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authorDenys Vlasenko2010-10-27 15:26:45 +0200
committerDenys Vlasenko2010-10-27 15:26:45 +0200
commit9ce642f9746dfc29d119d0680b769677e3ea6da6 (patch)
treef8d2bcd08c691979058b610b32573a742a3e3024 /libbb/crc32.c
parentdd88ba88f5082b1785539b1fb87af7320515b8c9 (diff)
downloadbusybox-9ce642f9746dfc29d119d0680b769677e3ea6da6.zip
busybox-9ce642f9746dfc29d119d0680b769677e3ea6da6.tar.gz
libbb: introduce and use common crc32 routine
function old new delta crc32_block_endian1 - 37 +37 crc32_block_endian0 - 34 +34 global_crc32_table - 8 +8 file_read 82 87 +5 gzip_main 211 214 +3 xz_crc32 40 35 -5 crc32_table 8 - -8 calculate_gunzip_crc 54 34 -20 lzo_crc32 54 25 -29 cksum_main 298 211 -87 ------------------------------------------------------------------------------ (add/remove: 3/1 grow/shrink: 2/4 up/down: 87/-149) Total: -62 bytes Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Diffstat (limited to 'libbb/crc32.c')
-rw-r--r--libbb/crc32.c24
1 files changed, 24 insertions, 0 deletions
diff --git a/libbb/crc32.c b/libbb/crc32.c
index 520b1ff..2cc6ea7 100644
--- a/libbb/crc32.c
+++ b/libbb/crc32.c
@@ -18,6 +18,8 @@
#include "libbb.h"
+uint32_t *global_crc32_table;
+
uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian)
{
uint32_t polynomial = endian ? 0x04c11db7 : 0xedb88320;
@@ -40,3 +42,25 @@ uint32_t* FAST_FUNC crc32_filltable(uint32_t *crc_table, int endian)
return crc_table - 256;
}
+
+uint32_t FAST_FUNC crc32_block_endian1(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table)
+{
+ const void *end = (uint8_t*)buf + len;
+
+ while (buf != end) {
+ val = (val << 8) ^ crc_table[(val >> 24) ^ *(uint8_t*)buf];
+ buf = (uint8_t*)buf + 1;
+ }
+ return val;
+}
+
+uint32_t FAST_FUNC crc32_block_endian0(uint32_t val, const void *buf, unsigned len, uint32_t *crc_table)
+{
+ const void *end = (uint8_t*)buf + len;
+
+ while (buf != end) {
+ val = crc_table [(uint8_t)val ^ *(uint8_t*)buf] ^ (val >> 8);
+ buf = (uint8_t*)buf + 1;
+ }
+ return val;
+}