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Cosmos/source/MatthijsTest/HuffmanAlgorithm.cs
mterwoord_cp 37c9966421
2008-05-19 09:41:18 +00:00

1430 lines
49 KiB
C#
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using System;
using System.Collections;
using System.ComponentModel;
using System.IO;
using System.Runtime.Serialization.Formatters.Binary;
using System.Threading;
namespace Huffman
{
/// <summary>
/// Handles attempt to extract archive that is protected with password,
/// by using wrong password.
/// </summary>
public delegate void WrongPasswordEventHandler();
/// <summary>
/// Invoked from all xxxxWithProgress functions whenever another 1 percent
/// of the function is done.
/// </summary>
public delegate void PercentCompletedEventHandler();
/// <summary>
/// Implementing the Huffman shrinking algorithm.
/// This algorithm was ment to be highly fast efficient, it's supports
/// Data streams with size of up to 2^32 - 1 bytes.
/// </summary>
public class HuffmanAlgorithm: IDisposable
{
#region Internal classes
//-------------------------------------------------------------------------------
/// <summary>
/// <c>FrequencyTable</c> build from bytes and their repeatition in the stream.
/// this is achieved by using 2 arrays with the of same size.
/// </summary>
[Serializable]
internal class FrequencyTable
{
/// <summary>
/// Saves all the varies types of bytes (up to 256 ) found in a stream.
/// </summary>
public Byte[] FoundBytes;
/// <summary>
/// Saves the amount of times each byte in the stream apears.
/// </summary>
public uint[] Frequency;
}//end of FrequencyTable class
//-------------------------------------------------------------------------------
/// <summary>
/// This is a node that the <c>HuffmanTree</c> made of.
/// It's used to translate bytes to bits sequence when archiving,
/// and bits sequence to bytes when extracting.
/// </summary>
internal class TreeNode
{
#region Members
public TreeNode
/// <summary>Pointer to the left son.</summery>
Lson=null,
/// <summary>Pointer to the right son.</summery>
Rson=null,
///<summery> Pointer to the parent of the node.</summery>
Parent=null;
/// <summary>
/// The Byte value of a leaf, it is relevant only when the node is actualy a leaf.
/// </summary>
public Byte ByteValue;
/// <summary>
/// This is the frequency value of the node
/// </summary>
public ulong Value;
#endregion
}//End of TreeNode class
//-------------------------------------------------------------------------------
/// <summary>
/// <c>HuffmanTree</c> is the iplementation of a Huffman algorithm tree.
/// It's used to translate bytes to bits sequence when archiving,
/// and bits sequence to bytes when extracting.
/// </summary>
internal class HuffmanTree
{
#region Members
/// <summary>
/// This array hold the value of a byte and it is as long as a frequency table.
/// </summary>
public readonly TreeNode[] Leafs;
/// <summary>The frequency table to build the Huffman tree with.</summary>
public readonly FrequencyTable FT;
/// <summary>
/// This holds nodes without parents;
/// </summary>
private ArrayList OrphanNodes= new ArrayList();
/// <summary>
/// The root node in the tree to be build;
/// </summary>
public readonly TreeNode RootNode;
#endregion
/// <summary>Build a Huffman tree out of a frequency table.</summary>
internal HuffmanTree(FrequencyTable FT)
{
ushort Length = (ushort)FT.FoundBytes.Length;
this.FT= FT;
Leafs = new TreeNode[Length];
if( Length > 1 )
{
for(ushort i=0; i< Length; ++i)
{
Leafs[i]=new TreeNode();
Leafs[i].ByteValue = FT.FoundBytes[i];
Leafs[i].Value = FT.Frequency[i];
}
OrphanNodes.AddRange(Leafs);
RootNode = BuildTree();
}
else
{//No need to create a tree (only one node below rootnode)
TreeNode TempNode = new TreeNode();
TempNode.ByteValue =FT.FoundBytes[0];
TempNode.Value = FT.Frequency[0];
RootNode = new TreeNode();
RootNode.Lson = RootNode.Rson =TempNode;
}
OrphanNodes.Clear();
OrphanNodes=null;
}
//-------------------------------------------------------------------------------
/// <summary>
/// This function build a tree from the frequency table
/// </summary>
/// <returns>The root of the tree.</returns>
private TreeNode BuildTree()
{
TreeNode small, smaller, NewParentNode=null;
/*stop when the tree is fully build( only one root )*/
while( OrphanNodes.Count > 1 )
{
/*This will return the parent less nodes that thier value togather will
*be the smallest one and remove them from the ArrayList*/
FindSmallestOrphanNodes(out smaller,out small);
NewParentNode = new TreeNode();
NewParentNode.Value = small.Value + smaller.Value;
NewParentNode.Lson = smaller;
NewParentNode.Rson = small;
smaller.Parent = small.Parent = NewParentNode;
OrphanNodes.Add(NewParentNode);
}
//returning the root of the tree (always the last new parent)
return NewParentNode;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Finds the smallest and the 2nd smallest value orphan nodes
/// and removes them them from the arraylist.
/// </summary>
/// <param name="Smallest">The smallest node in the <c>OrphanNodes</c> list.</param>
/// <param name="Small">The 2nd smallest node in the <c>OrphanNodes</c> list.</param>
private void FindSmallestOrphanNodes(out TreeNode Smallest, out TreeNode Small)
{
Smallest = Small = null;
//Scanning backward
ulong Tempvalue=18446744073709551614;
TreeNode TempNode=null;
int i, j=0;
int ArrSize = OrphanNodes.Count-1;
//scanning for the smallest value orphan node
for(i= ArrSize ; i!=-1 ; --i )
{
TempNode = (TreeNode)OrphanNodes[i];
if( TempNode.Value < Tempvalue )
{
Tempvalue = TempNode.Value;
Smallest = TempNode;
j=i;
}
}
OrphanNodes.RemoveAt(j);
--ArrSize;
Tempvalue=18446744073709551614;
//scanning for the second smallest value orphan node
for(i= ArrSize; i>-1 ; --i )
{
TempNode = (TreeNode)OrphanNodes[i];
if( TempNode.Value < Tempvalue )
{
Tempvalue = TempNode.Value;
Small = TempNode;
j=i;
}
}
OrphanNodes.RemoveAt(j);
}
//-------------------------------------------------------------------------------
}//end of HuffmanTree class
//-------------------------------------------------------------------------------
/// <summary>
/// This is a stack of 8 bits (1 byte)
/// uses to manipulate the bits of a stream(when been extracted or archived).
/// It's pushing and poping acts more like a queue then a stack.
/// </summary>
internal struct BitsStack
{
/// <summary>
/// The unit to write and read from a stream.
/// </summary>
public Byte Container;
private byte Amount;
/// <summary>
/// Indicated if the stack unit is full with 8 bits.
/// </summary>
/// <returns>true if full, false if not.</returns>
public bool IsFull()
{
return Amount==8;
}
/// <summary>
/// Indicated if the stack unit is empty(0 bits).
/// </summary>
/// <returns>true if empty, false if not.</returns>
public bool IsEmpty()
{
return Amount == 0;
}
/// <summary>
/// Get the number of bits, currently located in the stack.
/// </summary>
/// <returns>Number of bits located in the stack.</returns>
public Byte NumOfBits()
{
return Amount;
}
/// <summary>
/// This function removes all the bits from the stack.
/// </summary>
public void Empty(){Amount=Container=0;}
/// <summary>
/// Push a bit to the left of the stack (Most significant bit).
/// </summary>
/// <remarks>The stack must have at least 1 free bit slot.</remarks>
/// <param name="Flag">The bit to add the stack(true = 1, false = 0)</param>
/// <exception cref="Exception">
/// When attempting to push a bit from a full stack.
/// </exception>
public void PushFlag(bool Flag)
{
if( Amount== 8)throw new Exception("Stack is full");
Container>>=1;
if( Flag )Container|=128;
++Amount;
}
/// <summary>
/// Pops a bit from the right of the stack (Least significant bit).
/// </summary>
/// <returns></returns>
/// <remarks>The stack must'nt be empty this function called.</remarks>
/// <exception cref="Exception">
/// When attempting to pop a bit from an empty stack.
/// </exception>
public bool PopFlag()
{
if( Amount == 0)throw new Exception("Stack is empty");
bool t= (Container & 1)!=0;
--Amount;
Container>>=1;
return t;
}
/// <summary>
/// Fill the stack with 8 bits. If the stack is full, the given byte will
/// override the old bits.
/// </summary>
/// <param name="Data">Byte(8 bits) to put in the current stack.</param>
public void FillStack(Byte Data)
{
Container = Data;
Amount=8;
}
}
//-------------------------------------------------------------------------------
/// <summary>
/// This is the file/stream header that attached to each archived file or stream at the begining.
/// </summary>
[Serializable]
internal class FileHeader
{
/// <summary>The version of the archiving code.</summary>
public readonly byte version;
/// <summary>The frequency table of the archived data.</summary>
public readonly FrequencyTable FT;
/// <summary>The size of the data before archiving it.</summary>
public readonly long OriginalSize;
/// <summary>Number of extra bits added to the last byte of the data.</summary>
public readonly byte ComplementsBits;
/// <summary>Security key to the archived stream\file.</summary>
public readonly ushort Key;
/// <summary>
/// Builds a new header that holds info about an archived file\stream.
/// </summary>
/// <param name="ver">The version of the archiving program.</param>
/// <param name="T">The frequency table to rebuild the file from.</param>
/// <param name="OrgSize">The size of the file\stream before archiving it.</param>
/// <param name="BitsToFill">
/// Number of extra bits added to the last byte in the archived file.
/// </param>
/// <param name="PasswordKey">Key to gain access to the file\stream later.</param>
public FileHeader(Byte ver, FrequencyTable T, ref long OrgSize,
byte BitsToFill, ushort PasswordKey)
{
version=ver; FT=T; OriginalSize=OrgSize; ComplementsBits=BitsToFill;
Key = PasswordKey;
}
}
#endregion
//-------------------------------------------------------------------------------
#region Members
//-------------------------------------------------------------------------------
/// <summary>
/// This is a temporary array to sign where it's location in the
/// <c>BuildFrequencyTable</c> function (the value is the location.
/// </summary>
private Byte[] ByteLocation = new Byte[256];
/// <summary>
/// This array indicated if the byte with the value that correspond
/// to the index of the array (0-255) was found or not in the stream.
/// </summary>
private bool[] IsByteExist;
/// <summary>Holds the bytes that where found.</summary>
private ArrayList BytesList = new ArrayList();
/// <summary>Holds the amount of repetitions of byte.</summary>
private ArrayList AmountList = new ArrayList();
/// <summary>I use this list to write the reverse path to a Byte.</summary>
private ArrayList BitsList = new ArrayList();
/// <summary>Uses to write and read the Headers to and from a stream.</summary>
private BinaryFormatter BinFormat = new BinaryFormatter();
/// <summary>This stack is used to write extracted and shrinked bytes.</summary>
private BitsStack Stack = new BitsStack();
/// <summary>
/// Invoked whenever attempt to extract password protected file\stream, by
/// using the wrong password. In case this event isn't handaled by the users
/// an exeption will be thrown(in password error case).
/// </summary>
private WrongPasswordEventHandler OnWrongPassword;
/// <summary>
/// Invoked from all xxxxWithProgress functions whenever another 1 percent
/// of the function is done.
/// </summary>
private PercentCompletedEventHandler OnPercentCompleted;
#endregion
//-------------------------------------------------------------------------------
#region Public Functions
//-------------------------------------------------------------------------------
/// <summary>
/// Build a frequency table and Huffman tree and shrinking the stream data.
/// </summary>
/// <param name="Data">
/// The data streem to shrink, it will start shrinking from the position of the given
/// stream as it was given and in the end of the function it's position
/// won't be at the end of the stream and it won't be closed.
/// </param>
/// <param name="Password">
/// A password to add to the archive, to mark as "password less" assign null instead.
/// </param>
/// <returns>The archived stream, positioned at start.</returns>
/// <remarks>
/// The given stream must be readable, seekable and it's length
/// must exceed zero.
/// </remarks>
public Stream Shrink(Stream Data, char[] Password)
{
//Tempdirectory
String TempDir=Environment.GetEnvironmentVariable("temp");
//Generating the header data from the stream and creating a HuffmanTree
HuffmanTree HT = new HuffmanTree( BuildFrequencyTable(Data) );
//Creating temporary file
FileStream tempFS= new FileStream( TempDir + @"\TempArch.tmp", FileMode.Create);
//Writing header
WriteHeader(tempFS, HT.FT, Data.Length, 11, GetComplementsBits(HT), Password );
long DataSize= Data.Length;
TreeNode TempNode=null;
Byte Original; //the byte we read from the original stream
short j; int k;
for(long i=0;i< DataSize; ++i)
{
Original = (Byte)Data.ReadByte();
TempNode = HT.Leafs[ ByteLocation[Original] ];
while( TempNode.Parent!=null )
{
//If I'm left sone of my parent push 1 else push 0
BitsList.Add(TempNode.Parent.Lson == TempNode);
TempNode = TempNode.Parent;//Climb up the tree.
}
BitsList.Reverse();
k = BitsList.Count;
for(j=0; j<k; ++j )
{
Stack.PushFlag( (bool)BitsList[j] );
if(Stack.IsFull())
{
tempFS.WriteByte(Stack.Container);
Stack.Empty();
}
}
BitsList.Clear();
}
//Writing the last byte if the stack wasn't compleatly full.
if( !Stack.IsEmpty() )
{
Byte BitsToComplete = (Byte)(8 - Stack.NumOfBits());
for(byte Count=0; Count< BitsToComplete; ++Count)//complete to full 8 bits
Stack.PushFlag(false);
tempFS.WriteByte(Stack.Container);
Stack.Empty();
}
tempFS.Seek( 0, SeekOrigin.Begin );
return tempFS;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Build a frequency table and Huffman tree and shrinking the stream data.
/// This function version, calls the PercentComplete event handler
/// When anothe 1 percent compleated.
/// </summary>
/// <param name="Data">
/// The data streem to shrink, shrinking starts from the position of the given stream
/// as it was given and in the end of the function it's position won't be at the end
/// of the stream and it won't be closed.
/// </param>
/// <param name="Password">
/// A password to add to the archive, to mark as "password less" assign null instead.
/// </param>
/// <returns>The archived stream, positioned at start.</returns>
/// <remarks>
/// The given stream must be readable, seekable and it's length
/// must exceed zero.
/// </remarks>
public Stream ShrinkWithProgress(Stream Data, char[] Password)
{
//Tempdirectory
String TempDir=Environment.GetEnvironmentVariable("temp");
//Generating the header data from the stream and creating a HuffmanTree
HuffmanTree HT = new HuffmanTree( BuildFrequencyTable(Data) );
//Creating temporary file
FileStream tempFS= new FileStream( TempDir + @"\TempArch.tmp", FileMode.Create);
//Writing header
WriteHeader(tempFS, HT.FT, Data.Length, 11, GetComplementsBits(HT), Password );
long DataSize= Data.Length;
TreeNode TempNode=null;
Byte Original; //the byte we read from the original stream
short j; int k; float ProgressRatio = 0;
for(long i=0;i< DataSize; ++i)
{
Original = (Byte)Data.ReadByte();
TempNode = HT.Leafs[ ByteLocation[Original] ];
while( TempNode.Parent!=null )
{
//If I'm left sone of my parent push 1 else push 0
BitsList.Add(TempNode.Parent.Lson == TempNode);
TempNode = TempNode.Parent;//Climb up the tree.
}
BitsList.Reverse();
k = BitsList.Count;
for(j=0; j<k; ++j )
{
Stack.PushFlag( (bool)BitsList[j] );
if( Stack.IsFull() )
{
tempFS.WriteByte(Stack.Container);
Stack.Empty();
}
}
BitsList.Clear();
if( ((float)(i))/DataSize - ProgressRatio > 0.01 )
{
ProgressRatio+=0.01f;
if( OnPercentCompleted!=null ) OnPercentCompleted();
}
}
//Writing the last byte if the stack wasn't compleatly full.
if( !Stack.IsEmpty() )
{
Byte BitsToComplete = (Byte)(8 - Stack.NumOfBits());
for(byte Count=0; Count< BitsToComplete; ++Count)//complete to full 8 bits
Stack.PushFlag(false);
tempFS.WriteByte(Stack.Container);
Stack.Empty();
}
tempFS.Seek( 0, SeekOrigin.Begin );
return tempFS;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Build a frequency table and Huffman tree and shrinking the stream data to a new file.
/// into a file.
/// </summary>
/// <param name="Data">
/// The data streem to shrink, it will start shrinking from the position of the given
/// stream as it was given and in the end of the function it's position
/// won't be at the end of the stream and it won't be closed.
/// </param>
/// <param name="OutputFile">Path to a file to same the shrinked data in.</param>
/// <param name="Password">
/// A passward to add to the archive, to mark as "passward less" assign null instead.
/// </param>
/// <returns>The expanded stream, positioned at start.</returns>
/// <remarks>
/// The given stream must be readable, seekable and it's length
/// must exceed zero.
/// </remarks>
public void Shrink(Stream Data, string OutputFile, char [] Password)
{
//Generating the header data from the stream and creating a HuffmanTree
HuffmanTree HT = new HuffmanTree( BuildFrequencyTable(Data) );
//Creating temporary file
FileStream tempFS= new FileStream( OutputFile , FileMode.Create);
//Writing header
WriteHeader(tempFS, HT.FT, Data.Length, 11, GetComplementsBits(HT), Password);
long DataSize= Data.Length;
TreeNode TempNode=null;
Byte Original; //the byte we read from the original stream
short j; int k;
for(long i=0;i< DataSize; ++i)
{
Original = (Byte)Data.ReadByte();
TempNode = HT.Leafs[ ByteLocation[Original] ];
while( TempNode.Parent!=null )
{
//If I'm left sone of my parent push 1 else push 0
BitsList.Add(TempNode.Parent.Lson == TempNode);
TempNode = TempNode.Parent;//Climb up the tree.
}
BitsList.Reverse();
k = BitsList.Count;
for(j=0; j<k; ++j )
{
Stack.PushFlag( (bool)BitsList[j] );
if(Stack.IsFull())
{
tempFS.WriteByte(Stack.Container);
Stack.Empty();
}
}
BitsList.Clear();
}
//Writing the last byte if the stack wasn't compleatly full.
if( !Stack.IsEmpty() )
{
Byte BitsToComplete = (Byte)(8 - Stack.NumOfBits());
for(byte Count=0; Count< BitsToComplete; ++Count)//complete to full 8 bits
Stack.PushFlag(false);
tempFS.WriteByte(Stack.Container);
Stack.Empty();
}
tempFS.Seek( 0, SeekOrigin.Begin );
tempFS.Close();
}
//-------------------------------------------------------------------------------
/// <summary>
/// Build a frequency table and Huffman tree and shrinking the stream data to a new file.
/// into a file.
/// This function version, calls the PercentComplete event handler
/// When anothe 1 percent compleated.
/// </summary>
/// <param name="Data">
/// The data streem to shrink, shrinking starts from the position of the given stream
/// as it was given and in the end of the function it's position won't be at the end
/// of the stream and it won't be closed.
/// </param>
/// <param name="OutputFile">Path to a file to same the shrinked data in.</param>
/// <param name="Password">
/// A passward to add to the archive, to mark as "passward less" assign null instead.
/// </param>
/// <returns>The expanded stream, positioned at the start.</returns>
/// <remarks>
/// The given stream must be readable, seekable and it's length
/// must exceed zero.
/// </remarks>
public void ShrinkWithProgress(Stream Data, string OutputFile, char [] Password)
{
//Generating the header data from the stream and creating a HuffmanTree
HuffmanTree HT = new HuffmanTree( BuildFrequencyTable(Data) );
//Creating temporary file
FileStream tempFS= new FileStream( OutputFile , FileMode.Create);
//Writing header
WriteHeader(tempFS, HT.FT, Data.Length, 11, GetComplementsBits(HT), Password);
long DataSize= Data.Length;
TreeNode TempNode=null;
Byte Original; //the byte we read from the original stream
short j; int k; float ProgressRatio = 0;
for(long i=0;i< DataSize; ++i)
{
Original = (Byte)Data.ReadByte();
TempNode = HT.Leafs[ ByteLocation[Original] ];
while( TempNode.Parent!=null )
{
//If I'm left sone of my parent push 1 else push 0
BitsList.Add(TempNode.Parent.Lson == TempNode);
TempNode = TempNode.Parent;//Climb up the tree.
}
BitsList.Reverse();
k = BitsList.Count;
for(j=0; j<k; ++j )
{
Stack.PushFlag( (bool)BitsList[j] );
if(Stack.IsFull())
{
tempFS.WriteByte(Stack.Container);
Stack.Empty();
}
}
BitsList.Clear();
if( ((float)(i))/DataSize - ProgressRatio > 0.01 )
{
ProgressRatio+=0.01f;
if( OnPercentCompleted!=null ) OnPercentCompleted();
}
}
//Writing the last byte if the stack wasn't compleatly full.
if( !Stack.IsEmpty() )
{
Byte BitsToComplete = (Byte)(8 - Stack.NumOfBits());
for(byte Count=0; Count< BitsToComplete; ++Count)//complete to full 8 bits
Stack.PushFlag(false);
tempFS.WriteByte(Stack.Container);
Stack.Empty();
}
tempFS.Seek( 0, SeekOrigin.Begin );
tempFS.Close();
}
//-------------------------------------------------------------------------------
/// <summary>
/// Build a frequency table and Huffman tree and extract the archive.
/// </summary>
/// <param name="Data">The data streem to shrink</param>
/// <param name="Password">
/// A Key to open the archive with, to mark as "passward less" assign null instead.
/// </param>
/// <returns>
/// The data stream to extract, but if wrong password error occur
/// and the <c>WrongPassword</c> event is handeled, it's returns null.
/// </returns>
/// <exception cref="Exception">
/// On attempt to extract data that wasn't coded with the <c>HuffmanAlgorithm</c> class,
/// Or on attempt to extract a password protected stream\file with the wrong password.
/// (If the <c>WrongPassword</c> event is been handeled by the user the 2nd exception is'nt
/// relevant).
/// </exception>
/// <remarks>
/// The given stream must be readable, seekable and it's length
/// must exceed zero. The given stream must be archived stream of the right type.
/// </remarks>
public Stream Extract(Stream Data, char[] Password)
{
Data.Seek(0, SeekOrigin.Begin);
//Tempdirectory
String TempDir=Environment.GetEnvironmentVariable("temp");
FileHeader Header;
//Reading the header data from the stream
if( !IsArchivedStream(Data) ) throw new Exception("The given stream is't Huffmans algorithm archive type.");
Header = (FileHeader)BinFormat.Deserialize(Data);
//If the stream\file protected and password doesn't fit
if(Header.Key !=0 && Header.Key != PasswordGen( Password ))
{
//Invoke if user handles it
if(OnWrongPassword!=null)
{
new Thread( new ThreadStart(OnWrongPassword)).Start();
return null;
}
else throw new Exception("Wrong password error, on attempt to extract protected data.");
}
//Gernerating Huffman tree out of the frequency table in the header
HuffmanTree HT = new HuffmanTree( Header.FT );
//Creating temporary file
FileStream tempFS= new FileStream( TempDir + @"\TempArch.tmp", FileMode.Create);
BitsStack Stack = new BitsStack();
long DataSize= Data.Length - Data.Position;
if( Header.ComplementsBits==0 )DataSize+=1;
TreeNode TempNode=null;
while( true )
{
TempNode = HT.RootNode;
//As long it's not a leaf, go down the tree
while(TempNode.Lson!=null && TempNode.Rson!=null)
{
//If the stack is empty refill it.
if( Stack.IsEmpty() )
{
Stack.FillStack( (Byte)Data.ReadByte() );
if( (--DataSize) == 0 )
{
goto AlmostDone;
}
}
//Going left or right according to the bit
TempNode = Stack.PopFlag() ? TempNode.Lson : TempNode.Rson;
}
//By now reached for a leaf and writes it's data.
tempFS.WriteByte( TempNode.ByteValue );
}//end of while
//To this lable u can jump only from the while loop (only one byte left).
AlmostDone:
short BitsLeft = (Byte)( Stack.NumOfBits() - Header.ComplementsBits);
//Writing the rest of the last byte.
if(BitsLeft != 8 )
{
bool Test = TempNode.Lson==null && TempNode.Rson==null;
while( BitsLeft > 0)
{
//If at itteration, TempNode not done going down the huffman tree.
if( Test ) TempNode = HT.RootNode;
while(TempNode.Lson!=null && TempNode.Rson!=null)
{
//Going left or right according to the bit
TempNode = Stack.PopFlag() ? TempNode.Lson : TempNode.Rson;
--BitsLeft;
}
//By now reached for a leaf and writes it's data.
tempFS.WriteByte( TempNode.ByteValue );
Test=true;
}
}
tempFS.Seek( 0, SeekOrigin.Begin );
return tempFS;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Build a frequency table and Huffman tree and extract the archive.
/// This function version, calls the PercentComplete event handler
/// When anothe 1 percent compleated.
/// </summary>
/// <param name="Data">The data streem to shrink</param>
/// <param name="Password">
/// A Key to open the archive with, to mark as "passward less" assign null instead.
/// </param>
/// <returns>
/// The data stream to extract, but if wrong password error occur
/// and the <c>WrongPassword</c> event is handeled, it's returns null.
/// </returns>
/// <exception cref="Exception">
/// On attempt to extract data that wasn't coded with the <c>HuffmanAlgorithm</c> class,
/// Or on attempt to extract a password protected stream\file with the wrong password.
/// (If the <c>WrongPassword</c> event is been handeled by the user the 2nd exception is'nt
/// relevant).
/// </exception>
/// <remarks>
/// The given stream must be readable, seekable and it's length
/// must exceed zero. The given stream must be archived stream of the right type.
/// </remarks>
public Stream ExtractWithProgress(Stream Data, char[] Password)
{
Data.Seek(0, SeekOrigin.Begin);
//Tempdirectory
String TempDir=Environment.GetEnvironmentVariable("temp");
FileHeader Header;
//Reading the header data from the stream
if( !IsArchivedStream(Data) ) throw new Exception("The given stream is't Huffmans algorithm archive type.");
Header = (FileHeader)BinFormat.Deserialize(Data);
//If the stream\file protected and password doesn't fit
if(Header.Key !=0 && Header.Key != PasswordGen( Password ))
{
//Invoke if user handles it
if(OnWrongPassword!=null)
{
new Thread( new ThreadStart(OnWrongPassword)).Start();
return null;
}
else throw new Exception("Wrong password error, on attempt to extract protected data.");
}
//Gernerating Huffman tree out of the frequency table in the header
HuffmanTree HT = new HuffmanTree( Header.FT );
//Creating temporary file
FileStream tempFS= new FileStream( TempDir + @"\TempArch.tmp", FileMode.Create);
BitsStack Stack = new BitsStack();
long DataSize= Data.Length - Data.Position;
if( Header.ComplementsBits==0 )DataSize+=1;
TreeNode TempNode=null;
long DataSize2 = DataSize; float ProgressRatio=0;//Needed to calculate progress.
while( true )
{
TempNode = HT.RootNode;
//As long it's not a leaf, go down the tree
while(TempNode.Lson!=null && TempNode.Rson!=null)
{
//If the stack is empty refill it.
if( Stack.IsEmpty() )
{
Stack.FillStack( (Byte)Data.ReadByte() );
if( (--DataSize) == 0 )
{
goto AlmostDone;
}
}
//Going left or right according to the bit
TempNode = Stack.PopFlag() ? TempNode.Lson : TempNode.Rson;
}
//By now reached for a leaf and writes it's data.
tempFS.WriteByte( TempNode.ByteValue );
if( ((float)(DataSize2-DataSize))/DataSize2 - ProgressRatio > 0.01 )
{
ProgressRatio+=0.01f;
if( OnPercentCompleted!=null ) OnPercentCompleted();
}
}//end of while
//To this lable u can jump only from the while loop (only one byte left).
AlmostDone:
short BitsLeft = (Byte)( Stack.NumOfBits() - Header.ComplementsBits);
//Writing the rest of the last byte.
if(BitsLeft != 8 )
{
bool Test = TempNode.Lson==null && TempNode.Rson==null;
while( BitsLeft > 0)
{
//If at itteration, TempNode not done going down the huffman tree.
if( Test ) TempNode = HT.RootNode;
while(TempNode.Lson!=null && TempNode.Rson!=null)
{
//Going left or right according to the bit
TempNode = Stack.PopFlag() ? TempNode.Lson : TempNode.Rson;
--BitsLeft;
}
//By now reached for a leaf and writes it's data.
tempFS.WriteByte( TempNode.ByteValue );
Test=true;
}
}
tempFS.Seek( 0, SeekOrigin.Begin );
return tempFS;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Build a frequency table and Huffman tree and extract the archive to a new file.
/// </summary>
/// <param name="Data">The data streem to shrink</param>
/// <param name="OutputFile">Path to to save the extracted data.</param>
/// <param name="Password">
/// A Key to open the archive with, to mark as "passward less" assign null instead.
/// </param>
/// <returns>
/// flag that indicates if extraction went well or not: true = successful,
/// false = wrong password error occured (the WrongPassword event will take place).
/// </returns>
/// <exception cref="Exception">
/// On attempt to extract data that wasn't coded with the <c>HuffmanAlgorithm</c> class,
/// Or on attempt to extract a password protected stream\file with the wrong password.
/// (If the <c>WrongPassword</c> event is been handeled by the user the 2nd exception is'nt
/// relevant).
/// </exception>
/// <remarks>
/// The given stream must be readable, seekable and it's length
/// must exceed zero. The given stream must be archived stream of the right type.
/// </remarks>
public bool Extract(Stream Data, string OutputFile, char[] Password)
{
Data.Seek(0, SeekOrigin.Begin);
FileHeader Header;
//Reading the header data from the stream
if( !IsArchivedStream(Data) ) throw new Exception("The given stream is't my Huffman algorithm type.");
Header = (FileHeader)BinFormat.Deserialize(Data);
//If the stream\file protected and password doesn't fit
if(Header.Key !=0 && Header.Key != PasswordGen( Password ))
{
//Invoke if user handles it
if(OnWrongPassword!=null)
{
new Thread( new ThreadStart(OnWrongPassword)).Start();
return false;
}
else throw new Exception("Wrong password error, on attempt to extract protected data.");
}
//Gernerating Huffman tree out of the frequency table in the header
HuffmanTree HT = new HuffmanTree( Header.FT );
//Creating temporary file
FileStream tempFS= new FileStream(OutputFile, FileMode.Create);
BitsStack Stack = new BitsStack();
long DataSize= Data.Length - Data.Position;
if( Header.ComplementsBits==0 )DataSize+=1;
TreeNode TempNode=null;
while( true )
{
TempNode = HT.RootNode;
//As long it's not a leaf, go down the tree
while(TempNode.Lson!=null && TempNode.Rson!=null)
{
//If the stack is empty refill it.
if( Stack.IsEmpty() )
{
Stack.FillStack( (Byte)Data.ReadByte() );
if( (--DataSize) == 0 )
{
goto AlmostDone;
}
}
//Going left or right according to the bit
TempNode = Stack.PopFlag() ? TempNode.Lson : TempNode.Rson;
}
//By now reached for a leaf and writes it's data.
tempFS.WriteByte( TempNode.ByteValue );
}//end of while
//To this lable u can jump only from the while loop (only one byte left).
AlmostDone:
short BitsLeft = (Byte)( Stack.NumOfBits() - Header.ComplementsBits);
//Writing the rest of the last byte.
if(BitsLeft != 8 )
{
bool Test = TempNode.Lson==null && TempNode.Rson==null;
while( BitsLeft > 0)
{
//If at itteration, TempNode not done going down the huffman tree.
if( Test ) TempNode = HT.RootNode;
while(TempNode.Lson!=null && TempNode.Rson!=null)
{
//Going left or right according to the bit
TempNode = Stack.PopFlag() ? TempNode.Lson : TempNode.Rson;
--BitsLeft;
}
//By now reached for a leaf and writes it's data.
tempFS.WriteByte( TempNode.ByteValue );
Test=true;
}
}
tempFS.Close();
return true;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Build a frequency table and Huffman tree and extract the archive to a new file.
/// This function version, calls the PercentComplete event handler
/// When anothe 1 percent compleated.
/// </summary>
/// <param name="Data">The data streem to shrink</param>
/// <param name="OutputFile">Path to to save the extracted data.</param>
/// <param name="Password">
/// A Key to open the archive with, to mark as "passward less" assign null instead.
/// </param>
/// <returns>
/// flag that indicates if extraction went well or not: true = successful,
/// false = wrong password error occured (the WrongPassword event will take place).
/// </returns>
/// <exception cref="Exception">
/// On attempt to extract data that wasn't coded with the <c>HuffmanAlgorithm</c> class,
/// Or on attempt to extract a password protected stream\file with the wrong password.
/// (If the <c>WrongPassword</c> event is been handeled by the user the 2nd exception is'nt
/// relevant).
/// </exception>
/// <remarks>
/// The given stream must be readable, seekable and it's length
/// must exceed zero. The given stream must be archived stream of the right type.
/// </remarks>
public bool ExtractWithProgress(Stream Data, string OutputFile, char[] Password)
{
Data.Seek(0, SeekOrigin.Begin);
FileHeader Header;
//Reading the header data from the stream
if( !IsArchivedStream(Data) ) throw new Exception("The given stream is't my Huffman algorithm type.");
Header = (FileHeader)BinFormat.Deserialize(Data);
//If the stream\file protected and password doesn't fit
if(Header.Key !=0 && Header.Key != PasswordGen( Password ))
{
//Invoke if user handles it
if(OnWrongPassword!=null)
{
new Thread( new ThreadStart(OnWrongPassword)).Start();
return false;
}
else throw new Exception("Wrong password error, on attempt to extract protected data.");
}
//Gernerating Huffman tree out of the frequency table in the header
HuffmanTree HT = new HuffmanTree( Header.FT );
//Creating temporary file
FileStream tempFS= new FileStream(OutputFile, FileMode.Create);
BitsStack Stack = new BitsStack();
long DataSize= Data.Length - Data.Position;
if( Header.ComplementsBits==0 )DataSize+=1;
TreeNode TempNode=null;
long DataSize2 = DataSize; float ProgressRatio=0;//Needed to calculate progress.
while( true )
{
TempNode = HT.RootNode;
//As long it's not a leaf, go down the tree
while(TempNode.Lson!=null && TempNode.Rson!=null)
{
//If the stack is empty refill it.
if( Stack.IsEmpty() )
{
Stack.FillStack( (Byte)Data.ReadByte() );
if( (--DataSize) == 0 )
goto AlmostDone;
}
//Going left or right according to the bit
TempNode = Stack.PopFlag() ? TempNode.Lson : TempNode.Rson;
}
//By now reached for a leaf and writes it's data.
tempFS.WriteByte( TempNode.ByteValue );
if( ((float)(DataSize2-DataSize))/DataSize2 - ProgressRatio > 0.01 )
{
ProgressRatio+=0.01f;
if( OnPercentCompleted!=null ) OnPercentCompleted();
}
}//end of while
//To this lable u can jump only from the while loop (only one byte left).
AlmostDone:
short BitsLeft = (Byte)( Stack.NumOfBits() - Header.ComplementsBits);
//Writing the rest of the last byte.
if(BitsLeft != 8 )
{
bool Test = TempNode.Lson==null && TempNode.Rson==null;
while( BitsLeft > 0)
{
//If at itteration, TempNode not done going down the huffman tree.
if( Test ) TempNode = HT.RootNode;
while(TempNode.Lson!=null && TempNode.Rson!=null)
{
//Going left or right according to the bit
TempNode = Stack.PopFlag() ? TempNode.Lson : TempNode.Rson;
--BitsLeft;
}
//By now reached for a leaf and writes it's data.
tempFS.WriteByte( TempNode.ByteValue );
Test=true;
}
}
tempFS.Close();
return true;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Checks if a data stream is archived.
/// </summary>
/// <param name="Data">The stream to test.</param>
/// <returns>true if the stream is archive, false if not.</returns>
public bool IsArchivedStream(Stream Data)
{
Data.Seek(0, SeekOrigin.Begin);
bool test = true;
try
{
FileHeader Header = (FileHeader)BinFormat.Deserialize(Data);
Header=null;
}
catch(Exception)
{
//if header wasn't found
test = false;
}
finally
{
Data.Seek(0, SeekOrigin.Begin);
}
return test;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Checks if a given archived data stream is password protected.
/// </summary>
/// <param name="Data">Archived stream to test.</param>
/// <returns>true if the stream is password protected, false if not.</returns>
/// <exception cref="Exception">
/// When the given stream isn't correct Huffman archived stream or has been corrupted.
/// </exception>
public bool IsPasswardProtectedStream(Stream Data)
{
Data.Seek(0, SeekOrigin.Begin);
bool test = true;
try
{
FileHeader Header = (FileHeader)BinFormat.Deserialize(Data);
test = (Header.Key != 0);
Header=null;
}
catch(Exception)
{
//if header wasn't found
throw new Exception("Error, the given stream isn't Huffman archived or corrupted.");
}
finally
{
Data.Seek(0, SeekOrigin.Begin);
}
return test;
}
//-------------------------------------------------------------------------------
/// <summary>
/// This function calculates the the archiving ratio of a given archived stream.
/// </summary>
/// <param name="Data">Archived stream to calculate archiving ratio to.</param>
/// <returns>The archiving ratio.</returns>
/// <exception cref="Exception">
/// When the given stream isn't correct Huffman archived stream or has been corrupted.
/// </exception>
public float GetArchivingRatio(Stream Data)
{
Data.Seek(0, SeekOrigin.Begin);
float Result;
try
{
FileHeader Header = (FileHeader)BinFormat.Deserialize(Data);
Result = (100f*Data.Length)/Header.OriginalSize;
Header=null;
}
catch(Exception)
{
//if header wasn't found
throw new Exception("Error, the given stream isn't Huffman archived or corrupted.");
}
finally
{
Data.Seek(0, SeekOrigin.Begin);
}
return Result;
}
#endregion
//-------------------------------------------------------------------------------
#region Public events
/// <summary>
/// This is Asynchronic event and accures when the <c>Extract</c> function returns
/// on wrong password error.
/// Invoked whenever attempt to extract password protected file\stream, by
/// using the wrong password(Fatal error). In case this event isn't handaled by the users
/// an exeption will be thrown(in password error case).
/// </summary>
[Description("Invoked whenever attempt to extract password protected file\\stream " +
"by using the wrong password. In case this event isn't handaled by the users "+
"an exeption will be thrown(in password error case).")
]
[Category("Behavior")]
public event WrongPasswordEventHandler WrongPassword
{
add{OnWrongPassword+=value;}
remove{OnWrongPassword-=value;}
}
//-------------------------------------------------------------------------------
/// <summary>
/// This is Asynchronic event and invoked only from xxxxWithProgress functions.
/// Invoked whenever another 1 percent of the function is done.
/// </summary>
[Description("This is Asynchronic event and invoked only from xxxxWithProgress "+
"functions. Invoked whenever another 1 percent of the function is done.")
]
[Category("Action")]
public event PercentCompletedEventHandler PercentCompleted
{
add{OnPercentCompleted+=value;}
remove{OnPercentCompleted-=value;}
}
#endregion
//-------------------------------------------------------------------------------
#region Private Functions
//-------------------------------------------------------------------------------
/// <summary>
/// Scanning for repeated bytes and according to them build frequency table.
/// </summary>
/// <param name="DataSource">The stream to build <c>FrequencyTable</c> for.</param>
/// <returns>The generated frequency table.</returns>
/// <remarks>
/// DataSource must be readable and seekable stream.
/// Don't try to extract somthing smaller then 415 bytes(it's not worth it)
/// </remarks>
private FrequencyTable BuildFrequencyTable(Stream DataSource)
{
long OriginalPosition = DataSource.Position;
FrequencyTable FT = new FrequencyTable();
IsByteExist = new bool[256]; //false by default
Byte bTemp;
//Counting bytes and saving them
for(long i=0; i<DataSource.Length; ++i )
{
bTemp = (Byte)DataSource.ReadByte();
if( IsByteExist[ bTemp ] ) //If the byte was found before increase the repeatition
AmountList[ ByteLocation[bTemp] ]= (uint)AmountList[ ByteLocation[bTemp] ] + 1;
else/*If new byte*/
{
IsByteExist[ bTemp ]=true; //Mark as found
ByteLocation[ bTemp ] = (Byte)BytesList.Count ; //Save the new location of the byte in the bouth ArrayLists
AmountList.Add(1u); //Marking that one was found
BytesList.Add(bTemp);
}
}
int ArraySize=BytesList.Count;
//Moving the data from the arraylists to std arrays
FT.FoundBytes = new byte[ArraySize];
FT.Frequency = new uint[ArraySize];
short ArraysSize = (short)ArraySize;
//Copy the list to arrays;
for(short i=0; i<ArraysSize; ++i )
{
FT.FoundBytes[i] = (Byte)BytesList[i];
FT.Frequency[i] = (uint)AmountList[i];
}
//sort the arrays according to the Frequency
SortArrays( FT.Frequency, FT.FoundBytes, ArraysSize );
//Cleaning resources
IsByteExist = null;
BytesList.Clear();
AmountList.Clear();
DataSource.Seek(OriginalPosition, SeekOrigin.Begin);
return FT;
}
//-------------------------------------------------------------------------------
/// <summary>
/// This function takes a password cstring and converts it to a ushort number
/// that's fit the header of a shrinked file.
/// </summary>
/// <param name="Password">
/// Password to a shrinked file (8 chars tops), is it's null, no password will
/// take place in the file (zero value).
/// </param>
/// <returns>A numeric representation of the given password.</returns>
/// <exception cref="Exception">
/// When a given password is longer then 8 characters.
/// </exception>
private ushort PasswordGen(char[] Password)
{
if(Password==null )return 0;
if(Password.Length > 8)
throw new Exception("Password's is 8 chars length tops, you've entered " +
Password.Length + " bytes.");
Byte Size = (byte)Password.Length;
ushort Result=0;
for(Byte i=0; i<Size; ++i)
Result += (ushort)((Password[i] + 1)*i);
return Result;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Bouble sort <c>FrequencyTable</c>( according frequency level )
/// and making the same changes on the corresponding array.
/// </summary>
/// <param name="SortTarget">The array to sort by.</param>
/// <param name="TweenArray">
/// The array that will take the same swaping as the target array.
/// </param>
private void SortArrays(uint[] SortTarget, Byte[] TweenArray, short size)
{
--size;
bool TestSwitch=false;
Byte BTemp;
uint uiTemp;
short i,j;
for(i=0; i < size ; ++i )
{
for(j=0; j < size ; ++j )
{
if( SortTarget[j] < SortTarget[j+1] )
{
TestSwitch = true;//Making switch action
uiTemp = SortTarget[j];
SortTarget[j] = SortTarget[j+1];
SortTarget[j+1]=uiTemp;
//Doing same to corresponding array
BTemp = TweenArray[j];
TweenArray[j] = TweenArray[j+1];
TweenArray[j+1]=BTemp;
}
}//end of for
if(!TestSwitch)break;//if no switch action in this round, no need for more.
TestSwitch = false;
}//end of for
for(i=0;i<SortTarget.Length; ++i )
ByteLocation[ TweenArray[i] ]=(Byte)i;
}
//-------------------------------------------------------------------------------
/// <summary>
/// Write a header to the stream. This header is vital when extracting the data.
/// </summary>
/// <param name="St">The output stream.</param>
/// <param name="FT">The frequency table of the data.</param>
/// <param name="OriginalSize">The original of the data before shrinking.</param>
/// <param name="version">The version of the shrinking code.</param>
/// <param name="ComplementsBits">Number of extra bits added to the last byte of the data.</param>
/// <param name="Password">A key to gain access to the archived file\stream.</param>
private void WriteHeader(Stream St,FrequencyTable FT , long OriginalSize,
Byte version, Byte ComplementsBits, char[] Password)
{
FileHeader Header = new FileHeader(version, FT, ref OriginalSize,
ComplementsBits, PasswordGen(Password ));
BinFormat.Serialize(St, Header);
}
//-------------------------------------------------------------------------------
/// <summary>
/// Calculates the amount of complements bits, needed for the last byte writing.
/// </summary>
/// <param name="HT">The huffman tree of the stream to be archived.</param>
/// <returns>Amount of complements bits</returns>
private Byte GetComplementsBits(HuffmanTree HT)
{
//Getting the deapth of each leaf in the huffman tree
short i = (short)HT.Leafs.Length;
ushort[] NodesDeapth=new ushort[i];
long SizeInOfBits=0;
while( --i != -1 )
{
TreeNode TN = HT.Leafs[i];
while( TN.Parent!=null )
{
TN = TN.Parent;
++NodesDeapth[i];
}
SizeInOfBits+=NodesDeapth[i]*HT.FT.Frequency[i];
}
return (byte)( 8 - SizeInOfBits%8 );
}
#endregion
//-------------------------------------------------------------------------------
#region IDisposable Members
public void Dispose()
{
BytesList = null;
IsByteExist=null;
AmountList = null;
BinFormat = null;
BitsList=null;
ByteLocation = null;
OnWrongPassword = null;
OnPercentCompleted=null;
}
#endregion
//-----------------------------------------------------------------------------
}
}
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