tech.mlsql.common.utils.kv

Class KVStoreView<T>

java.lang.Object

tech.mlsql.common.utils.kv.KVStoreView<T>

All Implemented Interfaces:

Iterable<T>

public abstract class KVStoreView<T>
extends Object
implements Iterable<T>

A configurable view that allows iterating over values in a KVStore.

The different methods can be used to configure the behavior of the iterator. Calling the same method multiple times is allowed; the most recent value will be used.

The iterators returned by this view are of type KVStoreIterator; they auto-close when used in a for loop that exhausts their contents, but when used manually, they need to be closed explicitly unless all elements are read.

Constructor Summary

Constructors

Constructor and Description
KVStoreView(Class<T> type)

Method Summary

Modifier and Type	Method and Description
KVStoreIterator<T>	closeableIterator() Returns an iterator for the current configuration.
KVStoreView<T>	first(Object value) Iterates starting at the given value of the chosen index (inclusive).
KVStoreView<T>	index(String name) Iterates according to the given index.
KVStoreView<T>	last(Object value) Stops iteration at the given value of the chosen index (inclusive).
KVStoreView<T>	max(long max) Stops iteration after a number of elements has been retrieved.
KVStoreView<T>	parent(Object value) Defines the value of the parent index when iterating over a child index.
KVStoreView<T>	reverse() Reverses the order of iteration.
KVStoreView<T>	skip(long n) Skips a number of elements at the start of iteration.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.lang.Iterable

forEach, iterator, spliterator

Constructor Detail

KVStoreView

public KVStoreView(Class<T> type)

Method Detail

reverse

public KVStoreView<T> reverse()

Reverses the order of iteration. By default, iterates in ascending order.

index

public KVStoreView<T> index(String name)

Iterates according to the given index.

parent

public KVStoreView<T> parent(Object value)

Defines the value of the parent index when iterating over a child index. Only elements that match the parent index's value will be included in the iteration.

Required for iterating over child indices, will generate an error if iterating over a parent-less index.

first

public KVStoreView<T> first(Object value)

Iterates starting at the given value of the chosen index (inclusive).

last

public KVStoreView<T> last(Object value)

Stops iteration at the given value of the chosen index (inclusive).

max

public KVStoreView<T> max(long max)

Stops iteration after a number of elements has been retrieved.

skip

public KVStoreView<T> skip(long n)

Skips a number of elements at the start of iteration. Skipped elements are not accounted when using max(long).

closeableIterator

public KVStoreIterator<T> closeableIterator()
                                     throws Exception

Returns an iterator for the current configuration.

Throws:

Exception