Package org.aksw.commons.io.hadoop

Class SeekableInputStreams

java.lang.Object

org.aksw.commons.io.hadoop.SeekableInputStreams

public class SeekableInputStreams
extends Object

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	SeekableInputStreams.GetPosition
static interface	SeekableInputStreams.GetPositionFn<T>
static interface	SeekableInputStreams.SetPosition
static interface	SeekableInputStreams.SetPositionFn<T>

Constructor Summary

Constructors

Constructor	Description
SeekableInputStreams()

Method Summary

Modifier and Type	Method	Description
static ReadableByteChannel	advertiseEndOfBlock(InputStream decodedIn, int endOfBlockMarker)	The argument for invoking this methods must be a seekable input streams that implements hadoop's protocol for splittable codecs using READ_MODE.BYBLOCK.
static <T extends ReadableByteChannel> SeekableInputStream	create(InputStream in, SeekableInputStreams.GetPosition getPosition, SeekableInputStreams.SetPosition setPosition)
static SeekableInputStream	create(InputStream in, org.apache.hadoop.fs.Seekable seekable)
static <T extends ReadableByteChannel> SeekableInputStream	create(T channel, SeekableInputStreams.GetPositionFn<? super T> getPosition, SeekableInputStreams.SetPositionFn<? super T> setPosition)
static org.apache.hadoop.fs.Seekable	createSeekable(SeekableInputStreams.GetPosition getPosition, SeekableInputStreams.SetPosition setPosition)
static org.aksw.commons.io.input.SeekableReadableChannel<byte[]>	wrap(SeekableInputStream in)	Bridge SeekableInputStream to the channel API

Methods inherited from class java.lang.Object

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

Constructor Detail

SeekableInputStreams

public SeekableInputStreams()

Method Detail

createSeekable

public static org.apache.hadoop.fs.Seekable createSeekable(SeekableInputStreams.GetPosition getPosition,
                                                           SeekableInputStreams.SetPosition setPosition)

create

public static <T extends ReadableByteChannel> SeekableInputStream create(T channel,
                                                                         SeekableInputStreams.GetPositionFn<? super T> getPosition,
                                                                         SeekableInputStreams.SetPositionFn<? super T> setPosition)

wrap

public static org.aksw.commons.io.input.SeekableReadableChannel<byte[]> wrap(SeekableInputStream in)

Bridge SeekableInputStream to the channel API

create

public static <T extends ReadableByteChannel> SeekableInputStream create(InputStream in,
                                                                         SeekableInputStreams.GetPosition getPosition,
                                                                         SeekableInputStreams.SetPosition setPosition)

create

public static SeekableInputStream create(InputStream in,
                                         org.apache.hadoop.fs.Seekable seekable)

advertiseEndOfBlock

public static ReadableByteChannel advertiseEndOfBlock(InputStream decodedIn,
                                                      int endOfBlockMarker)
                                               throws IOException

The argument for invoking this methods must be a seekable input streams that implements hadoop's protocol for splittable codecs using READ_MODE.BYBLOCK. Whereas hadoop's protocol will alawys read 1 byte beyond the split boundary, this wrapper will stop exactly at that boundary. Internally a push-back input stream is used to push that single "read-ahead" byte back once it is encountered. A block boundary is advertised by a call to read() by returing -2. This return value indicates that read() may be called again and will return at least one more byte. A return value of -1 indicates "end of file" just as usual.

Parameters:

decodedIn -

endOfBlockMarker - The value to return when an end of block is detected

Returns:

Throws:

IOException