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| author | Lasse Collin <lasse.collin@tukaani.org> | 2011-05-01 12:24:23 +0300 |
|---|---|---|
| committer | Lasse Collin <lasse.collin@tukaani.org> | 2011-05-01 12:24:23 +0300 |
| commit | 7a480e485938884ef3021b48c3b0b9f9699dc9b6 (patch) | |
| tree | 21d5755f218c14d35905a516a7ff07dd46872254 | |
| parent | c29e6630c1450c630c4e7b783bdd76515db9004c (diff) | |
| download | xz-7a480e485938884ef3021b48c3b0b9f9699dc9b6.tar.gz | |
xz: Fix input file position when --single-stream is used.
Now the following works as you would expect:
echo foo | xz > foo.xz
echo bar | xz >> foo.xz
( xz -dc --single-stream ; xz -dc --single-stream ) < foo.xz
Note that it doesn't work if the input is not seekable
or if there is Stream Padding between the concatenated
.xz Streams.
| -rw-r--r-- | src/xz/coder.c | 1 | ||||
| -rw-r--r-- | src/xz/file_io.c | 15 | ||||
| -rw-r--r-- | src/xz/file_io.h | 13 |
3 files changed, 29 insertions, 0 deletions
diff --git a/src/xz/coder.c b/src/xz/coder.c index 316f560..b470e58 100644 --- a/src/xz/coder.c +++ b/src/xz/coder.c @@ -594,6 +594,7 @@ coder_normal(file_pair *pair) if (ret == LZMA_STREAM_END) { if (opt_single_stream) { + io_fix_src_pos(pair, strm.avail_in); success = true; break; } diff --git a/src/xz/file_io.c b/src/xz/file_io.c index 370b61b..f9807a6 100644 --- a/src/xz/file_io.c +++ b/src/xz/file_io.c @@ -840,6 +840,21 @@ io_close(file_pair *pair, bool success) } +extern void +io_fix_src_pos(file_pair *pair, size_t rewind_size) +{ + assert(rewind_size <= IO_BUFFER_SIZE); + + if (rewind_size > 0) { + // This doesn't need to work on unseekable file descriptors, + // so just ignore possible errors. + (void)lseek(pair->src_fd, -(off_t)(rewind_size), SEEK_CUR); + } + + return; +} + + extern size_t io_read(file_pair *pair, io_buf *buf_union, size_t size) { diff --git a/src/xz/file_io.h b/src/xz/file_io.h index 967da86..ef63932 100644 --- a/src/xz/file_io.h +++ b/src/xz/file_io.h @@ -102,6 +102,19 @@ extern void io_close(file_pair *pair, bool success); extern size_t io_read(file_pair *pair, io_buf *buf, size_t size); +/// \brief Fix the position in src_fd +/// +/// This is used when --single-thream has been specified and decompression +/// is successful. If the input file descriptor supports seeking, this +/// function fixes the input position to point to the next byte after the +/// decompressed stream. +/// +/// \param pair File pair having the source file open for reading +/// \param rewind_size How many bytes of extra have been read i.e. +/// how much to seek backwards. +extern void io_fix_src_pos(file_pair *pair, size_t rewind_size); + + /// \brief Read from source file from given offset to a buffer /// /// This is remotely similar to standard pread(). This uses lseek() though, |