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gzip: code shrink

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huft_build() has way too many params

function                                             old     new   delta
inflate_block                                       1293    1281     -12
huft_build                                          1085    1058     -27
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-39)             Total: -39 bytes

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
This commit is contained in:
Denys Vlasenko 2019-10-19 18:33:49 +02:00
parent 95867147f5
commit c763392458
1 changed files with 26 additions and 27 deletions
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53
archival/libarchive/decompress_gunzip.c
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@ -277,22 +277,19 @@ static unsigned fill_bitbuffer(STATE_PARAM unsigned bitbuffer, unsigned *current
/* Given a list of code lengths and a maximum table size, make a set of /* 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 * tables to decode that set of codes.
* the given code set is incomplete (the tables are still built in this
* case), two if the input is invalid (an oversubscribed set of lengths)
* - in this case stores NULL in *t.
* *
* b: code lengths in bits (all assumed <= BMAX) * b: code lengths in bits (all assumed <= BMAX)
* n: number of codes (assumed <= N_MAX) * n: number of codes (assumed <= N_MAX)
* s: number of simple-valued codes (0..s-1) * s: number of simple-valued codes (0..s-1)
* d: list of base values for non-simple codes * d: list of base values for non-simple codes
* e: list of extra bits for non-simple codes * e: list of extra bits for non-simple codes
* t: result: starting table
* m: maximum lookup bits, returns actual * m: maximum lookup bits, returns actual
* result: starting table
*/ */
static int huft_build(const unsigned *b, const unsigned n, static huft_t* huft_build(const unsigned *b, const unsigned n,
const unsigned s, const unsigned short *d, const unsigned s, const uint16_t *d,
const unsigned char *e, huft_t **t, unsigned *m) const uint8_t *e, unsigned *m)
{ {
unsigned a; /* counter for codes of length k */ unsigned a; /* counter for codes of length k */
unsigned c[BMAX + 1]; /* bit length count table */ unsigned c[BMAX + 1]; /* bit length count table */
@ -314,12 +311,12 @@ static int huft_build(const unsigned *b, const unsigned n,
unsigned *xp; /* pointer into x */ unsigned *xp; /* pointer into x */
int y; /* number of dummy codes added */ int y; /* number of dummy codes added */
unsigned z; /* number of entries in current table */ unsigned z; /* number of entries in current table */
huft_t *result;
huft_t **t;
/* Length of EOB code, if any */ /* Length of EOB code, if any */
eob_len = n > 256 ? b[256] : BMAX; eob_len = n > 256 ? b[256] : BMAX;
*t = NULL;
/* Generate counts for each bit length */ /* Generate counts for each bit length */
memset(c, 0, sizeof(c)); memset(c, 0, sizeof(c));
p = b; p = b;
@ -335,9 +332,8 @@ static int huft_build(const unsigned *b, const unsigned n,
q[1].b = 1; q[1].b = 1;
q[2].e = 99; /* invalid code marker */ q[2].e = 99; /* invalid code marker */
q[2].b = 1; q[2].b = 1;
*t = q + 1;
*m = 1; *m = 1;
return 0; return q + 1;
} }
/* Find minimum and maximum length, bound *m by those */ /* Find minimum and maximum length, bound *m by those */
@ -353,11 +349,11 @@ static int huft_build(const unsigned *b, const unsigned n,
for (y = 1 << j; j < i; j++, y <<= 1) { for (y = 1 << j; j < i; j++, y <<= 1) {
y -= c[j]; y -= c[j];
if (y < 0) if (y < 0)
return 2; /* bad input: more codes than bits */ return NULL; /* bad input: more codes than bits */
} }
y -= c[i]; y -= c[i];
if (y < 0) if (y < 0)
return 2; return NULL;
c[i] += y; c[i] += y;
/* Generate starting offsets into the value table for each length */ /* Generate starting offsets into the value table for each length */
@ -384,6 +380,8 @@ static int huft_build(const unsigned *b, const unsigned n,
} while (++i < n); } while (++i < n);
/* Generate the Huffman codes and for each, make the table entries */ /* Generate the Huffman codes and for each, make the table entries */
result = NULL;
t = &result;
x[0] = i = 0; /* first Huffman code is zero */ x[0] = i = 0; /* first Huffman code is zero */
p = v; /* grab values in bit order */ p = v; /* grab values in bit order */
htl = -1; /* no tables yet--level -1 */ htl = -1; /* no tables yet--level -1 */
@ -475,8 +473,10 @@ static int huft_build(const unsigned *b, const unsigned n,
/* return actual size of base table */ /* return actual size of base table */
*m = ws[1]; *m = ws[1];
/* Return 1 if we were given an incomplete table */ if (y != 0 && g != 1) /* we were given an incomplete table */
return y != 0 && g != 1; return NULL;
return result;
} }
@ -777,14 +777,14 @@ static int inflate_block(STATE_PARAM smallint *e)
for (; i < 288; i++) /* make a complete, but wrong code set */ for (; i < 288; i++) /* make a complete, but wrong code set */
ll[i] = 8; ll[i] = 8;
bl = 7; bl = 7;
huft_build(ll, 288, 257, cplens, cplext, &inflate_codes_tl, &bl); inflate_codes_tl = huft_build(ll, 288, 257, cplens, cplext, &bl);
/* huft_build() never return nonzero - we use known data */ /* huft_build() never returns error here - we use known data */
/* set up distance table */ /* set up distance table */
for (i = 0; i < 30; i++) /* make an incomplete code set */ for (i = 0; i < 30; i++) /* make an incomplete code set */
ll[i] = 5; ll[i] = 5;
bd = 5; bd = 5;
huft_build(ll, 30, 0, cpdist, cpdext, &inflate_codes_td, &bd); inflate_codes_td = huft_build(ll, 30, 0, cpdist, cpdext, &bd);
/* set up data for inflate_codes() */ /* set up data for inflate_codes() */
inflate_codes_setup(PASS_STATE bl, bd); inflate_codes_setup(PASS_STATE bl, bd);
@ -850,9 +850,9 @@ static int inflate_block(STATE_PARAM smallint *e)
/* build decoding table for trees - single level, 7 bit lookup */ /* build decoding table for trees - single level, 7 bit lookup */
bl = 7; bl = 7;
i = huft_build(ll, 19, 19, NULL, NULL, &inflate_codes_tl, &bl); inflate_codes_tl = huft_build(ll, 19, 19, NULL, NULL, &bl);
if (i != 0) { if (!inflate_codes_tl) {
abort_unzip(PASS_STATE_ONLY); //return i; /* incomplete code set */ abort_unzip(PASS_STATE_ONLY); /* incomplete code set */
} }
/* read in literal and distance code lengths */ /* read in literal and distance code lengths */
@ -915,14 +915,13 @@ static int inflate_block(STATE_PARAM smallint *e)
/* build the decoding tables for literal/length and distance codes */ /* build the decoding tables for literal/length and distance codes */
bl = lbits; bl = lbits;
inflate_codes_tl = huft_build(ll, nl, 257, cplens, cplext, &bl);
i = huft_build(ll, nl, 257, cplens, cplext, &inflate_codes_tl, &bl); if (!inflate_codes_tl) {
if (i != 0) {
abort_unzip(PASS_STATE_ONLY); abort_unzip(PASS_STATE_ONLY);
} }
bd = dbits; bd = dbits;
i = huft_build(ll + nl, nd, 0, cpdist, cpdext, &inflate_codes_td, &bd); inflate_codes_td = huft_build(ll + nl, nd, 0, cpdist, cpdext, &bd);
if (i != 0) { if (!inflate_codes_td) {
abort_unzip(PASS_STATE_ONLY); abort_unzip(PASS_STATE_ONLY);
} }