glibc/io/file_change_detection.c
Paul Eggert 2b778ceb40 Update copyright dates with scripts/update-copyrights
I used these shell commands:

../glibc/scripts/update-copyrights $PWD/../gnulib/build-aux/update-copyright
(cd ../glibc && git commit -am"[this commit message]")

and then ignored the output, which consisted lines saying "FOO: warning:
copyright statement not found" for each of 6694 files FOO.
I then removed trailing white space from benchtests/bench-pthread-locks.c
and iconvdata/tst-iconv-big5-hkscs-to-2ucs4.c, to work around this
diagnostic from Savannah:
remote: *** pre-commit check failed ...
remote: *** error: lines with trailing whitespace found
remote: error: hook declined to update refs/heads/master
2021-01-02 12:17:34 -08:00

119 lines
3.4 KiB
C

/* Detecting file changes using modification times.
Copyright (C) 2017-2021 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, see
<https://www.gnu.org/licenses/>. */
#include <file_change_detection.h>
#include <errno.h>
#include <stddef.h>
bool
__file_is_unchanged (const struct file_change_detection *left,
const struct file_change_detection *right)
{
if (left->size < 0 || right->size < 0)
/* Negative sizes are used as markers and never match. */
return false;
else if (left->size == 0 && right->size == 0)
/* Both files are empty or do not exist, so they have the same
content, no matter what the other fields indicate. */
return true;
else
return left->size == right->size
&& left->ino == right->ino
&& left->mtime.tv_sec == right->mtime.tv_sec
&& left->mtime.tv_nsec == right->mtime.tv_nsec
&& left->ctime.tv_sec == right->ctime.tv_sec
&& left->ctime.tv_nsec == right->ctime.tv_nsec;
}
libc_hidden_def (__file_is_unchanged)
void
__file_change_detection_for_stat (struct file_change_detection *file,
const struct stat64 *st)
{
if (S_ISDIR (st->st_mode))
/* Treat as empty file. */
file->size = 0;
else if (!S_ISREG (st->st_mode))
/* Non-regular files cannot be cached. */
file->size = -1;
else
{
file->size = st->st_size;
file->ino = st->st_ino;
file->mtime = st->st_mtim;
file->ctime = st->st_ctim;
}
}
libc_hidden_def (__file_change_detection_for_stat)
bool
__file_change_detection_for_path (struct file_change_detection *file,
const char *path)
{
struct stat64 st;
if (__stat64 (path, &st) != 0)
switch (errno)
{
case EACCES:
case EISDIR:
case ELOOP:
case ENOENT:
case ENOTDIR:
case EPERM:
/* Ignore errors due to file system contents. Instead, treat
the file as empty. */
file->size = 0;
return true;
default:
/* Other errors are fatal. */
return false;
}
else /* stat64 was successfull. */
{
__file_change_detection_for_stat (file, &st);
return true;
}
}
libc_hidden_def (__file_change_detection_for_path)
bool
__file_change_detection_for_fp (struct file_change_detection *file,
FILE *fp)
{
if (fp == NULL)
{
/* The file does not exist. */
file->size = 0;
return true;
}
else
{
struct stat64 st;
if (__fstat64 (__fileno (fp), &st) != 0)
/* If we already have a file descriptor, all errors are fatal. */
return false;
else
{
__file_change_detection_for_stat (file, &st);
return true;
}
}
}
libc_hidden_def (__file_change_detection_for_fp)