com.google.cloud.hadoop.gcsio

Interface SeekableReadableByteChannel

All Superinterfaces:

AutoCloseable, Channel, Closeable, ReadableByteChannel

All Known Implementing Classes:

GoogleCloudStorageReadChannel

public interface SeekableReadableByteChannel
extends ReadableByteChannel

A readable byte channel that supports seek operation. Note: JDK 1.7 supports SeekableByteChannel but we cannot use it here for two reasons: -- 1.7 is not yet enabled internally in Google. -- Hadoop v0.20.205.0 that we plan to use is built using 1.6. Because of these reasons, we define our own SeekableReadableByteChannel. At some point in future when the 2 issues above are resolved, we should get rid of our own interface and start using SeekableByteChannel. For that reason, We have made our own SeekableReadableByteChannel identical to the one supplied by Java 1.7. Note that SeekableByteChannel in Java 1.7 supports both reading and writing. GCS does not support random access writes. We will likely throw IllegalStateException if one tries to read from or seek for a channel opened for writing.

Method Summary

Methods

Modifier and Type	Method and Description
long	position() Returns this channel's position.
SeekableReadableByteChannel	position(long newPosition) Sets this channel's position.
long	size() Returns the current size of entity to which this channel is connected.

Methods inherited from interface java.nio.channels.ReadableByteChannel

read

Methods inherited from interface java.nio.channels.Channel

close, isOpen

Method Detail

position

long position()
              throws IOException

Returns this channel's position.

Returns:

This channel's position.

Throws:

IOException

position

SeekableReadableByteChannel position(long newPosition)
                                     throws IOException

Sets this channel's position.

Parameters:

newPosition - The new position, counting the number of bytes from the beginning of the entity.

Returns:

This channel.

Throws:

IOException

size

long size()
          throws IOException

Returns the current size of entity to which this channel is connected.

Throws:

IOException