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
/* deflate_huff.c -- compress data using huffman encoding only strategy
*
* Copyright (C) 1995-2013 Jean-loup Gailly and Mark Adler
* For conditions of distribution and use, see copyright notice in zlib.h
*/
#include "zbuild.h"
#include "deflate.h"
#include "deflate_p.h"
#include "functable.h"
/* ===========================================================================
* For Z_HUFFMAN_ONLY, do not look for matches. Do not maintain a hash table.
* (It will be regenerated if this run of deflate switches away from Huffman.)
*/
Z_INTERNAL block_state deflate_huff(deflate_state *s, int flush) {
int bflush = 0; /* set if current block must be flushed */
for (;;) {
/* Make sure that we have a literal to write. */
if (s->lookahead == 0) {
PREFIX(fill_window)(s);
if (s->lookahead == 0) {
if (flush == Z_NO_FLUSH)
return need_more;
break; /* flush the current block */
}
}
/* Output a literal byte */
bflush = zng_tr_tally_lit(s, s->window[s->strstart]);
s->lookahead--;
s->strstart++;
if (bflush)
FLUSH_BLOCK(s, 0);
}
s->insert = 0;
if (flush == Z_FINISH) {
FLUSH_BLOCK(s, 1);
return finish_done;
}
if (s->sym_next)
FLUSH_BLOCK(s, 0);
return block_done;
}