mirror of
https://git.tukaani.org/xz.git
synced 2024-04-04 12:36:23 +02:00
xz: Add io_seek_src().
This commit is contained in:
parent
bba477257d
commit
c28f0b3d00
2 changed files with 30 additions and 3 deletions
|
@ -1169,16 +1169,30 @@ io_read(file_pair *pair, io_buf *buf_union, size_t size)
|
|||
|
||||
|
||||
extern bool
|
||||
io_pread(file_pair *pair, io_buf *buf, size_t size, off_t pos)
|
||||
io_seek_src(file_pair *pair, off_t pos)
|
||||
{
|
||||
// Using lseek() and read() is more portable than pread() and
|
||||
// for us it is as good as real pread().
|
||||
assert(pos >= 0);
|
||||
|
||||
if (lseek(pair->src_fd, pos, SEEK_SET) != pos) {
|
||||
message_error(_("%s: Error seeking the file: %s"),
|
||||
pair->src_name, strerror(errno));
|
||||
return true;
|
||||
}
|
||||
|
||||
pair->src_eof = false;
|
||||
|
||||
return false;
|
||||
}
|
||||
|
||||
|
||||
extern bool
|
||||
io_pread(file_pair *pair, io_buf *buf, size_t size, off_t pos)
|
||||
{
|
||||
// Using lseek() and read() is more portable than pread() and
|
||||
// for us it is as good as real pread().
|
||||
if (io_seek_src(pair, pos))
|
||||
return true;
|
||||
|
||||
const size_t amount = io_read(pair, buf, size);
|
||||
if (amount == SIZE_MAX)
|
||||
return true;
|
||||
|
|
|
@ -129,6 +129,19 @@ extern size_t io_read(file_pair *pair, io_buf *buf, size_t size);
|
|||
extern void io_fix_src_pos(file_pair *pair, size_t rewind_size);
|
||||
|
||||
|
||||
/// \brief Seek to the given absolute position in the source file
|
||||
///
|
||||
/// This calls lseek() and also clears pair->src_eof.
|
||||
///
|
||||
/// \param pair Seekable source file
|
||||
/// \param pos Offset relative to the beginning of the file,
|
||||
/// from which the data should be read.
|
||||
///
|
||||
/// \return On success, false is returned. On error, error message
|
||||
/// is printed and true is returned.
|
||||
extern bool io_seek_src(file_pair *pair, off_t pos);
|
||||
|
||||
|
||||
/// \brief Read from source file from given offset to a buffer
|
||||
///
|
||||
/// This is remotely similar to standard pread(). This uses lseek() though,
|
||||
|
|
Loading…
Reference in a new issue