]>
Commit | Line | Data |
---|---|---|
631cf64b | 1 | /* Detecting file changes using modification times. |
6d7e8eda | 2 | Copyright (C) 2017-2023 Free Software Foundation, Inc. |
631cf64b FW |
3 | This file is part of the GNU C Library. |
4 | ||
5 | The GNU C Library is free software; you can redistribute it and/or | |
6 | modify it under the terms of the GNU Lesser General Public | |
7 | License as published by the Free Software Foundation; either | |
8 | version 2.1 of the License, or (at your option) any later version. | |
9 | ||
10 | The GNU C Library is distributed in the hope that it will be useful, | |
11 | but WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | Lesser General Public License for more details. | |
14 | ||
15 | You should have received a copy of the GNU Lesser General Public | |
16 | License along with the GNU C Library; if not, see | |
17 | <https://www.gnu.org/licenses/>. */ | |
18 | ||
19 | #include <file_change_detection.h> | |
20 | ||
21 | #include <errno.h> | |
22 | #include <stddef.h> | |
23 | ||
24 | bool | |
25 | __file_is_unchanged (const struct file_change_detection *left, | |
26 | const struct file_change_detection *right) | |
27 | { | |
28 | if (left->size < 0 || right->size < 0) | |
29 | /* Negative sizes are used as markers and never match. */ | |
30 | return false; | |
31 | else if (left->size == 0 && right->size == 0) | |
32 | /* Both files are empty or do not exist, so they have the same | |
33 | content, no matter what the other fields indicate. */ | |
34 | return true; | |
35 | else | |
36 | return left->size == right->size | |
37 | && left->ino == right->ino | |
38 | && left->mtime.tv_sec == right->mtime.tv_sec | |
39 | && left->mtime.tv_nsec == right->mtime.tv_nsec | |
40 | && left->ctime.tv_sec == right->ctime.tv_sec | |
41 | && left->ctime.tv_nsec == right->ctime.tv_nsec; | |
42 | } | |
43 | libc_hidden_def (__file_is_unchanged) | |
44 | ||
45 | void | |
46 | __file_change_detection_for_stat (struct file_change_detection *file, | |
52a5fe70 | 47 | const struct __stat64_t64 *st) |
631cf64b FW |
48 | { |
49 | if (S_ISDIR (st->st_mode)) | |
50 | /* Treat as empty file. */ | |
51 | file->size = 0; | |
52 | else if (!S_ISREG (st->st_mode)) | |
53 | /* Non-regular files cannot be cached. */ | |
54 | file->size = -1; | |
55 | else | |
56 | { | |
57 | file->size = st->st_size; | |
58 | file->ino = st->st_ino; | |
30adcf5a AZ |
59 | file->mtime = (struct __timespec64) { st->st_mtim.tv_sec, |
60 | st->st_mtim.tv_nsec }; | |
61 | file->ctime = (struct __timespec64) { st->st_ctim.tv_sec, | |
62 | st->st_ctim.tv_nsec }; | |
631cf64b FW |
63 | } |
64 | } | |
65 | libc_hidden_def (__file_change_detection_for_stat) | |
66 | ||
67 | bool | |
68 | __file_change_detection_for_path (struct file_change_detection *file, | |
69 | const char *path) | |
70 | { | |
52a5fe70 AZ |
71 | struct __stat64_t64 st; |
72 | if (__stat64_time64 (path, &st) != 0) | |
631cf64b FW |
73 | switch (errno) |
74 | { | |
75 | case EACCES: | |
76 | case EISDIR: | |
77 | case ELOOP: | |
78 | case ENOENT: | |
79 | case ENOTDIR: | |
80 | case EPERM: | |
81 | /* Ignore errors due to file system contents. Instead, treat | |
82 | the file as empty. */ | |
83 | file->size = 0; | |
84 | return true; | |
85 | default: | |
86 | /* Other errors are fatal. */ | |
87 | return false; | |
88 | } | |
7f0d9e61 | 89 | else /* stat64 was successful. */ |
631cf64b FW |
90 | { |
91 | __file_change_detection_for_stat (file, &st); | |
92 | return true; | |
93 | } | |
94 | } | |
95 | libc_hidden_def (__file_change_detection_for_path) | |
96 | ||
97 | bool | |
98 | __file_change_detection_for_fp (struct file_change_detection *file, | |
99 | FILE *fp) | |
100 | { | |
101 | if (fp == NULL) | |
102 | { | |
103 | /* The file does not exist. */ | |
104 | file->size = 0; | |
105 | return true; | |
106 | } | |
107 | else | |
108 | { | |
52a5fe70 AZ |
109 | struct __stat64_t64 st; |
110 | if (__fstat64_time64 (__fileno (fp), &st) != 0) | |
631cf64b FW |
111 | /* If we already have a file descriptor, all errors are fatal. */ |
112 | return false; | |
113 | else | |
114 | { | |
115 | __file_change_detection_for_stat (file, &st); | |
116 | return true; | |
117 | } | |
118 | } | |
119 | } | |
120 | libc_hidden_def (__file_change_detection_for_fp) |