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bzip2 decompression: simple code shrink

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function                                             old     new   delta
unpack_bz2_stream_prime                               60      55      -5
get_header_tar                                      1508    1496     -12

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2010-06-30 19:43:44 +02:00
parent fa5ea17b5f
commit 620e863ba2
2 changed files with 9 additions and 6 deletions
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6
archival/libunarchive/decompress_bunzip2.c
View File

@ -692,9 +692,9 @@ unpack_bz2_stream(int src_fd, int dst_fd)
IF_DESKTOP(long long) int FAST_FUNC
unpack_bz2_stream_prime(int src_fd, int dst_fd)
{
unsigned char magic[2];
xread(src_fd, magic, 2);
if (magic[0] != 'B' || magic[1] != 'Z') {
uint16_t magic2;
xread(src_fd, &magic2, 2);
if (magic2 != BZIP2_MAGIC) {
bb_error_msg_and_die("invalid magic");
}
return unpack_bz2_stream(src_fd, dst_fd);

9
archival/libunarchive/get_header_tar.c
View File

@ -196,27 +196,30 @@ char FAST_FUNC get_header_tar(archive_handle_t *archive_handle)
) {
#if ENABLE_FEATURE_TAR_AUTODETECT
char FAST_FUNC (*get_header_ptr)(archive_handle_t *);
uint16_t magic2;
autodetect:
magic2 = *(uint16_t*)tar.name;
/* tar gz/bz autodetect: check for gz/bz2 magic.
* If we see the magic, and it is the very first block,
* we can switch to get_header_tar_gz/bz2/lzma().
* Needs seekable fd. I wish recv(MSG_PEEK) works
* on any fd... */
# if ENABLE_FEATURE_SEAMLESS_GZ
if (tar.name[0] == 0x1f && tar.name[1] == (char)0x8b) { /* gzip */
if (magic2 == GZIP_MAGIC) {
get_header_ptr = get_header_tar_gz;
} else
# endif
# if ENABLE_FEATURE_SEAMLESS_BZ2
if (tar.name[0] == 'B' && tar.name[1] == 'Z'
if (magic2 == BZIP2_MAGIC
&& tar.name[2] == 'h' && isdigit(tar.name[3])
) { /* bzip2 */
get_header_ptr = get_header_tar_bz2;
} else
# endif
# if ENABLE_FEATURE_SEAMLESS_XZ
//TODO
//TODO: if (magic2 == XZ_MAGIC1)...
//else
# endif
goto err;
/* Two different causes for lseek() != 0: