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302 lines
10 KiB
302 lines
10 KiB
/* DEC/CMS REPLACEMENT HISTORY, Element CompPirv.H */
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/* *1 14-NOV-1996 10:26:00 ANIGBOGU "[113914]Private declarations for all compression/decompression functions" */
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/* DEC/CMS REPLACEMENT HISTORY, Element CompPirv.H */
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/* PUBLIC FILE
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******************************************************************************
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**
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** (c) Copyright Schlumberger Technology Corp., unpublished work, created 1996.
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**
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** This computer program includes Confidential, Proprietary Information and is
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** a Trade Secret of Schlumberger Technology Corp. All use, disclosure, and/or
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** reproduction is prohibited unless authorized in writing by Schlumberger.
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** All Rights Reserved.
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**
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******************************************************************************
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**
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** compress/CompPirv.h
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**
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** PURPOSE
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**
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** Common declarations for all compression/decompression modules
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**
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** SPECIAL REQUIREMENTS & NOTES
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**
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** AUTHOR
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**
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** J. C. Anigbogu
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** Austin Systems Center
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** Nov 1996
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**
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******************************************************************************
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*/
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#include <stdio.h>
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#include <stdlib.h>
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#include "CompPub.h"
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#include "slbCrc32.h"
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#if defined(VMS)
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#define OS_CODE 0x02
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#endif
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#if defined(Unix)
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#define OS_CODE 0x03
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#endif
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/* Common defaults */
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#ifndef OS_CODE
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#define OS_CODE 0x0b /* assume WindowsNT or Windows95*/
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#endif
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#include <string.h>
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#define memzero(String, Size) memset ((void *)(String), 0, (Size))
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#define STORED 0
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/* methods 1 to 7 reserved */
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#define DEFLATED 8
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#define MAX_METHODS 9
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/*
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* For compression, input is done in window[]. For decompression, output
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* is done in window.
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*/
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#ifndef INBUFSIZ
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#define INBUFSIZ 0x8000 /* input buffer size */
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#endif
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#ifndef OUTBUFSIZ
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#define OUTBUFSIZ 16384 /* output buffer size */
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#endif
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#ifndef DISTBUFSIZE
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#define DISTBUFSIZE 0x8000 /* buffer for distances, see Trees.c */
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#endif
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#ifndef WSIZE
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#define WSIZE 0x8000 /* window size--must be a power of two, and */
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#endif /* at least 32K for zip's deflate method */
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#ifndef DWSIZE
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#define DWSIZE 0x10000 /* 2L * WSIZE */
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#endif
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#ifndef BITS
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#define BITS 16
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#endif
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typedef struct CompData
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{
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unsigned char *Data;
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int Size;
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struct CompData *next;
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} CompData_t;
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typedef struct CompParam
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{
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unsigned long InputSize; /* valid bytes in inbuf */
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unsigned long Index; /* index of next byte to be processed in inbuf */
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unsigned long OutBytes; /* bytes in output buffer */
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unsigned long GlobalSize; /* bytes in inbut g_inbuf */
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unsigned long BytesIn; /* number of input bytes */
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unsigned long BytesOut; /* number of output bytes */
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unsigned long HeaderBytes; /* number of bytes in gzip header */
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unsigned long WindowSize; /* window size, 2*WSIZE */
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Crc32 *pCRC; /* Cyclic Redundancy Check */
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unsigned long BitBuffer; /* Global bit buffer */
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unsigned int BitsInBitBuffer; /* bits in global bit buffer */
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unsigned short DistBuffer[DISTBUFSIZE]; /* buffer for distances, see trees.c */
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unsigned short HashLink[1L<<BITS]; /* hash link (see deflate.c) */
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unsigned char InputBuffer[INBUFSIZ]; /* input buffer */
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unsigned char *Input; /* pointer to input buffer */
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unsigned char Output[OUTBUFSIZ]; /* output buffer */
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unsigned char Window[DWSIZE]; /* Sliding window */
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unsigned char *GlobalInput; /* global input buffer */
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CompData_t *CompressedOutput; /* compressed output list */
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CompData_t *PtrOutput; /* pointer to compressed output list */
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} CompParam_t;
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typedef struct DeflateParam
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{
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long BlockStart;
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unsigned int PrevLength;
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unsigned int StringStart; /* start of string to insert */
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unsigned int MatchStart; /* start of matching string */
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unsigned int MaxChainLength;
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unsigned int MaxLazyMatch;
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unsigned int GoodMatch;
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int NiceMatch; /* Stop searching when current match exceeds this */
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} DeflateParam_t;
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/* long BlockStart:
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* window position at the beginning of the current output block. Gets
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* negative when the window is moved backwards.
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*/
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/* PrevLength:
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* Length of the best match at previous step. Matches not greater than this
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* are discarded. This is used in the lazy match evaluation.
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*/
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/* MaxChainLength:
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* To speed up deflation, hash chains are never searched beyond this length.
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* A higher limit improves compression ratio but degrades the speed.
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*/
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/* MaxLazyMatch:
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* Attempt to find a better match only when the current match is strictly
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* smaller than this value. This mechanism is used only for compression
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* levels >= 4.
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*/
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/* GoodMatch: */
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/* Use a faster search when the previous match is longer than this */
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/* Values for MaxLazyMatch, GoodMatch and MaxChainLength, depending on
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* the desired pack level (0..9). The values given below have been tuned to
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* exclude worst case performance for pathological data. Better values may be
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* found for specific data.
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*/
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/* ===========================================================================
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* Data used by the "bit string" routines (Bits.c) and zip (Zip.c)
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*/
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typedef struct LocalBits
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{
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unsigned int BitBuffer;
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unsigned int ValidBits;
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} LocalBits_t;
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/* BitBuffer: Output buffer. bits are inserted starting at the bottom
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* (least significant bits).
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*/
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/* ValidBits: Number of valid bits in BitBuffer. All bits above the last valid bit
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* are always zero.
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*/
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typedef struct LocalDef
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{
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unsigned int HashIndex; /* hash index of string to be inserted */
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int EndOfInput; /* flag set at end of input buffer */
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unsigned int Lookahead; /* number of valid bytes ahead in window */
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int CompLevel; /* compression level (1..9) */
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} LocalDef_t;
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/* for compatibility with old zip sources (to be cleaned) */
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#define GZIP_MAGIC "\037\213" /* Magic header for gzip format, 1F 8B */
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#define MIN_MATCH 3
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#define MAX_MATCH 258
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/* The minimum and maximum match lengths */
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#define MIN_LOOKAHEAD (MAX_MATCH+MIN_MATCH+1)
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/* Minimum amount of lookahead, except at the end of the input file.
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* See Deflate.c for comments about the MIN_MATCH+1.
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*/
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#define MAX_DIST (WSIZE-MIN_LOOKAHEAD)
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/* In order to simplify the code, particularly on 16 bit machines, match
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* distances are limited to MAX_DIST instead of WSIZE.
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*/
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#define STORED_BLOCK 0
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#define STATIC_TREES 1
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#define DYN_TREES 2
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/* The three kinds of block type */
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#define GetByte(c) \
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(c->Index < c->InputSize ? c->Input[c->Index++] : FillInputBuffer(0,c))
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#define TryByte(c) \
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(c->Index < c->InputSize ? c->Input[c->Index++] : FillInputBuffer(1,c))
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/* PutByte is used for the compressed output
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*/
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#define PutByte(c,o) {o->Output[o->OutBytes++]=(unsigned char)(c); \
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if (o->OutBytes==OUTBUFSIZ) \
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FlushOutputBuffer(o);}
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/* Output a 16 bit value, lsb first */
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#define PutShort(w,c) \
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{ if (c->OutBytes < OUTBUFSIZ-2) { \
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c->Output[c->OutBytes++] = (unsigned char) ((w) & 0xff); \
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c->Output[c->OutBytes++] = (unsigned char) ((unsigned short)(w) >> 8); \
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} else { \
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PutByte((unsigned char)((w) & 0xff),c); \
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PutByte((unsigned char)((unsigned short)(w) >> 8),c); \
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} \
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}
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/* Output a 32 bit value to the bit stream, LSB first */
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#define PutLong(n,c) { \
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PutShort(((n) & 0xffff),c); \
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PutShort(((unsigned long)(n)) >> 16,c); \
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}
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/* Macros for getting two-byte and four-byte header values */
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#define SH(p) ((unsigned short)(unsigned char)((p)[0]) | ((unsigned short)(unsigned char)((p)[1]) << 8))
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#define LG(p) ((unsigned long)(SH(p)) | ((unsigned long)(SH((p)+2)) << 16))
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/* Diagnostic functions */
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#ifdef DEBUG
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# define Assert(cond,msg) {if(!(cond)) error(msg);}
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#else
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# define Assert(cond,msg)
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#endif
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#ifndef MAX
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#define MAX(a,b) (((a)>(b))?(a):(b))
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#endif
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#ifndef MIN
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#define MIN(a,b) (((a)<(b))?(a):(b))
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#endif
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/* in Zip.c: */
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extern CompressStatus_t Zip(int Level, CompParam_t *Comp);
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extern int FillBuffer(unsigned char *Buffer, unsigned int Size, CompParam_t *Comp);
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int ReadBuffer(char *Buffer, unsigned int Size, CompParam_t *Comp);
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/* in Unzip.c */
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extern CompressStatus_t Unzip(int Method, CompParam_t *Comp);
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/* in Deflate.c */
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CompressStatus_t InitLongestMatch(int PackLevel, unsigned short
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*Flags, DeflateParam_t *Defl,
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LocalDef_t *Deflt, CompParam_t *Comp);
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unsigned long Deflate(int Level, LocalBits_t *Bits, DeflateParam_t *Defl,
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LocalDef_t *Deflt, CompParam_t *Comp);
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/* in Trees.c */
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void InitMatchBuffer(void);
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int TallyFrequencies(int Dist, int LengthC, int Level,
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DeflateParam_t *Defl, CompParam_t *Comp);
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unsigned long FlushBlock(char *Buffer, unsigned long stored_len, int Eof,
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LocalBits_t *Bits, CompParam_t *Comp);
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/* in Bits.c */
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void InitializeBits(LocalBits_t *Bits);
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void SendBits(int Value, int Length, LocalBits_t *Bits,
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CompParam_t *Comp);
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unsigned int ReverseBits(unsigned int Value, int Length);
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void WindupBits(LocalBits_t *Bits, CompParam_t *Comp);
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void CopyBlock(char *Input, unsigned int Length, int Header,
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LocalBits_t *Bits, CompParam_t *Comp);
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/* in Util.c: */
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extern unsigned long UpdateCRC(CompParam_t *Comp, unsigned char *Input,
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unsigned int Size);
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extern void ClearBuffers(CompParam_t *Comp);
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extern int FillInputBuffer(int EOF_OK, CompParam_t *Comp);
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extern CompressStatus_t FlushOutputBuffer(CompParam_t *Comp);
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extern CompressStatus_t FlushWindow(CompParam_t *Comp);
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extern CompressStatus_t WriteBuffer(CompParam_t *Comp, void *Buffer,
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unsigned int Count);
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/* in Inflate.c */
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extern CompressStatus_t Inflate(CompParam_t *Comp);
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