From c28f0b3d00af87b92dda229831548d8eb0067d1d Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Wed, 5 Apr 2017 18:47:22 +0300 Subject: xz: Add io_seek_src(). --- src/xz/file_io.c | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) (limited to 'src/xz/file_io.c') diff --git a/src/xz/file_io.c b/src/xz/file_io.c index 041bed88..48ef8223 100644 --- a/src/xz/file_io.c +++ b/src/xz/file_io.c @@ -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; -- cgit v1.2.3