Class LzwInputStream

This filter stream is used to decompress a LZW format stream. Specifically, a stream that uses the LZC compression method. This file format is usually associated with the .Z file extension.

See http://en.wikipedia.org/wiki/Compress See http://wiki.wxwidgets.org/Development:_Z_File_Format

The file header consists of 3 (or optionally 4) bytes. The first two bytes contain the magic marker "0x1f 0x9d", followed by a byte of flags.

Based on Java code by Ronald Tschalar, which in turn was based on the unlzw.c code in the gzip package.

Inheritance

System.Object

System.MarshalByRefObject

System.IO.Stream

LzwInputStream

Implements

System.IDisposable

Inherited Members

System.IO.Stream.Null

System.IO.Stream.BeginRead(System.Byte[], System.Int32, System.Int32, System.AsyncCallback, System.Object)

System.IO.Stream.BeginWrite(System.Byte[], System.Int32, System.Int32, System.AsyncCallback, System.Object)

System.IO.Stream.Close()

System.IO.Stream.CopyTo(System.IO.Stream)

System.IO.Stream.CopyTo(System.IO.Stream, System.Int32)

System.IO.Stream.CopyToAsync(System.IO.Stream)

System.IO.Stream.CopyToAsync(System.IO.Stream, System.Int32)

System.IO.Stream.CopyToAsync(System.IO.Stream, System.Int32, System.Threading.CancellationToken)

System.IO.Stream.CreateWaitHandle()

System.IO.Stream.Dispose()

System.IO.Stream.EndRead(System.IAsyncResult)

System.IO.Stream.EndWrite(System.IAsyncResult)

System.IO.Stream.FlushAsync()

System.IO.Stream.FlushAsync(System.Threading.CancellationToken)

System.IO.Stream.ObjectInvariant()

System.IO.Stream.ReadAsync(System.Byte[], System.Int32, System.Int32)

System.IO.Stream.ReadAsync(System.Byte[], System.Int32, System.Int32, System.Threading.CancellationToken)

System.IO.Stream.Synchronized(System.IO.Stream)

System.IO.Stream.WriteAsync(System.Byte[], System.Int32, System.Int32)

System.IO.Stream.WriteAsync(System.Byte[], System.Int32, System.Int32, System.Threading.CancellationToken)

System.IO.Stream.CanTimeout

System.IO.Stream.ReadTimeout

System.IO.Stream.WriteTimeout

System.MarshalByRefObject.GetLifetimeService()

System.MarshalByRefObject.InitializeLifetimeService()

System.MarshalByRefObject.MemberwiseClone(System.Boolean)

System.Object.Equals(System.Object)

System.Object.Equals(System.Object, System.Object)

System.Object.GetHashCode()

System.Object.GetType()

System.Object.MemberwiseClone()

System.Object.ReferenceEquals(System.Object, System.Object)

System.Object.ToString()

Namespace: ICSharpCode.SharpZipLib.Lzw

Assembly: ICSharpCode.SharpZipLib.dll

Syntax

public class LzwInputStream : Stream, IDisposable

Examples

This sample shows how to unzip a compressed file

using System;
using System.IO;

using ICSharpCode.SharpZipLib.Core;
using ICSharpCode.SharpZipLib.LZW;

class MainClass
{
    public static void Main(string[] args)
    {
        using (Stream inStream = new LzwInputStream(File.OpenRead(args[0])))
        using (FileStream outStream = File.Create(Path.GetFileNameWithoutExtension(args[0]))) {
            byte[] buffer = new byte[4096];
            StreamUtils.Copy(inStream, outStream, buffer);
                        // OR
                        inStream.Read(buffer, 0, buffer.Length);
                        // now do something with the buffer
        }
    }
}

Constructors

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LzwInputStream(Stream)

Creates a LzwInputStream

Declaration

public LzwInputStream(Stream baseInputStream)

Parameters

Type	Name	Description
System.IO.Stream	baseInputStream	The stream to read compressed data from (baseInputStream LZW format)

Properties

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CanRead

Gets a value indicating whether the current stream supports reading

Declaration

public override bool CanRead { get; }

Property Value

Type	Description
System.Boolean

Overrides

System.IO.Stream.CanRead

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CanSeek

Gets a value of false indicating seeking is not supported for this stream.

Declaration

public override bool CanSeek { get; }

Property Value

Type	Description
System.Boolean

Overrides

System.IO.Stream.CanSeek

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CanWrite

Gets a value of false indicating that this stream is not writeable.

Declaration

public override bool CanWrite { get; }

Property Value

Type	Description
System.Boolean

Overrides

System.IO.Stream.CanWrite

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IsStreamOwner

Gets or sets a flag indicating ownership of underlying stream. When the flag is true System.IO.Stream.Dispose() will close the underlying stream also.

Declaration

public bool IsStreamOwner { get; set; }

Property Value

Type	Description
System.Boolean

Remarks

The default value is true.

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Length

A value representing the length of the stream in bytes.

Declaration

public override long Length { get; }

Property Value

Type	Description
System.Int64

Overrides

System.IO.Stream.Length

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Position

The current position within the stream. Throws a NotSupportedException when attempting to set the position

Declaration

public override long Position { get; set; }

Property Value

Type	Description
System.Int64

Overrides

System.IO.Stream.Position

Exceptions

Type	Condition
System.NotSupportedException	Attempting to set the position

Methods

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Dispose(Boolean)

Closes the input stream. When IsStreamOwner is true the underlying stream is also closed.

Declaration

protected override void Dispose(bool disposing)

Parameters

Type	Name	Description
System.Boolean	disposing

Overrides

System.IO.Stream.Dispose(System.Boolean)

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Flush()

Flushes the baseInputStream

Declaration

public override void Flush()

Overrides

System.IO.Stream.Flush()

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Read(Byte[], Int32, Int32)

Reads decompressed data into the provided buffer byte array

Declaration

public override int Read(byte[] buffer, int offset, int count)

Parameters

Type	Name	Description
System.Byte[]	buffer	The array to read and decompress data into
System.Int32	offset	The offset indicating where the data should be placed
System.Int32	count	The number of bytes to decompress

Returns

Type	Description
System.Int32	The number of bytes read. Zero signals the end of stream

Overrides

System.IO.Stream.Read(System.Byte[], System.Int32, System.Int32)

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ReadByte()

See System.IO.Stream.ReadByte()

Declaration

public override int ReadByte()

Returns

Type	Description
System.Int32

Overrides

System.IO.Stream.ReadByte()

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Seek(Int64, SeekOrigin)

Sets the position within the current stream Always throws a NotSupportedException

Declaration

public override long Seek(long offset, SeekOrigin origin)

Parameters

Type	Name	Description
System.Int64	offset	The relative offset to seek to.
System.IO.SeekOrigin	origin	The System.IO.SeekOrigin defining where to seek from.

Returns

Type	Description
System.Int64	The new position in the stream.

Overrides

System.IO.Stream.Seek(System.Int64, System.IO.SeekOrigin)

Exceptions

Type	Condition
System.NotSupportedException	Any access

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SetLength(Int64)

Set the length of the current stream Always throws a NotSupportedException

Declaration

public override void SetLength(long value)

Parameters

Type	Name	Description
System.Int64	value	The new length value for the stream.

Overrides

System.IO.Stream.SetLength(System.Int64)

Exceptions

Type	Condition
System.NotSupportedException	Any access

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Write(Byte[], Int32, Int32)

Writes a sequence of bytes to stream and advances the current position This method always throws a NotSupportedException

Declaration

public override void Write(byte[] buffer, int offset, int count)

Parameters

Type	Name	Description
System.Byte[]	buffer	The buffer containing data to write.
System.Int32	offset	The offset of the first byte to write.
System.Int32	count	The number of bytes to write.

Overrides

System.IO.Stream.Write(System.Byte[], System.Int32, System.Int32)

Exceptions

Type	Condition
System.NotSupportedException	Any access

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WriteByte(Byte)

Writes one byte to the current stream and advances the current position Always throws a NotSupportedException

Declaration

public override void WriteByte(byte value)

Parameters

Type	Name	Description
System.Byte	value	The byte to write.

Overrides

System.IO.Stream.WriteByte(System.Byte)

Exceptions

Type	Condition
System.NotSupportedException	Any access

Implements

System.IDisposable