196 lines
5.5 KiB
C
196 lines
5.5 KiB
C
/*
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* Copyright (c) 1985, 1986 The Regents of the University of California.
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* 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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* James A. Woods, derived from original work by Spencer Thomas
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* 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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#ifndef __cmcompress__h_
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#define __cmcompress__h_
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#include <stdio.h>
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#ifdef __cplusplus
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extern "C"
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{
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#endif
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/*
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* Set USERMEM to the maximum amount of physical user memory available
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* in bytes. USERMEM is used to determine the maximum BITS that can be used
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* for compression.
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*
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* SACREDMEM is the amount of physical memory saved for others; compress
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* will hog the rest.
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*/
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#ifndef SACREDMEM
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#define SACREDMEM 0
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#endif
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#ifndef USERMEM
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# define USERMEM 450000 /* default user memory */
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#endif
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#ifdef pdp11
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# define BITS 12 /* max bits/code for 16-bit machine */
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# define NO_UCHAR /* also if "unsigned char" functions as signed char */
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# undef USERMEM
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#endif /* pdp11 */ /* don't forget to compile with -i */
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#ifdef USERMEM
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# if USERMEM >= (433484+SACREDMEM)
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# define PBITS 16
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# else
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# if USERMEM >= (229600+SACREDMEM)
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# define PBITS 15
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# else
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# if USERMEM >= (127536+SACREDMEM)
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# define PBITS 14
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# else
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# if USERMEM >= (73464+SACREDMEM)
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# define PBITS 13
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# else
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# define PBITS 12
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# endif
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# endif
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# endif
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# endif
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# undef USERMEM
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#endif /* USERMEM */
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#ifdef PBITS /* Preferred BITS for this memory size */
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# ifndef BITS
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# define BITS PBITS
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# endif /* BITS */
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#endif /* PBITS */
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#if BITS == 16
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# define HSIZE 69001 /* 95% occupancy */
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#endif
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#if BITS == 15
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# define HSIZE 35023 /* 94% occupancy */
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#endif
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#if BITS == 14
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# define HSIZE 18013 /* 91% occupancy */
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#endif
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#if BITS == 13
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# define HSIZE 9001 /* 91% occupancy */
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#endif
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#if BITS <= 12
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# define HSIZE 5003 /* 80% occupancy */
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#endif
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/*
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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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*/
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#if BITS > 15
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typedef long int code_int;
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#else
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typedef int code_int;
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#endif
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#ifdef SIGNED_COMPARE_SLOW
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typedef unsigned long int count_int;
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typedef unsigned short int count_short;
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#else
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typedef long int count_int;
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#endif
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#ifdef NO_UCHAR
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typedef char char_type;
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#else
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typedef unsigned char char_type;
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#endif /* UCHAR */
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struct cmcompress_stream
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{
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int n_bits; /* number of bits/code */
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int maxbits; /* user settable max # bits/code */
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code_int maxcode; /* maximum code, given n_bits */
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code_int maxmaxcode; /* should NEVER generate this code */
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count_int htab [HSIZE];
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unsigned short codetab [HSIZE];
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code_int hsize; /* for dynamic table sizing */
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code_int free_ent; /* first unused entry */
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int nomagic; /* Use a 3-byte magic number header, unless old file */
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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 block_compress;
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int clear_flg;
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long int ratio;
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count_int checkpoint;
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#ifdef DEBUG
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int debug;
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int verbose;
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#endif
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/* compress internals */
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int offset;
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long int in_count; /* length of input */
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long int bytes_out; /* length of compressed output */
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long int out_count; /* # of codes output (for debugging) */
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/* internals */
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code_int ent;
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code_int hsize_reg;
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int hshift;
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long fcode;
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int first_pass;
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/* For input and output */
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int (*input_stream)(void*);
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int (*output_stream)(void*, const char*,int);
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void* client_data;
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};
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int cmcompress_compress_initialize(struct cmcompress_stream* cdata);
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int cmcompress_compress_start(struct cmcompress_stream* cdata);
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int cmcompress_compress(struct cmcompress_stream* cdata, void* buff, size_t n);
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int cmcompress_compress_finalize(struct cmcompress_stream* cdata);
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#ifdef __cplusplus
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}
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#endif
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#endif /* __cmcompress__h_ */
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