/* trees.c -- output deflated data using Huffman coding
- * Copyright (C) 1995-2003 Jean-loup Gailly
+ * Copyright (C) 1995-2005 Jean-loup Gailly
* For conditions of distribution and use, see copyright notice in zlib.h
*/
while (n != 0) {
m = s->heap[--h];
if (m > max_code) continue;
- if (tree[m].Len != (unsigned) bits) {
+ if ((unsigned) tree[m].Len != (unsigned) bits) {
Trace((stderr,"code %d bits %d->%d\n", m, tree[m].Len, bits));
s->opt_len += ((long)bits - (long)tree[m].Len)
*(long)tree[m].Freq;
/* Build the Huffman trees unless a stored block is forced */
if (s->level > 0) {
- /* Check if the file is ascii or binary */
- if (s->strm->data_type == Z_UNKNOWN) set_data_type(s);
+ /* Check if the file is binary or text */
+ if (stored_len > 0 && s->strm->data_type == Z_UNKNOWN)
+ set_data_type(s);
/* Construct the literal and distance trees */
build_tree(s, (tree_desc *)(&(s->l_desc)));
#ifdef FORCE_STATIC
} else if (static_lenb >= 0) { /* force static trees */
#else
- } else if (static_lenb == opt_lenb) {
+ } else if (s->strategy == Z_FIXED || static_lenb == opt_lenb) {
#endif
send_bits(s, (STATIC_TREES<<1)+eof, 3);
compress_block(s, (ct_data *)static_ltree, (ct_data *)static_dtree);
}
/* ===========================================================================
- * Set the data type to ASCII or BINARY, using a crude approximation:
- * binary if more than 20% of the bytes are <= 6 or >= 128, ascii otherwise.
- * IN assertion: the fields freq of dyn_ltree are set and the total of all
- * frequencies does not exceed 64K (to fit in an int on 16 bit machines).
+ * Set the data type to BINARY or TEXT, using a crude approximation:
+ * set it to Z_TEXT if all symbols are either printable characters (33 to 255)
+ * or white spaces (9 to 13, or 32); or set it to Z_BINARY otherwise.
+ * IN assertion: the fields Freq of dyn_ltree are set.
*/
local void set_data_type(s)
deflate_state *s;
{
- int n = 0;
- unsigned ascii_freq = 0;
- unsigned bin_freq = 0;
- while (n < 7) bin_freq += s->dyn_ltree[n++].Freq;
- while (n < 128) ascii_freq += s->dyn_ltree[n++].Freq;
- while (n < LITERALS) bin_freq += s->dyn_ltree[n++].Freq;
- s->strm->data_type = bin_freq > (ascii_freq >> 2) ? Z_BINARY : Z_ASCII;
+ int n;
+
+ for (n = 0; n < 9; n++)
+ if (s->dyn_ltree[n].Freq != 0)
+ break;
+ if (n == 9)
+ for (n = 14; n < 32; n++)
+ if (s->dyn_ltree[n].Freq != 0)
+ break;
+ s->strm->data_type = (n == 32) ? Z_TEXT : Z_BINARY;
}
/* ===========================================================================