alluxio.client.keyvalue

Class ByteBufferKeyValuePartitionReader

java.lang.Object

alluxio.client.keyvalue.ByteBufferKeyValuePartitionReader

All Implemented Interfaces:

KeyValueIterable, KeyValuePartitionReader, Closeable, AutoCloseable

@NotThreadSafe
public final class ByteBufferKeyValuePartitionReader
extends Object
implements KeyValuePartitionReader

Reader that implements KeyValuePartitionReader to access a key-value file using random access API.

Nested Class Summary

Nested classes/interfaces inherited from interface alluxio.client.keyvalue.KeyValuePartitionReader

KeyValuePartitionReader.Factory

Constructor Summary

Constructors

Constructor and Description
ByteBufferKeyValuePartitionReader(ByteBuffer fileBytes) Constructs ByteBufferKeyValuePartitionReader.

Method Summary

Modifier and Type	Method and Description
void	close()
byte[]	get(byte[] key) Gets the value associated with the given key in the key-value partition, returning null if the key is not found.
ByteBuffer	get(ByteBuffer key) Gets the value associated with the given key in the key-value partition, returning null if the key is not found.
Index	getIndex()
PayloadReader	getPayloadReader()
KeyValueIterator	iterator()
int	size()

Methods inherited from class java.lang.Object

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

Constructor Detail

ByteBufferKeyValuePartitionReader

public ByteBufferKeyValuePartitionReader(ByteBuffer fileBytes)

Constructs ByteBufferKeyValuePartitionReader.

Parameters:

fileBytes - the byte buffer as underline storage to read from

Method Detail

get

public byte[] get(byte[] key)
           throws IOException

Gets the value associated with the given key in the key-value partition, returning null if the key is not found.

This could be slow when value size is large, use this cautiously or get(ByteBuffer) which may avoid copying data.

Specified by:

get in interface KeyValuePartitionReader

Parameters:

key - key to get, cannot be null

Returns:

bytes of the value if found, null otherwise

Throws:

IOException

get

public ByteBuffer get(ByteBuffer key)
               throws IOException

Description copied from interface: KeyValuePartitionReader

Gets the value associated with the given key in the key-value partition, returning null if the key is not found. Both key and value are in ByteBuffer to make zero-copy possible for better performance.

Specified by:

get in interface KeyValuePartitionReader

Parameters:

key - key to get, cannot be null

Returns:

bytes of the value if found, null otherwise

Throws:

IOException

close

public void close()

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

iterator

public KeyValueIterator iterator()

Specified by:

iterator in interface KeyValueIterable

Returns:

a KeyValueIterator for iterating over key-value pairs in the store

size

public int size()
         throws IOException,
                AlluxioException

Specified by:

size in interface KeyValuePartitionReader

Returns:

the number of key-value pairs in the partition

Throws:

IOException

AlluxioException

getIndex

public Index getIndex()

Returns:

the Index reconstructed from the byte buffer

getPayloadReader

public PayloadReader getPayloadReader()

Returns:

the PayloadReader for reading payloads from the byte buffer