This is de_lzh.c in view mode; [Download] [Up]
#include "macunpack.h"
#ifdef ZMA
#define DELZH
#endif /* ZMA */
#ifdef LZH
#define DELZH
#endif /* LZH */
#ifdef DELZH
#include "globals.h"
#include "../util/masks.h"
#include "../fileio/wrfile.h"
#include "bits_be.h"
/* This code is valid for bitsused upto 15. */
#define DICBIT 13 /* 12(-lh4-) or 13(-lh5-) */
#define UCHAR_MAX 255
#define THRESHOLD 3
static int decoded;
static int bitsused;
static unsigned int blocksize;
static unsigned int decode_c();
static unsigned int decode_p();
static void make_table();
/* lzh compression */
void de_lzh(ibytes, obytes, data, bits)
long ibytes;
long obytes;
char **data;
int bits;
{
unsigned int i, r, c;
int remains;
bit_be_inbytes = ibytes;
bit_be_filestart = *data;
bitsused = bits;
bit_be_init_getbits();
blocksize = 0;
decoded = 0;
r = 0;
for(;;) {
c = decode_c();
if(decoded) {
*data = bit_be_filestart;
return;
}
if(c <= UCHAR_MAX) {
out_ptr[r++] = c;
obytes--;
if(obytes == 0) {
*data = bit_be_filestart;
return;
}
} else {
remains = c - (UCHAR_MAX + 1 - THRESHOLD);
i = (r - decode_p() - 1);
while(--remains >= 0) {
out_ptr[r++] = out_ptr[i++];
obytes--;
if(obytes == 0) {
*data = bit_be_filestart;
return;
}
}
}
}
}
#define MAXMATCH 256
#define NC (UCHAR_MAX + MAXMATCH + 2 - THRESHOLD)
#define CBIT 9
#define CODE_BIT 16
#define NP (DICBIT + 1)
#define NT (CODE_BIT + 3)
#define PBIT 4 /* smallest integer such that (1U << PBIT) > NP */
#define TBIT 5 /* smallest integer such that (1U << TBIT) > NT */
#if NT > NP
# define NPT NT
#else
# define NPT NP
#endif
static unsigned int left[2 * NC - 1], right[2 * NC - 1];
static unsigned char c_len[NC], pt_len[NPT];
static unsigned int c_table[4096], pt_table[256];
static void read_pt_len(nn, nbit, i_special)
int nn;
int nbit;
int i_special;
{
int i, c, n;
unsigned int mask;
n = bit_be_getbits(nbit);
if (n == 0) {
c = bit_be_getbits(nbit);
for (i = 0; i < nn; i++) {
pt_len[i] = 0;
}
for (i = 0; i < 256; i++) {
pt_table[i] = c;
}
} else {
i = 0;
while (i < n) {
c = bit_be_bitbuf >> (BITBUFSIZ - 3);
if (c == 7) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 3);
while (mask & bit_be_bitbuf) {
mask >>= 1;
c++;
}
}
bit_be_fillbuf((c < 7) ? 3 : c - 3);
pt_len[i++] = c;
if (i == i_special) {
c = bit_be_getbits(2);
while (--c >= 0) {
pt_len[i++] = 0;
}
}
}
while (i < nn) {
pt_len[i++] = 0;
}
make_table(nn, pt_len, 8, pt_table);
}
}
static void read_c_len()
{
int i, c, n;
unsigned int mask;
n = bit_be_getbits(CBIT);
if (n == 0) {
c = bit_be_getbits(CBIT);
for (i = 0; i < NC; i++) {
c_len[i] = 0;
}
for (i = 0; i < 4096; i++) {
c_table[i] = c;
}
} else {
i = 0;
while (i < n) {
c = pt_table[bit_be_bitbuf >> (BITBUFSIZ - 8)];
if (c >= NT) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 8);
do {
if (bit_be_bitbuf & mask) {
c = right[c];
} else {
c = left [c];
}
mask >>= 1;
} while (c >= NT);
}
bit_be_fillbuf((int)pt_len[c]);
if (c <= 2) {
if (c == 0) {
c = 1;
} else if (c == 1) {
c = bit_be_getbits(4) + 3;
} else {
c = bit_be_getbits(CBIT) + 20;
}
while (--c >= 0) {
c_len[i++] = 0;
}
} else {
c_len[i++] = c - 2;
}
}
while (i < NC) {
c_len[i++] = 0;
}
make_table(NC, c_len, 12, c_table);
}
}
static unsigned int decode_c()
{
unsigned int j, mask;
if (blocksize == 0) {
blocksize = bit_be_getbits(16);
if (blocksize == 0) {
decoded = 1;
return 0;
}
read_pt_len(NT, TBIT, 3);
read_c_len();
read_pt_len(bitsused + 1, PBIT, -1);
}
blocksize--;
j = c_table[bit_be_bitbuf >> (BITBUFSIZ - 12)];
if (j >= NC) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 12);
do {
if (bit_be_bitbuf & mask) {
j = right[j];
} else {
j = left [j];
}
mask >>= 1;
} while (j >= NC);
}
bit_be_fillbuf((int)c_len[j]);
return j;
}
static unsigned int decode_p()
{
unsigned int j, mask;
j = pt_table[bit_be_bitbuf >> (BITBUFSIZ - 8)];
if (j > bitsused) {
mask = (unsigned) 1 << (BITBUFSIZ - 1 - 8);
do {
if (bit_be_bitbuf & mask) {
j = right[j];
} else {
j = left [j];
}
mask >>= 1;
} while (j > bitsused);
}
bit_be_fillbuf((int)pt_len[j]);
if (j != 0) {
j = ((unsigned) 1 << (j - 1)) + bit_be_getbits((int) (j - 1));
}
return j;
}
static void make_table(nchar, bitlen, tablebits, table)
int nchar;
unsigned char bitlen[];
int tablebits;
unsigned int table[];
{
unsigned int count[17], weight[17], start[18], *p;
unsigned int i, k, len, ch, jutbits, avail, nextcode, mask;
for (i = 1; i <= 16; i++) {
count[i] = 0;
}
for (i = 0; i < nchar; i++) {
count[bitlen[i]]++;
}
start[1] = 0;
for (i = 1; i <= 16; i++) {
start[i + 1] = start[i] + (count[i] << (16 - i));
}
jutbits = 16 - tablebits;
for (i = 1; i <= tablebits; i++) {
start[i] >>= jutbits;
weight[i] = (unsigned) 1 << (tablebits - i);
}
while (i <= 16) {
weight[i] = (unsigned) 1 << (16 - i);
i++;
}
i = start[tablebits + 1] >> jutbits;
if (i != (unsigned int)((unsigned) 1 << 16)) {
k = 1 << tablebits;
while (i != k) {
table[i++] = 0;
}
}
avail = nchar;
mask = (unsigned) 1 << (15 - tablebits);
for (ch = 0; ch < nchar; ch++) {
if ((len = bitlen[ch]) == 0) {
continue;
}
nextcode = start[len] + weight[len];
if (len <= tablebits) {
for (i = start[len]; i < nextcode; i++) {
table[i] = ch;
}
} else {
k = start[len];
p = &table[k >> jutbits];
i = len - tablebits;
while (i != 0) {
if (*p == 0) {
right[avail] = left[avail] = 0;
*p = avail++;
}
if (k & mask) {
p = &right[*p];
} else {
p = &left[*p];
}
k <<= 1;
i--;
}
*p = ch;
}
start[len] = nextcode;
}
}
#else /* DELZH */
int delzh; /* keep lint and some compilers happy */
#endif /* DELZH */
These are the contents of the former NiCE NeXT User Group NeXTSTEP/OpenStep software archive, currently hosted by Netfuture.ch.