sizeof(*iter));
205         struct dir_iterator *dir_iterator = &iter->base;
206         int saved_errno;
207
208         strbuf_init(&iter->base.path, PATH_MAX);
209         strbuf_addstr(&iter->base.path, path);
210
211         ALLOC_GROW(iter->levels, 10, iter->levels_alloc);
212         iter->levels_nr = 0;
213         iter->flags = flags;
214
215         /*
216          * Note: stat already checks for NULL or empty strings and
217          * inexistent paths.
218          */
219         if (stat(iter->base.path.buf, &iter->base.st) < 0) {
220                 saved_errno = errno;
221                 goto error_out;
222         }
223
224         if (!S_ISDIR(iter->base.st.st_mode)) {
225                 saved_errno = ENOTDIR;
226                 goto error_out;
227         }
228
229         return dir_iterator;
230
231 error_out:
232         dir_iterator_abort(dir_iterator);
233         errno = saved_errno;
234         return NULL;
235 }