com.pervasive.datarush.io

Interface SplitInputStream

All Known Implementing Classes:

SplitInputStreamImpl

public interface SplitInputStream

Interface defining an input data stream that works within the boundaries of a defined split. A split has a beginning and ending offset that defines the boundary of the split.

The contract for spanning the end of the split follows:

• A read that encounters a split boundary will return only the data within the split. Data from the current split and the next split are not mixed within the same buffer.
• Before the read operation that encounters the split boundary returns, an indicator that the boundary has been crossed should be set. This indicator is returned by the hasOverrun() method.
• The availableInSplit() method should return the number of bytes left in the split (or an estimate) or zero if the split boundary has been crossed.
• Reading past the split boundary is allowed. This is needed for formats that may need to search for the end of a record that spans splits.

Method Summary

Methods

Modifier and Type	Method and Description
long	availableInSplit() Gets the number of bytes remaining in the split.
void	close() Close the underlying raw data stream.
boolean	hasOverrun() Indicates whether the reader has read past the end of the split.
int	read(byte[] buffer, int offset, int length) Read data from the split input stream.

Method Detail

availableInSplit

long availableInSplit()

Gets the number of bytes remaining in the split.

Returns:

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

hasOverrun

boolean hasOverrun()

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

Returns:

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

read

int read(byte[] buffer,
       int offset,
       int length)
         throws IOException

Read data from the split input stream. By convention, if reading before the end of a split, the read will only return data contained within the split. A subsequent read will read data beyond the split.

Parameters:

buffer - input buffer

offset - offset to start filling in buffer

length - amount of data to read

Returns:

number of bytes read or -1 if EOD has been reached

Throws:

IOException - thrown if an I/O error occurs

close

void close()

Close the underlying raw data stream.