io.pravega.client.tables

Interface IteratorState

public interface IteratorState

Represents the state of a resumable iterator. Such an iterator can be executed asynchronously and continued after an interruption. Each iteration will result in a new request to the server (which is stateless). The entire state of the iterator is encoded in this object and and is used by the server to decide what to return for the next iteration call.

Each IteratorState instance is coupled to the Key-Value Table that it was created for and is tailored for the type of iteration that generates it (i.e., KeyValueTable.keyIterator(java.lang.String, int, io.pravega.client.tables.IteratorState) vs KeyValueTable.entryIterator(java.lang.String, int, io.pravega.client.tables.IteratorState)). As such, an IteratorState instance is non-transferable between different types of iterations or between different Key-Value Tables. It is OK to pass a IteratorState generated from a KeyValueTable instance to another KeyValueTable instance for the same Key-Value Table.

Method Summary

Modifier and Type	Method and Description
static IteratorState	fromBytes(java.nio.ByteBuffer buffer) Creates a new IteratorState from the given ByteBuffer.
boolean	isEmpty() Gets a value indicating whether this IteratorState instance is empty.
java.nio.ByteBuffer	toBytes() Serializes this IteratorState to a ByteBuffer.

Method Detail

toBytes

java.nio.ByteBuffer toBytes()

Serializes this IteratorState to a ByteBuffer. This can later be used to create a new IteratorState using fromBytes(ByteBuffer).

Returns:

A ByteBuffer.

isEmpty

boolean isEmpty()

Gets a value indicating whether this IteratorState instance is empty.

Returns:

True if empty, false otherwise.

fromBytes

static IteratorState fromBytes(java.nio.ByteBuffer buffer)

Creates a new IteratorState from the given ByteBuffer.

Parameters:

buffer - A ByteBuffer created via toBytes().

Returns:

A IteratorState.