it.unimi.dsi.fastutil.io
Class FastByteArrayOutputStream

java.lang.Object
  extended by java.io.OutputStream
      extended by it.unimi.dsi.fastutil.io.MeasurableOutputStream
          extended by it.unimi.dsi.fastutil.io.FastByteArrayOutputStream
All Implemented Interfaces:
MeasurableStream, RepositionableStream, java.io.Closeable, java.io.Flushable

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
 byte[] array
          The array backing the output stream.
static int DEFAULT_INITIAL_CAPACITY
          The array backing the output stream.
 int length
          The number of valid bytes in array.
 
Constructor Summary
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
 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, write
 
Methods inherited from class java.lang.Object
equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

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 Detail

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 Detail

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 java.io.OutputStream

write

public void write(byte[] b,
                  int off,
                  int len)
           throws java.io.IOException
Overrides:
write in class java.io.OutputStream
Throws:
java.io.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 java.io.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:
java.io.IOException