Package it.unimi.dsi.fastutil.io

Class FastByteArrayOutputStream

java.lang.Object

java.io.OutputStream

it.unimi.dsi.fastutil.io.MeasurableOutputStream

it.unimi.dsi.fastutil.io.FastByteArrayOutputStream

All Implemented Interfaces:

MeasurableStream, RepositionableStream, Closeable, Flushable, AutoCloseable

public class FastByteArrayOutputStream
extends MeasurableOutputStream
implements RepositionableStream

Simple, fast byte-array output stream that exposes the backing array.

ByteArrayOutputStream is nice, but to get its content you must generate each time a new object. This doesn't happen here.

This class will automatically enlarge the backing array, doubling its size whenever new space is needed. The reset() method will mark the content as empty, but will not decrease the capacity: use trim() for that purpose.

Author:

Sebastiano Vigna

Field Summary

Fields

Modifier and Type	Field	Description
byte[]	array	The array backing the output stream.
static final int	DEFAULT_INITIAL_CAPACITY	The array backing the output stream.
int	length	The number of valid bytes in array.

Constructor Summary

Constructors

Constructor	Description
FastByteArrayOutputStream()	Creates a new array output stream with an initial capacity of DEFAULT_INITIAL_CAPACITY bytes.
FastByteArrayOutputStream(byte[] a)	Creates a new array output stream wrapping a given byte array.
FastByteArrayOutputStream(int initialCapacity)	Creates a new array output stream with a given initial capacity.

Method Summary

Modifier and Type	Method	Description
long	length()	Returns the overall length of this stream (optional operation).
long	position()	Returns the current stream position.
void	position(long newPosition)	Sets the current stream position.
void	reset()	Marks this array output stream as empty.
void	trim()	Ensures that the length of the backing array is equal to length.
void	write(byte[] b, int off, int len)
void	write(int b)

Methods inherited from class java.io.OutputStream

close, flush, nullOutputStream, write

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

DEFAULT_INITIAL_CAPACITY

public static final int DEFAULT_INITIAL_CAPACITY

The array backing the output stream.

See Also:

• Constant Field Values

array

public byte[] array

The array backing the output stream.

length

public int length

The number of valid bytes in array.

Constructor Details

FastByteArrayOutputStream

public FastByteArrayOutputStream()

Creates a new array output stream with an initial capacity of DEFAULT_INITIAL_CAPACITY bytes.

FastByteArrayOutputStream

public FastByteArrayOutputStream(int initialCapacity)

Creates a new array output stream with a given initial capacity.

Parameters:

initialCapacity - the initial length of the backing array.

FastByteArrayOutputStream

public FastByteArrayOutputStream(byte[] a)

Creates a new array output stream wrapping a given byte array.

Parameters:

a - the byte array to wrap.

Method Details

reset

public void reset()

Marks this array output stream as empty.

trim

public void trim()

Ensures that the length of the backing array is equal to length.

write

public void write(int b)

Specified by:

write in class OutputStream

write

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

Overrides:

write in class OutputStream

Throws:

IOException

position

public void position(long newPosition)

Description copied from interface: RepositionableStream

Sets the current stream position.

Specified by:

position in interface RepositionableStream

Parameters:

newPosition - the new stream position.

position

public long position()

Description copied from interface: RepositionableStream

Returns the current stream position.

Specified by:

position in interface MeasurableStream

Specified by:

position in interface RepositionableStream

Returns:

the current stream position.

length

public long length()
            throws IOException

Description copied from interface: MeasurableStream

Returns the overall length of this stream (optional operation). In most cases, this will require the stream to perform some extra action, possibly changing the state of the input stream itself (typically, reading all the bytes up to the end, or flushing on output stream). Implementing classes should always document what state will the input stream be in after calling this method, and which kind of exception could be thrown.

Specified by:

length in interface MeasurableStream

Throws:

IOException