alluxio.client.keyvalue

Interface Index

All Known Implementing Classes:

LinearProbingIndex

public interface Index

Interface of key-value index. An implementation of this interface is supposed to index keys and capable of returning value of a given key from payload buffer.

Method Summary

Modifier and Type	Method and Description
int	byteCount()
ByteBuffer	get(ByteBuffer key, PayloadReader reader) Gets the bytes of value given the key and payload storage reader.
byte[]	getBytes()
int	keyCount()
Iterator<ByteBuffer>	keyIterator(PayloadReader reader) Gets an iterator to iterate over all keys.
ByteBuffer	nextKey(ByteBuffer currentKey, PayloadReader reader) Gets the next key relative to the current provided key.
boolean	put(byte[] key, byte[] value, PayloadWriter writer) Puts a key into the index and stores key and value data into payload storage.

Method Detail

put

boolean put(byte[] key,
            byte[] value,
            PayloadWriter writer)
     throws IOException

Puts a key into the index and stores key and value data into payload storage.

Parameters:

key - bytes of key

value - bytes of value

writer - writer to store key-value payload

Returns:

true on success, false otherwise (e.g., unresolvable hash collision)

Throws:

IOException

get

ByteBuffer get(ByteBuffer key,
               PayloadReader reader)
        throws IOException

Gets the bytes of value given the key and payload storage reader.

Parameters:

key - bytes of key

reader - reader to access key-value payload

Returns:

ByteBuffer of value, or null if not found

Throws:

IOException

getBytes

byte[] getBytes()

Returns:

byte array which contains raw bytes of this index

byteCount

int byteCount()

Returns:

size of this index in bytes

keyCount

int keyCount()

Returns:

the number of keys inserted

nextKey

ByteBuffer nextKey(ByteBuffer currentKey,
                   PayloadReader reader)

Gets the next key relative to the current provided key.

This could be more efficient than iterating over keyIterator(PayloadReader) to find the next key.

Parameters:

currentKey - the current key, or null if there is no initial key known yet

reader - reader to access key-value payload

Returns:

the next key, or null if there are no remaining keys

keyIterator

Iterator<ByteBuffer> keyIterator(PayloadReader reader)

Gets an iterator to iterate over all keys.

This could be more efficient than repeatedly calling nextKey(ByteBuffer, PayloadReader).

Parameters:

reader - reader to access key-value payload

Returns:

an iterator of keys, the iterator does not support remove