edu.illinois.cs.cogcomp.lbj.coref.util.io
Class RandomAccessByteBuffer

java.lang.Object
  edu.illinois.cs.cogcomp.lbj.coref.util.io.RandomAccessByteBuffer

All Implemented Interfaces:

RandomAccessData, RandomAccessInput

public class RandomAccessByteBuffer
extends java.lang.Object
implements RandomAccessInput

Loads and stores a buffer of bytes from a source such as a InputStream, and provides methods to read in a random access fashion. Suitable as a drop in replacement for a read-only RandomAccessFile, with any data source.

Field Summary

protected byte[]	bytes
protected long	cursor

Constructor Summary

RandomAccessByteBuffer(java.io.InputStream in)
Creates a data-buffer by reading all input from the input stream, and storing it in a byte buffer.

Method Summary

long	getFilePointer() Returns the current offset in the data, in bytes.
long	length() Gets the number of bytes of data.
int	read() Reads a byte of data from the cursor position.
void	seek(long pos) Sets the offset in the data, in bytes.

Methods inherited from class java.lang.Object

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

Field Detail

cursor

protected long cursor

bytes

protected byte[] bytes

Constructor Detail

RandomAccessByteBuffer

public RandomAccessByteBuffer(java.io.InputStream in)

Creates a data-buffer by reading all input from the input stream, and storing it in a byte buffer. Data is read until -1, the end of the stream, or an IOException is reached. This constructor blocks until all data has been read from the stream.

Parameters:

in - The stream from which to read the data.

Method Detail

getFilePointer

public long getFilePointer()
                    throws java.io.IOException

Description copied from interface: RandomAccessData

Returns the current offset in the data, in bytes.

Specified by:

getFilePointer in interface RandomAccessData

Returns:

The offset in bytes relative to the beginning of the data.

Throws:

java.io.IOException - if an I/O error is encountered.

seek

public void seek(long pos)
          throws java.io.IOException

Description copied from interface: RandomAccessData

Sets the offset in the data, in bytes. The offset may be set beyond the end of the data, and this does not change the data length. Only writing after setting the pointer beyond the end of the data will change the data size.

Specified by:

seek in interface RandomAccessData

Parameters:

pos - The desired offset, in bytes.

Throws:

java.io.IOException - if pos is negative, or if an I/O error is encountered.

length

public long length()
            throws java.io.IOException

Description copied from interface: RandomAccessData

Gets the number of bytes of data.

Specified by:

length in interface RandomAccessData

Returns:

The number of bytes of data.

Throws:

java.io.IOException - if an I/O error is encountered.

read

public int read()

Description copied from interface: RandomAccessInput

Reads a byte of data from the cursor position. The byte is returned as an integer in the inclusive range 0-255. This method blocks if no input is available. This method behaves just as InputStream's read method.

Specified by:

read in interface RandomAccessInput

Returns:

The next byte of data, or -1 if the end of file has been reached.