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, java.io.Closeable, java.io.Flushable, java.lang.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 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 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