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>

4 files changed, 15 insertions, 42 deletions

diff --git a/archival/gzip.c b/archival/gzip.c
index 32528d96b..4d399063d 100644
--- a/archival/gzip.c
+++ b/archival/gzip.c
@@ -340,7 +340,7 @@ struct globals {
 	ulg bits_sent;			/* bit length of the compressed data */
 #endif
 
-	uint32_t *crc_32_tab;
+	/*uint32_t *crc_32_tab;*/
 	uint32_t crc;	/* shift register contents */
 };
 
@@ -393,15 +393,9 @@ static void put_32bit(ulg n)
  * pointer, then initialize the crc shift register contents instead.
  * Return the current crc in either case.
  */
-static uint32_t updcrc(uch * s, unsigned n)
+static void updcrc(uch * s, unsigned n)
 {
-	uint32_t c = G1.crc;
-	while (n) {
-		c = G1.crc_32_tab[(uch)(c ^ *s++)] ^ (c >> 8);
-		n--;
-	}
-	G1.crc = c;
-	return c;
+	G1.crc = crc32_block_endian0(G1.crc, s, n, global_crc32_table /*G1.crc_32_tab*/);
 }
 
 
@@ -2104,8 +2098,8 @@ int gzip_main(int argc UNUSED_PARAM, char **argv)
 	ALLOC(uch, G1.window, 2L * WSIZE);
 	ALLOC(ush, G1.prev, 1L << BITS);
 
-	/* Initialise the CRC32 table */
-	G1.crc_32_tab = crc32_filltable(NULL, 0);
+	/* Initialize the CRC32 table */
+	global_crc32_table = crc32_filltable(NULL, 0);
 
 	return bbunpack(argv, pack_gzip, append_ext, "gz");
 }
diff --git a/archival/libunarchive/decompress_unxz.c b/archival/libunarchive/decompress_unxz.c
index faba9ca82..ca427231e 100644
--- a/archival/libunarchive/decompress_unxz.c
+++ b/archival/libunarchive/decompress_unxz.c
@@ -22,17 +22,9 @@
 
 /* We use our own crc32 function */
 #define XZ_INTERNAL_CRC32 0
-static uint32_t *crc32_table;
 static uint32_t xz_crc32(const uint8_t *buf, size_t size, uint32_t crc)
 {
-	crc = ~crc;
-
-	while (size != 0) {
-		crc = crc32_table[*buf++ ^ (crc & 0xFF)] ^ (crc >> 8);
-		--size;
-	}
-
-	return ~crc;
+	return ~crc32_block_endian0(~crc, buf, size, global_crc32_table);
 }
 
 /* We use arch-optimized unaligned accessors */
@@ -53,8 +45,8 @@ unpack_xz_stream(int src_fd, int dst_fd)
 	unsigned char *membuf;
 	IF_DESKTOP(long long) int total = 0;
 
-	if (!crc32_table)
-		crc32_table = crc32_filltable(NULL, /*endian:*/ 0);
+	if (!global_crc32_table)
+		global_crc32_table = crc32_filltable(NULL, /*endian:*/ 0);
 
 	memset(&iobuf, 0, sizeof(iobuf));
 	/* Preload XZ file signature */
diff --git a/archival/libunarchive/decompress_unzip.c b/archival/libunarchive/decompress_unzip.c
index 20fda9d26..cb8a3d737 100644
--- a/archival/libunarchive/decompress_unzip.c
+++ b/archival/libunarchive/decompress_unzip.c
@@ -925,10 +925,7 @@ static int inflate_block(STATE_PARAM smallint *e)
 /* Two callsites, both in inflate_get_next_window */
 static void calculate_gunzip_crc(STATE_PARAM_ONLY)
 {
-	unsigned n;
-	for (n = 0; n < gunzip_outbuf_count; n++) {
-		gunzip_crc = gunzip_crc_table[((int) gunzip_crc ^ (gunzip_window[n])) & 0xff] ^ (gunzip_crc >> 8);
-	}
+	gunzip_crc = crc32_block_endian0(gunzip_crc, gunzip_window, gunzip_outbuf_count, gunzip_crc_table);
 	gunzip_bytes_out += gunzip_outbuf_count;
 }
 
diff --git a/archival/lzop.c b/archival/lzop.c
index c6e718ad7..acb34fe14 100644
--- a/archival/lzop.c
+++ b/archival/lzop.c
@@ -393,7 +393,7 @@ typedef struct header_t {
 } header_t;
 
 struct globals {
-	const uint32_t *lzo_crc32_table;
+	/*const uint32_t *lzo_crc32_table;*/
 	chksum_t chksum_in;
 	chksum_t chksum_out;
 } FIX_ALIASING;
@@ -468,19 +468,10 @@ lzo_adler32(uint32_t adler, const uint8_t* buf, unsigned len)
 static FAST_FUNC uint32_t
 lzo_crc32(uint32_t c, const uint8_t* buf, unsigned len)
 {
-	uint32_t crc;
+	//if (buf == NULL) - impossible
+	//	return 0;
 
-	if (buf == NULL)
-		return 0;
-
-	crc = ~c;
-	if (len != 0) do {
-		crc = G.lzo_crc32_table[(uint8_t)((int)crc ^ *buf)] ^ (crc >> 8);
-		buf += 1;
-		len -= 1;
-	} while (len > 0);
-
-	return ~crc;
+	return ~crc32_block_endian0(~c, buf, len, global_crc32_table);
 }
 
 /**********************************************************************/
@@ -679,8 +670,7 @@ static NOINLINE smallint lzo_compress(const header_t *h)
 		if (dst_len < src_len) {
 			/* write checksum of compressed block */
 			if (h->flags & F_ADLER32_C)
-				write32(lzo_adler32(ADLER32_INIT_VALUE, b2,
-							dst_len));
+				write32(lzo_adler32(ADLER32_INIT_VALUE, b2, dst_len));
 			if (h->flags & F_CRC32_C)
 				write32(lzo_crc32(CRC32_INIT_VALUE, b2, dst_len));
 			/* write compressed block data */
@@ -1080,6 +1070,6 @@ int lzop_main(int argc UNUSED_PARAM, char **argv)
 	if (applet_name[0] == 'u')
 		option_mask32 |= OPT_DECOMPRESS;
 
-	G.lzo_crc32_table = crc32_filltable(NULL, 0);
+	global_crc32_table = crc32_filltable(NULL, 0);
 	return bbunpack(argv, pack_lzop, make_new_name_lzop, /*unused:*/ NULL);
 }