BackpressureDrainManager.BackpressureQueueCallback

All Known Implementing Classes:

OperatorOnBackpressureBuffer.BufferSubscriber

Enclosing class:

BackpressureDrainManager
```
public static interface BackpressureDrainManager.BackpressureQueueCallback
```
Interface representing the minimal callbacks required to operate the drain part of a backpressure system.

Method Summary

All Methods Instance Methods Abstract Methods
Modifier and Type	Method	Description
`boolean`	`accept(java.lang.Object value)`	Override this method to deliver an element to downstream.
`void`	`complete(java.lang.Throwable exception)`	Override this method to deliver a normal or exceptional terminal event.
`java.lang.Object`	`peek()`	Override this method to peek for the next element, null meaning no next element available now.
`java.lang.Object`	`poll()`	Override this method to poll (consume) the next element, null meaning no next element available now.

- Method Detail
  - peek
```
java.lang.Object peek()
```
    Override this method to peek for the next element, null meaning no next element available now.
    It will be called plain and while holding this object's monitor.
    
    Returns:
    
    the next element or null if no next element available
  - poll
```
java.lang.Object poll()
```
    Override this method to poll (consume) the next element, null meaning no next element available now.
    
    Returns:
    
    the next element or null if no next element available
  - accept
```
boolean accept(java.lang.Object value)
```
    Override this method to deliver an element to downstream. The logic ensures that this happens only in the right conditions.
    
    Parameters:
    
    value - the value to deliver, not null
    
    Returns:
    
    true indicates that one should terminate the emission loop unconditionally and not deliver any further elements or terminal events.
  - complete
```
void complete(java.lang.Throwable exception)
```
    Override this method to deliver a normal or exceptional terminal event.
    
    Parameters:
    
    exception - if not null, contains the terminal exception