1994-05-27 12:33:43 +00:00
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/*-
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* Copyright (c) 1985, 1986, 1992, 1993
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* The Regents of the University of California. All rights reserved.
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*
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* This code is derived from software contributed to Berkeley by
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* Diomidis Spinellis and James A. Woods, derived from original
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* work by Spencer Thomas and Joseph Orost.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. All advertising materials mentioning features or use of this software
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* must display the following acknowledgement:
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* This product includes software developed by the University of
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* California, Berkeley and its contributors.
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* 4. Neither the name of the University nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#if defined(LIBC_SCCS) && !defined(lint)
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static char sccsid[] = "@(#)zopen.c 8.1 (Berkeley) 6/27/93";
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#endif /* LIBC_SCCS and not lint */
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2001-12-10 21:13:08 +00:00
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#include <sys/cdefs.h>
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__FBSDID("$FreeBSD$");
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1994-05-27 12:33:43 +00:00
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/*-
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* fcompress.c - File compression ala IEEE Computer, June 1984.
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*
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* Compress authors:
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* Spencer W. Thomas (decvax!utah-cs!thomas)
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* Jim McKie (decvax!mcvax!jim)
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* Steve Davies (decvax!vax135!petsd!peora!srd)
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* Ken Turkowski (decvax!decwrl!turtlevax!ken)
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* James A. Woods (decvax!ihnp4!ames!jaw)
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* Joe Orost (decvax!vax135!petsd!joe)
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*
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* Cleaned up and converted to library returning I/O streams by
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* Diomidis Spinellis <dds@doc.ic.ac.uk>.
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*
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* zopen(filename, mode, bits)
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* Returns a FILE * that can be used for read or write. The modes
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* supported are only "r" and "w". Seeking is not allowed. On
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* reading the file is decompressed, on writing it is compressed.
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* The output is compatible with compress(1) with 16 bit tables.
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* Any file produced by compress(1) can be read.
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*/
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <errno.h>
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#include <signal.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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1996-08-20 20:49:39 +00:00
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#include "zopen.h"
|
1994-05-27 12:33:43 +00:00
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#define BITS 16 /* Default bits. */
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#define HSIZE 69001 /* 95% occupancy */
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/* A code_int must be able to hold 2**BITS values of type int, and also -1. */
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typedef long code_int;
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typedef long count_int;
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typedef u_char char_type;
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static char_type magic_header[] =
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{'\037', '\235'}; /* 1F 9D */
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#define BIT_MASK 0x1f /* Defines for third byte of header. */
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#define BLOCK_MASK 0x80
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/*
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* Masks 0x40 and 0x20 are free. I think 0x20 should mean that there is
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* a fourth header byte (for expansion).
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*/
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#define INIT_BITS 9 /* Initial number of bits/code. */
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#define MAXCODE(n_bits) ((1 << (n_bits)) - 1)
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struct s_zstate {
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FILE *zs_fp; /* File stream for I/O */
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char zs_mode; /* r or w */
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enum {
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S_START, S_MIDDLE, S_EOF
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} zs_state; /* State of computation */
|
2001-12-02 23:58:38 +00:00
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u_int zs_n_bits; /* Number of bits/code. */
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u_int zs_maxbits; /* User settable max # bits/code. */
|
1994-05-27 12:33:43 +00:00
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|
code_int zs_maxcode; /* Maximum code, given n_bits. */
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code_int zs_maxmaxcode; /* Should NEVER generate this code. */
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count_int zs_htab [HSIZE];
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u_short zs_codetab [HSIZE];
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code_int zs_hsize; /* For dynamic table sizing. */
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code_int zs_free_ent; /* First unused entry. */
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|
|
/*
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|
* Block compression parameters -- after all codes are used up,
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|
* and compression rate changes, start over.
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|
*/
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|
int zs_block_compress;
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|
int zs_clear_flg;
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|
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long zs_ratio;
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count_int zs_checkpoint;
|
2001-12-02 23:58:38 +00:00
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|
u_int zs_offset;
|
1994-05-27 12:33:43 +00:00
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|
long zs_in_count; /* Length of input. */
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long zs_bytes_out; /* Length of compressed output. */
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long zs_out_count; /* # of codes output (for debugging). */
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|
char_type zs_buf[BITS];
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|
union {
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struct {
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long zs_fcode;
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code_int zs_ent;
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code_int zs_hsize_reg;
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|
int zs_hshift;
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|
|
} w; /* Write paramenters */
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struct {
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|
char_type *zs_stackp;
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int zs_finchar;
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code_int zs_code, zs_oldcode, zs_incode;
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int zs_roffset, zs_size;
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char_type zs_gbuf[BITS];
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|
|
} r; /* Read parameters */
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|
|
} u;
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|
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};
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|
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|
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|
|
/* Definitions to retain old variable names */
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|
#define fp zs->zs_fp
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#define zmode zs->zs_mode
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#define state zs->zs_state
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#define n_bits zs->zs_n_bits
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#define maxbits zs->zs_maxbits
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#define maxcode zs->zs_maxcode
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#define maxmaxcode zs->zs_maxmaxcode
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#define htab zs->zs_htab
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#define codetab zs->zs_codetab
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#define hsize zs->zs_hsize
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#define free_ent zs->zs_free_ent
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#define block_compress zs->zs_block_compress
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#define clear_flg zs->zs_clear_flg
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#define ratio zs->zs_ratio
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#define checkpoint zs->zs_checkpoint
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#define offset zs->zs_offset
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|
#define in_count zs->zs_in_count
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|
#define bytes_out zs->zs_bytes_out
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|
#define out_count zs->zs_out_count
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|
#define buf zs->zs_buf
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|
#define fcode zs->u.w.zs_fcode
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#define hsize_reg zs->u.w.zs_hsize_reg
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#define ent zs->u.w.zs_ent
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#define hshift zs->u.w.zs_hshift
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#define stackp zs->u.r.zs_stackp
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#define finchar zs->u.r.zs_finchar
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|
#define code zs->u.r.zs_code
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#define oldcode zs->u.r.zs_oldcode
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#define incode zs->u.r.zs_incode
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|
#define roffset zs->u.r.zs_roffset
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|
#define size zs->u.r.zs_size
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|
#define gbuf zs->u.r.zs_gbuf
|
|
|
|
|
|
|
|
/*
|
|
|
|
* To save much memory, we overlay the table used by compress() with those
|
|
|
|
* used by decompress(). The tab_prefix table is the same size and type as
|
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|
|
* the codetab. The tab_suffix table needs 2**BITS characters. We get this
|
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|
|
* from the beginning of htab. The output stack uses the rest of htab, and
|
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|
|
* contains characters. There is plenty of room for any possible stack
|
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|
|
* (stack used to be 8000 characters).
|
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|
*/
|
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|
#define htabof(i) htab[i]
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#define codetabof(i) codetab[i]
|
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|
|
|
|
|
|
#define tab_prefixof(i) codetabof(i)
|
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|
|
#define tab_suffixof(i) ((char_type *)(htab))[i]
|
|
|
|
#define de_stack ((char_type *)&tab_suffixof(1 << BITS))
|
|
|
|
|
|
|
|
#define CHECK_GAP 10000 /* Ratio check interval. */
|
|
|
|
|
|
|
|
/*
|
|
|
|
* the next two codes should not be changed lightly, as they must not
|
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|
|
* lie within the contiguous general code space.
|
|
|
|
*/
|
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|
|
#define FIRST 257 /* First free entry. */
|
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|
|
#define CLEAR 256 /* Table clear output code. */
|
|
|
|
|
2002-03-22 01:22:50 +00:00
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|
|
static int cl_block(struct s_zstate *);
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|
|
static void cl_hash(struct s_zstate *, count_int);
|
|
|
|
static code_int getcode(struct s_zstate *);
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|
|
static int output(struct s_zstate *, code_int);
|
|
|
|
static int zclose(void *);
|
|
|
|
static int zread(void *, char *, int);
|
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|
|
static int zwrite(void *, const char *, int);
|
1994-05-27 12:33:43 +00:00
|
|
|
|
|
|
|
/*-
|
|
|
|
* Algorithm from "A Technique for High Performance Data Compression",
|
|
|
|
* Terry A. Welch, IEEE Computer Vol 17, No 6 (June 1984), pp 8-19.
|
|
|
|
*
|
|
|
|
* Algorithm:
|
|
|
|
* Modified Lempel-Ziv method (LZW). Basically finds common
|
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|
|
* substrings and replaces them with a variable size code. This is
|
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|
|
* deterministic, and can be done on the fly. Thus, the decompression
|
|
|
|
* procedure needs no input table, but tracks the way the table was built.
|
|
|
|
*/
|
|
|
|
|
|
|
|
/*-
|
|
|
|
* compress write
|
|
|
|
*
|
|
|
|
* Algorithm: use open addressing double hashing (no chaining) on the
|
|
|
|
* prefix code / next character combination. We do a variant of Knuth's
|
|
|
|
* algorithm D (vol. 3, sec. 6.4) along with G. Knott's relatively-prime
|
|
|
|
* secondary probe. Here, the modular division first probe is gives way
|
|
|
|
* to a faster exclusive-or manipulation. Also do block compression with
|
|
|
|
* an adaptive reset, whereby the code table is cleared when the compression
|
|
|
|
* ratio decreases, but after the table fills. The variable-length output
|
|
|
|
* codes are re-sized at this point, and a special CLEAR code is generated
|
|
|
|
* for the decompressor. Late addition: construct the table according to
|
|
|
|
* file size for noticeable speed improvement on small files. Please direct
|
|
|
|
* questions about this implementation to ames!jaw.
|
|
|
|
*/
|
|
|
|
static int
|
2002-07-28 15:32:17 +00:00
|
|
|
zwrite(void *cookie, const char *wbp, int num)
|
1994-05-27 12:33:43 +00:00
|
|
|
{
|
2001-12-02 13:31:22 +00:00
|
|
|
code_int i;
|
|
|
|
int c, disp;
|
1994-05-27 12:33:43 +00:00
|
|
|
struct s_zstate *zs;
|
2005-05-18 05:24:08 +00:00
|
|
|
const u_char *bp;
|
1994-05-27 12:33:43 +00:00
|
|
|
u_char tmp;
|
|
|
|
int count;
|
|
|
|
|
|
|
|
if (num == 0)
|
|
|
|
return (0);
|
|
|
|
|
|
|
|
zs = cookie;
|
|
|
|
count = num;
|
2005-05-18 05:24:08 +00:00
|
|
|
bp = (const u_char *)wbp;
|
1994-05-27 12:33:43 +00:00
|
|
|
if (state == S_MIDDLE)
|
|
|
|
goto middle;
|
|
|
|
state = S_MIDDLE;
|
|
|
|
|
1995-01-02 10:04:02 +00:00
|
|
|
maxmaxcode = 1L << maxbits;
|
1994-05-27 12:33:43 +00:00
|
|
|
if (fwrite(magic_header,
|
|
|
|
sizeof(char), sizeof(magic_header), fp) != sizeof(magic_header))
|
|
|
|
return (-1);
|
1994-12-31 04:40:52 +00:00
|
|
|
tmp = (u_char)((maxbits) | block_compress);
|
1994-05-27 12:33:43 +00:00
|
|
|
if (fwrite(&tmp, sizeof(char), sizeof(tmp), fp) != sizeof(tmp))
|
|
|
|
return (-1);
|
|
|
|
|
|
|
|
offset = 0;
|
|
|
|
bytes_out = 3; /* Includes 3-byte header mojo. */
|
|
|
|
out_count = 0;
|
|
|
|
clear_flg = 0;
|
|
|
|
ratio = 0;
|
|
|
|
in_count = 1;
|
|
|
|
checkpoint = CHECK_GAP;
|
|
|
|
maxcode = MAXCODE(n_bits = INIT_BITS);
|
|
|
|
free_ent = ((block_compress) ? FIRST : 256);
|
|
|
|
|
|
|
|
ent = *bp++;
|
|
|
|
--count;
|
|
|
|
|
|
|
|
hshift = 0;
|
|
|
|
for (fcode = (long)hsize; fcode < 65536L; fcode *= 2L)
|
|
|
|
hshift++;
|
|
|
|
hshift = 8 - hshift; /* Set hash code range bound. */
|
|
|
|
|
|
|
|
hsize_reg = hsize;
|
|
|
|
cl_hash(zs, (count_int)hsize_reg); /* Clear hash table. */
|
|
|
|
|
|
|
|
middle: for (i = 0; count--;) {
|
|
|
|
c = *bp++;
|
|
|
|
in_count++;
|
|
|
|
fcode = (long)(((long)c << maxbits) + ent);
|
|
|
|
i = ((c << hshift) ^ ent); /* Xor hashing. */
|
|
|
|
|
|
|
|
if (htabof(i) == fcode) {
|
|
|
|
ent = codetabof(i);
|
|
|
|
continue;
|
|
|
|
} else if ((long)htabof(i) < 0) /* Empty slot. */
|
|
|
|
goto nomatch;
|
|
|
|
disp = hsize_reg - i; /* Secondary hash (after G. Knott). */
|
|
|
|
if (i == 0)
|
|
|
|
disp = 1;
|
|
|
|
probe: if ((i -= disp) < 0)
|
|
|
|
i += hsize_reg;
|
|
|
|
|
|
|
|
if (htabof(i) == fcode) {
|
|
|
|
ent = codetabof(i);
|
|
|
|
continue;
|
|
|
|
}
|
|
|
|
if ((long)htabof(i) >= 0)
|
|
|
|
goto probe;
|
|
|
|
nomatch: if (output(zs, (code_int) ent) == -1)
|
|
|
|
return (-1);
|
|
|
|
out_count++;
|
|
|
|
ent = c;
|
|
|
|
if (free_ent < maxmaxcode) {
|
|
|
|
codetabof(i) = free_ent++; /* code -> hashtable */
|
|
|
|
htabof(i) = fcode;
|
|
|
|
} else if ((count_int)in_count >=
|
|
|
|
checkpoint && block_compress) {
|
|
|
|
if (cl_block(zs) == -1)
|
|
|
|
return (-1);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
return (num);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
2002-07-28 15:32:17 +00:00
|
|
|
zclose(void *cookie)
|
1994-05-27 12:33:43 +00:00
|
|
|
{
|
|
|
|
struct s_zstate *zs;
|
|
|
|
int rval;
|
|
|
|
|
|
|
|
zs = cookie;
|
|
|
|
if (zmode == 'w') { /* Put out the final code. */
|
|
|
|
if (output(zs, (code_int) ent) == -1) {
|
|
|
|
(void)fclose(fp);
|
|
|
|
free(zs);
|
|
|
|
return (-1);
|
|
|
|
}
|
|
|
|
out_count++;
|
|
|
|
if (output(zs, (code_int) - 1) == -1) {
|
|
|
|
(void)fclose(fp);
|
|
|
|
free(zs);
|
|
|
|
return (-1);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
rval = fclose(fp) == EOF ? -1 : 0;
|
|
|
|
free(zs);
|
|
|
|
return (rval);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*-
|
|
|
|
* Output the given code.
|
|
|
|
* Inputs:
|
|
|
|
* code: A n_bits-bit integer. If == -1, then EOF. This assumes
|
|
|
|
* that n_bits =< (long)wordsize - 1.
|
|
|
|
* Outputs:
|
|
|
|
* Outputs code to the file.
|
|
|
|
* Assumptions:
|
|
|
|
* Chars are 8 bits long.
|
|
|
|
* Algorithm:
|
|
|
|
* Maintain a BITS character long buffer (so that 8 codes will
|
|
|
|
* fit in it exactly). Use the VAX insv instruction to insert each
|
|
|
|
* code in turn. When the buffer fills up empty it and start over.
|
|
|
|
*/
|
|
|
|
|
|
|
|
static char_type lmask[9] =
|
|
|
|
{0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80, 0x00};
|
|
|
|
static char_type rmask[9] =
|
|
|
|
{0x00, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f, 0xff};
|
|
|
|
|
|
|
|
static int
|
2002-07-28 15:32:17 +00:00
|
|
|
output(struct s_zstate *zs, code_int ocode)
|
1994-05-27 12:33:43 +00:00
|
|
|
{
|
2001-12-02 13:31:22 +00:00
|
|
|
int r_off;
|
2001-12-02 23:58:38 +00:00
|
|
|
u_int bits;
|
2001-12-02 13:31:22 +00:00
|
|
|
char_type *bp;
|
1994-05-27 12:33:43 +00:00
|
|
|
|
|
|
|
r_off = offset;
|
|
|
|
bits = n_bits;
|
|
|
|
bp = buf;
|
|
|
|
if (ocode >= 0) {
|
|
|
|
/* Get to the first byte. */
|
|
|
|
bp += (r_off >> 3);
|
|
|
|
r_off &= 7;
|
|
|
|
/*
|
|
|
|
* Since ocode is always >= 8 bits, only need to mask the first
|
|
|
|
* hunk on the left.
|
|
|
|
*/
|
1998-12-06 22:58:23 +00:00
|
|
|
*bp = (*bp & rmask[r_off]) | ((ocode << r_off) & lmask[r_off]);
|
1994-05-27 12:33:43 +00:00
|
|
|
bp++;
|
|
|
|
bits -= (8 - r_off);
|
|
|
|
ocode >>= 8 - r_off;
|
|
|
|
/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
|
|
|
|
if (bits >= 8) {
|
|
|
|
*bp++ = ocode;
|
|
|
|
ocode >>= 8;
|
|
|
|
bits -= 8;
|
|
|
|
}
|
|
|
|
/* Last bits. */
|
|
|
|
if (bits)
|
|
|
|
*bp = ocode;
|
|
|
|
offset += n_bits;
|
|
|
|
if (offset == (n_bits << 3)) {
|
|
|
|
bp = buf;
|
|
|
|
bits = n_bits;
|
|
|
|
bytes_out += bits;
|
|
|
|
if (fwrite(bp, sizeof(char), bits, fp) != bits)
|
|
|
|
return (-1);
|
|
|
|
bp += bits;
|
|
|
|
bits = 0;
|
|
|
|
offset = 0;
|
|
|
|
}
|
|
|
|
/*
|
|
|
|
* If the next entry is going to be too big for the ocode size,
|
|
|
|
* then increase it, if possible.
|
|
|
|
*/
|
|
|
|
if (free_ent > maxcode || (clear_flg > 0)) {
|
|
|
|
/*
|
|
|
|
* Write the whole buffer, because the input side won't
|
|
|
|
* discover the size increase until after it has read it.
|
|
|
|
*/
|
|
|
|
if (offset > 0) {
|
|
|
|
if (fwrite(buf, 1, n_bits, fp) != n_bits)
|
|
|
|
return (-1);
|
|
|
|
bytes_out += n_bits;
|
|
|
|
}
|
|
|
|
offset = 0;
|
|
|
|
|
|
|
|
if (clear_flg) {
|
|
|
|
maxcode = MAXCODE(n_bits = INIT_BITS);
|
|
|
|
clear_flg = 0;
|
|
|
|
} else {
|
|
|
|
n_bits++;
|
|
|
|
if (n_bits == maxbits)
|
|
|
|
maxcode = maxmaxcode;
|
|
|
|
else
|
|
|
|
maxcode = MAXCODE(n_bits);
|
|
|
|
}
|
|
|
|
}
|
|
|
|
} else {
|
|
|
|
/* At EOF, write the rest of the buffer. */
|
|
|
|
if (offset > 0) {
|
|
|
|
offset = (offset + 7) / 8;
|
|
|
|
if (fwrite(buf, 1, offset, fp) != offset)
|
|
|
|
return (-1);
|
|
|
|
bytes_out += offset;
|
|
|
|
}
|
|
|
|
offset = 0;
|
|
|
|
}
|
|
|
|
return (0);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Decompress read. This routine adapts to the codes in the file building
|
|
|
|
* the "string" table on-the-fly; requiring no table to be stored in the
|
|
|
|
* compressed file. The tables used herein are shared with those of the
|
|
|
|
* compress() routine. See the definitions above.
|
|
|
|
*/
|
|
|
|
static int
|
2002-07-28 15:32:17 +00:00
|
|
|
zread(void *cookie, char *rbp, int num)
|
1994-05-27 12:33:43 +00:00
|
|
|
{
|
2001-12-02 13:31:22 +00:00
|
|
|
u_int count;
|
1994-05-27 12:33:43 +00:00
|
|
|
struct s_zstate *zs;
|
|
|
|
u_char *bp, header[3];
|
|
|
|
|
|
|
|
if (num == 0)
|
|
|
|
return (0);
|
|
|
|
|
|
|
|
zs = cookie;
|
|
|
|
count = num;
|
|
|
|
bp = (u_char *)rbp;
|
|
|
|
switch (state) {
|
|
|
|
case S_START:
|
|
|
|
state = S_MIDDLE;
|
|
|
|
break;
|
|
|
|
case S_MIDDLE:
|
|
|
|
goto middle;
|
|
|
|
case S_EOF:
|
|
|
|
goto eof;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Check the magic number */
|
|
|
|
if (fread(header,
|
|
|
|
sizeof(char), sizeof(header), fp) != sizeof(header) ||
|
|
|
|
memcmp(header, magic_header, sizeof(magic_header)) != 0) {
|
|
|
|
errno = EFTYPE;
|
|
|
|
return (-1);
|
|
|
|
}
|
|
|
|
maxbits = header[2]; /* Set -b from file. */
|
|
|
|
block_compress = maxbits & BLOCK_MASK;
|
|
|
|
maxbits &= BIT_MASK;
|
|
|
|
maxmaxcode = 1L << maxbits;
|
|
|
|
if (maxbits > BITS) {
|
|
|
|
errno = EFTYPE;
|
|
|
|
return (-1);
|
|
|
|
}
|
|
|
|
/* As above, initialize the first 256 entries in the table. */
|
|
|
|
maxcode = MAXCODE(n_bits = INIT_BITS);
|
|
|
|
for (code = 255; code >= 0; code--) {
|
|
|
|
tab_prefixof(code) = 0;
|
|
|
|
tab_suffixof(code) = (char_type) code;
|
|
|
|
}
|
|
|
|
free_ent = block_compress ? FIRST : 256;
|
|
|
|
|
|
|
|
finchar = oldcode = getcode(zs);
|
|
|
|
if (oldcode == -1) /* EOF already? */
|
|
|
|
return (0); /* Get out of here */
|
|
|
|
|
|
|
|
/* First code must be 8 bits = char. */
|
|
|
|
*bp++ = (u_char)finchar;
|
|
|
|
count--;
|
|
|
|
stackp = de_stack;
|
|
|
|
|
|
|
|
while ((code = getcode(zs)) > -1) {
|
|
|
|
|
|
|
|
if ((code == CLEAR) && block_compress) {
|
|
|
|
for (code = 255; code >= 0; code--)
|
|
|
|
tab_prefixof(code) = 0;
|
|
|
|
clear_flg = 1;
|
|
|
|
free_ent = FIRST - 1;
|
|
|
|
if ((code = getcode(zs)) == -1) /* O, untimely death! */
|
|
|
|
break;
|
|
|
|
}
|
|
|
|
incode = code;
|
|
|
|
|
|
|
|
/* Special case for KwKwK string. */
|
|
|
|
if (code >= free_ent) {
|
|
|
|
*stackp++ = finchar;
|
|
|
|
code = oldcode;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Generate output characters in reverse order. */
|
|
|
|
while (code >= 256) {
|
|
|
|
*stackp++ = tab_suffixof(code);
|
|
|
|
code = tab_prefixof(code);
|
|
|
|
}
|
|
|
|
*stackp++ = finchar = tab_suffixof(code);
|
|
|
|
|
|
|
|
/* And put them out in forward order. */
|
|
|
|
middle: do {
|
|
|
|
if (count-- == 0)
|
|
|
|
return (num);
|
|
|
|
*bp++ = *--stackp;
|
|
|
|
} while (stackp > de_stack);
|
|
|
|
|
|
|
|
/* Generate the new entry. */
|
|
|
|
if ((code = free_ent) < maxmaxcode) {
|
|
|
|
tab_prefixof(code) = (u_short) oldcode;
|
|
|
|
tab_suffixof(code) = finchar;
|
|
|
|
free_ent = code + 1;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* Remember previous code. */
|
|
|
|
oldcode = incode;
|
|
|
|
}
|
|
|
|
state = S_EOF;
|
|
|
|
eof: return (num - count);
|
|
|
|
}
|
|
|
|
|
|
|
|
/*-
|
|
|
|
* Read one code from the standard input. If EOF, return -1.
|
|
|
|
* Inputs:
|
|
|
|
* stdin
|
|
|
|
* Outputs:
|
|
|
|
* code or -1 is returned.
|
|
|
|
*/
|
|
|
|
static code_int
|
2002-07-28 15:32:17 +00:00
|
|
|
getcode(struct s_zstate *zs)
|
1994-05-27 12:33:43 +00:00
|
|
|
{
|
2001-12-02 13:31:22 +00:00
|
|
|
code_int gcode;
|
|
|
|
int r_off, bits;
|
|
|
|
char_type *bp;
|
1994-05-27 12:33:43 +00:00
|
|
|
|
|
|
|
bp = gbuf;
|
|
|
|
if (clear_flg > 0 || roffset >= size || free_ent > maxcode) {
|
|
|
|
/*
|
|
|
|
* If the next entry will be too big for the current gcode
|
|
|
|
* size, then we must increase the size. This implies reading
|
|
|
|
* a new buffer full, too.
|
|
|
|
*/
|
|
|
|
if (free_ent > maxcode) {
|
|
|
|
n_bits++;
|
|
|
|
if (n_bits == maxbits) /* Won't get any bigger now. */
|
|
|
|
maxcode = maxmaxcode;
|
|
|
|
else
|
|
|
|
maxcode = MAXCODE(n_bits);
|
|
|
|
}
|
|
|
|
if (clear_flg > 0) {
|
|
|
|
maxcode = MAXCODE(n_bits = INIT_BITS);
|
|
|
|
clear_flg = 0;
|
|
|
|
}
|
|
|
|
size = fread(gbuf, 1, n_bits, fp);
|
|
|
|
if (size <= 0) /* End of file. */
|
|
|
|
return (-1);
|
|
|
|
roffset = 0;
|
|
|
|
/* Round size down to integral number of codes. */
|
|
|
|
size = (size << 3) - (n_bits - 1);
|
|
|
|
}
|
|
|
|
r_off = roffset;
|
|
|
|
bits = n_bits;
|
|
|
|
|
|
|
|
/* Get to the first byte. */
|
|
|
|
bp += (r_off >> 3);
|
|
|
|
r_off &= 7;
|
|
|
|
|
|
|
|
/* Get first part (low order bits). */
|
|
|
|
gcode = (*bp++ >> r_off);
|
|
|
|
bits -= (8 - r_off);
|
|
|
|
r_off = 8 - r_off; /* Now, roffset into gcode word. */
|
|
|
|
|
|
|
|
/* Get any 8 bit parts in the middle (<=1 for up to 16 bits). */
|
|
|
|
if (bits >= 8) {
|
|
|
|
gcode |= *bp++ << r_off;
|
|
|
|
r_off += 8;
|
|
|
|
bits -= 8;
|
|
|
|
}
|
|
|
|
|
|
|
|
/* High order bits. */
|
|
|
|
gcode |= (*bp & rmask[bits]) << r_off;
|
|
|
|
roffset += n_bits;
|
|
|
|
|
|
|
|
return (gcode);
|
|
|
|
}
|
|
|
|
|
|
|
|
static int
|
2002-07-28 15:32:17 +00:00
|
|
|
cl_block(struct s_zstate *zs) /* Table clear for block compress. */
|
1994-05-27 12:33:43 +00:00
|
|
|
{
|
2001-12-02 13:31:22 +00:00
|
|
|
long rat;
|
1994-05-27 12:33:43 +00:00
|
|
|
|
|
|
|
checkpoint = in_count + CHECK_GAP;
|
|
|
|
|
|
|
|
if (in_count > 0x007fffff) { /* Shift will overflow. */
|
|
|
|
rat = bytes_out >> 8;
|
|
|
|
if (rat == 0) /* Don't divide by zero. */
|
|
|
|
rat = 0x7fffffff;
|
|
|
|
else
|
|
|
|
rat = in_count / rat;
|
|
|
|
} else
|
|
|
|
rat = (in_count << 8) / bytes_out; /* 8 fractional bits. */
|
|
|
|
if (rat > ratio)
|
|
|
|
ratio = rat;
|
|
|
|
else {
|
|
|
|
ratio = 0;
|
|
|
|
cl_hash(zs, (count_int) hsize);
|
|
|
|
free_ent = FIRST;
|
|
|
|
clear_flg = 1;
|
|
|
|
if (output(zs, (code_int) CLEAR) == -1)
|
|
|
|
return (-1);
|
|
|
|
}
|
|
|
|
return (0);
|
|
|
|
}
|
|
|
|
|
|
|
|
static void
|
2002-07-28 15:32:17 +00:00
|
|
|
cl_hash(struct s_zstate *zs, count_int cl_hsize) /* Reset code table. */
|
1994-05-27 12:33:43 +00:00
|
|
|
{
|
2001-12-02 13:31:22 +00:00
|
|
|
count_int *htab_p;
|
|
|
|
long i, m1;
|
1994-05-27 12:33:43 +00:00
|
|
|
|
|
|
|
m1 = -1;
|
|
|
|
htab_p = htab + cl_hsize;
|
|
|
|
i = cl_hsize - 16;
|
|
|
|
do { /* Might use Sys V memset(3) here. */
|
|
|
|
*(htab_p - 16) = m1;
|
|
|
|
*(htab_p - 15) = m1;
|
|
|
|
*(htab_p - 14) = m1;
|
|
|
|
*(htab_p - 13) = m1;
|
|
|
|
*(htab_p - 12) = m1;
|
|
|
|
*(htab_p - 11) = m1;
|
|
|
|
*(htab_p - 10) = m1;
|
|
|
|
*(htab_p - 9) = m1;
|
|
|
|
*(htab_p - 8) = m1;
|
|
|
|
*(htab_p - 7) = m1;
|
|
|
|
*(htab_p - 6) = m1;
|
|
|
|
*(htab_p - 5) = m1;
|
|
|
|
*(htab_p - 4) = m1;
|
|
|
|
*(htab_p - 3) = m1;
|
|
|
|
*(htab_p - 2) = m1;
|
|
|
|
*(htab_p - 1) = m1;
|
|
|
|
htab_p -= 16;
|
|
|
|
} while ((i -= 16) >= 0);
|
|
|
|
for (i += 16; i > 0; i--)
|
|
|
|
*--htab_p = m1;
|
|
|
|
}
|
|
|
|
|
|
|
|
FILE *
|
2002-07-28 15:32:17 +00:00
|
|
|
zopen(const char *fname, const char *mode, int bits)
|
1994-05-27 12:33:43 +00:00
|
|
|
{
|
|
|
|
struct s_zstate *zs;
|
|
|
|
|
1998-12-06 22:58:23 +00:00
|
|
|
if ((mode[0] != 'r' && mode[0] != 'w') || mode[1] != '\0' ||
|
1994-05-27 12:33:43 +00:00
|
|
|
bits < 0 || bits > BITS) {
|
|
|
|
errno = EINVAL;
|
|
|
|
return (NULL);
|
|
|
|
}
|
|
|
|
|
|
|
|
if ((zs = calloc(1, sizeof(struct s_zstate))) == NULL)
|
|
|
|
return (NULL);
|
|
|
|
|
|
|
|
maxbits = bits ? bits : BITS; /* User settable max # bits/code. */
|
1995-01-02 10:04:02 +00:00
|
|
|
maxmaxcode = 1L << maxbits; /* Should NEVER generate this code. */
|
1994-05-27 12:33:43 +00:00
|
|
|
hsize = HSIZE; /* For dynamic table sizing. */
|
|
|
|
free_ent = 0; /* First unused entry. */
|
|
|
|
block_compress = BLOCK_MASK;
|
|
|
|
clear_flg = 0;
|
|
|
|
ratio = 0;
|
|
|
|
checkpoint = CHECK_GAP;
|
|
|
|
in_count = 1; /* Length of input. */
|
|
|
|
out_count = 0; /* # of codes output (for debugging). */
|
|
|
|
state = S_START;
|
|
|
|
roffset = 0;
|
|
|
|
size = 0;
|
|
|
|
|
|
|
|
/*
|
|
|
|
* Layering compress on top of stdio in order to provide buffering,
|
|
|
|
* and ensure that reads and write work with the data specified.
|
|
|
|
*/
|
|
|
|
if ((fp = fopen(fname, mode)) == NULL) {
|
|
|
|
free(zs);
|
|
|
|
return (NULL);
|
|
|
|
}
|
|
|
|
switch (*mode) {
|
|
|
|
case 'r':
|
|
|
|
zmode = 'r';
|
|
|
|
return (funopen(zs, zread, NULL, NULL, zclose));
|
|
|
|
case 'w':
|
|
|
|
zmode = 'w';
|
|
|
|
return (funopen(zs, NULL, zwrite, NULL, zclose));
|
|
|
|
}
|
|
|
|
/* NOTREACHED */
|
1998-12-06 22:58:23 +00:00
|
|
|
return (NULL);
|
1994-05-27 12:33:43 +00:00
|
|
|
}
|