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130 lines
3.7 KiB
ObjectPascal
130 lines
3.7 KiB
ObjectPascal
{ Copyright (C) <2005> <Andrew Haines> chmbase.pas
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This library is free software; you can redistribute it and/or modify it
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under the terms of the GNU Library General Public License as published by
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the Free Software Foundation; either version 2 of the License, or (at your
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option) any later version.
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This program is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
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for more details.
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You should have received a copy of the GNU Library General Public License
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along with this library; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
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}
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{
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See the file COPYING.modifiedLGPL, included in this distribution,
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for details about the copyright.
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}
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unit chmbase;
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{$mode objfpc}{$H+}
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interface
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uses
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Classes, SysUtils, LCLProc;
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type
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{$PACKRECORDS C}
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TITSFHeader= record
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ITSFsig: array [0..3] of char;
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Version: LongWord;
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HeaderLength: LongWord;
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Unknown_1: LongWord;
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TimeStamp: LongWord; //bigendian
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LanguageID: LongWord;
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Guid1: TGuid;
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Guid2: TGuid;
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end;
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TITSFHeaderEntry = record
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PosFromZero: QWord;
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Length: QWord;
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end;
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//Version 3 has this qword. 2 does not
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TITSFHeaderSuffix = record
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Offset: QWord; // offset within file of content section 0
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end;
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TITSPHeaderPrefix = record
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Unknown1: LongWord;// = $01FE
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Unknown2: LongWord;// = 0
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FileSize: QWord;
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Unknown3: LongWord;// =0
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Unknown4: LongWord;// =0
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end;
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TITSPHeader = record
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ITSPsig: array [0..3] of char; // = 'ITSP'
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Version: LongWord; // =1
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DirHeaderLength: Longword; // Length of the directory header
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Unknown1: LongWord; // =$0a
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ChunkSize: LongWord; // $1000
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Density: LongWord; // usually = 2
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IndexTreeDepth: LongWord;// 1 if there is no index 2 if there is one level of PMGI chunks
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IndexOfRootChunk: LongInt;// -1 if no root chunk
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FirstPMGLChunkIndex,
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LastPMGLChunkIndex: LongWord;
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Unknown2: LongInt; // = -1
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DirectoryChunkCount: LongWord;
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LanguageID: LongWord;
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GUID: TGuid;
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LengthAgain: LongWord; //??? $54
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Unknown3: LongInt; // = -1
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Unknown4: LongInt; // = -1
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Unknown5: LongInt; // = -1
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end;
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TPMGchunktype = (ctPMGL, ctPMGI, ctUnknown);
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TPMGListChunk = record
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PMGLsig: array [0..3] of char;
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UnusedSpace: Longword; ///!!! this value can also represent the size of quickref area in the end of the chunk
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Unknown1: Longword; //always 0
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PreviousChunkIndex: LongInt; // chunk number of the prev listing chunk when reading dir in sequence
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// (-1 if this is the first listing chunk)
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NextChunkIndex: LongInt; // chunk number of the next listing chunk (-1 if this is the last chunk)
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end;
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TPMGListChunkEntry = record
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//NameLength: LongInt; we don't need this permanantly so I've moved it to a temp var
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Name: String;
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ContentSection: LongWord;//QWord;
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ContentOffset: QWord;
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DecompressedLength: QWord;
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end;
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// this function will advance the stream to the end of the compressed integer
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// and return the value
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function GetCompressedInteger(var Stream: TStream): QWord;
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implementation
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function GetCompressedInteger(var Stream: TStream): QWord;
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var
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total: QWord = 0;
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temp: Byte;
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Sanity: Integer = 0;
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begin
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temp := Stream.ReadByte;
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while temp >= $80 do begin
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total := total shl 7;
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total := total + temp and $7f;
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temp := Stream.ReadByte;
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Inc(Sanity);
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if Sanity > 8 then begin
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Result := 0;
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Exit;
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end;
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end;
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Result := (total shl 7) + temp;
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Result := LEtoN(Result);
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end;
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end.
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