shaba/systemd
1
0
Fork 0
mirror of https://github.com/systemd/systemd.git synced 2024-11-01 00:51:24 +03:00
Code

fileio: introduce read_virtual_file_fd()

Browse Source
This commit is contained in:
Antony Deepak Thomas 2021-09-29 12:47:49 +09:00 committed by Yu Watanabe
parent 83455d0c8b
commit 46a0f5cac8
2 changed files with 17 additions and 8 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

24
src/basic/fileio.c
View File

@ -375,9 +375,8 @@ int verify_file(const char *fn, const char *blob, bool accept_extra_nl) {
return 1;
}
int read_virtual_file(const char *filename, size_t max_size, char **ret_contents, size_t *ret_size) {
int read_virtual_file_fd(int fd, size_t max_size, char **ret_contents, size_t *ret_size) {
_cleanup_free_ char *buf = NULL;
_cleanup_close_ int fd = -1;
size_t n, size;
int n_retries;
bool truncated = false;
@ -395,10 +394,7 @@ int read_virtual_file(const char *filename, size_t max_size, char **ret_contents
* contents* may be returned. (Though the read is still done using one syscall.) Returns 0 on
* partial success, 1 if untruncated contents were read. */
fd = open(filename, O_RDONLY|O_NOCTTY|O_CLOEXEC);
if (fd < 0)
return -errno;
assert(fd >= 0);
assert(max_size <= READ_VIRTUAL_BYTES_MAX || max_size == SIZE_MAX);
/* Limit the number of attempts to read the number of bytes returned by fstat(). */
@ -434,8 +430,8 @@ int read_virtual_file(const char *filename, size_t max_size, char **ret_contents
n_retries--;
} else if (n_retries > 1) {
/* Files in /proc are generally smaller than the page size so let's start with a page size
* buffer from malloc and only use the max buffer on the final try. */
/* Files in /proc are generally smaller than the page size so let's start with
* a page size buffer from malloc and only use the max buffer on the final try. */
size = MIN3(page_size() - 1, READ_VIRTUAL_BYTES_MAX, max_size);
n_retries = 1;
} else {
@ -524,6 +520,18 @@ int read_virtual_file(const char *filename, size_t max_size, char **ret_contents
return !truncated;
}
int read_virtual_file(const char *filename, size_t max_size, char **ret_contents, size_t *ret_size) {
_cleanup_close_ int fd = -1;
assert(filename);
fd = open(filename, O_RDONLY | O_NOCTTY | O_CLOEXEC);
if (fd < 0)
return -errno;
return read_virtual_file_fd(fd, max_size, ret_contents, ret_size);
}
int read_full_stream_full(
FILE *f,
const char *filename,

1
src/basic/fileio.h
View File

@ -67,6 +67,7 @@ static inline int read_full_file(const char *filename, char **ret_contents, size
return read_full_file_full(AT_FDCWD, filename, UINT64_MAX, SIZE_MAX, 0, NULL, ret_contents, ret_size);
}
int read_virtual_file_fd(int fd, size_t max_size, char **ret_contents, size_t *ret_size);
int read_virtual_file(const char *filename, size_t max_size, char **ret_contents, size_t *ret_size);
static inline int read_full_virtual_file(const char *filename, char **ret_contents, size_t *ret_size) {
return read_virtual_file(filename, SIZE_MAX, ret_contents, ret_size);