(zlib) Cleanups

This commit is contained in:
twinaphex
2021-10-03 07:50:23 +02:00
parent cd61841777
commit 478a8ec99a
7 changed files with 9 additions and 1940 deletions
+1 -191
View File
@@ -32,8 +32,6 @@
/* @(#) $Id$ */
/* #define GEN_TREES_H */
#include "deflate.h"
#ifdef DEBUG
@@ -80,39 +78,7 @@ local const uch bl_order[BL_CODES]
#define DIST_CODE_LEN 512 /* see definition of array dist_code below */
#if defined(GEN_TREES_H) || !defined(STDC)
/* non ANSI compilers may not accept trees.h */
local ct_data static_ltree[L_CODES+2];
/* The static literal tree. Since the bit lengths are imposed, there is no
* need for the L_CODES extra codes used during heap construction. However
* The codes 286 and 287 are needed to build a canonical tree (see _tr_init
* below).
*/
local ct_data static_dtree[D_CODES];
/* The static distance tree. (Actually a trivial tree since all codes use
* 5 bits.)
*/
uch _dist_code[DIST_CODE_LEN];
/* Distance codes. The first 256 values correspond to the distances
* 3 .. 258, the last 256 values correspond to the top 8 bits of
* the 15 bit distances.
*/
uch _length_code[MAX_MATCH-MIN_MATCH+1];
/* length code for each normalized match length (0 == MIN_MATCH) */
local int base_length[LENGTH_CODES];
/* First normalized length for each code (0 = MIN_MATCH) */
local int base_dist[D_CODES];
/* First normalized distance for each code (0 = distance of 1) */
#else
# include "trees.h"
#endif /* GEN_TREES_H */
#include "trees.h"
struct static_tree_desc_s {
const ct_data *static_tree; /* static tree or NULL */
@@ -135,7 +101,6 @@ local static_tree_desc static_bl_desc =
* Local (static) routines in this file.
*/
local void tr_static_init OF((void));
local void init_block OF((deflate_state *s));
local void pqdownheap OF((deflate_state *s, ct_data *tree, int k));
local void gen_bitlen OF((deflate_state *s, tree_desc *desc));
@@ -155,10 +120,6 @@ local void bi_flush OF((deflate_state *s));
local void copy_block OF((deflate_state *s, charf *buf, unsigned len,
int header));
#ifdef GEN_TREES_H
local void gen_trees_header OF((void));
#endif
#ifndef DEBUG
# define send_code(s, c, tree) send_bits(s, tree[c].Code, tree[c].Len)
/* Send a code of the given tree. c and tree must not have side effects */
@@ -226,163 +187,12 @@ local void send_bits(s, value, length)
#endif /* DEBUG */
/* the arguments must not have side effects */
/* ===========================================================================
* Initialize the various 'constant' tables.
*/
local void tr_static_init()
{
#if defined(GEN_TREES_H) || !defined(STDC)
static int static_init_done = 0;
int n; /* iterates over tree elements */
int bits; /* bit counter */
int length; /* length value */
int code; /* code value */
int dist; /* distance index */
ush bl_count[MAX_BITS+1];
/* number of codes at each bit length for an optimal tree */
if (static_init_done) return;
/* For some embedded targets, global variables are not initialized: */
#ifdef NO_INIT_GLOBAL_POINTERS
static_l_desc.static_tree = static_ltree;
static_l_desc.extra_bits = extra_lbits;
static_d_desc.static_tree = static_dtree;
static_d_desc.extra_bits = extra_dbits;
static_bl_desc.extra_bits = extra_blbits;
#endif
/* Initialize the mapping length (0..255) -> length code (0..28) */
length = 0;
for (code = 0; code < LENGTH_CODES-1; code++) {
base_length[code] = length;
for (n = 0; n < (1<<extra_lbits[code]); n++) {
_length_code[length++] = (uch)code;
}
}
Assert (length == 256, "tr_static_init: length != 256");
/* Note that the length 255 (match length 258) can be represented
* in two different ways: code 284 + 5 bits or code 285, so we
* overwrite length_code[255] to use the best encoding:
*/
_length_code[length-1] = (uch)code;
/* Initialize the mapping dist (0..32K) -> dist code (0..29) */
dist = 0;
for (code = 0 ; code < 16; code++) {
base_dist[code] = dist;
for (n = 0; n < (1<<extra_dbits[code]); n++) {
_dist_code[dist++] = (uch)code;
}
}
Assert (dist == 256, "tr_static_init: dist != 256");
dist >>= 7; /* from now on, all distances are divided by 128 */
for ( ; code < D_CODES; code++) {
base_dist[code] = dist << 7;
for (n = 0; n < (1<<(extra_dbits[code]-7)); n++) {
_dist_code[256 + dist++] = (uch)code;
}
}
Assert (dist == 256, "tr_static_init: 256+dist != 512");
/* Construct the codes of the static literal tree */
for (bits = 0; bits <= MAX_BITS; bits++) bl_count[bits] = 0;
n = 0;
while (n <= 143) static_ltree[n++].Len = 8, bl_count[8]++;
while (n <= 255) static_ltree[n++].Len = 9, bl_count[9]++;
while (n <= 279) static_ltree[n++].Len = 7, bl_count[7]++;
while (n <= 287) static_ltree[n++].Len = 8, bl_count[8]++;
/* Codes 286 and 287 do not exist, but we must include them in the
* tree construction to get a canonical Huffman tree (longest code
* all ones)
*/
gen_codes((ct_data *)static_ltree, L_CODES+1, bl_count);
/* The static distance tree is trivial: */
for (n = 0; n < D_CODES; n++) {
static_dtree[n].Len = 5;
static_dtree[n].Code = bi_reverse((unsigned)n, 5);
}
static_init_done = 1;
# ifdef GEN_TREES_H
gen_trees_header();
# endif
#endif /* defined(GEN_TREES_H) || !defined(STDC) */
}
/* ===========================================================================
* Genererate the file trees.h describing the static trees.
*/
#ifdef GEN_TREES_H
# ifndef DEBUG
# include <stdio.h>
# endif
# define SEPARATOR(i, last, width) \
((i) == (last)? "\n};\n\n" : \
((i) % (width) == (width)-1 ? ",\n" : ", "))
void gen_trees_header()
{
FILE *header = fopen("trees.h", "w");
int i;
Assert (header != NULL, "Can't open trees.h");
fprintf(header,
"/* header created automatically with -DGEN_TREES_H */\n\n");
fprintf(header, "local const ct_data static_ltree[L_CODES+2] = {\n");
for (i = 0; i < L_CODES+2; i++) {
fprintf(header, "{{%3u},{%3u}}%s", static_ltree[i].Code,
static_ltree[i].Len, SEPARATOR(i, L_CODES+1, 5));
}
fprintf(header, "local const ct_data static_dtree[D_CODES] = {\n");
for (i = 0; i < D_CODES; i++) {
fprintf(header, "{{%2u},{%2u}}%s", static_dtree[i].Code,
static_dtree[i].Len, SEPARATOR(i, D_CODES-1, 5));
}
fprintf(header, "const uch ZLIB_INTERNAL _dist_code[DIST_CODE_LEN] = {\n");
for (i = 0; i < DIST_CODE_LEN; i++) {
fprintf(header, "%2u%s", _dist_code[i],
SEPARATOR(i, DIST_CODE_LEN-1, 20));
}
fprintf(header,
"const uch ZLIB_INTERNAL _length_code[MAX_MATCH-MIN_MATCH+1]= {\n");
for (i = 0; i < MAX_MATCH-MIN_MATCH+1; i++) {
fprintf(header, "%2u%s", _length_code[i],
SEPARATOR(i, MAX_MATCH-MIN_MATCH, 20));
}
fprintf(header, "local const int base_length[LENGTH_CODES] = {\n");
for (i = 0; i < LENGTH_CODES; i++) {
fprintf(header, "%1u%s", base_length[i],
SEPARATOR(i, LENGTH_CODES-1, 20));
}
fprintf(header, "local const int base_dist[D_CODES] = {\n");
for (i = 0; i < D_CODES; i++) {
fprintf(header, "%5u%s", base_dist[i],
SEPARATOR(i, D_CODES-1, 10));
}
fclose(header);
}
#endif /* GEN_TREES_H */
/* ===========================================================================
* Initialize the tree data structures for a new zlib stream.
*/
void ZLIB_INTERNAL _tr_init(s)
deflate_state *s;
{
tr_static_init();
s->l_desc.dyn_tree = s->dyn_ltree;
s->l_desc.stat_desc = &static_l_desc;