emo/busybox
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

cksum: code shrink

Browse Source 
function                                             old     new   delta
cksum_main                                           281     262     -19

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko
2018-02-01 11:44:52 +01:00
parent ddacb03e87
commit da49e7057a
1 changed files with 24 additions and 23 deletions
Download Patch File Download Diff File Expand all files Collapse all files

47
coreutils/cksum.c
View File

@ -31,9 +31,6 @@ int cksum_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int cksum_main(int argc UNUSED_PARAM, char **argv) int cksum_main(int argc UNUSED_PARAM, char **argv)
{ {
uint32_t *crc32_table = crc32_filltable(NULL, 1); uint32_t *crc32_table = crc32_filltable(NULL, 1);
uint32_t crc;
off_t length, filesize;
int bytes_read;
int exit_code = EXIT_SUCCESS; int exit_code = EXIT_SUCCESS;
#if ENABLE_DESKTOP #if ENABLE_DESKTOP
@ -45,38 +42,42 @@ int cksum_main(int argc UNUSED_PARAM, char **argv)
setup_common_bufsiz(); setup_common_bufsiz();
do { do {
uint32_t crc;
off_t filesize;
int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input); int fd = open_or_warn_stdin(*argv ? *argv : bb_msg_standard_input);
if (fd < 0) { if (fd < 0) {
exit_code = EXIT_FAILURE; exit_code = EXIT_FAILURE;
continue; continue;
} }
crc = 0; crc = 0;
length = 0; filesize = 0;
#define read_buf bb_common_bufsiz1 #define read_buf bb_common_bufsiz1
while ((bytes_read = safe_read(fd, read_buf, COMMON_BUFSIZE)) > 0) { for (;;) {
length += bytes_read; uoff_t t;
int bytes_read = safe_read(fd, read_buf, COMMON_BUFSIZE);
if (bytes_read > 0) {
filesize += bytes_read;
} else {
/* Checksum filesize bytes, LSB first, and exit */
close(fd);
fd = -1; /* break flag */
t = filesize;
bytes_read = 0;
while (t != 0) {
read_buf[bytes_read++] = (uint8_t)t;
t >>= 8;
}
}
crc = crc32_block_endian1(crc, read_buf, bytes_read, crc32_table); crc = crc32_block_endian1(crc, read_buf, bytes_read, crc32_table);
if (fd < 0)
break;
} }
close(fd);
filesize = length;
while (length) {
crc = (crc << 8) ^ crc32_table[(uint8_t)(crc >> 24) ^ (uint8_t)length];
/* must ensure that shift is unsigned! */
if (sizeof(length) <= sizeof(unsigned))
length = (unsigned)length >> 8;
else if (sizeof(length) <= sizeof(unsigned long))
length = (unsigned long)length >> 8;
else
length = (unsigned long long)length >> 8;
}
crc = ~crc; crc = ~crc;
printf((*argv ? "%u %"OFF_FMT"u %s\n" : "%u %"OFF_FMT"u\n"),
printf((*argv ? "%"PRIu32" %"OFF_FMT"i %s\n" : "%"PRIu32" %"OFF_FMT"i\n"), (unsigned)crc, filesize, *argv);
crc, filesize, *argv);
} while (*argv && *++argv); } while (*argv && *++argv);
fflush_stdout_and_exit(exit_code); fflush_stdout_and_exit(exit_code);