Initial Checkin

1 files changed, 227 insertions, 0 deletions

diff --git a/java/io/BufferedOutputStream.java b/java/io/BufferedOutputStream.java
new file mode 100644
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--- /dev/null
+++ b/java/io/BufferedOutputStream.java
@@ -0,0 +1,227 @@
+/*************************************************************************
+/* BufferedOutputStream.java -- Buffer output into large blocks before writing
+/*
+/* Copyright (c) 1998 Free Software Foundation, Inc.
+/* Written by Aaron M. Renn (arenn@urbanophile.com)
+/*
+/* This program is free software; you can redistribute it and/or modify
+/* it under the terms of the GNU Library General Public License as published 
+/* by the Free Software Foundation, version 2. (see COPYING.LIB)
+/*
+/* This program is distributed in the hope that it will be useful, but
+/* WITHOUT ANY WARRANTY; without even the implied warranty of
+/* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+/* GNU General Public License for more details.
+/*
+/* You should have received a copy of the GNU General Public License
+/* along with this program; if not, write to the Free Software Foundation
+/* Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307 USA
+/*************************************************************************/
+
+package java.io;
+
+/**
+  * This class accumulates bytes written in a buffer instead of immediately
+  * writing the data to the underlying output sink. The bytes are instead
+  * as one large block when the buffer is filled, or when the stream is
+  * closed or explicitly flushed. This mode operation can provide a more
+  * efficient mechanism for writing versus doing numerous small unbuffered
+  * writes.
+  *
+  * @version 0.0
+  *
+  * @author Aaron M. Renn (arenn@urbanophile.com)
+  */
+public class BufferedOutputStream extends FilterOutputStream
+{
+
+/*************************************************************************/
+
+/*
+ * Class Variables
+ */
+
+/**
+  * This is the default buffer size
+  */
+private static final int DEFAULT_BUFFER_SIZE = 512;
+
+/*************************************************************************/
+
+/*
+ * Instance Variables
+ */
+
+/**
+  * This is the internal byte array used for buffering output before
+  * writing it.
+  */
+protected byte[] buf;
+
+/**
+  * This is the number of bytes that are currently in the buffer and
+  * are waiting to be written to the underlying stream.  It always points to
+  * the index into the buffer where the next byte of data will be stored
+  */
+protected int count;
+
+/*************************************************************************/
+
+/*
+ * Constructors
+ */
+
+/**
+  * This method initializes a new <code>BufferedOutputStream</code> instance
+  * that will write to the specified subordinate <code>OutputStream</code>
+  * and which will use a default buffer size of 512 bytes.
+  *
+  * @param out The underlying <code>OutputStream</code> to write data to
+  */
+public
+BufferedOutputStream(OutputStream out)
+{
+  this(out, DEFAULT_BUFFER_SIZE);
+}
+
+/*************************************************************************/
+
+/**
+  * This method initializes a new <code>BufferedOutputStream</code> instance
+  * that will write to the specified subordinate <code>OutputStream</code>
+  * and which will use the specified buffer size
+  *
+  * @param out The underlying <code>OutputStream</code> to write data to
+  * @param size The size of the internal buffer
+  */
+public
+BufferedOutputStream(OutputStream out, int size)
+{
+  super(out);
+
+  buf = new byte[size];
+}
+
+/*************************************************************************/
+
+/*
+ * Instance Methods
+ */
+
+/**
+  * This method causes any currently buffered bytes to be immediately
+  * written to the underlying output stream.
+  *
+  * @exception IOException If an error occurs
+  */
+public void
+flush() throws IOException
+{
+  if (count == 0)
+    return;
+
+  out.write(buf, 0, count);
+  count = 0;
+}
+
+/*************************************************************************/
+
+/**
+  * This method flushes any remaining buffered bytes then closes the 
+  * underlying output stream.  Any further attempts to write to this stream
+  * may throw an exception
+  */
+public void
+close() throws IOException
+{
+  flush();
+  out.close();
+}
+
+/*************************************************************************/
+
+/**
+  * This method runs when the object is garbage collected.  It is 
+  * responsible for ensuring that all buffered bytes are written and
+  * for closing the underlying stream.
+  *
+  * @exception IOException If an error occurs (ignored by the Java runtime)
+  */
+protected void
+finalize() throws IOException
+{
+  close();
+}
+
+/*************************************************************************/
+
+/**
+  * This method writes a single byte of data.  This will be written to the
+  * buffer instead of the underlying data source.  However, if the buffer
+  * is filled as a result of this write request, it will be flushed to the
+  * underlying output stream.
+  *
+  * @param b The byte of data to be written, passed as an int
+  *
+  * @exception IOException If an error occurs
+  */
+public void
+write(int b) throws IOException
+{
+  buf[count] = (byte)(b & 0xFF);
+
+  ++count;
+  if (count == buf.length)
+    flush();
+}
+
+/*************************************************************************/
+
+/**
+  * This method writes <code>len</code> bytes from the byte array 
+  * <code>buf</code> starting at position <code>offset</code> in the buffer. 
+  * These bytes will be written to the internal buffer.  However, if this
+  * write operation fills the buffer, the buffer will be flushed to the
+  * underlying output stream.
+  *
+  * @param buf The array of bytes to write.
+  * @param offset The index into the byte array to start writing from.
+  * @param len The number of bytes to write.
+  *
+  * @exception IOException If an error occurs
+  */
+public void
+write(byte[] buf, int offset, int len) throws IOException
+{
+  // Buffer can hold everything
+  if (len < (this.buf.length - count))
+    {
+      System.arraycopy(buf, offset, this.buf, count, len);
+      count += len;
+
+      if (count == buf.length)
+        flush();
+    }
+  else
+    {
+      flush();
+       
+      // Loop and write out full buffer chunks. As an optimization, 
+      // don't buffer these, just write them
+      int i = 0;
+      if ((len / this.buf.length) != 0)
+        for (i = 0; i < (len / this.buf.length); i++)
+          out.write(buf, offset + (i * this.buf.length), this.buf.length);
+
+      // Buffer the remaining bytes
+      if ((len % buf.length) != 0)
+        {
+          System.arraycopy(buf, offset + (i * this.buf.length), this.buf, count, 
+                           len - (i * this.buf.length));
+          count += (len - (i * this.buf.length));
+        }
+    }
+}
+
+} // class BufferedOutputStream 
+