Module datarush.commons

Package com.pervasive.datarush.io

Class SplitInputStreamImpl

java.lang.Object

java.io.InputStream

com.pervasive.datarush.io.BinaryReader

com.pervasive.datarush.io.SplitInputStreamImpl

All Implemented Interfaces:

SplitInputStream, Closeable, AutoCloseable

public class SplitInputStreamImpl
extends BinaryReader
implements SplitInputStream

A wrapper for input streams providing windowing behavior. Reads start at the first byte of the window. Readers may continue reading as far as the end of the source, although the stream does keep track of whether the reader has has passed the end of the window.

Field Summary

Fields

Modifier and Type	Field	Description
static int	DEFAULT_BUFFER	The default size for the read buffer, in bytes.
protected long	splitEnd
protected long	splitStart

Fields inherited from class com.pervasive.datarush.io.BinaryReader

absolutePosition, buffer, position, size, source

Constructor Summary

Constructors

Constructor	Description
SplitInputStreamImpl(InputStream source, long startOffset, long endOffset)	Create a new input stream for the specified split.
SplitInputStreamImpl(InputStream source, long startOffset, long endOffset, int bufferSize)	Create a new input stream for the specified window.

Method Summary

Modifier and Type	Method	Description
long	availableInSplit()	Gets the number of bytes remaining in the split.
protected int	fillBuffer()	Fills the working buffer
boolean	hasOverrun()	Indicates whether the reader has read past the end of the split.
protected void	moveToSplit()
long	overrunPastSplit()	Gets the number of bytes which have been read beyond the end of the split.
boolean	skipTo(byte[] bytes)	Advances the position of the stream to the first byte after the specified pattern.

Methods inherited from class com.pervasive.datarush.io.BinaryReader

available, close, getAbsolutePosition, isEmpty, loadNextBuffer, mark, markSupported, read, read, read, readBase128Int, readBase128Long, readByte, readBytes, readChar, readChars, readDouble, readFloat, readInt, readLong, readSingleByteChars, readUnsignedBase128Int, readUnsignedBase128Long, reset, skip, skipBytes, toString

Methods inherited from class java.io.InputStream

nullInputStream, readAllBytes, readNBytes, readNBytes, transferTo

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.pervasive.datarush.io.SplitInputStream

close, read

Field Detail

DEFAULT_BUFFER

public static final int DEFAULT_BUFFER

The default size for the read buffer, in bytes.

See Also:

Constant Field Values

splitStart

protected final long splitStart

splitEnd

protected final long splitEnd

Constructor Detail

SplitInputStreamImpl

public SplitInputStreamImpl(InputStream source,
                            long startOffset,
                            long endOffset)
                     throws IOException

Create a new input stream for the specified split. I/O is performed using buffers of size DEFAULT_BUFFER. The resulting stream will be positioned the beginning of the window.

As I/O is buffered, it is neither necessary nor preferable to use a BufferedInputStream as the source.

Parameters:

source - the stream providing the split data

startOffset - the position of the first byte in the window; this is relative to the starting position of source.

endOffset - the position of the last byte in the window, exclusive; this is relative to the starting position of source.

Throws:

IOException - if errors occur opening the split data source

SplitInputStreamImpl

public SplitInputStreamImpl(InputStream source,
                            long startOffset,
                            long endOffset,
                            int bufferSize)
                     throws IOException

Create a new input stream for the specified window. I/O is performed using the specified buffer size. The resulting stream will be positioned the beginning of the window.

As I/O is buffered, it is neither necessary nor preferable to use a BufferedInputStream as the source.

Parameters:

source - the stream providing the split data

startOffset - the position of the first byte in the window; this is relative to the starting position of source.

endOffset - the position of the last byte in the window, exclusive; this is relative to the starting position of source.

bufferSize - the size of the I/O buffer to use for reads, in bytes

Throws:

IOException - if errors occur opening the split data source

Method Detail

moveToSplit

protected void moveToSplit()
                    throws IOException

Throws:

IOException

fillBuffer

protected int fillBuffer()
                  throws IOException

Description copied from class: BinaryReader

Fills the working buffer

Overrides:

fillBuffer in class BinaryReader

Throws:

IOException

availableInSplit

public long availableInSplit()

Gets the number of bytes remaining in the split.

Specified by:

availableInSplit in interface SplitInputStream

Returns:

the number of bytes left to read in the split. If the split has been completely read, this is 0.

overrunPastSplit

public long overrunPastSplit()

Gets the number of bytes which have been read beyond the end of the split.

Returns:

the number of bytes read which were outside of the split. If there are still available bytes in the split, this is 0.

hasOverrun

public boolean hasOverrun()

Indicates whether the reader has read past the end of the split.

Specified by:

hasOverrun in interface SplitInputStream

Returns:

true if all bytes in the split has been read, false if any remain.

skipTo

public boolean skipTo(byte[] bytes)
               throws IOException

Advances the position of the stream to the first byte after the specified pattern.

Parameters:

bytes - the pattern to find in the stream

Returns:

false if end of data is reached, true otherwise.

Throws:

IOException - if an I/O error occurs while reading the stream