[BusyBox] Patch: libbb/unzip.c size reduction
rbrown64 at csc.com.au
rbrown64 at csc.com.au
Sat Dec 1 01:06:31 UTC 2001
text data bss dec hex filename
6356 4 36 6396 18fc libbb/unzip.o -- i?86 linux
6200 428 36 6664 1a08 libbb/unzip.o.0
2001-12-01 Rodney Brown <rbrown64 at csc.com.au>
* libbb/unzip.c: Space reductions.
* archival/bunzip2.c: Declare BZ2_crc32Table const.
--- TODO 2001/12/01 01:50:37 1.1
+++ TODO 2001/12/01 02:00:38
@@ -56,3 +56,8 @@ and then start with the biggest things a
xargs could use a -l option
------------------------------------------------------------------
+
+libbb/unzip.c and archival/gzip.c have common constant static arrays and
+code for initializing the CRC array. Both use CRC-32 and could use
+common code for CRC calculation. Within archival/gzip.c, the CRC
+array should be malloc-ed as it is in libbb/unzip.c .
--- Changelog 2001/12/01 01:50:37 1.1
+++ Changelog 2001/12/01 01:51:05
@@ -15,7 +15,7 @@
-- a whole bunch of ash size optimizations
-- Fix for ash leading redirections (i.e. '2>/dev/null ls rubbish')
* Rodney Brown <RDBrown at mira.net>
- -- Optimized gzip.c, shrinking it be ~1.5k
+ -- Optimized gzip.c, shrinking it by ~1.5k
* Matt Kraai
-- Fix sed s/[/]// handling (closes: #1208).
-- Fix `-/bin/sh' invocation (closes: #1209).
--- libbb/unzip.c 2001/11/30 11:06:14 1.2
+++ libbb/unzip.c 2001/12/01 02:06:49
@@ -124,19 +124,12 @@ static void abort_gzip(void)
static void make_crc_table(void)
{
unsigned long table_entry; /* crc shift register */
- unsigned long poly = 0; /* polynomial exclusive-or pattern */
+ const unsigned long poly = 0xedb88320L; /* polynomial exclusive-or pattern */
int i; /* counter for all possible eight bit values */
int k; /* byte being shifted into crc apparatus */
- /* terms of polynomial defining this crc (except x^32): */
- static int p[] = {0,1,2,4,5,7,8,10,11,12,16,22,23,26};
-
crc_table = (unsigned long *) malloc(256 * sizeof(unsigned long));
- /* Make exclusive-or pattern from polynomial (0xedb88320) */
- for (i = 0; i < sizeof(p)/sizeof(int); i++)
- poly |= 1L << (31 - p[i]);
-
/* Compute and print table of CRC's, five per line */
for (i = 0; i < 256; i++) {
table_entry = i;
@@ -192,6 +185,8 @@ static int huft_free(huft_t *t)
return 0;
}
+typedef unsigned char extra_bits_t;
+
/* Given a list of code lengths and a maximum table size, make a set of
* tables to decode that set of codes. Return zero on success, one if
* the given code set is incomplete (the tables are still built in this
@@ -207,7 +202,7 @@ static int huft_free(huft_t *t)
* m: maximum lookup bits, returns actual
*/
static int huft_build(unsigned int *b, const unsigned int n, const unsigned int s,
- const unsigned short *d, const unsigned short *e, huft_t **t, int *m)
+ const unsigned short *d, const extra_bits_t *e, huft_t **t, int *m)
{
unsigned a; /* counter for codes of length k */
unsigned c[BMAX + 1]; /* bit length count table */
@@ -499,6 +494,30 @@ static int inflate_codes(huft_t *tl, huf
return 0;
}
+static const unsigned short cplens[] = { /* Copy lengths for literal codes 257..285 */
+ 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
+ 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
+};
+/* note: see note #13 above about the 258 in this list. */
+static const extra_bits_t cplext[] = { /* Extra bits for literal codes 257..285 */
+ 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
+ 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
+}; /* 99==invalid */
+static const unsigned short cpdist[] = { /* Copy offsets for distance codes 0..29 */
+ 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
+ 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
+ 8193, 12289, 16385, 24577
+};
+static const extra_bits_t cpdext[] = { /* Extra bits for distance codes */
+ 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
+ 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
+ 12, 12, 13, 13
+};
+/* Tables for deflate from PKZIP's appnote.txt. */
+static const extra_bits_t border[] = { /* Order of the bit length code lengths */
+ 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
+};
+
/*
* decompress an inflated block
* e: last block flag
@@ -510,25 +529,6 @@ static int inflate_block(int *e)
unsigned t; /* block type */
register unsigned long b; /* bit buffer */
register unsigned k; /* number of bits in bit buffer */
- static unsigned short cplens[] = { /* Copy lengths for literal codes 257..285 */
- 3, 4, 5, 6, 7, 8, 9, 10, 11, 13, 15, 17, 19, 23, 27, 31,
- 35, 43, 51, 59, 67, 83, 99, 115, 131, 163, 195, 227, 258, 0, 0
- };
- /* note: see note #13 above about the 258 in this list. */
- static unsigned short cplext[] = { /* Extra bits for literal codes 257..285 */
- 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 2, 2, 2, 2,
- 3, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 0, 99, 99
- }; /* 99==invalid */
- static unsigned short cpdist[] = { /* Copy offsets for distance codes 0..29 */
- 1, 2, 3, 4, 5, 7, 9, 13, 17, 25, 33, 49, 65, 97, 129, 193,
- 257, 385, 513, 769, 1025, 1537, 2049, 3073, 4097, 6145,
- 8193, 12289, 16385, 24577
- };
- static unsigned short cpdext[] = { /* Extra bits for distance codes */
- 0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
- 7, 7, 8, 8, 9, 9, 10, 10, 11, 11,
- 12, 12, 13, 13
- };
/* make local bit buffer */
b = bb;
@@ -667,12 +667,8 @@ static int inflate_block(int *e)
}
case 2: /* Inflate dynamic */
{
- /* Tables for deflate from PKZIP's appnote.txt. */
- static unsigned border[] = { /* Order of the bit length code lengths */
- 16, 17, 18, 0, 8, 7, 9, 6, 10, 5, 11, 4, 12, 3, 13, 2, 14, 1, 15
- };
- int dbits = 6; /* bits in base distance lookup table */
- int lbits = 9; /* bits in base literal/length lookup table */
+ const int dbits = 6; /* bits in base distance lookup table */
+ const int lbits = 9; /* bits in base literal/length lookup table */
int i; /* temporary variables */
unsigned j;
--- archival/bunzip2.c 2001/11/30 10:43:23 1.1
+++ archival/bunzip2.c 2001/11/30 10:44:33
@@ -276,7 +276,7 @@ int numFileNames;
int numFilesProcessed;
int exitValue;
-unsigned int BZ2_crc32Table[256] = {
+const unsigned int BZ2_crc32Table[256] = {
/*-- Ugly, innit? --*/
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