mirror of
https://gitlab.com/freepascal.org/lazarus/lazarus.git
synced 2025-05-28 17:22:45 +02:00
211 lines
5.8 KiB
ObjectPascal
211 lines
5.8 KiB
ObjectPascal
{ Copyright (C) <2005> <Andrew Haines> chmbase.pas
|
|
|
|
This library is free software; you can redistribute it and/or modify it
|
|
under the terms of the GNU Library General Public License as published by
|
|
the Free Software Foundation; either version 2 of the License, or (at your
|
|
option) any later version.
|
|
|
|
This program is distributed in the hope that it will be useful, but WITHOUT
|
|
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
|
|
FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License
|
|
for more details.
|
|
|
|
You should have received a copy of the GNU Library General Public License
|
|
along with this library; if not, write to the Free Software Foundation,
|
|
Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
}
|
|
{
|
|
See the file COPYING.FPC, included in this distribution,
|
|
for details about the copyright.
|
|
}
|
|
unit wikichmbase;
|
|
|
|
{$mode objfpc}{$H+}
|
|
|
|
interface
|
|
|
|
uses
|
|
Classes, SysUtils;
|
|
|
|
const
|
|
CHMPackageVersion = '2.6.0'; // to be put in readme
|
|
|
|
type
|
|
{$PACKRECORDS C}
|
|
TITSFHeader= record
|
|
ITSFsig: array [0..3] of char;
|
|
Version: LongWord;
|
|
HeaderLength: LongWord;
|
|
Unknown_1: LongWord;
|
|
TimeStamp: LongWord; //bigendian
|
|
LanguageID: LongWord;
|
|
end;
|
|
TITSFHeaderEntry = record
|
|
PosFromZero: QWord;
|
|
Length: QWord;
|
|
end;
|
|
|
|
//Version 3 has this qword. 2 does not
|
|
TITSFHeaderSuffix = record
|
|
Offset: QWord; // offset within file of content section 0
|
|
end;
|
|
|
|
TITSPHeaderPrefix = record
|
|
Unknown1: LongWord;// = $01FE
|
|
Unknown2: LongWord;// = 0
|
|
FileSize: QWord;
|
|
Unknown3: LongWord;// =0
|
|
Unknown4: LongWord;// =0
|
|
end;
|
|
|
|
TITSPHeader = record
|
|
ITSPsig: array [0..3] of char; // = 'ITSP'
|
|
Version: LongWord; // =1
|
|
DirHeaderLength: Longword; // Length of the directory header
|
|
Unknown1: LongWord; // =$0a
|
|
ChunkSize: LongWord; // $1000
|
|
Density: LongWord; // usually = 2
|
|
IndexTreeDepth: LongWord;// 1 if there is no index 2 if there is one level of PMGI chunks
|
|
IndexOfRootChunk: LongInt;// -1 if no root chunk
|
|
FirstPMGLChunkIndex,
|
|
LastPMGLChunkIndex: LongWord;
|
|
Unknown2: LongInt; // = -1
|
|
DirectoryChunkCount: LongWord;
|
|
LanguageID: LongWord;
|
|
GUID: TGuid;
|
|
LengthAgain: LongWord; //??? $54
|
|
Unknown3: LongInt; // = -1
|
|
Unknown4: LongInt; // = -1
|
|
Unknown5: LongInt; // = -1
|
|
end;
|
|
|
|
TDirChunkType = (ctPMGL, ctPMGI, ctAOLL, ctAOLI, ctUnknown);
|
|
|
|
TPMGListChunk = record
|
|
PMGLsig: array [0..3] of char;
|
|
UnusedSpace: Longword; ///!!! this value can also represent the size of quickref area in the end of the chunk
|
|
Unknown1: Longword; //always 0
|
|
PreviousChunkIndex: LongInt; // chunk number of the prev listing chunk when reading dir in sequence
|
|
// (-1 if this is the first listing chunk)
|
|
NextChunkIndex: LongInt; // chunk number of the next listing chunk (-1 if this is the last chunk)
|
|
end;
|
|
|
|
PPMGListChunkEntry = ^TPMGListChunkEntry;
|
|
TPMGListChunkEntry = record
|
|
//NameLength: LongInt; we don't need this permanantly so I've moved it to a temp var
|
|
Name: String;
|
|
ContentSection: LongWord;//QWord;
|
|
ContentOffset: QWord;
|
|
DecompressedLength: QWord;
|
|
end;
|
|
|
|
TPMGIIndexChunk = record
|
|
PMGIsig: array [0..3] of char;
|
|
UnusedSpace: LongWord; // has a quickref area
|
|
end;
|
|
|
|
TPMGIIndexChunkEntry = record
|
|
Name: String;
|
|
ListingChunk: DWord;
|
|
end;
|
|
|
|
|
|
const
|
|
ITSFHeaderGUID : TGuid = '{7C01FD10-7BAA-11D0-9E0C-00A0C922E6EC}';
|
|
ITSFFileSig: array [0..3] of char = 'ITSF';
|
|
|
|
ITSPHeaderGUID : TGuid = '{5D02926A-212E-11D0-9DF9-00A0C922E6EC}';
|
|
ITSPHeaderSig: array [0..3] of char = 'ITSP';
|
|
|
|
// this function will advance the stream to the end of the compressed integer
|
|
// and return the value
|
|
function GetCompressedInteger(const Stream: TStream): DWord;
|
|
// returns the number of bytes written to the stream
|
|
function WriteCompressedInteger(const Stream: TStream; ANumber: DWord): DWord;
|
|
function WriteCompressedInteger(Buffer: Pointer; ANumber: DWord): DWord;
|
|
|
|
// stupid needed function
|
|
function ChmCompareText(S1, S2: String): Integer; inline;
|
|
|
|
|
|
implementation
|
|
|
|
function GetCompressedInteger(const Stream: TStream): DWord;
|
|
var
|
|
total: QWord = 0;
|
|
temp: Byte;
|
|
Sanity: Integer = 0;
|
|
begin
|
|
try
|
|
temp := Stream.ReadByte;
|
|
while temp >= $80 do begin
|
|
total := total shl 7;
|
|
total := total + temp and $7f;
|
|
temp := Stream.ReadByte;
|
|
Inc(Sanity);
|
|
if Sanity > 8 then begin
|
|
Result := 0;
|
|
Exit;
|
|
end;
|
|
end;
|
|
Result := (total shl 7) + temp;
|
|
except
|
|
Result := 0;
|
|
end;
|
|
end;
|
|
|
|
// returns how many bytes were written
|
|
function WriteCompressedInteger(const Stream: TStream; ANumber: DWord): DWord;
|
|
var
|
|
Buffer: QWord; // Easily large enough
|
|
begin
|
|
Result := WriteCompressedInteger(@Buffer, ANumber);
|
|
Result := Stream.Write(Buffer, Result);
|
|
end;
|
|
|
|
// returns how many bytes were written
|
|
function WriteCompressedInteger(Buffer: Pointer; ANumber: DWord): DWord;
|
|
var
|
|
bit: dword;
|
|
mask: QWord;
|
|
buf: PByte;
|
|
Value: QWord = 0;
|
|
TheEnd: DWord = 0;
|
|
begin
|
|
bit := 28; //((sizeof(dWord)*8)div 7)*7; // = 28
|
|
buf := @Value;
|
|
{$push}
|
|
{$R-}
|
|
while True do begin
|
|
mask := $7f shl bit;
|
|
if (bit = 0) or ((ANumber and mask)<>0) then break;
|
|
Dec(bit, 7);
|
|
end;
|
|
while True do begin
|
|
buf^ := Byte(((ANumber shr bit)and $7f));
|
|
if(bit = 0) then break;
|
|
buf^ := buf^ or $80;
|
|
Inc(buf);
|
|
Dec(bit, 7);
|
|
Inc(TheEnd);
|
|
end;
|
|
|
|
{$pop}
|
|
|
|
buf := @Value;
|
|
Result := TheEnd+1;
|
|
Move(Value, Buffer^, Result);
|
|
{$ifdef chm_debug}
|
|
if Result > 8 then WriteLn(' ', ANumber,' WRITE_COMPRESSED_INTEGER too big!: ', Result, ' ');
|
|
{$endif}
|
|
end;
|
|
|
|
function ChmCompareText(S1, S2: String): Integer; inline;
|
|
begin
|
|
// for our purposes the CompareText function will not work.
|
|
Result := CompareStr(LowerCase(S1), Lowercase(S2));
|
|
end;
|
|
|
|
end.
|
|
|