com.google.appengine.tools.mapreduce.inputs

Class GoogleCloudStorageLevelDbInputReader

java.lang.Object

com.google.appengine.tools.mapreduce.InputReader<ByteBuffer>

com.google.appengine.tools.mapreduce.inputs.LevelDbInputReader

com.google.appengine.tools.mapreduce.inputs.GoogleCloudStorageLevelDbInputReader

All Implemented Interfaces:

Serializable

public final class GoogleCloudStorageLevelDbInputReader
extends LevelDbInputReader

A simple wrapper of LevelDb wrapper for GCS to provide getProgress() and do lazy initialization.

See Also:

Serialized Form

Constructor Summary

Constructors

Constructor and Description
GoogleCloudStorageLevelDbInputReader(com.google.appengine.tools.cloudstorage.GcsFilename file, int bufferSize)

Method Summary

Methods

Modifier and Type	Method and Description
ReadableByteChannel	createReadableByteChannel()
long	estimateMemoryRequirement() Returns the estimated memory that will be used by this reader in bytes.
Double	getProgress() Returns the relative progress reading this input as a number from 0 to 1.

Methods inherited from class com.google.appengine.tools.mapreduce.inputs.LevelDbInputReader

beginShard, beginSlice, endShard, getBytesRead, next

Methods inherited from class com.google.appengine.tools.mapreduce.InputReader

close, endSlice, getContext, open, setContext

Methods inherited from class java.lang.Object

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

Constructor Detail

GoogleCloudStorageLevelDbInputReader

public GoogleCloudStorageLevelDbInputReader(com.google.appengine.tools.cloudstorage.GcsFilename file,
                                    int bufferSize)

Parameters:

file - File to be read.

bufferSize - The buffersize to be used by the Gcs prefetching read channel.

Method Detail

getProgress

public Double getProgress()

Description copied from class: InputReader

Returns the relative progress reading this input as a number from 0 to 1. Returns null if relative progress cannot be determined.

Overrides:

getProgress in class InputReader<ByteBuffer>

createReadableByteChannel

public ReadableByteChannel createReadableByteChannel()

Specified by:

createReadableByteChannel in class LevelDbInputReader

Returns:

A Serializable ReadableByteChannel from which data may be read.

estimateMemoryRequirement

public long estimateMemoryRequirement()

Description copied from class: InputReader

Returns the estimated memory that will be used by this reader in bytes. (This is normally just set to the size of the buffers used by the implementation)

Overrides:

estimateMemoryRequirement in class InputReader<ByteBuffer>