org.jboss.cache.io
Class ExposedByteArrayOutputStream

java.lang.Object
  java.io.OutputStream
      java.io.ByteArrayOutputStream
          org.jboss.cache.io.ExposedByteArrayOutputStream

All Implemented Interfaces:

Closeable, Flushable

@NotThreadSafe
public class ExposedByteArrayOutputStream
extends ByteArrayOutputStream

Extends ByteArrayOutputStream, but exposes the internal buffer. Using this, callers don't need to call toByteArray() which copies the internal buffer.

Also overrides the superclass' behavior of always doubling the size of the internal buffer any time more capacity is needed. This class doubles the size until the internal buffer reaches a configurable max size (default is 4MB), after which it begins growing the buffer in 25% increments. This is intended to help prevent an OutOfMemoryError during a resize of a large buffer.

A version of this class was originally created by Bela Ban as part of the JGroups library.

This class is not threadsafe as it will not support concurrent readers and writers.

Version:

$Id: ExposedByteArrayOutputStream.java 7168 2008-11-19 17:37:20Z jason.greene@jboss.com $

Author:

Brian Stansberry

Field Summary

static int

DEFAULT_DOUBLING_SIZE Default buffer size after which if more buffer capacity is needed the buffer will grow by 25% rather than 100%

Fields inherited from class java.io.ByteArrayOutputStream

buf, count

Constructor Summary

ExposedByteArrayOutputStream()

ExposedByteArrayOutputStream(int size)

ExposedByteArrayOutputStream(int size, int maxDoublingSize)
Creates a new byte array output stream, with a buffer capacity of the specified size, in bytes.

Method Summary

int	getMaxDoublingSize() Gets the highest internal buffer size after which if more capacity is needed the buffer will grow in 25% increments rather than 100%.
int	getNewBufferSize(int curSize, int minNewSize) Gets the number of bytes to which the internal buffer should be resized.
byte[]	getRawBuffer() Gets the internal buffer array.
void	write(byte[] b, int off, int len)
void	write(int b)

Methods inherited from class java.io.ByteArrayOutputStream

close, reset, size, toByteArray, toString, toString, toString, writeTo

Methods inherited from class java.io.OutputStream

flush, write

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

DEFAULT_DOUBLING_SIZE

public static final int DEFAULT_DOUBLING_SIZE

Default buffer size after which if more buffer capacity is needed the buffer will grow by 25% rather than 100%

See Also:

Constant Field Values

Constructor Detail

ExposedByteArrayOutputStream

public ExposedByteArrayOutputStream()

ExposedByteArrayOutputStream

public ExposedByteArrayOutputStream(int size)

ExposedByteArrayOutputStream

public ExposedByteArrayOutputStream(int size,
                                    int maxDoublingSize)

Creates a new byte array output stream, with a buffer capacity of the specified size, in bytes.

Parameters:

size - the initial size.

maxDoublingSize - the buffer size, after which if more capacity is needed the buffer will grow by 25% rather than 100%

Throws:

IllegalArgumentException - if size is negative.

Method Detail

getRawBuffer

public final byte[] getRawBuffer()

Gets the internal buffer array. Note that the length of this array will almost certainly be longer than the data written to it; call size() to get the number of bytes of actual data.

write

public void write(byte[] b,
                  int off,
                  int len)

Overrides:

write in class ByteArrayOutputStream

write

public void write(int b)

Overrides:

write in class ByteArrayOutputStream

getMaxDoublingSize

public final int getMaxDoublingSize()

Gets the highest internal buffer size after which if more capacity is needed the buffer will grow in 25% increments rather than 100%.

getNewBufferSize

public final int getNewBufferSize(int curSize,
                                  int minNewSize)

Gets the number of bytes to which the internal buffer should be resized.

Parameters:

curSize - the current number of bytes

minNewSize - the minimum number of bytes required

Returns:

the size to which the internal buffer should be resized