ReceivingMailbox (Pinot Query Runtime 1.0.0 API)

java.lang.Object
- org.apache.pinot.query.mailbox.ReceivingMailbox

```
public class ReceivingMailbox
extends Object
```
Mailbox that's used to receive data. Ownership of the ReceivingMailbox is with the MailboxService, which is unlike the SendingMailbox whose ownership lies with the send operator. This is because the ReceivingMailbox can be initialized even before the corresponding OpChain is registered on the receiver, whereas the SendingMailbox is initialized when the send operator is running.

Nested Class Summary

Nested Classes
Modifier and Type Class Description

static interface ReceivingMailbox.Reader

static class ReceivingMailbox.ReceivingMailboxStatus

Field Summary

Fields
Modifier and Type Field Description

static int DEFAULT_MAX_PENDING_BLOCKS

Constructor Summary

Constructors
Constructor Description

ReceivingMailbox(String id)

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`void`	`cancel()`	Cancels the mailbox.
`String`	`getId()`
`int`	`getNumPendingBlocks()`
`ReceivingMailbox.ReceivingMailboxStatus`	`offer(TransferableBlock block, long timeoutMs)`	Offers a non-error block into the mailbox within the timeout specified, returns whether the block is successfully added.
`TransferableBlock`	`poll()`	Returns the first block from the mailbox, or `null` if there is no block received yet.
`void`	`registeredReader(ReceivingMailbox.Reader reader)`
`void`	`setErrorBlock(TransferableBlock errorBlock)`	Sets an error block into the mailbox.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - DEFAULT_MAX_PENDING_BLOCKS
```
public static final int DEFAULT_MAX_PENDING_BLOCKS
```
    See Also:
    
    Constant Field Values
- Constructor Detail
  - ReceivingMailbox
```
public ReceivingMailbox(String id)
```
- Method Detail
  - registeredReader
```
public void registeredReader(ReceivingMailbox.Reader reader)
```
  - getId
```
public String getId()
```
  - offer
```
public ReceivingMailbox.ReceivingMailboxStatus offer(TransferableBlock block,
                                                     long timeoutMs)
```
    Offers a non-error block into the mailbox within the timeout specified, returns whether the block is successfully added. If the block is not added, an error block is added to the mailbox.
  - setErrorBlock
```
public void setErrorBlock(TransferableBlock errorBlock)
```
    Sets an error block into the mailbox. No more blocks are accepted after calling this method.
  - poll
```
@Nullable
public TransferableBlock poll()
```
    Returns the first block from the mailbox, or null if there is no block received yet. Error block is returned if exists.
  - cancel
```
public void cancel()
```
    Cancels the mailbox. No more blocks are accepted after calling this method. Should only be called by the receive operator to clean up the remaining blocks.
  - getNumPendingBlocks
```
public int getNumPendingBlocks()
```