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xz: support concatenated .xz streams

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function                                             old     new   delta
xz_dec_reset                                           -      77     +77
unpack_xz_stream                                    2402    2397      -5

Signed-off-by: Lasse Collin <lasse.collin@tukaani.org>
Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Lasse Collin 2013-02-27 17:26:40 +01:00 committed by Denys Vlasenko
parent 433757413f
commit 380c8a0763
1 changed files with 36 additions and 7 deletions
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43
archival/libarchive/decompress_unxz.c
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@ -40,6 +40,7 @@ static uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
IF_DESKTOP(long long) int FAST_FUNC IF_DESKTOP(long long) int FAST_FUNC
unpack_xz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd) unpack_xz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd)
{ {
enum xz_ret xz_result;
struct xz_buf iobuf; struct xz_buf iobuf;
struct xz_dec *state; struct xz_dec *state;
unsigned char *membuf; unsigned char *membuf;
@ -63,9 +64,8 @@ unpack_xz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd)
/* Limit memory usage to about 64 MiB. */ /* Limit memory usage to about 64 MiB. */
state = xz_dec_init(XZ_DYNALLOC, 64*1024*1024); state = xz_dec_init(XZ_DYNALLOC, 64*1024*1024);
xz_result = X_OK;
while (1) { while (1) {
enum xz_ret r;
if (iobuf.in_pos == iobuf.in_size) { if (iobuf.in_pos == iobuf.in_size) {
int rd = safe_read(src_fd, membuf, BUFSIZ); int rd = safe_read(src_fd, membuf, BUFSIZ);
if (rd < 0) { if (rd < 0) {
@ -73,28 +73,57 @@ unpack_xz_stream(transformer_aux_data_t *aux, int src_fd, int dst_fd)
total = -1; total = -1;
break; break;
} }
if (rd == 0 && xz_result == XZ_STREAM_END)
break;
iobuf.in_size = rd; iobuf.in_size = rd;
iobuf.in_pos = 0; iobuf.in_pos = 0;
} }
if (xz_result == XZ_STREAM_END) {
/*
* Try to start decoding next concatenated stream.
* Stream padding must always be a multiple of four
* bytes to preserve four-byte alignment. To keep the
* code slightly smaller, we aren't as strict here as
* the .xz spec requires. We just skip all zero-bytes
* without checking the alignment and thus can accept
* files that aren't valid, e.g. the XZ utils test
* files bad-0pad-empty.xz and bad-0catpad-empty.xz.
*/
do {
if (membuf[iobuf.in_pos] != 0) {
xz_dec_reset(state);
goto do_run;
}
iobuf.in_pos++;
} while (iobuf.in_pos < iobuf.in_size);
}
do_run:
// bb_error_msg(">in pos:%d size:%d out pos:%d size:%d", // bb_error_msg(">in pos:%d size:%d out pos:%d size:%d",
// iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size); // iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size);
r = xz_dec_run(state, &iobuf); xz_result = xz_dec_run(state, &iobuf);
// bb_error_msg("<in pos:%d size:%d out pos:%d size:%d r:%d", // bb_error_msg("<in pos:%d size:%d out pos:%d size:%d r:%d",
// iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size, r); // iobuf.in_pos, iobuf.in_size, iobuf.out_pos, iobuf.out_size, xz_result);
if (iobuf.out_pos) { if (iobuf.out_pos) {
xwrite(dst_fd, iobuf.out, iobuf.out_pos); xwrite(dst_fd, iobuf.out, iobuf.out_pos);
IF_DESKTOP(total += iobuf.out_pos;) IF_DESKTOP(total += iobuf.out_pos;)
iobuf.out_pos = 0; iobuf.out_pos = 0;
} }
if (r == XZ_STREAM_END) { if (xz_result == XZ_STREAM_END) {
break; /*
* Can just "break;" here, if not for concatenated
* .xz streams.
* Checking for padding may require buffer
* replenishment. Can't do it here.
*/
continue;
} }
if (r != XZ_OK && r != XZ_UNSUPPORTED_CHECK) { if (xz_result != XZ_OK && xz_result != XZ_UNSUPPORTED_CHECK) {
bb_error_msg("corrupted data"); bb_error_msg("corrupted data");
total = -1; total = -1;
break; break;
} }
} }
xz_dec_end(state); xz_dec_end(state);
free(membuf); free(membuf);