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reactos/irc/TechBot/CHMLibrary/Storage/CHMStream.cs

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Import TechBot svn path=/trunk/; revision=13064
2005-01-15 19:27:25 +00:00
using System;
using System.Diagnostics;
using System.Text;
using System.Data;
using System.Text.RegularExpressions;
using System.Collections;
using System.Collections.Specialized;
using System.IO;
using System.Runtime.InteropServices;
namespace CHMStream
{
/// <summary>
/// Summary description for CHMFile.
/// </summary>
///
public class CHMStream : IDisposable
{
public MemoryStream OpenStream(chmUnitInfo Info)
{
if (Info==null)
return null;
MemoryStream st=new MemoryStream();
this.ExtractFile(Info,st);
return st;
}
public MemoryStream OpenStream(string FileName)
{
chmUnitInfo info=this.GetFileInfo(FileName);
if (info==null)
return null;
return OpenStream(info);
}
private string m_CHMFileName;
public string CHMFileName
{
get
{
return m_CHMFileName;
}
}
public CHMStream()
{
}
public CHMStream(string CHMFileName)
{
OpenCHM(CHMFileName);
}
public void OpenCHM(string CHMFileName)
{
m_CHMFileName=CHMFileName;
FileInfo fi=new FileInfo(m_CHMFileName);
Dir=fi.DirectoryName;
m_CHMName=fi.Name;
fi=null;
chm_open(m_CHMFileName);
}
private bool m_bCHMLoaded=false;
public bool CHMLoaded
{
get
{
return m_bCHMLoaded;
}
}
private string m_CHMName="";
public string CHMName
{
get
{
return m_CHMName;
}
}
private string Dir="";
private string m_FileFind="";
private string m_FileFindLastPart="";
private chmUnitInfo m_FileInfo=null;
private int m_FileCount=0;
public void FindFile(chmUnitInfo Info, ref CHMStream.CHM_ENUMERATOR Status)
{
string LocalFile=Info.path;
LocalFile=LocalFile.Replace("/",@"\");
if (!LocalFile.StartsWith(@"\"))
LocalFile=@"\"+LocalFile;
LocalFile=LocalFile.ToLower();
if (m_FileFind.Length<=LocalFile.Length)
{
if (LocalFile.IndexOf(m_FileFind)==LocalFile.Length-m_FileFind.Length)
{
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_SUCCESS;
m_FileInfo=Info;
return;
}
}
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE;
}
public void FileCount(chmUnitInfo Info, ref CHMStream.CHM_ENUMERATOR Status)
{
m_FileCount++;
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE;
}
private ArrayList m_FileList=null;
private string m_strByExt="";
public void FileList(chmUnitInfo Info, ref CHMStream.CHM_ENUMERATOR Status)
{
m_FileList.Add(Info.path);
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE;
}
public void FileListByExtension(chmUnitInfo Info, ref CHMStream.CHM_ENUMERATOR Status)
{
FileInfo fi=new FileInfo(Info.path);
if (fi.Extension.ToLower()==m_strByExt.ToLower())
m_FileList.Add(Info.path);
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE;
}
public void FindFileIndex(chmUnitInfo Info, ref CHMStream.CHM_ENUMERATOR Status)
{
if (m_FileCount==m_FileFindIndex)
{
m_FileInfo=Info;
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_SUCCESS;
}
else
{
m_FileCount++;
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE;
}
}
public int GetFileCount()
{
if (!m_bCHMLoaded)
return 0;
m_FileCount=0;
this.CHMFileFoundEvent+=new CHMStream.CHMFileFound(FileCount);
this.chm_enumerate(CHM_ENUMERATE.CHM_ENUMERATE_ALL);
this.CHMFileFoundEvent-=new CHMStream.CHMFileFound(FileCount);
return m_FileCount;
}
public ArrayList GetFileList()
{
if (!m_bCHMLoaded)
return null;
m_FileList=null;
m_FileList=new ArrayList(1000);
this.CHMFileFoundEvent+=new CHMStream.CHMFileFound(FileList);
this.chm_enumerate(CHM_ENUMERATE.CHM_ENUMERATE_ALL);
this.CHMFileFoundEvent-=new CHMStream.CHMFileFound(FileList);
return m_FileList;
}
public ArrayList GetFileListByExtenstion(string Ext)
{
if (!m_bCHMLoaded)
return null;
m_FileList=null;
m_FileList=new ArrayList(1000);
m_strByExt=Ext;
this.CHMFileFoundEvent+=new CHMStream.CHMFileFound(FileListByExtension);
this.chm_enumerate(CHM_ENUMERATE.CHM_ENUMERATE_ALL);
this.CHMFileFoundEvent-=new CHMStream.CHMFileFound(FileListByExtension);
return m_FileList;
}
public chmUnitInfo GetFileInfo(string FileName)
{
if (!m_bCHMLoaded)
return null;
m_FileFind=FileName.ToLower().Replace("/",@"\");
// Remove all leading '..\'
do
{
if (m_FileFind.StartsWith(@"..\"))
m_FileFind=m_FileFind.Substring(3);
else
break;
}
while(true);
if (!m_FileFind.StartsWith(@"\"))
m_FileFind=@"\"+m_FileFind;
string []parts=m_FileFind.Split('\\');
m_FileFindLastPart=@"\"+parts[parts.GetUpperBound(0)];
this.CHMFileFoundEvent+=new CHMStream.CHMFileFound(FindFile);
m_FileInfo=null;
this.chm_enumerate(CHM_ENUMERATE.CHM_ENUMERATE_ALL);
this.CHMFileFoundEvent-=new CHMStream.CHMFileFound(FindFile);
return m_FileInfo;
}
private int m_FileFindIndex=0;
public chmUnitInfo GetFileInfo(int FileIndex)
{
if (!m_bCHMLoaded)
return null;
m_FileFindIndex=FileIndex;
this.CHMFileFoundEvent+=new CHMStream.CHMFileFound(FindFileIndex);
m_FileCount=0;
m_FileInfo=null;
this.chm_enumerate(CHM_ENUMERATE.CHM_ENUMERATE_ALL);
this.CHMFileFoundEvent-=new CHMStream.CHMFileFound(FindFileIndex);
return m_FileInfo;
}
public chmUnitInfo GetFileInfoByExtension(string Ext)
{
this.CHMFileFoundEvent+=new CHMStream.CHMFileFound(FindFileByExtension);
m_FileInfo=null;
m_FileFind=Ext.ToLower();
this.chm_enumerate(CHMStream.CHM_ENUMERATE.CHM_ENUMERATE_ALL);
this.CHMFileFoundEvent-=new CHMStream.CHMFileFound(FindFileByExtension);
return m_FileInfo;
}
public bool ExtractFile(string FileName, System.IO.Stream st)
{
if (!m_bCHMLoaded)
return false;
chmUnitInfo Info=GetFileInfo(FileName);
return ExtractFile(Info,st);
}
public bool ExtractFile(chmUnitInfo Info, System.IO.Stream st)
{
if (!m_bCHMLoaded)
return false;
if (Info==null)
return false;
else
{
chm_retrieve_object(Info,st,0,Info.length);
}
return true;
}
public string ExtractTextFile(string FileName)
{
if (!m_bCHMLoaded)
return "CHM File not loaded";
chmUnitInfo Info=GetFileInfo(FileName);
return ExtractTextFile(Info);
}
public string ExtractTextFile(chmUnitInfo Info)
{
if (!m_bCHMLoaded)
return "CHM File not loaded";
if (Info==null)
return "";
if (Info.path.Length>=2)
{
if (Info.path.Substring(0,2).CompareTo("/#")==0)
return "";
if (Info.path.Substring(0,2).CompareTo("/$")==0)
return "";
}
MemoryStream st=new MemoryStream((int)Info.length);
this.chm_retrieve_object(Info,st,0,Info.length);
if (st.Length==0)
return "";
string Text="";
ASCIIEncoding ascii=new ASCIIEncoding();
Text=ascii.GetString(st.ToArray(),0,50);
// UTF Decoding
if (Text.IndexOf("UTF-8")!=-1)
{
UTF8Encoding utf8 = new UTF8Encoding();
Text=utf8.GetString(st.ToArray(),0,(int)st.Length);
}
else
Text=ascii.GetString(st.ToArray(),0,(int)st.Length);
return Text;
}
public void FindFileByExtension(chmUnitInfo Info, ref CHMStream.CHM_ENUMERATOR Status)
{
if ((Info.path.StartsWith("::")) || (Info.path.StartsWith("#")) ||(Info.path.StartsWith("$")))
{
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE;
return;
}
FileInfo Fi=new FileInfo(Info.path);
if (Fi.Extension.ToLower()==m_FileFind)
{
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_SUCCESS;
m_FileInfo=Info;
}
else
Status=CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE;
}
public bool GetCHMParts(string Url, ref string CHMFileName, ref string FileName, ref string Anchor)
{
Regex ParseURLRegEx= new Regex( @"ms-its:(?'CHMFile'.*)::(?'Topic'.*)", RegexOptions.IgnoreCase| RegexOptions.Singleline | RegexOptions.ExplicitCapture| RegexOptions.IgnorePatternWhitespace| RegexOptions.Compiled);
// Parse URL - Get CHM Filename & Page Name
// Format 'ms-its:file name.chm::/topic.htm'
if (ParseURLRegEx.IsMatch(Url))
{
Match m=ParseURLRegEx.Match(Url);
CHMFileName=m.Groups["CHMFile"].Value;
string Topic=m.Groups["Topic"].Value;
int idx=Topic.IndexOf("#");
if (idx>-1)
{
FileName=Topic.Substring(0,idx);
Anchor=Topic.Substring(idx+1);
}
else
FileName=Topic;
return true;
}
return false;
}
private string m_TempDir="";
string ReplaceFileName(Match m)
{
string strReplace = m.ToString();
// Process string.
if (m.Groups["FileName"]==null)
return strReplace;
string FileName=m.Groups["FileName"].Value;
string FileName2=FileName.Replace("/",@"\");
int idx=FileName2.IndexOf("::");
if (idx!=-1)
FileName2=FileName2.Substring(idx+2);
string []parts=FileName2.Split('\\');
string NewName=@"file://"+m_TempDir+parts[parts.GetUpperBound(0)];
strReplace=strReplace.Replace(FileName,NewName);
return strReplace;
}
public ArrayList GetFileList(ref string Text, string TempDir)
{
if (!m_bCHMLoaded)
return null;
m_TempDir=TempDir;
ArrayList FilesList=new ArrayList();
// Parse HTML for CCS, ima, etc
string regexContent=@"[\x2f a-zA-Z0-9\x5C\x2E\x28\x29\x23\x24\x25\x26\x27\x22\x21\x3F\x3E\x3D\x3C\x3B\x3A\x5B\x5D\x5E\x5F\x7D\x7C\x7B\x7E\x40\x2D\x2C\x2B\x2A]*\s*";
string regexFileName=@"\s*=\s*[""|'](?'FileName'[^""^']*)[""|']\s*";
Regex ScriptRegex = new Regex(@"<script[^>]*>.*</script>",
RegexOptions.IgnoreCase
| RegexOptions.Multiline
| RegexOptions.Singleline
| RegexOptions.IgnorePatternWhitespace
| RegexOptions.Compiled);
Regex XMLRegex = new Regex(@"<\?xml.*\?>",
RegexOptions.IgnoreCase
| RegexOptions.Multiline
| RegexOptions.Singleline
| RegexOptions.IgnorePatternWhitespace
| RegexOptions.Compiled);
Regex XMLRegex2 = new Regex(@"<xml[^>]*>.*</xml>",
RegexOptions.IgnoreCase
| RegexOptions.Multiline
| RegexOptions.Singleline
| RegexOptions.IgnorePatternWhitespace
| RegexOptions.Compiled);
Regex SRCRegex = new Regex(
@"src"+regexFileName,
RegexOptions.IgnoreCase
| RegexOptions.Multiline
| RegexOptions.Singleline
| RegexOptions.IgnorePatternWhitespace
| RegexOptions.Compiled);
Regex StyleSheetRegex = new Regex(
@"<link\s*"+regexContent+@"rel\s*=\s*[""|']stylesheet[""|']\s*"+regexContent + "href"+regexFileName,
RegexOptions.IgnoreCase
| RegexOptions.Multiline
| RegexOptions.Singleline
| RegexOptions.IgnorePatternWhitespace
| RegexOptions.Compiled);
// Remove Script Tags
Text=ScriptRegex.Replace(Text,"");
// Remove XML Tags
Text=XMLRegex.Replace(Text,"");
Text=XMLRegex2.Replace(Text,"");
StringBuilder s=new StringBuilder(Text);
if (StyleSheetRegex.IsMatch(Text))
{
Match m = StyleSheetRegex.Match(Text);
while (m.Success)
{
string FileName=m.Groups["FileName"].ToString();
FilesList.Add(FileName);
m=m.NextMatch();
}
Text=StyleSheetRegex.Replace(Text,new MatchEvaluator(ReplaceFileName));
}
if (SRCRegex.IsMatch(Text))
{
Match m = SRCRegex.Match(Text);
while (m.Success)
{
string FileName=m.Groups["FileName"].ToString();
FilesList.Add(FileName);
m=m.NextMatch();
}
Text=SRCRegex.Replace(Text,new MatchEvaluator(ReplaceFileName));
}
return FilesList;
}
public string GetHTMLAndFiles(string TempDir, string Url)
{
string HTMLText="";
if (TempDir.EndsWith(@"\")) TempDir=TempDir.Substring(TempDir.Length-1);
// Delete Temp Directory
if (Directory.Exists(TempDir))
Directory.Delete(TempDir,true);
// Create Temp Directory
if (!Directory.Exists(TempDir))
Directory.CreateDirectory(TempDir);
if (!TempDir.EndsWith(@"\")) TempDir+=@"\";
string m_TopicName="";
string m_CHMFile=CHMFileName;
string Anchor="";
if (!GetCHMParts(Url,ref m_CHMFile, ref m_TopicName, ref Anchor))
{
m_CHMFile=this.CHMFileName;
m_TopicName=Url;
}
if (m_TopicName=="")
return "#No TopicName defined in Url : "+ Url;
m_TopicName=m_TopicName.Replace("/",@"\");
if (!m_CHMFile.StartsWith(@"\"))
m_CHMFile=this.Dir+@"\"+m_CHMFile;
// Open CHM
CHMStream LocalCHM=this;
if (this.CHMFileName.ToLower().CompareTo(m_CHMFile.ToLower())!=0)
LocalCHM=new CHMStream(m_CHMFile);
// Get HTML
HTMLText=LocalCHM.ExtractTextFile(m_TopicName);
if (HTMLText=="")
return "#Failed to find Topic in CHM File : "+Url;
HTMLText=GetFiles(TempDir, HTMLText, LocalCHM);
return HTMLText;
}
public string GetFiles(string TempDir, string HTMLText, CHMStream chm)
{
return GetFiles(TempDir, HTMLText, chm,0);
}
public string GetFiles(string TempDir, string HTMLText, CHMStream chm, int Level)
{
// Get FilesList & Extract Files to Temp Dir
ArrayList FileList=chm.GetFileList(ref HTMLText, TempDir);
if (FileList!=null)
{
foreach(object obj in FileList)
{
string FileName=(string)obj;
string CHMFileName="";
string TopicName="";
string Anchor="";
CHMStream NewCHM=chm;
if (GetCHMParts(FileName,ref CHMFileName, ref TopicName, ref Anchor))
{
NewCHM=new CHMStream(chm.Dir+@"\"+CHMFileName);
if (!NewCHM.CHMLoaded)
NewCHM=null;
FileName=TopicName;
}
else
{
CHMFileName=chm.CHMFileName;
NewCHM=chm;
TopicName=FileName;
}
if (NewCHM==null)
continue;
if (((FileName.ToLower().EndsWith(".htm")) || (FileName.ToLower().EndsWith(".html"))) && (Level<2))
{
string HTMLText2=NewCHM.ExtractTextFile(FileName);
FileInfo Fi=new FileInfo(FileName);
string path=TempDir+Fi.Name;
HTMLText2=GetFiles(TempDir,HTMLText2, chm, Level+1);
if (File.Exists(path))
File.Delete(path);
StreamWriter st=new StreamWriter(path);
st.WriteLine(HTMLText2);
st.Close();
}
else
{
// Extract all other files as is
string FileName2=FileName.Replace("/",@"\");
if (FileName2.Substring(0,1)==@"\")
FileName2=FileName2.Substring(1);
string []parts=FileName2.Split('\\');
string path=TempDir+parts[parts.GetUpperBound(0)];
if (File.Exists(path))
File.Delete(path);
System.IO.FileStream st=new FileStream(path,FileMode.CreateNew);
NewCHM.ExtractFile(FileName2,st);
st.Close();
}
}
}
// return HTML string of main page
return HTMLText;
}
#region CHMStream Enums
// the two available spaces in a CHM file
// N.B.: The format supports arbitrarily many spaces, but only
// two appear to be used at present.
public enum CHM_COMPRESSION { CHM_UNCOMPRESSED=0, CHM_COMPRESSED=1};
// resolve a particular object from the archive
public enum CHM_RESOLVE { CHM_RESOLVE_SUCCESS=0, CHM_RESOLVE_FAILURE=1};
// retrieve part of an object from the archive
public enum CHM_ENUMERATE
{
None=0,
CHM_ENUMERATE_NORMAL =1,
CHM_ENUMERATE_META =2,
CHM_ENUMERATE_SPECIAL =4,
CHM_ENUMERATE_FILES =8,
CHM_ENUMERATE_DIRS =16,
CHM_ENUMERATE_ALL =31};
public enum CHM_ENUMERATOR
{
CHM_ENUMERATOR_FAILURE =0,
CHM_ENUMERATOR_SUCCESS =2,
CHM_ENUMERATOR_CONTINUE =1
};
#endregion
#region Internal Parameters
private int ffs(int val)
{
int bit=1;
int idx=1;
while (bit != 0 && (val & bit) == 0)
{
bit <<= 1;
++idx;
}
if (bit == 0)
return 0;
else
return idx;
}
// names of sections essential to decompression
private const string _CHMU_RESET_TABLE = @"::DataSpace/Storage/MSCompressed/Transform/{7FC28940-9D31-11D0-9B27-00A0C91E9C7C}/InstanceData/ResetTable";
private const string _CHMU_LZXC_CONTROLDATA = @"::DataSpace/Storage/MSCompressed/ControlData";
private const string _CHMU_CONTENT = @"::DataSpace/Storage/MSCompressed/Content";
private const string _CHMU_SPANINFO = @"::DataSpace/Storage/MSCompressed/SpanInfo";
private UInt64 dir_offset=0;
private UInt64 dir_len=0;
private UInt64 data_offset=0;
private Int32 index_root=0;
private Int32 index_head=0;
private UInt32 block_len=0;
private chmUnitInfo rt_unit;
private chmUnitInfo cn_unit;
private chmLzxcResetTable reset_table;
private bool compression_enabled=false;
// LZX control data
private int window_size=0;
private UInt32 reset_interval=0;
private UInt32 reset_blkcount=0;
private BinaryReader st=null;
// decompressor state
private lzw lzx_state;
private int lzx_last_block=0;
#endregion
#region Open CHM Stream
private bool CheckSig(string Sig1, char[] Sig2)
{
int i=0;
foreach(char ch in Sig1.ToCharArray())
{
if(ch!=Sig2[i])
return false;
i++;
}
return true;
}
// open an ITS archive
private bool chm_open(string filename)
{
chmItsfHeader itsfHeader=new chmItsfHeader();
chmItspHeader itspHeader=new chmItspHeader();
chmUnitInfo uiSpan=new chmUnitInfo();
chmUnitInfo uiLzxc=new chmUnitInfo();
chmLzxcControlData ctlData=new chmLzxcControlData();
m_bCHMLoaded=false;
if (!File.Exists(filename))
return false;
st=new BinaryReader(File.OpenRead(filename));
if (st==null)
return false;
// read and verify header
if (itsfHeader.Read_itsf_header(st)==0)
{
st.Close();
return false;
}
st.BaseStream.Seek((long)itsfHeader.dir_offset,SeekOrigin.Begin);
// stash important values from header
dir_offset = itsfHeader.dir_offset;
dir_len = itsfHeader.dir_len;
data_offset = itsfHeader.data_offset;
// now, read and verify the directory header chunk
if (itspHeader.Read_itsp_header(st)==0)
{
st.Close();
return false;
}
// grab essential information from ITSP header
dir_offset += (UInt64)itspHeader.header_len;
dir_len -= (UInt64)itspHeader.header_len;
index_root = itspHeader.index_root;
index_head = itspHeader.index_head;
block_len = itspHeader.block_len;
// if the index root is -1, this means we don't have any PMGI blocks.
// as a result, we must use the sole PMGL block as the index root
if (index_root == -1)
index_root = index_head;
compression_enabled=true;
// prefetch most commonly needed unit infos
// if (CHM_RESOLVE.CHM_RESOLVE_SUCCESS != chm_resolve_object(_CHMU_SPANINFO, ref uiSpan)
// || uiSpan.space == CHM_COMPRESSION.CHM_COMPRESSED ||
if (CHM_RESOLVE.CHM_RESOLVE_SUCCESS != chm_resolve_object(_CHMU_RESET_TABLE, ref rt_unit)
|| rt_unit.space == CHM_COMPRESSION.CHM_COMPRESSED
|| CHM_RESOLVE.CHM_RESOLVE_SUCCESS != chm_resolve_object(_CHMU_CONTENT,ref cn_unit)
|| cn_unit.space == CHM_COMPRESSION.CHM_COMPRESSED
|| CHM_RESOLVE.CHM_RESOLVE_SUCCESS != chm_resolve_object(_CHMU_LZXC_CONTROLDATA, ref uiLzxc)
|| uiLzxc.space == CHM_COMPRESSION.CHM_COMPRESSED)
{
compression_enabled=false;
// st.Close();
// return false;
}
// try to read span
// N.B.: we've already checked that uiSpan is in the uncompressed section,
// so this should not require attempting to decompress, which may
// rely on having a valid "span"
if (compression_enabled)
{
reset_table=new chmLzxcResetTable();
st.BaseStream.Seek((long)((long)data_offset + (long)rt_unit.start),SeekOrigin.Begin);
if (reset_table.Read_lzxc_reset_table(st)!=1)
{
compression_enabled=false;
}
}
if (compression_enabled)
{
// read control data
ctlData=new chmLzxcControlData();
st.BaseStream.Seek((long)((long)data_offset + (long)uiLzxc.start),SeekOrigin.Begin);
if (ctlData.Read_lzxc_control_data(st)!=1)
{
compression_enabled=false;
}
window_size = (int)ctlData.windowSize;
reset_interval = ctlData.resetInterval;
try
{
reset_blkcount = (uint)(reset_interval /
(window_size / 2) *
ctlData.windowsPerReset);
}
catch(Exception)
{
reset_blkcount=0;
}
}
m_bCHMLoaded=true;
return true;
}
#endregion
#region Close CHM Stream
// close an ITS archive
private void chm_close()
{
if (!m_bCHMLoaded)
return;
st.Close();
lzx_state.LZXteardown();
lzx_state=null;
}
#endregion
#region Find File in CHM Stream
// resolve a particular object from the archive
private CHMStream.CHM_RESOLVE chm_resolve_object(string objPath, ref chmUnitInfo ui)
{
Int32 curPage;
// starting page
curPage = index_root;
// until we have either returned or given up
while (curPage != -1)
{
st.BaseStream.Seek((long)((long)dir_offset + (long)(curPage*block_len)),SeekOrigin.Begin);
char[] sig=st.ReadChars(4);
st.BaseStream.Seek(-4,SeekOrigin.Current);
if (CheckSig("PMGL",sig))
{
chmPmglHeader PmglHeader=new chmPmglHeader();
if (PmglHeader.Read_pmgl_header(st)==1)
{
// scan block
ui=PmglHeader.FindObject(st,block_len,objPath);
if (ui== null)
return CHMStream.CHM_RESOLVE.CHM_RESOLVE_FAILURE;
// parse entry and return
return CHMStream.CHM_RESOLVE.CHM_RESOLVE_SUCCESS;
}
}
else if (CheckSig("PMGI",sig))
{
chmPmgiHeader pmgiHeader=new chmPmgiHeader();
pmgiHeader.Read_pmgi_header(st);
curPage = pmgiHeader._chm_find_in_PMGI(st, block_len, objPath);
}
else
// else, we are confused. give up.
return CHMStream.CHM_RESOLVE.CHM_RESOLVE_FAILURE;
}
// didn't find anything. fail.
return CHMStream.CHM_RESOLVE.CHM_RESOLVE_FAILURE;
}
#endregion
#region Extract File from CHM Stream
// * utility methods for dealing with compressed data
// get the bounds of a compressed block. return 0 on failure
private int _chm_get_cmpblock_bounds(System.IO.BinaryReader st, UInt64 block, ref UInt64 start, ref UInt64 len)
{
// for all but the last block, use the reset table
if (block < reset_table.block_count-1)
{
// unpack the start address
st.BaseStream.Seek((long)data_offset + (long)rt_unit.start + (long)reset_table.table_offset + (long)(block*8),SeekOrigin.Begin);
start=st.ReadUInt64();
len=st.ReadUInt64();
}
// for the last block, use the span in addition to the reset table
else
{
// unpack the start address
st.BaseStream.Seek((long)data_offset + (long)rt_unit.start + (long)reset_table.table_offset + (long)(block*8),SeekOrigin.Begin);
start=st.ReadUInt64();
len = reset_table.compressed_len;
}
// compute the length and absolute start address
len -= start;
start += data_offset + cn_unit.start;
return 1;
}
// decompress the block. must have lzx_mutex.
private ulong _chm_decompress_block(UInt64 block, System.IO.Stream OutBuffer)
{
// byte []cbuffer = new byte(reset_table.block_len + 6144);
ulong cmpStart=0; // compressed start
ulong cmpLen=0; // compressed len
UInt32 blockAlign = (UInt32)(block % reset_blkcount); // reset intvl. aln.
// check if we need previous blocks
if (blockAlign != 0)
{
/* fetch all required previous blocks since last reset */
for (UInt32 i = blockAlign; i > 0; i--)
{
UInt32 curBlockIdx = (UInt32)(block-i);
/* check if we most recently decompressed the previous block */
if ((ulong)lzx_last_block != curBlockIdx)
{
if ((curBlockIdx % reset_blkcount)==0)
{
lzx_state.LZXreset();
}
_chm_get_cmpblock_bounds(st,curBlockIdx, ref cmpStart, ref cmpLen);
st.BaseStream.Seek((long)cmpStart,SeekOrigin.Begin);
if (lzx_state.LZXdecompress(st,OutBuffer, ref cmpLen, ref reset_table.block_len) != lzw.DECR_OK)
return (Int64)0;
}
lzx_last_block = (int)(curBlockIdx);
}
}
else
{
if ((block % reset_blkcount)==0)
{
lzx_state.LZXreset();
}
}
// decompress the block we actually want
if (_chm_get_cmpblock_bounds(st, block, ref cmpStart, ref cmpLen)==0)
return 0;
st.BaseStream.Seek((long)cmpStart,SeekOrigin.Begin);
if (lzx_state.LZXdecompress(st, OutBuffer, ref cmpLen,ref reset_table.block_len) != lzw.DECR_OK)
return (Int64)0;
lzx_last_block = (int)block;
// XXX: modify LZX routines to return the length of the data they
// * decompressed and return that instead, for an extra sanity check.
return reset_table.block_len;
}
// grab a region from a compressed block
private ulong _chm_decompress_region(Stream buf, ulong start, ulong len)
{
ulong nBlock, nOffset;
ulong nLen;
ulong gotLen;
// byte [] ubuffer=null;
if (len <= 0)
return (Int64)0;
// figure out what we need to read
nBlock = start / reset_table.block_len;
nOffset = start % reset_table.block_len;
nLen = len;
if (nLen > (reset_table.block_len - nOffset))
nLen = reset_table.block_len - nOffset;
// data request not satisfied, so... start up the decompressor machine
if (lzx_state==null)
{
int window_size = ffs(this.window_size) - 1;
lzx_last_block = -1;
lzx_state=new lzw();
lzx_state.LZXinit(window_size);
}
// decompress some data
MemoryStream ms=new MemoryStream((int)reset_table.block_len+6144);
gotLen = _chm_decompress_block(nBlock, ms);
if (gotLen < nLen)
nLen = gotLen;
// memcpy(buf, ubuffer+nOffset, (unsigned int)nLen);
ms.Position=(long)nOffset;
for(ulong i=0;i<nLen;i++)
buf.WriteByte((byte)ms.ReadByte());
buf.Flush();
return nLen;
}
// retrieve (part of) an object
private ulong chm_retrieve_object(chmUnitInfo ui, Stream buf, ulong addr, ulong len)
{
// starting address must be in correct range
if (addr < 0 || addr >= (ulong)ui.length)
return (Int64)0;
// clip length
if (addr + (ulong)len > (ulong)ui.length)
len = (ulong)ui.length - (ulong)addr;
// if the file is uncompressed, it's simple
if (ui.space == CHMStream.CHM_COMPRESSION.CHM_UNCOMPRESSED)
{
// read data
long FilePos=st.BaseStream.Position;
st.BaseStream.Seek((long)((long)data_offset + (long)ui.start + (long)addr),SeekOrigin.Begin);
// byte [] buffer=st.ReadBytes((int)len);
buf.Write(st.ReadBytes((int)len),0,(int) len);
st.BaseStream.Seek(FilePos,SeekOrigin.Begin);
return (ulong)len;
}
// else if the file is compressed, it's a little trickier
else // ui->space == CHM_COMPRESSED
{
if (lzx_state!=null)
{
lzx_state.LZXteardown();
lzx_state=null;
}
ulong swath=0, total=0;
do
{
if (!compression_enabled)
return total;
// swill another mouthful
swath = _chm_decompress_region(buf, ui.start + addr, len);
// if we didn't get any...
if (swath == 0)
{
Trace.Assert((total!=ui.length),"De-compress failed","Length Required = "+ui.length.ToString()+" Length returned = "+total.ToString());
return total;
}
// update stats
total += swath;
len -= swath;
addr += swath;
} while (len != 0);
lzx_state=null;
Trace.Assert((len!=ui.length),"De-compress failed","Length Required = "+ui.length.ToString()+" Length returned = "+len.ToString());
return len;
}
}
#endregion
#region Enumerate functions
// Enumerate the objects in the .chm archive
// Use delegate to handle callback
public delegate void CHMFileFound(chmUnitInfo Info, ref CHMStream.CHM_ENUMERATOR Status);
public event CHMFileFound CHMFileFoundEvent;
public void OnFileFound(chmUnitInfo Info, ref CHMStream.CHM_ENUMERATOR Status)
{
if (CHMFileFoundEvent!=null)
CHMFileFoundEvent(Info,ref Status);
}
private int chm_enumerate(CHM_ENUMERATE what)
{
Int32 curPage;
// buffer to hold whatever page we're looking at
chmPmglHeader header;
uint end=0;
uint cur=0;
// the current ui
chmUnitInfo ui= new chmUnitInfo();
CHMStream.CHM_ENUMERATE flag=CHMStream.CHM_ENUMERATE.None;
// starting page
curPage = index_head;
// until we have either returned or given up
while (curPage != -1)
{
st.BaseStream.Seek((long)((long)dir_offset + (long)(curPage*block_len)),SeekOrigin.Begin);
// figure out start and end for this page
cur = (uint)st.BaseStream.Position;
header=new chmPmglHeader();
if (header.Read_pmgl_header(st)==0)
return 0;
end = (uint)(st.BaseStream.Position + block_len - (header.free_space)- chmPmglHeader._CHM_PMGL_LEN);
// loop over this page
while (st.BaseStream.Position < end)
{
if (header._chm_parse_PMGL_entry(st,ref ui)==0)
return 0;
// check for DIRS
if (ui.length == 0 && ((what & CHM_ENUMERATE.CHM_ENUMERATE_DIRS)==0))
continue;
// check for FILES
if (ui.length != 0 && ((what & CHM_ENUMERATE.CHM_ENUMERATE_FILES)==0))
continue;
// check for NORMAL vs. META
if (ui.path[0] == '/')
{
// check for NORMAL vs. SPECIAL
if (ui.path.Length>2)
{
if (ui.path[1] == '#' || ui.path[1] == '$')
flag = CHMStream.CHM_ENUMERATE.CHM_ENUMERATE_SPECIAL;
else
flag = CHMStream.CHM_ENUMERATE.CHM_ENUMERATE_NORMAL;
}
else
flag = CHMStream.CHM_ENUMERATE.CHM_ENUMERATE_META;
if ((what & flag)==0)
continue;
}
// call the enumerator
{
CHMStream.CHM_ENUMERATOR status = CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE;
OnFileFound(ui,ref status);
switch (status)
{
case CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_FAILURE:
return 0;
case CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_CONTINUE:
break;
case CHMStream.CHM_ENUMERATOR.CHM_ENUMERATOR_SUCCESS:
return 1;
default:
break;
}
}
}
// advance to next page
curPage = header.block_next;
}
return 1;
}
#endregion
#region IDisposable Members
private bool disposed=false;
public void Dispose()
{
Dispose(true);
// This object will be cleaned up by the Dispose method.
// Therefore, you should call GC.SupressFinalize to
// take this object off the finalization queue
// and prevent finalization code for this object
// from executing a second time.
GC.SuppressFinalize(this);
}
/// <summary>
/// Dispose(bool disposing) executes in two distinct scenarios.
/// If disposing equals true, the method has been called directly
/// or indirectly by a user's code. Managed and unmanaged resources
/// can be disposed.
/// If disposing equals false, the method has been called by the
/// runtime from inside the finalizer and you should not reference
/// other objects. Only unmanaged resources can be disposed.
/// </summary>
/// <param name="disposing">disposing flag</param>
private void Dispose(bool disposing)
{
// Check to see if Dispose has already been called.
if(!this.disposed)
{
// If disposing equals true, dispose all managed
// and unmanaged resources.
if(disposing)
{
// Dispose managed resources.
}
}
disposed = true;
}
#endregion
}
#region Structures used by CHM Storage
public class BaseStructure
{
public bool CheckSig(string Sig1, char[] Sig2)
{
int i=0;
foreach(char ch in Sig1.ToCharArray())
{
if (ch!=Sig2[i])
return false;
i++;
}
return true;
}
// skip a compressed dword
public void skip_cword(BinaryReader st)
{
byte b=0;
while ((b=st.ReadByte())>= 0x80);
}
// skip the data from a PMGL entry
public void _chm_skip_PMGL_entry_data(BinaryReader st)
{
skip_cword(st);
skip_cword(st);
skip_cword(st);
}
// parse a compressed dword
public UInt64 _chm_parse_cword(BinaryReader st)
{
UInt64 accum = 0;
byte temp=0;
while ((temp=st.ReadByte()) >= 0x80)
{
accum <<= 7;
accum += (ulong)(temp & 0x7f);
}
return (accum << 7) + temp;
}
// parse a utf-8 string into an ASCII char buffer
public int _chm_parse_UTF8(BinaryReader st, UInt64 count, ref string path)
{
UTF8Encoding utf8=new UTF8Encoding();
path=utf8.GetString(st.ReadBytes((int)count),0,(int)count);
return 1;
}
}
public class chmUnitInfo
{
public UInt64 start=0;
public UInt64 length=0;
public CHMStream.CHM_COMPRESSION space=CHMStream.CHM_COMPRESSION.CHM_UNCOMPRESSED;
public string path="";
}
// structure of ITSF headers
public class chmItsfHeader : BaseStructure
{
public const int _CHM_ITSF_V2_LEN=0x58;
public const int _CHM_ITSF_V3_LEN=0x60;
public char[] signature=null; // 0 (ITSF)
public Int32 version=0; // 4
public Int32 header_len=0; // 8
public Int32 unknown_000c=0; // c
public UInt32 last_modified=0; // 10
public UInt32 lang_id=0; // 14
public Guid dir_uuid; // 18
public Guid stream_uuid; // 28
public UInt64 unknown_offset=0; // 38
public UInt64 unknown_len=0; // 40
public UInt64 dir_offset=0; // 48
public UInt64 dir_len=0; // 50
public UInt64 data_offset=0; // 58 (Not present before V3)
public int Read_itsf_header(BinaryReader st)
{
signature=st.ReadChars(4);
if (CheckSig("ITSF",signature)==false)
return 0;
version=st.ReadInt32();
header_len=st.ReadInt32();
unknown_000c=st.ReadInt32();
last_modified=st.ReadUInt32();
lang_id=st.ReadUInt32();
dir_uuid=new Guid(st.ReadBytes(16));
stream_uuid=new Guid(st.ReadBytes(16));
unknown_offset=st.ReadUInt64();
unknown_len=st.ReadUInt64();
dir_offset=st.ReadUInt64();
dir_len=st.ReadUInt64();
if (version==2)
{
if (header_len != chmItsfHeader._CHM_ITSF_V2_LEN)
return 0;
}
else if (version==3)
{
if (header_len != chmItsfHeader._CHM_ITSF_V3_LEN)
return 0;
}
else return 0;
if (version==3)
data_offset=st.ReadUInt64();
else
data_offset = dir_offset + dir_len;
return 1;
}
}
// structure of ITSP headers
public class chmItspHeader : BaseStructure
{
const int CHM_ITSP_V1_LEN=0x54;
public char[] signature=null; // 0 (ITSP)
public Int32 version=0;
public Int32 header_len=0;
public Int32 unknown_000c=0;
public UInt32 block_len=0;
public Int32 blockidx_intvl=0;
public Int32 index_depth=0;
public Int32 index_root=0;
public Int32 index_head=0;
public Int32 unknown_0024=0;
public Int32 num_blocks=0;
public Int32 unknown_002c=0;
public UInt32 lang_id=0;
public Guid system_uuid;
public Guid unknown_0044;
public int Read_itsp_header(BinaryReader st)
{
signature=st.ReadChars(4); // 0 (ITSP)
if (CheckSig("ITSP",signature)==false)
return 0;
version=st.ReadInt32();
header_len=st.ReadInt32();
if (header_len!=CHM_ITSP_V1_LEN)
return 0;
unknown_000c=st.ReadInt32();
block_len=st.ReadUInt32();
blockidx_intvl=st.ReadInt32();
index_depth=st.ReadInt32();
index_root=st.ReadInt32();
index_head=st.ReadInt32();
unknown_0024=st.ReadInt32();
num_blocks=st.ReadInt32();
unknown_002c=st.ReadInt32();
lang_id=st.ReadUInt32();
system_uuid=new Guid(st.ReadBytes(16));
unknown_0044=new Guid(st.ReadBytes(16));
return 1;
}
}
public class chmPmglHeader : BaseStructure
{
public const int _CHM_PMGL_LEN=0x14;
public char[] signature=null; // 0 (PMGL)
public UInt32 free_space=0; // 4
public UInt32 unknown_0008=0; // 8
public Int32 block_prev=0; // c
public Int32 block_next=0; // 10
public int Read_pmgl_header(BinaryReader st)
{
signature=st.ReadChars(4);
if (CheckSig("PMGL",signature)==false)
return 0;
free_space=st.ReadUInt32();
unknown_0008=st.ReadUInt32();
block_prev=st.ReadInt32();
block_next=st.ReadInt32();
return 1;
}
// parse a PMGL entry into a chmUnitInfo struct; return 1 on success.
public int _chm_parse_PMGL_entry(BinaryReader st, ref chmUnitInfo ui)
{
UInt64 strLen;
// parse str len
strLen = _chm_parse_cword(st);
// parse path
if (_chm_parse_UTF8(st, strLen, ref ui.path)==0)
return 0;
// parse info
ui.space = (CHMStream.CHM_COMPRESSION)_chm_parse_cword(st);
ui.start = _chm_parse_cword(st);
ui.length = _chm_parse_cword(st);
return 1;
}
public chmUnitInfo FindObject(BinaryReader st, UInt32 block_len, string objPath)
{
UInt32 end = (UInt32)st.BaseStream.Position+ block_len - free_space - _CHM_PMGL_LEN;
// now, scan progressively
chmUnitInfo FoundObject=new chmUnitInfo();
while (st.BaseStream.Position < end)
{
_chm_parse_PMGL_entry(st,ref FoundObject);
if (FoundObject.path.ToLower().CompareTo(objPath.ToLower())==0)
return FoundObject;
}
FoundObject=null;
return null;
}
}
public class chmPmgiHeader : BaseStructure
{
public const int _CHM_PMGI_LEN=0x8;
public char[] signature=null; // 0 (PMGL)
public UInt32 free_space=0; // 4
public int Read_pmgi_header(BinaryReader st)
{
signature=st.ReadChars(4);
if ((signature[0]!='P') || (signature[1]!='M') || (signature[2]!='G') || (signature[3]!='I'))
return 0;
free_space=st.ReadUInt32();
return 1;
}
public Int32 _chm_find_in_PMGI(BinaryReader st, UInt32 block_len, string objPath)
{
int page=-1;
UInt64 strLen;
string buffer="";
uint end = (uint)st.BaseStream.Position + block_len - free_space - _CHM_PMGI_LEN;
// now, scan progressively
while (st.BaseStream.Position < end)
{
// grab the name
strLen = _chm_parse_cword(st);
buffer="";
if (_chm_parse_UTF8(st, strLen, ref buffer)==0)
return -1;
// check if it is the right name
if (buffer.ToLower().CompareTo(objPath.ToLower())>0)
return page;
// load next value for path
page = (int)_chm_parse_cword(st);
}
return page;
}
}
public class chmLzxcResetTable:BaseStructure
{
public UInt32 version=0;
public UInt32 block_count=0;
public UInt32 unknown=0;
public UInt32 table_offset=0;
public UInt64 uncompressed_len=0;
public UInt64 compressed_len=0;
public UInt64 block_len=0;
public int Read_lzxc_reset_table(BinaryReader st)
{
version=st.ReadUInt32();
block_count=st.ReadUInt32();
unknown=st.ReadUInt32();
table_offset=st.ReadUInt32();
uncompressed_len=st.ReadUInt64();
compressed_len=st.ReadUInt64();
block_len=st.ReadUInt64();
// check structure
if (version != 2)
return 0;
else
return 1;
}
}
// structure of LZXC control data block
public class chmLzxcControlData:BaseStructure
{
public const int _CHM_LZXC_MIN_LEN=0x18;
public const int _CHM_LZXC_V2_LEN=0x1c;
public UInt32 size=0; // 0
public char[] signature=null; // 4 (LZXC)
public UInt32 version=0; // 8
public UInt32 resetInterval=0; // c
public UInt32 windowSize=0; // 10
public UInt32 windowsPerReset=0; // 14
public UInt32 unknown_18=0; // 18
public int Read_lzxc_control_data(BinaryReader st)
{
size=st.ReadUInt32();
signature=st.ReadChars(4);
if (CheckSig("LZXC",signature)==false)
return 0;
version=st.ReadUInt32();
resetInterval=st.ReadUInt32();
windowSize=st.ReadUInt32();
windowsPerReset=st.ReadUInt32();
if (size>=_CHM_LZXC_V2_LEN)
unknown_18=st.ReadUInt32();
else
unknown_18 = 0;
if (version == 2)
{
resetInterval *= 0x8000;
windowSize *= 0x8000;
}
if (windowSize == 0 || resetInterval == 0)
return 0;
// for now, only support resetInterval a multiple of windowSize/2
if (windowSize == 1)
return 0;
if ((resetInterval % (windowSize/2)) != 0)
return 0;
return 1;
}
}
#endregion
#region LZW Decoder
internal class lzx_bits
{
public UInt32 bb=0;
public int bl=0;
}
internal class lzw
{
public lzw()
{
}
/* $Id: lzx.c,v 1.5 2002/10/09 01:16:33 jedwin Exp $ */
/***************************************************************************
* lzx.c - LZX decompression routines *
* ------------------- *
* *
* maintainer: Jed Wing <jedwin@ugcs.caltech.edu> *
* source: modified lzx.c from cabextract v0.5 *
* notes: This file was taken from cabextract v0.5, which was, *
* itself, a modified version of the lzx decompression code *
* from unlzx. *
* *
* platforms: In its current incarnation, this file has been tested on *
* two different Linux platforms (one, redhat-based, with a *
* 2.1.2 glibc and gcc 2.95.x, and the other, Debian, with *
* 2.2.4 glibc and both gcc 2.95.4 and gcc 3.0.2). Both were *
* Intel x86 compatible machines. *
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. Note that an exemption to this *
* license has been granted by Stuart Caie for the purposes of *
* distribution with CHMFile. This does not, to the best of my *
* knowledge, constitute a change in the license of this (the LZX) code *
* in general. *
* *
***************************************************************************/
/* some constants defined by the LZX specification */
private const int LZX_MIN_MATCH = 2;
private const int LZX_MAX_MATCH = 257;
private const int LZX_NUM_CHARS = 256;
private const int LZX_BLOCKTYPE_INVALID = 0; /* also blocktypes 4-7 invalid */
private const int LZX_BLOCKTYPE_VERBATIM = 1;
private const int LZX_BLOCKTYPE_ALIGNED = 2;
private const int LZX_BLOCKTYPE_UNCOMPRESSED = 3;
private const int LZX_PRETREE_NUM_ELEMENTS = 20;
private const int LZX_ALIGNED_NUM_ELEMENTS = 8; /* aligned offset tree #elements */
private const int LZX_NUM_PRIMARY_LENGTHS = 7; /* this one missing from spec! */
private const int LZX_NUM_SECONDARY_LENGTHS = 249; /* length tree #elements */
/* LZX huffman defines: tweak tablebits as desired */
private const int LZX_PRETREE_MAXSYMBOLS = LZX_PRETREE_NUM_ELEMENTS;
private const int LZX_PRETREE_TABLEBITS = 6;
private const int LZX_MAINTREE_MAXSYMBOLS = LZX_NUM_CHARS + 50*8;
private const int LZX_MAINTREE_TABLEBITS = 12;
private const int LZX_LENGTH_MAXSYMBOLS = LZX_NUM_SECONDARY_LENGTHS+1;
private const int LZX_LENGTH_TABLEBITS = 12;
private const int LZX_ALIGNED_MAXSYMBOLS = LZX_ALIGNED_NUM_ELEMENTS;
private const int LZX_ALIGNED_TABLEBITS = 7;
private const int LZX_LENTABLE_SAFETY = 64; /* we allow length table decoding overruns */
public const int DECR_OK = 0;
public const int DECR_DATAFORMAT = 1;
public const int DECR_ILLEGALDATA = 2;
public const int DECR_NOMEMORY = 3;
private byte[] window; /* the actual decoding window */
private ulong window_size; /* window size (32Kb through 2Mb) */
private ulong actual_size; /* window size when it was first allocated */
private ulong window_posn; /* current offset within the window */
private ulong R0, R1, R2; /* for the LRU offset system */
private UInt32 main_elements; /* number of main tree elements */
private int header_read; /* have we started decoding at all yet? */
private UInt32 block_type; /* type of this block */
private ulong block_length; /* uncompressed length of this block */
private ulong block_remaining; /* uncompressed bytes still left to decode */
private ulong frames_read; /* the number of CFDATA blocks processed */
private long intel_filesize; /* magic header value used for transform */
private long intel_curpos; /* current offset in transform space */
private int intel_started; /* have we seen any translatable data yet? */
private uint [] PRETREE_table = new uint[(1<<(6)) + (((20))<<1)];
private byte [] PRETREE_len = new byte [((20)) + (64)];
private uint [] MAINTREE_table= new uint[(1<<(12)) + (((256) + 50*8)<<1)];
private byte [] MAINTREE_len = new byte [((256) + 50*8) + (64)];
private uint [] LENGTH_table= new uint[(1<<(12)) + (((249)+1)<<1)];
private byte [] LENGTH_len = new byte [((249)+1) + (64)];
private uint [] ALIGNED_table= new uint[(1<<(7)) + (((8))<<1)];
private byte [] ALIGNED_len = new byte [((8)) + (64)];
private System.IO.BinaryReader BitSource=null;
private System.IO.Stream OutputStream=null;
/* LZX decruncher */
/* Microsoft's LZX document and their implementation of the
* com.ms.util.cab Java package do not concur.
*
* In the LZX document, there is a table showing the correlation between
* window size and the number of position slots. It states that the 1MB
* window = 40 slots and the 2MB window = 42 slots. In the implementation,
* 1MB = 42 slots, 2MB = 50 slots. The actual calculation is 'find the
* first slot whose position base is equal to or more than the required
* window size'. This would explain why other tables in the document refer
* to 50 slots rather than 42.
*
* The constant NUM_PRIMARY_LENGTHS used in the decompression pseudocode
* is not defined in the specification.
*
* The LZX document does not state the uncompressed block has an
* uncompressed length field. Where does this length field come from, so
* we can know how large the block is? The implementation has it as the 24
* bits following after the 3 blocktype bits, before the alignment
* padding.
*
* The LZX document states that aligned offset blocks have their aligned
* offset huffman tree AFTER the main and length trees. The implementation
* suggests that the aligned offset tree is BEFORE the main and length
* trees.
*
* The LZX document decoding algorithm states that, in an aligned offset
* block, if an extra_bits value is 1, 2 or 3, then that number of bits
* should be read and the result added to the match offset. This is
* correct for 1 and 2, but not 3, where just a huffman symbol (using the
* aligned tree) should be read.
*
* Regarding the E8 preprocessing, the LZX document states 'No translation
* may be performed on the last 6 bytes of the input block'. This is
* correct. However, the pseudocode provided checks for the *E8 leader*
* up to the last 6 bytes. If the leader appears between -10 and -7 bytes
* from the end, this would cause the next four bytes to be modified, at
* least one of which would be in the last 6 bytes, which is not allowed
* according to the spec.
*
* The specification states that the huffman trees must always contain at
* least one element. However, many CAB files contain blocks where the
* length tree is completely empty (because there are no matches), and
* this is expected to succeed.
*/
/* LZX uses what it calls 'position slots' to represent match offsets.
* What this means is that a small 'position slot' number and a small
* offset from that slot are encoded instead of one large offset for
* every match.
* - position_base is an index to the position slot bases
* - extra_bits states how many bits of offset-from-base data is needed.
*/
private byte [] extra_bits = {
0, 0, 0, 0, 1, 1, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6,
7, 7, 8, 8, 9, 9, 10, 10, 11, 11, 12, 12, 13, 13, 14, 14,
15, 15, 16, 16, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17, 17,
17, 17, 17
};
private ulong [] position_base = {
0, 1, 2, 3, 4, 6, 8, 12, 16, 24, 32, 48, 64, 96, 128, 192,
256, 384, 512, 768, 1024, 1536, 2048, 3072, 4096, 6144, 8192, 12288, 16384, 24576, 32768, 49152,
65536, 98304, 131072, 196608, 262144, 393216, 524288, 655360, 786432, 917504, 1048576, 1179648, 1310720, 1441792, 1572864, 1703936,
1835008, 1966080, 2097152
};
private UInt32 ReadUInt16()
{
UInt32 rc=0;
UInt32 Byte1=0;
UInt32 Byte2=0;
try
{
Byte1=BitSource.ReadByte();
Byte2=BitSource.ReadByte();
}
catch(Exception)
{
}
rc=(Byte2<<8)+Byte1;
return rc;
}
public bool LZXinit(int WindowSize)
{
ulong wndsize = (ulong)(1 << WindowSize);
int i, posn_slots;
/* LZX supports window sizes of 2^15 (32Kb) through 2^21 (2Mb) */
/* if a previously allocated window is big enough, keep it */
if (WindowSize< 15 || WindowSize> 21) return false;
/* allocate state and associated window */
window = new byte[wndsize];
if (window==null)
{
return false;
}
actual_size = wndsize;
window_size = wndsize;
/* calculate required position slots */
if (WindowSize == 20) posn_slots = 42;
else if (WindowSize== 21) posn_slots = 50;
else posn_slots = WindowSize << 1;
/** alternatively **/
/* posn_slots=i=0; while (i < wndsize) i += 1 << extra_bits[posn_slots++]; */
/* initialize other state */
R0 = R1 = R2 = 1;
main_elements = (uint)(LZX_NUM_CHARS + (posn_slots << 3));
header_read = 0;
frames_read = 0;
block_remaining = 0;
block_type = LZX_BLOCKTYPE_INVALID;
intel_curpos = 0;
intel_started = 0;
window_posn = 0;
/* initialise tables to 0 (because deltas will be applied to them) */
for (i = 0; i < LZX_MAINTREE_MAXSYMBOLS; i++) MAINTREE_len[i] = 0;
for (i = 0; i < LZX_LENGTH_MAXSYMBOLS; i++) LENGTH_len[i] = 0;
return true;
}
public void LZXteardown()
{
window=null;
}
public int LZXreset()
{
R0 = R1 = R2 = 1;
header_read = 0;
frames_read = 0;
block_remaining = 0;
block_type = LZX_BLOCKTYPE_INVALID;
intel_curpos = 0;
intel_started = 0;
window_posn = 0;
for (int i = 0; i < LZX_MAINTREE_MAXSYMBOLS + LZX_LENTABLE_SAFETY; i++) MAINTREE_len[i] = 0;
for (int i = 0; i < LZX_LENGTH_MAXSYMBOLS + LZX_LENTABLE_SAFETY; i++) LENGTH_len[i] = 0;
return DECR_OK;
}
/* Bitstream reading macros:
*
* INIT_BITSTREAM should be used first to set up the system
* READ_BITS(var,n) takes N bits from the buffer and puts them in var
*
* ENSURE_BITS(n) ensures there are at least N bits in the bit buffer
* PEEK_BITS(n) extracts (without removing) N bits from the bit buffer
* REMOVE_BITS(n) removes N bits from the bit buffer
*
* These bit access routines work by using the area beyond the MSB and the
* LSB as a free source of zeroes. This avoids having to mask any bits.
* So we have to know the bit width of the bitbuffer variable. This is
* sizeof(ulong) * 8, also defined as ULONG_BITS
*/
/* number of bits in ulong. Note: This must be at multiple of 16, and at
* least 32 for the bitbuffer code to work (ie, it must be able to ensure
* up to 17 bits - that's adding 16 bits when there's one bit left, or
* adding 32 bits when there are no bits left. The code should work fine
* for machines where ulong >= 32 bits.
*/
private int ULONG_BITS()
{
int rc=(System.Runtime.InteropServices.Marshal.SizeOf(typeof(System.UInt32))<<3);
return rc;
}
/* make_decode_table(nsyms, nbits, length[], table[])
*
* This function was coded by David Tritscher. It builds a fast huffman
* decoding table out of just a canonical huffman code lengths table.
*
* nsyms = total number of symbols in this huffman tree.
* nbits = any symbols with a code length of nbits or less can be decoded
* in one lookup of the table.
* length = A table to get code lengths from [0 to syms-1]
* table = The table to fill up with decoded symbols and pointers.
*
* Returns 0 for OK or 1 for error
*/
private int make_decode_table(ulong nsyms, byte nbits, ref byte [] length, ref UInt32[] table)
{
ulong sym;
ulong leaf;
byte bit_num = 1;
ulong fill;
ulong pos = 0; /* the current position in the decode table */
ulong table_mask = (ulong)(1 << nbits);
ulong bit_mask = table_mask >> 1; /* don't do 0 length codes */
ulong next_symbol = bit_mask; /* base of allocation for long codes */
/* fill entries for codes short enough for a direct mapping */
while (bit_num <= nbits)
{
for (sym = 0; sym < nsyms; sym++)
{
if (length[sym] == bit_num)
{
leaf = pos;
if((pos += bit_mask) > table_mask) return 1; /* table overrun */
/* fill all possible lookups of this symbol with the symbol itself */
fill = bit_mask;
while (fill-- > 0) table[leaf++] = (uint)sym;
}
}
bit_mask >>= 1;
bit_num++;
}
/* if there are any codes longer than nbits */
if (pos != table_mask)
{
/* clear the remainder of the table */
for (sym = pos; sym < table_mask; sym++) table[sym] = 0;
/* give ourselves room for codes to grow by up to 16 more bits */
pos <<= 16;
table_mask <<= 16;
bit_mask = 1 << 15;
while (bit_num <= 16)
{
for (sym = 0; sym < nsyms; sym++)
{
if (length[sym] == bit_num)
{
leaf = pos >> 16;
for (fill = 0; fill < (ulong)(bit_num - nbits); fill++)
{
/* if this path hasn't been taken yet, 'allocate' two entries */
if (table[leaf] == 0)
{
table[(next_symbol << 1)] = 0;
table[(next_symbol << 1) + 1] = 0;
table[leaf] = (uint)next_symbol++;
}
/* follow the path and select either left or right for next bit */
leaf = table[leaf] << 1;
if (((pos >> (byte)(15-fill)) & 1)==1)
leaf++;
}
table[leaf] = (uint)sym;
if ((pos += bit_mask) > table_mask)
return 1; /* table overflow */
}
}
bit_mask >>= 1;
bit_num++;
}
}
/* full table? */
if (pos == table_mask)
return 0;
/* either erroneous table, or all elements are 0 - let's find out. */
for (sym = 0; sym < nsyms; sym++) if (length[(uint)sym]!=0)
return 1;
return 0;
}
private int lzx_read_lens(byte []lens, ulong first, ulong last, ref lzx_bits lb)
{
ulong i,j, x,y;
int z;
UInt32 bitbuf = lb.bb;
int bitsleft = lb.bl;
UInt32 [] hufftbl=null;
for (x = 0; x < 20; x++)
{
do
{
while (bitsleft < (4))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
y = (bitbuf >> (ULONG_BITS()- (4)));
bitbuf <<= 4;
bitsleft -= 4;
}
while (false);
PRETREE_len[x] = (byte)y;
}
if (make_decode_table( 20, 6, ref PRETREE_len, ref PRETREE_table)!=0)
return 2;
for (x = first; x < last; )
{
do
{
while (bitsleft < 16)
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
hufftbl = PRETREE_table;
if ((i = hufftbl[((ulong)bitbuf >> (ULONG_BITS()- 6))]) >= 20)
{
j = (ulong)(1 << (byte)(ULONG_BITS()- ((6))));
do
{
j >>= 1;
i <<= 1;
if ((bitbuf & j)!=0)
i|=1;
else
i|=0;
if (j==0)
{
return (2);
}
}
while ((i = hufftbl[i]) >= 20);
}
z = (int)i;
j = PRETREE_len[z];
bitbuf <<= (byte)j;
bitsleft -= (int)j;
}
while (false);
if (z == 17)
{
do
{
while (bitsleft < (4))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
y = (bitbuf >> (ULONG_BITS()- (4)));
bitbuf <<= 4;
bitsleft -= 4;
}
while(false);
y += 4;
while ((y--)!=0)
lens[x++] = 0;
}
else if (z == 18)
{
do
{
while (bitsleft < (5))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
(y) = (bitbuf >> (ULONG_BITS()- (5)));
bitbuf <<= 5;
bitsleft -= 5;
}
while (false);
y += 20;
while ((y--)!=0)
lens[x++] = 0;
}
else if (z == 19)
{
do
{
while (bitsleft < (1))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
y = (bitbuf >> (ULONG_BITS()- (1)));
bitbuf <<= 1;
bitsleft -= 1;
}
while(false);
y += 4;
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
hufftbl = (PRETREE_table);
if ((i = hufftbl[(bitbuf >> (ULONG_BITS()- 6))]) >= 20)
{
j = (ulong)1 << (byte)(ULONG_BITS()- 6);
do
{
j >>= 1;
i <<= 1;
if ((bitbuf & j)==0)
i|=0;
else
i|=1;
if (j==0)
{
return (2);
}
}
while ((i = hufftbl[i]) >= 20);
}
z = (int)i;
j = PRETREE_len[z];
bitbuf <<= (byte)j;
bitsleft -= (int)j;
}
while(false);
z = lens[x] - z;
if (z < 0)
z += 17;
while ((y--)!=0)
lens[x++] = (byte)z;
}
else
{
z = lens[x] - z;
if (z < 0)
z += 17;
lens[x++] = (byte)z;
}
}
lb.bb = bitbuf;
lb.bl = bitsleft;
return 0;
}
public int LZXdecompress(System.IO.BinaryReader inpos, System.IO.Stream outpos, ref ulong inlen, ref ulong outlen)
{
BitSource=inpos;
OutputStream=outpos;
long endinp = BitSource.BaseStream.Position+(long)inlen;
ulong runsrc, rundest;
UInt32 [] hufftbl; /* used in READ_HUFFSYM macro as chosen decoding table */
UInt32 bitbuf;
int bitsleft;
ulong match_offset, i,j,k; /* ijk used in READ_HUFFSYM macro */
lzx_bits lb; /* used in READ_LENGTHS macro */
lb=new lzx_bits();
int togo = (int)outlen, this_run, main_element, aligned_bits;
int match_length, length_footer, extra, verbatim_bits;
bitsleft = 0;
bitbuf = 0;
/* read header if necessary */
if (header_read==0)
{
i = j = 0;
do
{
while (bitsleft < (1))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
k = (bitbuf >> (ULONG_BITS()- (1)));
bitbuf <<= 1;
bitsleft -= 1;
}
while(false);
if (k!=0)
{
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() -16 - bitsleft);
bitsleft += 16;
}
i = (bitbuf >> (ULONG_BITS()- (16)));
bitbuf <<= 16;
bitsleft -= 1;
}
while(false);
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
j = (bitbuf >> (ULONG_BITS()- (16)));
bitbuf <<= 16;
bitsleft -= 16;
}
while(false);
}
intel_filesize = (long)((i << 16) | j);
header_read = 1;
}
/* main decoding loop */
while (togo > 0)
{
if (block_remaining == 0)
{
if (block_type == (3))
{
if ((block_length & 1)!=0)
BitSource.ReadByte();
bitsleft = 0;
bitbuf = 0;
}
do
{
while (bitsleft < (3))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
(block_type) = (uint)(bitbuf >> (ULONG_BITS()- (3)));
bitbuf <<= 3;
bitsleft -= 3;
}
while (false);
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
(i) = (bitbuf >> (ULONG_BITS()- (16)));
bitbuf <<= 16;
bitsleft -= 16;
}
while (false);
do
{
while (bitsleft < (8))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
(j) = (bitbuf >> (ULONG_BITS()- (8)));
bitbuf <<= 8;
bitsleft -= 8;
}
while (false);
block_remaining = block_length = (i << 8) | j;
switch (block_type)
{
case (LZX_BLOCKTYPE_ALIGNED):
for (i = 0; i < 8; i++)
{
do
{
while (bitsleft < (3))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
(j) = (bitbuf >> (ULONG_BITS()- (3)));
bitbuf <<= 3;
bitsleft -= 3;
}
while (false);
(ALIGNED_len)[i] = (byte)j;
}
if (make_decode_table( 8, 7, ref ALIGNED_len, ref ALIGNED_table)!=0)
{
return (2);
}
do
{
lb.bb = bitbuf;
lb.bl = bitsleft;
if (lzx_read_lens(MAINTREE_len,0,256,ref lb)!=0)
{
return (2);
}
bitbuf = lb.bb;
bitsleft = lb.bl;
}
while (false);
do
{
lb.bb = bitbuf;
lb.bl = bitsleft;
if (lzx_read_lens(MAINTREE_len,256,main_elements,ref lb)!=0)
{
return (2);
}
bitbuf = lb.bb;
bitsleft = lb.bl;
}
while (false);
if (make_decode_table( (256 + 50*8), 12, ref MAINTREE_len, ref MAINTREE_table)!=0)
{
return (2);
}
if (MAINTREE_len[0xE8] != 0) intel_started = 1;
do
{
lb.bb = bitbuf;
lb.bl = bitsleft;
if (lzx_read_lens(LENGTH_len,0,249,ref lb)!=0)
{
return (2);
}
bitbuf = lb.bb;
bitsleft = lb.bl;
}
while (false);
if (make_decode_table( (249+1), 12, ref LENGTH_len, ref LENGTH_table)!=0)
{
return (2);
}
break;
case (LZX_BLOCKTYPE_VERBATIM):
do
{
lb.bb = bitbuf;
lb.bl = bitsleft;
if (lzx_read_lens(MAINTREE_len,0,256,ref lb)!=0)
{
return (2);
}
bitbuf = lb.bb;
bitsleft = lb.bl;
}
while (false);
do
{
lb.bb = bitbuf;
lb.bl = bitsleft;
if (lzx_read_lens(MAINTREE_len,256,main_elements,ref lb)!=0)
{
return (2);
}
bitbuf = lb.bb;
bitsleft = lb.bl;
}
while (false);
if (make_decode_table( (256 + 50*8), 12, ref MAINTREE_len, ref MAINTREE_table)!=0)
{
return (2);
}
if (MAINTREE_len[0xE8] != 0) intel_started = 1;
do
{
lb.bb = bitbuf;
lb.bl = bitsleft;
if (lzx_read_lens(LENGTH_len,0,249,ref lb)!=0)
{
return (2);
}
bitbuf = lb.bb;
bitsleft = lb.bl;
}
while (false);
if (make_decode_table( (249+1), 12, ref LENGTH_len, ref LENGTH_table)!=0)
{
return (2);
}
break;
case (LZX_BLOCKTYPE_UNCOMPRESSED):
intel_started = 1;
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - bitsleft);
bitsleft += 16;
}
if (bitsleft > 16)
{
BitSource.BaseStream.Seek(-2,System.IO.SeekOrigin.Current);
}
R0 = (ulong)(BitSource.ReadByte()+(BitSource.ReadByte()<<8)+(BitSource.ReadByte()<<16)+(BitSource.ReadByte()<<24));
R1 = (ulong)(BitSource.ReadByte()+(BitSource.ReadByte()<<8)+(BitSource.ReadByte()<<16)+(BitSource.ReadByte()<<24));
R2 = (ulong)(BitSource.ReadByte()+(BitSource.ReadByte()<<8)+(BitSource.ReadByte()<<16)+(BitSource.ReadByte()<<24));
break;
default:
return (DECR_ILLEGALDATA);
}
}
/* buffer exhaustion check */
if (BitSource.BaseStream.Position > (long) endinp)
{
/* it's possible to have a file where the next run is less than
* 16 bits in size. In this case, the READ_HUFFSYM() macro used
* in building the tables will exhaust the buffer, so we should
* allow for this, but not allow those accidentally read bits to
* be used (so we check that there are at least 16 bits
* remaining - in this boundary case they aren't really part of
* the compressed data)
*/
if (BitSource.BaseStream.Position> (long)(endinp+2) || bitsleft < 16)
return DECR_ILLEGALDATA;
}
while ((this_run = (int)block_remaining) > 0 && togo > 0)
{
if (this_run > togo)
this_run = togo;
togo -= this_run;
block_remaining -= (ulong)this_run;
/* apply 2^x-1 mask */
window_posn &= window_size - 1;
/* runs can't straddle the window wraparound */
if ((window_posn + (ulong)this_run) > window_size)
return DECR_DATAFORMAT;
switch (block_type)
{
case LZX_BLOCKTYPE_VERBATIM:
while (this_run > 0)
{
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
hufftbl = MAINTREE_table;
if ((i = hufftbl[(bitbuf >> (ULONG_BITS()- 12))]) >= 256 + 50*8)
{
j = (ulong)(1 << (ULONG_BITS()- 12));
do
{
j >>= 1;
i <<= 1;
if ((bitbuf & j)!=0)
i|=1;
else
i|=0;
if (j==0)
{
return (2);
}
}
while ((i = hufftbl[i]) >= (((256) + 50*8)));
}
j = MAINTREE_len[main_element = (int)i];
bitbuf <<= (byte)j;
bitsleft -= (byte)j;
}
while (false);
if (main_element < (256))
{
window[window_posn++] = (byte)main_element;
this_run--;
}
else
{
main_element -= (256);
match_length = main_element & (7);
if (match_length == (7))
{
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
hufftbl = (LENGTH_table);
if ((i = hufftbl[(bitbuf >> (ULONG_BITS()- 12))]) >= (((249)+1)))
{
j = (ulong)(1 << (ULONG_BITS()- ((12))));
do
{
j >>= 1;
i <<= 1;
if ((bitbuf & j)!=0)
i|=1;
else
i|=0;
if (j==0)
{
return (2);
}
}
while ((i = hufftbl[i]) >= (((249)+1)));
}
j = LENGTH_len[(length_footer) = (int)i];
bitbuf <<= (byte)j;
bitsleft -= (byte)j;
}
while (false);
match_length += length_footer;
}
match_length += (2);
match_offset = (ulong)(main_element >> 3);
if (match_offset > 2)
{
if (match_offset != 3)
{
extra = extra_bits[match_offset];
do
{
while (bitsleft < (extra))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
verbatim_bits = (int)(bitbuf >> (ULONG_BITS()- (extra)));
bitbuf <<= extra;
bitsleft -= extra;
}
while (false);
match_offset = position_base[match_offset] - 2 + (ulong)verbatim_bits;
}
else
{
match_offset = 1;
}
R2 = R1; R1 = R0; R0 = match_offset;
}
else if (match_offset == 0)
{
match_offset = R0;
}
else if (match_offset == 1)
{
match_offset = R1;
R1 = R0; R0 = match_offset;
}
else
{
match_offset = R2;
R2 = R0; R0 = match_offset;
}
rundest = window_posn;
// rundest= window+window_posn
runsrc = rundest - match_offset;
window_posn += (ulong)match_length;
this_run -= match_length;
// runsrc < window
while ((runsrc<0) && (match_length-- > 0))
{
window[rundest++]=window[runsrc+window_size];
// *rundest++ = *(runsrc + window_size);
runsrc++;
}
while (match_length-- > 0)
{
window[rundest++]=window[runsrc++];
// *rundest++ = *runsrc++;
}
}
}
break;
case LZX_BLOCKTYPE_ALIGNED:
while (this_run > 0)
{
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
hufftbl = MAINTREE_table;
if ((i = hufftbl[(bitbuf >> (ULONG_BITS()- 12))]) >= (((256) + 50*8)))
{
j = (ulong)1 << (ULONG_BITS()- ((12)));
do
{
j >>= 1;
i <<= 1;
if ((bitbuf & j)!=0)
i|=1;
else
i|=0;
if (j==0)
{
return (2);
}
}
while ((i = hufftbl[i]) >= (((256) + 50*8)));
}
j = MAINTREE_len[(main_element) = (int)i];
bitbuf <<= (int)j;
bitsleft -= (int)j;
}
while (false);
if (main_element < (256))
{
window[window_posn++] = (byte)main_element;
this_run--;
}
else
{
main_element -= (256);
match_length = main_element & (7);
if (match_length == (7))
{
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
hufftbl = LENGTH_table;
if ((i = hufftbl[(bitbuf >> (ULONG_BITS()- 12))]) >= (((249)+1)))
{
j = (ulong) 1 << (ULONG_BITS()- ((12)));
do
{
j >>= 1;
i <<= 1;
if ((bitbuf & j)!=0)
i|=1;
else
i|=0;
if (j==0)
{
return (2);
}
}
while ((i = hufftbl[i]) >= (((249)+1)));
}
j = LENGTH_len[length_footer = (int)i];
bitbuf <<= (int)j;
bitsleft -= (int)j;
}
while (false);
match_length += length_footer;
}
match_length += (2);
match_offset = (ulong)(main_element >> 3);
if (match_offset > 2)
{
extra = extra_bits[match_offset];
match_offset = position_base[match_offset] - 2;
if (extra > 3)
{
extra -= 3;
do
{
while (bitsleft < (extra))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
verbatim_bits = (int)(bitbuf >> (ULONG_BITS()- (extra)));
bitbuf <<= extra;
bitsleft -= extra;
}
while (false);
match_offset += (ulong)(verbatim_bits << 3);
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
hufftbl = (ALIGNED_table);
if ((i = hufftbl[(bitbuf >> (ULONG_BITS()- 7))]) >= 8)
{
j = (ulong)1 << (ULONG_BITS()- ((7)));
do
{
j >>= 1;
i <<= 1;
if ((bitbuf & j)!=0)
i|=1;
else
i|=0;
if (j==0)
{
return (2);
}
}
while ((i = hufftbl[i]) >= (((8))));
}
j = (ALIGNED_len)[(aligned_bits) = (int)i];
bitbuf <<= (int)j;
bitsleft -= (int)j;
}
while (false);
match_offset += (ulong)aligned_bits;
}
else if (extra == 3)
{
do
{
while (bitsleft < (16))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
hufftbl = (ALIGNED_table);
if ((i = hufftbl[(bitbuf >> (ULONG_BITS()- 7))]) >= 8)
{
j = (ulong)1 << (ULONG_BITS()- ((7)));
do
{
j >>= 1;
i <<= 1;
if ((bitbuf & j)!=0)
i|=1;
else
i|=0;
if (j!=0)
{
return (2);
}
}
while ((i = hufftbl[i]) >= 8);
}
j = (ALIGNED_len)[(aligned_bits) = (int)i];
bitbuf <<= (int)j;
bitsleft -= (int)j;
}
while (false);
match_offset += (ulong)aligned_bits;
}
else if (extra > 0)
{
do
{
while (bitsleft < (extra))
{
bitbuf |= (UInt32)ReadUInt16() << (ULONG_BITS() - 16 - bitsleft);
bitsleft += 16;
}
(verbatim_bits) = (int)(bitbuf >> (int)(ULONG_BITS()- (extra)));
bitbuf <<= extra;
bitsleft -= extra;
}
while (false);
match_offset += (ulong)verbatim_bits;
}
else
{
match_offset = 1;
}
R2 = R1; R1 = R0; R0 = match_offset;
}
else if (match_offset == 0)
{
match_offset = R0;
}
else if (match_offset == 1)
{
match_offset = R1;
R1 = R0; R0 = match_offset;
}
else
{
match_offset = R2;
R2 = R0; R0 = match_offset;
}
rundest = window_posn;
runsrc = rundest - match_offset;
window_posn += (ulong)match_length;
this_run -= match_length;
while ((runsrc<0) && (match_length-- > 0))
{
// *rundest++ = *(runsrc + window_size); runsrc++;
window[rundest++]=window[runsrc + window_size];
runsrc++;
}
while (match_length-- > 0)
{
// *rundest++ = *runsrc++;
window[rundest++]=window[runsrc++];
}
}
}
break;
case LZX_BLOCKTYPE_UNCOMPRESSED:
if ((BitSource.BaseStream.Position + (long)this_run) > (long)endinp)
return (2);
// memcpy(window + window_posn, inposCount, this_run);
for(i=0; i<(ulong)this_run;i++)
{
window[window_posn+i]=BitSource.ReadByte();
}
window_posn += (ulong)this_run;
break;
default:
return DECR_ILLEGALDATA; /* might as well */
}
}
}
if (togo != 0) return DECR_ILLEGALDATA;
// memcpy(outpos, window + ((!window_posn) ? window_size : window_posn) - outlen, (size_t) outlen);
ulong start=0;
if (window_posn==0)
start=(ulong)window_size;
else
start=(ulong)window_posn;
start-=(ulong)outlen;
long Pos=OutputStream.Position;
for(i=0;i<(ulong)outlen;i++)
{
OutputStream.WriteByte(window[start+i]);
}
OutputStream.Seek(Pos,System.IO.SeekOrigin.Begin);
/* intel E8 decoding */
if ((frames_read++ < 32768) && intel_filesize != 0)
{
if (outlen <= 6 || (intel_started==0))
{
intel_curpos += (long)outlen;
}
else
{
// UBYTE *data = outpos;
long dataend = OutputStream.Position + (int)outlen - 10;
long curpos = intel_curpos;
long filesize = intel_filesize;
long abs_off, rel_off;
intel_curpos = (long)curpos + (long)outlen;
while (OutputStream.Position < dataend)
{
if (OutputStream.ReadByte() != 0xE8)
{
curpos++;
continue;
}
abs_off = (long)(OutputStream.ReadByte() | (OutputStream.ReadByte() <<8) | (OutputStream.ReadByte() <<16) | (OutputStream.ReadByte() <<24));
if (abs_off < filesize)
{
if (abs_off >= 0)
rel_off = (long)(abs_off - curpos);
else
rel_off = (long)abs_off + filesize;
OutputStream.WriteByte((byte)(rel_off & 0x000000ff));
OutputStream.WriteByte((byte)((rel_off & 0x0000ff00)>>8));
OutputStream.WriteByte((byte)((rel_off & 0x00ff0000)>>16));
OutputStream.WriteByte((byte)((rel_off & 0xff000000)>>24));
}
curpos += 5;
}
}
}
return DECR_OK;
}
}
#endregion
}
Reference in a new issue Copy permalink