RingBufferTruck (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.regionserver.wal.RingBufferTruck

```
@InterfaceAudience.Private
 class RingBufferTruck
extends Object
```
A 'truck' to carry a payload across the FSHLog ring buffer from Handler to WAL. Has EITHER a FSWALEntry for making an append OR it has a SyncFuture to represent a 'sync' invocation. Truck instances are reused by the disruptor when it gets around to it so their payload references must be discarded on consumption to release them to GC.

Field Summary

Fields
Modifier and Type	Field and Description
`private FSWALEntry`	`entry`
`(package private) static com.lmax.disruptor.EventFactory<RingBufferTruck>`	`EVENT_FACTORY` Factory for making a bunch of these.
`private org.apache.htrace.Span`	`span` The tracing span for this entry.
`private SyncFuture`	`syncFuture` Either this syncFuture is set or entry is set, but not both.

Constructor Summary

Constructors
Constructor and Description

RingBufferTruck()

Constructors
Constructor and Description
`RingBufferTruck()`

Method Summary

Methods
Modifier and Type	Method and Description
`(package private) boolean`	`hasFSWALEntryPayload()` return `true` when this truck is carrying a `FSWALEntry`, `false` otherwise.
`(package private) boolean`	`hasSyncFuturePayload()` return `true` when this truck is carrying a `SyncFuture`, `false` otherwise.
`(package private) void`	`loadPayload(FSWALEntry entry, org.apache.htrace.Span span)` Load the truck with a `FSWALEntry` and associated `Span`.
`(package private) void`	`loadPayload(SyncFuture syncFuture)` Load the truck with a `SyncFuture`.
`(package private) FSWALEntry`	`unloadFSWALEntryPayload()` Unload the truck of its `FSWALEntry` payload.
`(package private) org.apache.htrace.Span`	`unloadSpanPayload()` Unload the truck of its `Span` payload.
`(package private) SyncFuture`	`unloadSyncFuturePayload()` Unload the truck of its `SyncFuture` payload.

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

- Field Detail
  - syncFuture
```
private SyncFuture syncFuture
```
    Either this syncFuture is set or entry is set, but not both.
  - entry
```
private FSWALEntry entry
```
  - span
```
private org.apache.htrace.Span span
```
    The tracing span for this entry. Can be null. TODO: Fix up tracing.
  - EVENT_FACTORY
```
static final com.lmax.disruptor.EventFactory<RingBufferTruck> EVENT_FACTORY
```
    Factory for making a bunch of these. Needed by the ringbuffer/disruptor.
- Constructor Detail
  - RingBufferTruck
```
RingBufferTruck()
```
- Method Detail
  - loadPayload
```
void loadPayload(FSWALEntry entry,
               org.apache.htrace.Span span)
```
    Load the truck with a FSWALEntry and associated Span.
  - loadPayload
```
void loadPayload(SyncFuture syncFuture)
```
    Load the truck with a SyncFuture.
  - hasFSWALEntryPayload
```
boolean hasFSWALEntryPayload()
```
    return true when this truck is carrying a FSWALEntry, false otherwise.
  - hasSyncFuturePayload
```
boolean hasSyncFuturePayload()
```
    return true when this truck is carrying a SyncFuture, false otherwise.
  - unloadFSWALEntryPayload
```
FSWALEntry unloadFSWALEntryPayload()
```
    Unload the truck of its FSWALEntry payload. The internal refernce is released.
  - unloadSyncFuturePayload
```
SyncFuture unloadSyncFuturePayload()
```
    Unload the truck of its SyncFuture payload. The internal refernce is released.
  - unloadSpanPayload
```
org.apache.htrace.Span unloadSpanPayload()
```
    Unload the truck of its Span payload. The internal reference is released.

Class RingBufferTruck

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

syncFuture

entry

span

EVENT_FACTORY

Constructor Detail

RingBufferTruck

Method Detail

loadPayload

loadPayload

hasFSWALEntryPayload

hasSyncFuturePayload

unloadFSWALEntryPayload

unloadSyncFuturePayload

unloadSpanPayload