521 lines
18 KiB
Plaintext
521 lines
18 KiB
Plaintext
Unit impaszlib;
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{ Original:
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zlib.h -- interface of the 'zlib' general purpose compression library
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version 1.1.0, Feb 24th, 1998
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Copyright (C) 1995-1998 Jean-loup Gailly and Mark Adler
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This software is provided 'as-is', without any express or implied
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warranty. In no event will the authors be held liable for any damages
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arising from the use of this software.
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Permission is granted to anyone to use this software for any purpose,
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including commercial applications, and to alter it and redistribute it
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freely, subject to the following restrictions:
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1. The origin of this software must not be misrepresented; you must not
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claim that you wrote the original software. If you use this software
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in a product, an acknowledgment in the product documentation would be
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appreciated but is not required.
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2. Altered source versions must be plainly marked as such, and must not be
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misrepresented as being the original software.
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3. This notice may not be removed or altered from any source distribution.
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Jean-loup Gailly Mark Adler
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jloup@gzip.org madler@alumni.caltech.edu
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The data format used by the zlib library is described by RFCs (Request for
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Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt
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(zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format).
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Pascal tranlastion
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Copyright (C) 1998 by Jacques Nomssi Nzali
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For conditions of distribution and use, see copyright notice in readme.txt
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}
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interface
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{$I imzconf.inc}
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uses
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imzutil;
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{ zconf.h -- configuration of the zlib compression library }
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{ zutil.c -- target dependent utility functions for the compression library }
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{ The 'zlib' compression library provides in-memory compression and
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decompression functions, including integrity checks of the uncompressed
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data. This version of the library supports only one compression method
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(deflation) but other algorithms will be added later and will have the same
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stream interface.
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Compression can be done in a single step if the buffers are large
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enough (for example if an input file is mmap'ed), or can be done by
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repeated calls of the compression function. In the latter case, the
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application must provide more input and/or consume the output
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(providing more output space) before each call.
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The library also supports reading and writing files in gzip (.gz) format
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with an interface similar to that of stdio.
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The library does not install any signal handler. The decoder checks
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the consistency of the compressed data, so the library should never
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crash even in case of corrupted input. }
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{ Compile with -DMAXSEG_64K if the alloc function cannot allocate more
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than 64k bytes at a time (needed on systems with 16-bit int). }
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{ Maximum value for memLevel in deflateInit2 }
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const
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MAX_MEM_LEVEL = 9;
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DEF_MEM_LEVEL = 8; { if MAX_MEM_LEVEL > 8 }
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{ Maximum value for windowBits in deflateInit2 and inflateInit2 }
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const
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MAX_WBITS = 15; { 32K LZ77 window }
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{ default windowBits for decompression. MAX_WBITS is for compression only }
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const
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DEF_WBITS = MAX_WBITS;
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{ The memory requirements for deflate are (in bytes):
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1 shl (windowBits+2) + 1 shl (memLevel+9)
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that is: 128K for windowBits=15 + 128K for memLevel = 8 (default values)
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plus a few kilobytes for small objects. For example, if you want to reduce
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the default memory requirements from 256K to 128K, compile with
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DMAX_WBITS=14 DMAX_MEM_LEVEL=7
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Of course this will generally degrade compression (there's no free lunch).
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The memory requirements for inflate are (in bytes) 1 shl windowBits
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that is, 32K for windowBits=15 (default value) plus a few kilobytes
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for small objects. }
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{ Huffman code lookup table entry--this entry is four bytes for machines
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that have 16-bit pointers (e.g. PC's in the small or medium model). }
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type
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pInflate_huft = ^inflate_huft;
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inflate_huft = Record
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Exop, { number of extra bits or operation }
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bits : Byte; { number of bits in this code or subcode }
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{pad : uInt;} { pad structure to a power of 2 (4 bytes for }
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{ 16-bit, 8 bytes for 32-bit int's) }
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base : uInt; { literal, length base, or distance base }
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{ or table offset }
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End;
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type
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huft_field = Array[0..(MaxInt div SizeOf(inflate_huft))-1] of inflate_huft;
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huft_ptr = ^huft_field;
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type
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ppInflate_huft = ^pInflate_huft;
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type
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inflate_codes_mode = ( { waiting for "i:"=input, "o:"=output, "x:"=nothing }
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START, { x: set up for LEN }
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LEN, { i: get length/literal/eob next }
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LENEXT, { i: getting length extra (have base) }
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DIST, { i: get distance next }
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DISTEXT, { i: getting distance extra }
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COPY, { o: copying bytes in window, waiting for space }
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LIT, { o: got literal, waiting for output space }
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WASH, { o: got eob, possibly still output waiting }
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ZEND, { x: got eob and all data flushed }
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BADCODE); { x: got error }
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{ inflate codes private state }
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type
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pInflate_codes_state = ^inflate_codes_state;
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inflate_codes_state = record
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mode : inflate_codes_mode; { current inflate_codes mode }
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{ mode dependent information }
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len : uInt;
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sub : record { submode }
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Case Byte of
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0:(code : record { if LEN or DIST, where in tree }
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tree : pInflate_huft; { pointer into tree }
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need : uInt; { bits needed }
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end);
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1:(lit : uInt); { if LIT, literal }
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2:(copy: record { if EXT or COPY, where and how much }
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get : uInt; { bits to get for extra }
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dist : uInt; { distance back to copy from }
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end);
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end;
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{ mode independent information }
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lbits : Byte; { ltree bits decoded per branch }
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dbits : Byte; { dtree bits decoder per branch }
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ltree : pInflate_huft; { literal/length/eob tree }
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dtree : pInflate_huft; { distance tree }
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end;
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type
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check_func = function(check : uLong;
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buf : pBytef;
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{const buf : array of byte;}
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len : uInt) : uLong;
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type
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inflate_block_mode =
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(ZTYPE, { get type bits (3, including end bit) }
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LENS, { get lengths for stored }
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STORED, { processing stored block }
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TABLE, { get table lengths }
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BTREE, { get bit lengths tree for a dynamic block }
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DTREE, { get length, distance trees for a dynamic block }
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CODES, { processing fixed or dynamic block }
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DRY, { output remaining window bytes }
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BLKDONE, { finished last block, done }
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BLKBAD); { got a data error--stuck here }
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type
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pInflate_blocks_state = ^inflate_blocks_state;
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{ inflate blocks semi-private state }
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inflate_blocks_state = record
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mode : inflate_block_mode; { current inflate_block mode }
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{ mode dependent information }
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sub : record { submode }
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case Byte of
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0:(left : uInt); { if STORED, bytes left to copy }
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1:(trees : record { if DTREE, decoding info for trees }
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table : uInt; { table lengths (14 bits) }
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index : uInt; { index into blens (or border) }
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blens : PuIntArray; { bit lengths of codes }
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bb : uInt; { bit length tree depth }
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tb : pInflate_huft; { bit length decoding tree }
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end);
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2:(decode : record { if CODES, current state }
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tl : pInflate_huft;
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td : pInflate_huft; { trees to free }
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codes : pInflate_codes_state;
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end);
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end;
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last : boolean; { true if this block is the last block }
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{ mode independent information }
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bitk : uInt; { bits in bit buffer }
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bitb : uLong; { bit buffer }
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hufts : huft_ptr; {pInflate_huft;} { single malloc for tree space }
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window : pBytef; { sliding window }
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zend : pBytef; { one byte after sliding window }
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read : pBytef; { window read pointer }
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write : pBytef; { window write pointer }
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checkfn : check_func; { check function }
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check : uLong; { check on output }
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end;
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type
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inflate_mode = (
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METHOD, { waiting for method byte }
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FLAG, { waiting for flag byte }
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DICT4, { four dictionary check bytes to go }
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DICT3, { three dictionary check bytes to go }
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DICT2, { two dictionary check bytes to go }
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DICT1, { one dictionary check byte to go }
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DICT0, { waiting for inflateSetDictionary }
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BLOCKS, { decompressing blocks }
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CHECK4, { four check bytes to go }
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CHECK3, { three check bytes to go }
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CHECK2, { two check bytes to go }
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CHECK1, { one check byte to go }
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DONE, { finished check, done }
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BAD); { got an error--stay here }
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{ inflate private state }
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type
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pInternal_state = ^internal_state; { or point to a deflate_state record }
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internal_state = record
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mode : inflate_mode; { current inflate mode }
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{ mode dependent information }
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sub : record { submode }
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case byte of
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0:(method : uInt); { if FLAGS, method byte }
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1:(check : record { if CHECK, check values to compare }
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was : uLong; { computed check value }
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need : uLong; { stream check value }
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end);
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2:(marker : uInt); { if BAD, inflateSync's marker bytes count }
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end;
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{ mode independent information }
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nowrap : boolean; { flag for no wrapper }
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wbits : uInt; { log2(window size) (8..15, defaults to 15) }
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blocks : pInflate_blocks_state; { current inflate_blocks state }
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end;
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type
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alloc_func = function(opaque : voidpf; items : uInt; size : uInt) : voidpf;
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free_func = procedure(opaque : voidpf; address : voidpf);
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type
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z_streamp = ^z_stream;
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z_stream = record
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next_in : pBytef; { next input byte }
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avail_in : uInt; { number of bytes available at next_in }
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total_in : uLong; { total nb of input bytes read so far }
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next_out : pBytef; { next output byte should be put there }
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avail_out : uInt; { remaining free space at next_out }
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total_out : uLong; { total nb of bytes output so far }
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msg : string[255]; { last error message, '' if no error }
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state : pInternal_state; { not visible by applications }
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zalloc : alloc_func; { used to allocate the internal state }
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zfree : free_func; { used to free the internal state }
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opaque : voidpf; { private data object passed to zalloc and zfree }
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data_type : int; { best guess about the data type: ascii or binary }
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adler : uLong; { adler32 value of the uncompressed data }
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reserved : uLong; { reserved for future use }
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end;
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{ The application must update next_in and avail_in when avail_in has
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dropped to zero. It must update next_out and avail_out when avail_out
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has dropped to zero. The application must initialize zalloc, zfree and
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opaque before calling the init function. All other fields are set by the
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compression library and must not be updated by the application.
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The opaque value provided by the application will be passed as the first
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parameter for calls of zalloc and zfree. This can be useful for custom
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memory management. The compression library attaches no meaning to the
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opaque value.
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zalloc must return Z_NULL if there is not enough memory for the object.
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On 16-bit systems, the functions zalloc and zfree must be able to allocate
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exactly 65536 bytes, but will not be required to allocate more than this
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if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS,
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pointers returned by zalloc for objects of exactly 65536 bytes *must*
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have their offset normalized to zero. The default allocation function
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provided by this library ensures this (see zutil.c). To reduce memory
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requirements and avoid any allocation of 64K objects, at the expense of
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compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h).
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The fields total_in and total_out can be used for statistics or
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progress reports. After compression, total_in holds the total size of
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the uncompressed data and may be saved for use in the decompressor
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(particularly if the decompressor wants to decompress everything in
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a single step). }
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const { constants }
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Z_NO_FLUSH = 0;
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Z_PARTIAL_FLUSH = 1;
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Z_SYNC_FLUSH = 2;
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Z_FULL_FLUSH = 3;
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Z_FINISH = 4;
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{ Allowed flush values; see deflate() below for details }
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Z_OK = 0;
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Z_STREAM_END = 1;
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Z_NEED_DICT = 2;
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Z_ERRNO = (-1);
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Z_STREAM_ERROR = (-2);
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Z_DATA_ERROR = (-3);
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Z_MEM_ERROR = (-4);
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Z_BUF_ERROR = (-5);
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Z_VERSION_ERROR = (-6);
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{ Return codes for the compression/decompression functions. Negative
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values are errors, positive values are used for special but normal events.}
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Z_NO_COMPRESSION = 0;
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Z_BEST_SPEED = 1;
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Z_BEST_COMPRESSION = 9;
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Z_DEFAULT_COMPRESSION = (-1);
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{ compression levels }
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Z_FILTERED = 1;
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Z_HUFFMAN_ONLY = 2;
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Z_DEFAULT_STRATEGY = 0;
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{ compression strategy; see deflateInit2() below for details }
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Z_BINARY = 0;
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Z_ASCII = 1;
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Z_UNKNOWN = 2;
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{ Possible values of the data_type field }
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Z_DEFLATED = 8;
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{ The deflate compression method (the only one supported in this version) }
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Z_NULL = NIL; { for initializing zalloc, zfree, opaque }
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{$IFDEF GZIO}
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var
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errno : int;
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{$ENDIF}
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{ common constants }
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{ The three kinds of block type }
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const
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STORED_BLOCK = 0;
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STATIC_TREES = 1;
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DYN_TREES = 2;
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{ The minimum and maximum match lengths }
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const
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MIN_MATCH = 3;
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MAX_MATCH = 258;
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const
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PRESET_DICT = $20; { preset dictionary flag in zlib header }
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{$IFDEF DEBUG}
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procedure Assert(cond : boolean; msg : string);
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{$ENDIF}
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procedure Trace(x : string);
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procedure Tracev(x : string);
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procedure Tracevv(x : string);
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procedure Tracevvv(x : string);
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procedure Tracec(c : boolean; x : string);
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procedure Tracecv(c : boolean; x : string);
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function zlibVersion : string;
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{ The application can compare zlibVersion and ZLIB_VERSION for consistency.
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If the first character differs, the library code actually used is
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not compatible with the zlib.h header file used by the application.
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This check is automatically made by deflateInit and inflateInit. }
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function zError(err : int) : string;
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function ZALLOC (var strm : z_stream; items : uInt; size : uInt) : voidpf;
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procedure ZFREE (var strm : z_stream; ptr : voidpf);
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procedure TRY_FREE (var strm : z_stream; ptr : voidpf);
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const
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ZLIB_VERSION : string[10] = '1.1.2';
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const
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z_errbase = Z_NEED_DICT;
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z_errmsg : Array[0..9] of string[21] = { indexed by 2-zlib_error }
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('need dictionary', { Z_NEED_DICT 2 }
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'stream end', { Z_STREAM_END 1 }
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'', { Z_OK 0 }
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'file error', { Z_ERRNO (-1) }
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'stream error', { Z_STREAM_ERROR (-2) }
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'data error', { Z_DATA_ERROR (-3) }
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'insufficient memory', { Z_MEM_ERROR (-4) }
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'buffer error', { Z_BUF_ERROR (-5) }
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'incompatible version',{ Z_VERSION_ERROR (-6) }
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'');
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const
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z_verbose : int = 1;
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function deflateInit_(var Stream: z_stream; Level: LongInt; const Version: string;
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Stream_size: LongInt): LongInt;
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function inflateInit_(var Stream: z_stream; const Version: string;
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Stream_size: Longint): LongInt;
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{$IFDEF DEBUG}
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procedure z_error (m : string);
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{$ENDIF}
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implementation
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uses
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imzdeflate, imzinflate;
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function deflateInit_(var Stream: z_stream; Level: LongInt; const Version: string;
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Stream_size: LongInt): LongInt;
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begin
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Result := imzdeflate.deflateInit_(@Stream, Level, Version, Stream_size);
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end;
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function inflateInit_(var Stream: z_stream; const Version: string;
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Stream_size: Longint): LongInt;
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begin
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Result := imzinflate.inflateInit_(@Stream, Version, Stream_size);
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end;
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function zError(err : int) : string;
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begin
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zError := z_errmsg[Z_NEED_DICT-err];
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end;
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function zlibVersion : string;
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begin
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zlibVersion := ZLIB_VERSION;
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end;
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procedure z_error (m : string);
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begin
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WriteLn(output, m);
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Write('Zlib - Halt...');
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ReadLn;
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Halt(1);
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end;
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procedure Assert(cond : boolean; msg : string);
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begin
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if not cond then
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z_error(msg);
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end;
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procedure Trace(x : string);
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begin
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WriteLn(x);
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end;
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procedure Tracev(x : string);
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begin
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if (z_verbose>0) then
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WriteLn(x);
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end;
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procedure Tracevv(x : string);
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begin
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if (z_verbose>1) then
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WriteLn(x);
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end;
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procedure Tracevvv(x : string);
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begin
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if (z_verbose>2) then
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WriteLn(x);
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end;
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procedure Tracec(c : boolean; x : string);
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begin
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if (z_verbose>0) and (c) then
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WriteLn(x);
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end;
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procedure Tracecv(c : boolean; x : string);
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begin
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if (z_verbose>1) and c then
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WriteLn(x);
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end;
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function ZALLOC (var strm : z_stream; items : uInt; size : uInt) : voidpf;
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begin
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ZALLOC := strm.zalloc(strm.opaque, items, size);
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end;
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procedure ZFREE (var strm : z_stream; ptr : voidpf);
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begin
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strm.zfree(strm.opaque, ptr);
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end;
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procedure TRY_FREE (var strm : z_stream; ptr : voidpf);
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begin
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{if @strm <> Z_NULL then}
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strm.zfree(strm.opaque, ptr);
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end;
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end.
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