inflaterinputstream.cs

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		/// <param name = "baseInputStream">
		/// The InputStream to read bytes from
		/// </param>
		public InflaterInputStream(Stream baseInputStream)
			: this(baseInputStream, new Inflater(), 4096)
		{
		}
		
		/// <summary>
		/// Create an InflaterInputStream with the specified decompressor
		/// and a default buffer size of 4KB.
		/// </summary>
		/// <param name = "baseInputStream">
		/// The source of input data
		/// </param>
		/// <param name = "inf">
		/// The decompressor used to decompress data read from baseInputStream
		/// </param>
		public InflaterInputStream(Stream baseInputStream, Inflater inf)
			: this(baseInputStream, inf, 4096)
		{
		}
		
		/// <summary>
		/// Create an InflaterInputStream with the specified decompressor
		/// and the specified buffer size.
		/// </summary>
		/// <param name = "baseInputStream">
		/// The InputStream to read bytes from
		/// </param>
		/// <param name = "inflater">
		/// The decompressor to use
		/// </param>
		/// <param name = "bufferSize">
		/// Size of the buffer to use
		/// </param>
		public InflaterInputStream(Stream baseInputStream, Inflater inflater, int bufferSize)
		{
			if (baseInputStream == null) {
				throw new ArgumentNullException("baseInputStream");
			}
			
			if (inflater == null) {
				throw new ArgumentNullException("inflater");
			}
			
			if (bufferSize <= 0) {
				throw new ArgumentOutOfRangeException("bufferSize");
			}
			
			this.baseInputStream = baseInputStream;
			this.inf = inflater;
			
			inputBuffer = new InflaterInputBuffer(baseInputStream, bufferSize);
		}
		
		#endregion

		/// <summary>
		/// Get/set flag indicating ownership of underlying stream.
		/// When the flag is true <see cref="Close"/> will close the underlying stream also.
		/// </summary>
		/// <remarks>
		/// The default value is true.
		/// </remarks>
		public bool IsStreamOwner
		{
			get { return isStreamOwner; }
			set { isStreamOwner = value; }
		}
		
		/// <summary>
		/// Skip specified number of bytes of uncompressed data
		/// </summary>
		/// <param name ="count">
		/// Number of bytes to skip
		/// </param>
		/// <returns>
		/// The number of bytes skipped, zero if the end of 
		/// stream has been reached
		/// </returns>
		/// <exception cref="ArgumentOutOfRangeException">
		/// Number of bytes to skip is less than zero
		/// </exception>
		public long Skip(long count)
		{
			if (count < 0) 
			{
				throw new ArgumentOutOfRangeException("count");
			}
			
			// v0.80 Skip by seeking if underlying stream supports it...
			if (baseInputStream.CanSeek) 
			{
				baseInputStream.Seek(count, SeekOrigin.Current);
				return count;
			} 
			else 
			{
				int len = 2048;
				if (count < len) 
				{
					len = (int) count;
				}
				byte[] tmp = new byte[len];
				return (long)baseInputStream.Read(tmp, 0, tmp.Length);
			}
		}
		
		/// <summary>
		/// Clear any cryptographic state.
		/// </summary>		
		protected void StopDecrypting()
		{
#if !NETCF_1_0			
			inputBuffer.CryptoTransform = null;
#endif			
		}

		/// <summary>
		/// Returns 0 once the end of the stream (EOF) has been reached.
		/// Otherwise returns 1.
		/// </summary>
		public virtual int Available 
		{
			get 
			{
				return inf.IsFinished ? 0 : 1;
			}
		}
		
		/// <summary>
		/// Fills the buffer with more data to decompress.
		/// </summary>
		/// <exception cref="SharpZipBaseException">
		/// Stream ends early
		/// </exception>
		protected void Fill()
		{
			inputBuffer.Fill();
			inputBuffer.SetInflaterInput(inf);
		}

		#region Stream Overrides
		/// <summary>
		/// Gets a value indicating whether the current stream supports reading
		/// </summary>
		public override bool CanRead 
		{
			get {
				return baseInputStream.CanRead;
			}
		}
		
		/// <summary>
		/// Gets a value of false indicating seeking is not supported for this stream.
		/// </summary>
		public override bool CanSeek {
			get {
				return false;
			}
		}
		
		/// <summary>
		/// Gets a value of false indicating that this stream is not writeable.
		/// </summary>
		public override bool CanWrite {
			get {
				return false;
			}
		}
		
		/// <summary>
		/// A value representing the length of the stream in bytes.
		/// </summary>
		public override long Length {
			get {
				return inputBuffer.RawLength;
			}
		}
		
		/// <summary>
		/// The current position within the stream.
		/// Throws a NotSupportedException when attempting to set the position
		/// </summary>
		/// <exception cref="NotSupportedException">Attempting to set the position</exception>
		public override long Position {
			get {
				return baseInputStream.Position;
			}
			set {
				throw new NotSupportedException("InflaterInputStream Position not supported");
			}
		}
		
		/// <summary>
		/// Flushes the baseInputStream
		/// </summary>
		public override void Flush()
		{
			baseInputStream.Flush();
		}
		
		/// <summary>
		/// Sets the position within the current stream
		/// Always throws a NotSupportedException
		/// </summary>
		/// <param name="offset">The relative offset to seek to.</param>
		/// <param name="origin">The <see cref="SeekOrigin"/> defining where to seek from.</param>
		/// <returns>The new position in the stream.</returns>
		/// <exception cref="NotSupportedException">Any access</exception>
		public override long Seek(long offset, SeekOrigin origin)
		{
			throw new NotSupportedException("Seek not supported");
		}
		
		/// <summary>
		/// Set the length of the current stream
		/// Always throws a NotSupportedException
		/// </summary>
		/// <param name="value">The new length value for the stream.</param>
		/// <exception cref="NotSupportedException">Any access</exception>
		public override void SetLength(long value)
		{
			throw new NotSupportedException("InflaterInputStream SetLength not supported");
		}
		
		/// <summary>
		/// Writes a sequence of bytes to stream and advances the current position
		/// This method always throws a NotSupportedException
		/// </summary>
		/// <param name="buffer">Thew buffer containing data to write.</param>
		/// <param name="offset">The offset of the first byte to write.</param>
		/// <param name="count">The number of bytes to write.</param>
		/// <exception cref="NotSupportedException">Any access</exception>
		public override void Write(byte[] buffer, int offset, int count)
		{
			throw new NotSupportedException("InflaterInputStream Write not supported");
		}
		
		/// <summary>
		/// Writes one byte to the current stream and advances the current position
		/// Always throws a NotSupportedException
		/// </summary>
		/// <param name="value">The byte to write.</param>
		/// <exception cref="NotSupportedException">Any access</exception>
		public override void WriteByte(byte value)
		{
			throw new NotSupportedException("InflaterInputStream WriteByte not supported");
		}
		
		/// <summary>
		/// Entry point to begin an asynchronous write.  Always throws a NotSupportedException.
		/// </summary>
		/// <param name="buffer">The buffer to write data from</param>
		/// <param name="offset">Offset of first byte to write</param>
		/// <param name="count">The maximum number of bytes to write</param>
		/// <param name="callback">The method to be called when the asynchronous write operation is completed</param>
		/// <param name="state">A user-provided object that distinguishes this particular asynchronous write request from other requests</param>
		/// <returns>An <see cref="System.IAsyncResult">IAsyncResult</see> that references the asynchronous write</returns>
		/// <exception cref="NotSupportedException">Any access</exception>
		public override IAsyncResult BeginWrite(byte[] buffer, int offset, int count, AsyncCallback callback, object state)
		{
			throw new NotSupportedException("InflaterInputStream BeginWrite not supported");
		}
		
		/// <summary>
		/// Closes the input stream.  When <see cref="IsStreamOwner"></see>
		/// is true the underlying stream is also closed.
		/// </summary>
		public override void Close()
		{
			if ( !isClosed ) {
				isClosed = true;
				if ( isStreamOwner ) {
					baseInputStream.Close();
				}
			}
		}

		/// <summary>
		/// Reads decompressed data into the provided buffer byte array
		/// </summary>
		/// <param name ="buffer">
		/// The array to read and decompress data into
		/// </param>
		/// <param name ="offset">
		/// The offset indicating where the data should be placed
		/// </param>
		/// <param name ="count">
		/// The number of bytes to decompress
		/// </param>
		/// <returns>The number of bytes read.  Zero signals the end of stream</returns>
		/// <exception cref="SharpZipBaseException">
		/// Inflater needs a dictionary
		/// </exception>
		public override int Read(byte[] buffer, int offset, int count) 
		{
			if (inf.IsNeedingDictionary)
			{
				throw new SharpZipBaseException("Need a dictionary");
			}

			int remainingBytes = count;
			while (true)
			{
				int bytesRead = inf.Inflate(buffer, offset, remainingBytes); 
				offset += bytesRead;
				remainingBytes -= bytesRead;

				if (remainingBytes == 0 || inf.IsFinished)
				{
					break; 
				}

				if ( inf.IsNeedingInput )
				{
					Fill();
				}
				else if ( bytesRead == 0 )
				{
					throw new ZipException("Dont know what to do");
				}
			}
			return count - remainingBytes;
		}
		#endregion
		#region Instance Fields
		/// <summary>
		/// Decompressor for this stream
		/// </summary>
		protected Inflater inf;

		/// <summary>
		/// <see cref="InflaterInputBuffer">Input buffer</see> for this stream.
		/// </summary>
		protected InflaterInputBuffer inputBuffer;

		/// <summary>
		/// Base stream the inflater reads from.
		/// </summary>
		protected Stream baseInputStream;
		
		/// <summary>
		/// The compressed size
		/// </summary>
		protected long csize;

		/// <summary>
		/// Flag indicating wether this instance has been closed or not.
		/// </summary>
		bool isClosed;

		/// <summary>
		/// Flag indicating wether this instance is designated the stream owner.
		/// When closing if this flag is true the underlying stream is closed.
		/// </summary>
		bool isStreamOwner = true;
		#endregion
	}
}