com.google.cloud.dataflow.sdk.io

Class BlockBasedSource.Block<T>

java.lang.Object

com.google.cloud.dataflow.sdk.io.BlockBasedSource.Block<T>

Enclosing class:

BlockBasedSource<T>

@Experimental(value=SOURCE_SINK)
protected abstract static class BlockBasedSource.Block<T>
extends Object

A Block represents a block of records that can be read.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Block()

Method Summary

Modifier and Type	Method and Description
abstract T	getCurrentRecord() Returns the current record.
abstract double	getFractionOfBlockConsumed() Returns the fraction of the block already consumed (i.e., not including the current record), if possible, as a value in [0, 1].
abstract boolean	readNextRecord() Reads the next record from the block and returns true iff one exists.

Methods inherited from class java.lang.Object

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

Constructor Detail

Block

protected Block()

Method Detail

getCurrentRecord

public abstract T getCurrentRecord()

Returns the current record.

readNextRecord

public abstract boolean readNextRecord()
                                throws IOException

Reads the next record from the block and returns true iff one exists.

Throws:

IOException

getFractionOfBlockConsumed

public abstract double getFractionOfBlockConsumed()

Returns the fraction of the block already consumed (i.e., not including the current record), if possible, as a value in [0, 1]. Successive calls to this method must be monotonically non-decreasing.

If it is not possible to compute the fraction of the block consumed (e.g., the total number of records is unknown and record offsets are unknown), this method may return zero.