1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
|
/*$Source: /usr/home/dhesi/zoo/RCS/maketbl.c,v $*/
/*$Id: maketbl.c,v 1.8 91/07/09 01:39:52 dhesi Exp $*/
/***********************************************************
maketbl.c -- make table for decoding
Adapted from "ar" archiver written by Haruhiko Okumura.
***********************************************************/
#include "options.h"
#include "zoo.h"
#include "ar.h"
#include "lzh.h"
extern void prterror();
void make_table(nchar, bitlen, tablebits, table)
int nchar;
uchar bitlen[];
int tablebits;
ushort table[];
{
ushort count[17], weight[17], start[18], *p;
uint 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));
if (start[17] != (ushort)((unsigned) 1 << 16))
prterror('f', "Bad decode table\n");
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 != (ushort)((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;
}
}
|
