Package org.apache.flink.connector.base.sink.writer

Class DequeRequestBuffer<RequestEntryT extends Serializable>

java.lang.Object

org.apache.flink.connector.base.sink.writer.DequeRequestBuffer<RequestEntryT>

All Implemented Interfaces:

RequestBuffer<RequestEntryT>

@Internal
public class DequeRequestBuffer<RequestEntryT extends Serializable>
extends Object
implements RequestBuffer<RequestEntryT>

Default wrapper implementation that uses an ArrayDeque as the underlying data structure.

Constructor Summary

Constructors

Constructor	Description
DequeRequestBuffer()	Creates an empty buffer backed by an ArrayDeque.

Method Summary

Modifier and Type	Method	Description
void	add(RequestEntryWrapper<RequestEntryT> entry, boolean prioritize)	Adds a request entry to the buffer.
Collection<RequestEntryWrapper<RequestEntryT>>	getBufferedState()	Retrieves all buffered request entries as a collection.
boolean	isEmpty()	Checks whether the buffer is empty.
RequestEntryWrapper<RequestEntryT>	peek()	Retrieves, but does not remove, the next available request entry from the buffer.
RequestEntryWrapper<RequestEntryT>	poll()	Retrieves and removes the next available request entry from the buffer.
int	size()	Returns the number of request entries currently in the buffer.
long	totalSizeInBytes()	Returns the total size of all buffered request entries in bytes.

Methods inherited from class java.lang.Object

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

Constructor Detail

DequeRequestBuffer

public DequeRequestBuffer()

Creates an empty buffer backed by an ArrayDeque.

Method Detail

add

public void add(RequestEntryWrapper<RequestEntryT> entry,
                boolean prioritize)

Adds a request entry to the buffer. If prioritize is true, the entry is inserted at the front (for retries). Otherwise, it is added at the end following FIFO order.

Specified by:

add in interface RequestBuffer<RequestEntryT extends Serializable>

Parameters:

entry - The request entry to add.

prioritize - If true, insert at the front; otherwise, add at the end.

peek

public RequestEntryWrapper<RequestEntryT> peek()

Retrieves, but does not remove, the next available request entry from the buffer. This allows checking the next request before processing.

Specified by:

peek in interface RequestBuffer<RequestEntryT extends Serializable>

Returns:

The next request entry, or null if the buffer is empty.

isEmpty

public boolean isEmpty()

Checks whether the buffer is empty. Useful for determining if there are pending entries before flushing.

Specified by:

isEmpty in interface RequestBuffer<RequestEntryT extends Serializable>

Returns:

True if the buffer contains no entries, false otherwise.

size

public int size()

Returns the number of request entries currently in the buffer. Can be used for batching decisions.

Specified by:

size in interface RequestBuffer<RequestEntryT extends Serializable>

Returns:

The total number of buffered entries.

getBufferedState

public Collection<RequestEntryWrapper<RequestEntryT>> getBufferedState()

Retrieves all buffered request entries as a collection. Implementations should return a snapshot of the buffer for checkpointing.

The returned collection:

• Must preserve the order in which entries were added (FIFO).
• Must not modify or clear the internal buffer.

Specified by:

getBufferedState in interface RequestBuffer<RequestEntryT extends Serializable>

Returns:

A collection of all buffered request entries.

poll

public RequestEntryWrapper<RequestEntryT> poll()

Retrieves and removes the next available request entry from the buffer. The removal order is determined by the implementation.

Specified by:

poll in interface RequestBuffer<RequestEntryT extends Serializable>

Returns:

The removed request entry, or null if the buffer is empty.

totalSizeInBytes

public long totalSizeInBytes()

Returns the total size of all buffered request entries in bytes.

Tracks the cumulative size of all elements in bufferedRequestEntries to facilitate the criterion for flushing after maxBatchSizeInBytes is reached.

Specified by:

totalSizeInBytes in interface RequestBuffer<RequestEntryT extends Serializable>

Returns:

The total buffered size in bytes.