[Adapdev-commits] Adapdev/src/Adapdev.NVelocity/IO VelocityWriter.cs,1.2,1.3

[Sean M. <int...@us...>]

Update of /cvsroot/adapdev/Adapdev/src/Adapdev.NVelocity/IO
In directory sc8-pr-cvs1.sourceforge.net:/tmp/cvs-serv22005/src/Adapdev.NVelocity/IO

Added Files:
	VelocityWriter.cs 
Log Message:


--- NEW FILE: VelocityWriter.cs ---
 //package org.apache.velocity.io;
//
//
//import java.io.IOException;
//import java.io.OutputStreamWriter;
//import java.io.Writer;

namespace NVelocity.IO
{
	using System;
	using System.IO;
	using System.Text;

	/**
     * Implementation of a fast Writer. It was originally taken from JspWriter
     * and modified to have less syncronization going on.
     *
     * @author <a href="mailto:jv...@ap...">Jason van Zyl</a>
     * @author <a href="mailto:jo...@la...">Jon S. Stevens</a>
     * @author Anil K. Vijendran
     * @version $Id: VelocityWriter.cs,v 1.3 2005/11/16 05:45:22 intesar66 Exp $
     */
	// TODO: class was final and it appears that readonly and final are not the same thing - most of the methods were final as well
	public class VelocityWriter : TextWriter
	{
		/**
	 * constant indicating that the Writer is not buffering output
	 */
		public static readonly int NO_BUFFER = 0;

		/**
	 * constant indicating that the Writer is buffered and is using the 
	 * implementation default buffer size
	 */
		public static readonly int DEFAULT_BUFFER = -1;

		/**
	 * constant indicating that the Writer is buffered and is unbounded; 
	 * this is used in BodyContent
	 */
		public static readonly int UNBOUNDED_BUFFER = -2;

		protected int bufferSize;
		protected Boolean autoFlush;

		private TextWriter writer;

		private char[] cb;
		private int nextChar;

		private static int defaultCharBufferSize = 8*1024;

		private Boolean flushed = false;

		/**
	 * Create a buffered character-output stream that uses a default-sized
	 * output buffer.
	 *
	 * @param  response  A Servlet Response
	 */

		public VelocityWriter(TextWriter writer) : this(writer, defaultCharBufferSize, true)
		{
		}

		/**
	 * private constructor.
	 */

		private VelocityWriter(int bufferSize, Boolean autoFlush)
		{
			this.bufferSize = bufferSize;
			this.autoFlush = autoFlush;
		}

		/**
	 * This method returns the size of the buffer used by the JspWriter.
	 *
	 * @return the size of the buffer in bytes, or 0 is unbuffered.
	 */

		public int getBufferSize()
		{
			return bufferSize;
		}

		/**
	 * This method indicates whether the JspWriter is autoFlushing.
	 *
	 * @return if this JspWriter is auto flushing or throwing IOExceptions on 
	 *         buffer overflow conditions
	 */

		public Boolean isAutoFlush()
		{
			return autoFlush;
		}

		/**
	 * Create a new buffered character-output stream that uses an output
	 * buffer of the given size.
	 *
	 * @param  response A Servlet Response
	 * @param  sz   	Output-buffer size, a positive integer
	 *
	 * @exception  IllegalArgumentException  If sz is <= 0
	 */

		public VelocityWriter(TextWriter writer, int sz, Boolean autoFlush) : this(sz, autoFlush)
		{
			if (sz < 0)
				throw new ArgumentOutOfRangeException("Buffer size <= 0");
			this.writer = writer;
			cb = sz == 0 ? null : new char[sz];
			nextChar = 0;
		}

		private void init(TextWriter writer, int sz, Boolean autoFlush)
		{
			this.writer = writer;
			if (sz > 0 && (cb == null || sz > cb.Length))
				cb = new char[sz];
			nextChar = 0;
			this.autoFlush = autoFlush;
			this.bufferSize = sz;
		}

		/**
	 * Flush the output buffer to the underlying character stream, without
	 * flushing the stream itself.  This method is non-private only so that it
	 * may be invoked by PrintStream.
	 */

		private void flushBuffer()
		{ //throws IOException
			if (bufferSize == 0)
				return;
			flushed = true;
			if (nextChar == 0)
				return;
			writer.Write(cb, 0, nextChar);
			nextChar = 0;
		}

		/**
	 * Discard the output buffer.
	 */

		public void clear()
		{
			nextChar = 0;
		}

		private void bufferOverflow()
		{ // throws IOException
			throw new IOException("overflow");
		}

		/**
	 * Flush the stream.
	 *
	 */

		public void flush()
		{ // throws IOException
			flushBuffer();
			if (writer != null)
			{
				writer.Flush();
			}
		}

		/**
	 * Close the stream.
	 *
	 */

		public void close()
		{ //throws IOException {
			if (writer == null)
				return;
			flush();
		}

		/**
	 * @return the number of bytes unused in the buffer
	 */

		public int getRemaining()
		{
			return bufferSize - nextChar;
		}

		/**
	 * Write a single character.
	 *
	 */

		public void write(int c)
		{ //throws IOException {
			if (bufferSize == 0)
			{
				writer.Write(c);
			}
			else
			{
				if (nextChar >= bufferSize)
					if (autoFlush)
						flushBuffer();
					else
						bufferOverflow();
				cb[nextChar++] = (char) c;
			}
		}

		/**
	 * Our own little min method, to avoid loading java.lang.Math if we've run
	 * out of file descriptors and we're trying to print a stack trace.
	 */

		private int min(int a, int b)
		{
			if (a < b) return a;
			return b;
		}

		/**
	 * Write a portion of an array of characters.
	 *
	 * <p> Ordinarily this method stores characters from the given array into
	 * this stream's buffer, flushing the buffer to the underlying stream as
	 * needed.  If the requested length is at least as large as the buffer,
	 * however, then this method will flush the buffer and write the characters
	 * directly to the underlying stream.  Thus redundant
	 * <code>DiscardableBufferedWriter</code>s will not copy data unnecessarily.
	 *
	 * @param  cbuf  A character array
	 * @param  off   Offset from which to start reading characters
	 * @param  len   Number of characters to write
	 *
	 */

		public void write(char[] cbuf, int off, int len)
		{
			//throws IOException    {
			if (bufferSize == 0)
			{
				writer.Write(cbuf, off, len);
				return;
			}

			if (len == 0)
			{
				return;
			}

			if (len >= bufferSize)
			{
				/* If the request length exceeds the size of the output buffer,
		flush the buffer and then write the data directly.  In this
		way buffered streams will cascade harmlessly. */
				if (autoFlush)
					flushBuffer();
				else
					bufferOverflow();
				writer.Write(cbuf, off, len);
				return;
			}

			int b = off, t = off + len;
			while (b < t)
			{
				int d = min(bufferSize - nextChar, t - b);
				Array.Copy(cbuf, b, cb, nextChar, d);
				b += d;
				nextChar += d;
				if (nextChar >= bufferSize)
					if (autoFlush)
						flushBuffer();
					else
						bufferOverflow();
			}
		}

		/**
	 * Write an array of characters.  This method cannot be inherited from the
	 * Writer class because it must suppress I/O exceptions.
	 */

		public void write(char[] buf)
		{ //throws IOException {
			write(buf, 0, buf.Length);
		}

		/**
	 * Write a portion of a String.
	 *
	 * @param  s     String to be written
	 * @param  off   Offset from which to start reading characters
	 * @param  len   Number of characters to be written
	 *
	 */

		public void write(String s, int off, int len)
		{ //throws IOException {
			if (bufferSize == 0)
			{
				writer.Write(s, off, len);
				return;
			}
			int b = off, t = off + len;
			while (b < t)
			{
				int d = min(bufferSize - nextChar, t - b);
				Array.Copy(s.ToCharArray(), b, cb, nextChar, b + d);
				b += d;
				nextChar += d;
				if (nextChar >= bufferSize)
					if (autoFlush)
						flushBuffer();
					else
						bufferOverflow();
			}
		}

		/**
	 * Write a string.  This method cannot be inherited from the Writer class
	 * because it must suppress I/O exceptions.
	 */

		public void write(String s)
		{ //throws IOException {
			write(s, 0, s.Length);
		}

		/**
	 * resets this class so that it can be reused
	 *
	 */

		public void recycle(TextWriter writer)
		{
			this.writer = writer;
			flushed = false;
			clear();
		}

		// needed to extend TextWriter
		public override Encoding Encoding
		{
			get { return writer.Encoding; }
		}

	}
}