diff options
Diffstat (limited to 'lib/zlib/src/trees.c')
| -rw-r--r-- | lib/zlib/src/trees.c | 38 |
1 files changed, 21 insertions, 17 deletions
diff --git a/lib/zlib/src/trees.c b/lib/zlib/src/trees.c index a265973..acb8053 100644 --- a/lib/zlib/src/trees.c +++ b/lib/zlib/src/trees.c @@ -1,5 +1,5 @@ /* 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 */ @@ -29,7 +29,7 @@ * Addison-Wesley, 1983. ISBN 0-201-06672-6. */ -/* @(#) $Id: trees.c,v 1.4 2005-06-06 11:16:16 pixel Exp $ */ +/* @(#) $Id: trees.c,v 1.5 2005-10-13 16:12:18 pixel Exp $ */ /* #define GEN_TREES_H */ @@ -555,7 +555,7 @@ local void gen_bitlen(s, desc) 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; @@ -930,8 +930,9 @@ void _tr_flush_block(s, buf, stored_len, eof) /* 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))); @@ -982,7 +983,7 @@ void _tr_flush_block(s, buf, stored_len, eof) #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); @@ -1117,21 +1118,24 @@ local void compress_block(s, ltree, 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; } /* =========================================================================== |