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Make inflate() reentrant - no more global variables.

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(The gzip image activator now needs a good code tidy up.)
This commit is contained in:
Geoff Rehmet 1994-10-07 23:18:18 +00:00
parent ee38c19853
commit 2f7048bff0
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=3418
2 changed files with 67 additions and 42 deletions
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94
sys/kern/inflate.c
View File

@ -41,9 +41,6 @@
#include <vm/vm_kern.h>
/* Stuff to make inflate() work */
# define uch u_char
# define ush u_short
# define ulg u_long
# define memzero(dest,len) bzero(dest,len)
# define NOMEMCPY
#define FPRINTF printf
@ -385,15 +382,14 @@ struct huft {
# define OF(a) ()
# endif /* ?__STDC__ */
#endif
static int huft_build OF((struct gzip *,unsigned *, unsigned, unsigned, const ush *, const ush *,
struct huft **, int *));
static int huft_build OF((struct gzip *,unsigned *, unsigned, unsigned, const ush *, const ush *, struct huft **, int *, struct gz_global *));
static int huft_free OF((struct gzip *,struct huft *));
static int inflate_codes OF((struct gzip *,struct huft *, struct huft *, int, int));
static int inflate_stored OF((struct gzip *));
static int inflate_fixed OF((struct gzip *));
static int inflate_dynamic OF((struct gzip *));
static int inflate_block OF((struct gzip *,int *));
static int inflate_free OF((struct gzip *));
static int inflate_codes OF((struct gzip *,struct huft *, struct huft *, int, int, struct gz_global *));
static int inflate_stored OF((struct gzip *, struct gz_global *));
static int inflate_fixed OF((struct gzip *, struct gz_global *));
static int inflate_dynamic OF((struct gzip *, struct gz_global *));
static int inflate_block OF((struct gzip *,int *, struct gz_global *));
static int inflate_free OF((struct gzip *, struct gz_global *));
/* The inflate algorithm uses a sliding 32K byte window on the uncompressed
@ -426,7 +422,7 @@ static const ush cpdext[] = { /* Extra bits for distance codes */
12, 12, 13, 13};
/* And'ing with mask[n] masks the lower n bits */
const ush mask[] = {
static const ush mask[] = {
0x0000,
0x0001, 0x0003, 0x0007, 0x000f, 0x001f, 0x003f, 0x007f, 0x00ff,
0x01ff, 0x03ff, 0x07ff, 0x0fff, 0x1fff, 0x3fff, 0x7fff, 0xffff
@ -453,9 +449,12 @@ const ush mask[] = {
block. See the huft_build() routine.
*/
/* !!! XXX !!! */
ulg bb; /* bit buffer */
unsigned bk; /* bits in bit buffer */
/*
* The following 2 were global variables.
* They are now fields of the gz_global structure.
*/
#define bb (glbl->bb) /* bit buffer */
#define bk (glbl->bk) /* bits in bit buffer */
#ifndef CHECK_EOF
# define NEEDBITS(n) {while(k<(n)){b|=((ulg)NEXTBYTE)<<k;k+=8;}}
@ -500,19 +499,21 @@ unsigned bk; /* bits in bit buffer */
*/
const int lbits = 9; /* bits in base literal/length lookup table */
const int dbits = 6; /* bits in base distance lookup table */
static const int lbits = 9; /* bits in base literal/length lookup table */
static const int dbits = 6; /* bits in base distance lookup table */
/* If BMAX needs to be larger than 16, then h and x[] should be ulg. */
#define BMAX 16 /* maximum bit length of any code (16 for explode) */
#define N_MAX 288 /* maximum number of codes in any set */
/* !!! XXX !!! */
unsigned hufts; /* track memory usage */
/*
* This also used to be a global variable
*/
#define hufts (glbl->hufts)
static int huft_build(gz,b, n, s, d, e, t, m)
static int huft_build(gz,b, n, s, d, e, t, m, glbl)
struct gzip *gz;
unsigned *b; /* code lengths in bits (all assumed <= BMAX) */
unsigned n; /* number of codes (assumed <= N_MAX) */
@ -521,6 +522,7 @@ const ush *d; /* list of base values for non-simple codes */
const ush *e; /* list of extra bits for non-simple codes */
struct huft **t; /* result: starting table */
int *m; /* maximum lookup bits, returns actual */
struct gz_global * glbl;
/* 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
@ -743,10 +745,11 @@ struct huft *t; /* table to free */
#else
static int inflate_codes(gz,tl, td, bl, bd)
static int inflate_codes(gz,tl, td, bl, bd, glbl)
struct gzip *gz;
struct huft *tl, *td; /* literal/length and distance decoder tables */
int bl, bd; /* number of bits decoded by tl[] and td[] */
struct gz_global * glbl;/* global variables */
/* inflate (decompress) the codes in a deflated (compressed) block.
Return an error code or zero if it all goes ok. */
{
@ -854,8 +857,9 @@ int bl, bd; /* number of bits decoded by tl[] and td[] */
static int inflate_stored(gz)
static int inflate_stored(gz, glbl)
struct gzip *gz;
struct gz_global * glbl;
/* "decompress" an inflated type 0 (stored) block. */
{
unsigned n; /* number of bytes in block */
@ -909,13 +913,15 @@ struct gzip *gz;
/* Globals for literal tables (built once) */
/* !!! XXX !!! */
struct huft *fixed_tl = (struct huft *)NULL;
struct huft *fixed_td;
int fixed_bl, fixed_bd;
/* The real variables are now in the struct gz_global */
#define fixed_tl (glbl->fixed_tl)
#define fixed_td (glbl->fixed_td)
#define fixed_bl (glbl->fixed_bl)
#define fixed_bd (glbl->fixed_bd)
static int inflate_fixed(gz)
static int inflate_fixed(gz, glbl)
struct gzip *gz;
struct gz_global *glbl;
/* decompress an inflated type 1 (fixed Huffman codes) block. We should
either replace this with a custom decoder, or at least precompute the
Huffman tables. */
@ -938,7 +944,7 @@ struct gzip *gz;
l[i] = 8;
fixed_bl = 7;
if ((i = huft_build(gz,l, 288, 257, cplens, cplext,
&fixed_tl, &fixed_bl)) != 0)
&fixed_tl, &fixed_bl, glbl)) != 0)
{
fixed_tl = (struct huft *)NULL;
return i;
@ -948,7 +954,8 @@ struct gzip *gz;
for (i = 0; i < 30; i++) /* make an incomplete code set */
l[i] = 5;
fixed_bd = 5;
if ((i = huft_build(gz,l, 30, 0, cpdist, cpdext, &fixed_td, &fixed_bd)) > 1)
if ((i = huft_build(gz,l, 30, 0, cpdist, cpdext,
&fixed_td, &fixed_bd, glbl)) > 1)
{
huft_free(gz,fixed_tl);
fixed_tl = (struct huft *)NULL;
@ -958,13 +965,14 @@ struct gzip *gz;
/* decompress until an end-of-block code */
return inflate_codes(gz,fixed_tl, fixed_td, fixed_bl, fixed_bd) != 0;
return inflate_codes(gz,fixed_tl, fixed_td, fixed_bl, fixed_bd, glbl) != 0;
}
static int inflate_dynamic(gz)
static int inflate_dynamic(gz, glbl)
struct gzip *gz;
struct gz_global * glbl;
/* decompress an inflated type 2 (dynamic Huffman codes) block. */
{
int i; /* temporary variables */
@ -1025,7 +1033,7 @@ struct gzip *gz;
/* build decoding table for trees--single level, 7 bit lookup */
bl = 7;
if ((i = huft_build(gz,ll, 19, 19, NULL, NULL, &tl, &bl)) != 0)
if ((i = huft_build(gz,ll, 19, 19, NULL, NULL, &tl, &bl, glbl)) != 0)
{
if (i == 1)
huft_free(gz,tl);
@ -1091,7 +1099,7 @@ struct gzip *gz;
/* build the decoding tables for literal/length and distance codes */
bl = lbits;
if ((i = huft_build(gz,ll, nl, 257, cplens, cplext, &tl, &bl)) != 0)
if ((i = huft_build(gz,ll, nl, 257, cplens, cplext, &tl, &bl, glbl)) != 0)
{
if (i == 1 && !qflag) {
FPRINTF( "(incomplete l-tree) ");
@ -1100,7 +1108,7 @@ struct gzip *gz;
return i; /* incomplete code set */
}
bd = dbits;
if ((i = huft_build(gz,ll + nl, nd, 0, cpdist, cpdext, &td, &bd)) != 0)
if ((i = huft_build(gz,ll + nl, nd, 0, cpdist, cpdext, &td, &bd, glbl)) != 0)
{
if (i == 1 && !qflag) {
FPRINTF( "(incomplete d-tree) ");
@ -1117,7 +1125,7 @@ struct gzip *gz;
/* decompress until an end-of-block code */
if (inflate_codes(gz,tl, td, bl, bd))
if (inflate_codes(gz,tl, td, bl, bd, glbl))
return 1;
@ -1129,9 +1137,10 @@ struct gzip *gz;
static int inflate_block(gz,e)
static int inflate_block(gz,e, glbl)
struct gzip *gz;
int *e; /* last block flag */
struct gz_global * glbl;
/* decompress an inflated block */
{
unsigned t; /* block type */
@ -1163,11 +1172,11 @@ int *e; /* last block flag */
/* inflate that block type */
if (t == 2)
return inflate_dynamic(gz);
return inflate_dynamic(gz, glbl);
if (t == 0)
return inflate_stored(gz);
return inflate_stored(gz, glbl);
if (t == 1)
return inflate_fixed(gz);
return inflate_fixed(gz, glbl);
/* bad block type */
@ -1186,6 +1195,8 @@ struct gz_global * glbl;
unsigned h; /* maximum struct huft's malloc'ed */
fixed_tl = (struct huft *)NULL;
/* initialize window, bit buffer */
wp = 0;
bk = 0;
@ -1196,7 +1207,7 @@ struct gz_global * glbl;
h = 0;
do {
hufts = 0;
if ((r = inflate_block(gz,&e)) != 0)
if ((r = inflate_block(gz,&e, glbl)) != 0)
return r;
if (hufts > h)
h = hufts;
@ -1215,8 +1226,9 @@ struct gz_global * glbl;
static int inflate_free(gz)
static int inflate_free(gz, glbl)
struct gzip *gz;
struct gz_global * glbl;
{
if (fixed_tl != (struct huft *)NULL)
{

15
sys/sys/inflate.h
View File

@ -46,6 +46,12 @@
#include <vm/vm.h>
#include <vm/vm_kern.h>
/* needed to make inflate() work */
#define uch u_char
#define ush u_short
#define ulg u_long
#define WSIZE 0x8000
struct gzip {
@ -68,10 +74,17 @@ struct gzip {
* This structure is used in order to make inflate() reentrant.
*/
struct gz_global {
int foo;
ulg bb; /* bit buffer */
unsigned bk; /* bits in bit buffer */
unsigned hufts; /* track memory usage */
struct huft *fixed_tl; /* must init to NULL !! */
struct huft *fixed_td;
int fixed_bl;
int fixed_bd;
};
int inflate __P((struct gzip *, struct gz_global *));
int do_aout_hdr __P((struct gzip *));
#define slide (gz->gz_slide)
#define wp (gz->gz_wp)