TableEventHandler (Apache HBase 1.2.12 API)

java.lang.Object
- org.apache.hadoop.hbase.executor.EventHandler
- - org.apache.hadoop.hbase.master.handler.TableEventHandler

All Implemented Interfaces:

Comparable<Runnable>, Runnable

Direct Known Subclasses:

RestoreSnapshotHandler
```
@InterfaceAudience.Private
public abstract class TableEventHandler
extends EventHandler
```
Base class for performing operations against tables. Checks on whether the process can go forward are done in constructor rather than later on in process(). The idea is to fail fast rather than later down in an async invocation of process() (which currently has no means of reporting back issues once started).

Nested Class Summary
- Nested classes/interfaces inherited from class org.apache.hadoop.hbase.executor.EventHandler
  EventHandler.EventHandlerListener

Field Summary

Fields
Modifier and Type	Field and Description
`private boolean`	`isPrepareCalled`
`private static org.apache.commons.logging.Log`	`LOG`
`protected MasterServices`	`masterServices`
`protected TableLockManager.TableLock`	`tableLock`
`protected TableName`	`tableName`

Fields inherited from class org.apache.hadoop.hbase.executor.EventHandler
eventType, seqids, server, waitingTimeForEvents

Constructor Summary

Constructors
Constructor and Description
`TableEventHandler(EventType eventType, TableName tableName, Server server, MasterServices masterServices)`

Method Summary

Methods
Modifier and Type	Method and Description
`protected void`	`completed(Throwable exception)` Called after that process() is completed.
`HTableDescriptor`	`getTableDescriptor()` Gets a TableDescriptor from the masterServices.
`protected abstract void`	`handleTableOperation(List<HRegionInfo> regions)`
`(package private) byte[]`	`hasColumnFamily(HTableDescriptor htd, byte[] cf)`
`private boolean`	`isOnlineSchemaChangeAllowed()`
`TableEventHandler`	`prepare()` Event handlers should do all the necessary checks in this method (rather than in the constructor, or in process()) so that the caller, which is mostly executed in the ipc context can fail fast.
`protected void`	`prepareWithTableLock()` Called from prepare() while holding the table lock.
`void`	`process()` This method is the main processing loop to be implemented by the various subclasses.
`protected void`	`releaseTableLock()`
`boolean`	`reOpenAllRegions(List<HRegionInfo> regions)`

Methods inherited from class org.apache.hadoop.hbase.executor.EventHandler
compareTo, getEventType, getInformativeName, getListener, getPriority, getSeqid, handleException, run, setListener, toString

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

Field Detail

LOG

private static final org.apache.commons.logging.Log LOG

masterServices

protected final MasterServices masterServices

tableName
```
protected final TableName tableName
```

tableLock

protected TableLockManager.TableLock tableLock

isPrepareCalled
```
private boolean isPrepareCalled
```

Constructor Detail

TableEventHandler

public TableEventHandler(EventType eventType,
                 TableName tableName,
                 Server server,
                 MasterServices masterServices)

Method Detail
- prepare
```
public TableEventHandler prepare()
                          throws IOException
```
  Description copied from class: EventHandler
  
  Event handlers should do all the necessary checks in this method (rather than in the constructor, or in process()) so that the caller, which is mostly executed in the ipc context can fail fast. Process is executed async from the client ipc, so this method gives a quick chance to do some basic checks. Should be called after constructing the EventHandler, and before process().
  
  Overrides:
  
  prepare in class EventHandler
  
  Returns:
  the instance of this class
  
  Throws:
  
  IOException
- prepareWithTableLock
```
protected void prepareWithTableLock()
                             throws IOException
```
  Called from prepare() while holding the table lock. Subclasses can do extra initialization, and not worry about the releasing the table lock.
  
  Throws:
  
  IOException
- isOnlineSchemaChangeAllowed
```
private boolean isOnlineSchemaChangeAllowed()
```
- process
```
public void process()
```
  Description copied from class: EventHandler
  
  This method is the main processing loop to be implemented by the various subclasses.
  
  Specified by:
  
  process in class EventHandler
- releaseTableLock
```
protected void releaseTableLock()
```
- completed
```
protected void completed(Throwable exception)
```
  Called after that process() is completed.
  
  Parameters:
  exception - null if process() is successful or not null if something has failed.
- reOpenAllRegions
```
public boolean reOpenAllRegions(List<HRegionInfo> regions)
                         throws IOException
```
  Throws:
  
  IOException
- getTableDescriptor
```
public HTableDescriptor getTableDescriptor()
                                    throws FileNotFoundException,
                                           IOException
```
  Gets a TableDescriptor from the masterServices. Can Throw exceptions.
  
  Returns:
  Table descriptor for this table
  
  Throws:
  
  FileNotFoundException
  
  IOException
- hasColumnFamily
```
byte[] hasColumnFamily(HTableDescriptor htd,
                     byte[] cf)
                 throws InvalidFamilyOperationException
```
  Throws:
  
  InvalidFamilyOperationException
- handleTableOperation
```
protected abstract void handleTableOperation(List<HRegionInfo> regions)
                                      throws IOException,
                                             CoordinatedStateException
```
  Throws:
  
  IOException
  
  CoordinatedStateException

Class TableEventHandler

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.hadoop.hbase.executor.EventHandler

Field Summary

Fields inherited from class org.apache.hadoop.hbase.executor.EventHandler

Constructor Summary

Method Summary

Methods inherited from class org.apache.hadoop.hbase.executor.EventHandler

Methods inherited from class java.lang.Object

Field Detail

LOG

masterServices

tableName

tableLock

isPrepareCalled

Constructor Detail

TableEventHandler

Method Detail

prepare

prepareWithTableLock

isOnlineSchemaChangeAllowed

process

releaseTableLock

completed

reOpenAllRegions

getTableDescriptor

hasColumnFamily

handleTableOperation