org.apache.flink.connector.file.src.util

Class Pool<T>

java.lang.Object

org.apache.flink.connector.file.src.util.Pool<T>

Type Parameters:

T - The type of object cached in the pool.

@PublicEvolving
public class Pool<T>
extends Object

A pool to cache and recycle heavyweight objects, to reduce object allocation.

This pool can be used in the BulkFormat.Reader, when the returned objects are heavyweight and need to be reused for efficiency. Because the reading happens in I/O threads while the record processing happens in Flink's main processing threads, these objects cannot be reused immediately after being returned. They can be reused, once they are recycled back to the pool.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Pool.Recycler<T> A Recycler puts objects into the pool that the recycler is associated with.

Constructor Summary

Constructors

Constructor and Description
Pool(int poolCapacity) Creates a pool with the given capacity.

Method Summary

Modifier and Type	Method and Description
void	add(T object) Adds an entry to the pool with an optional payload.
T	pollEntry() Gets the next cached entry.
Pool.Recycler<T>	recycler() Gets the recycler for this pool.
T	tryPollEntry() Tries to get the next cached entry.

Methods inherited from class java.lang.Object

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

Constructor Detail

Pool

public Pool(int poolCapacity)

Creates a pool with the given capacity. No more than that many elements may be added to the pool.

Method Detail

recycler

public Pool.Recycler<T> recycler()

Gets the recycler for this pool. The recycler returns its given objects back to this pool.

add

public void add(T object)

Adds an entry to the pool with an optional payload. This method fails if called more often than the pool capacity specified during construction.

pollEntry

public T pollEntry()
            throws InterruptedException

Gets the next cached entry. This blocks until the next entry is available.

Throws:

InterruptedException

tryPollEntry

@Nullable
public T tryPollEntry()

Tries to get the next cached entry. If the pool is empty, this method returns null.