org.apache.hadoop.hbase.client

Class AsyncReversedScannerCallable

java.lang.Object

org.apache.hadoop.hbase.client.AsyncRegionServerCallable<org.apache.hadoop.hbase.client.Result[]>

org.apache.hadoop.hbase.client.AsyncScannerCallable

org.apache.hadoop.hbase.client.AsyncReversedScannerCallable

All Implemented Interfaces:

AsyncRetryingCallable<org.apache.hadoop.hbase.client.Result[]>

@InterfaceAudience.Public
@InterfaceStability.Evolving
public class AsyncReversedScannerCallable
extends AsyncScannerCallable

A reversed ScannerCallable which supports backward scanning.

Field Summary

Fields

Modifier and Type	Field and Description
protected byte[]	locateStartRow The start row for locating regions.

Fields inherited from class org.apache.hadoop.hbase.client.AsyncScannerCallable

controller, instantiated, isRegionServerRemote, scanMetrics

Fields inherited from class org.apache.hadoop.hbase.client.AsyncRegionServerCallable

client, connection, location, MIN_WAIT_DEAD_SERVER, row, tableName

Constructor Summary

Constructors

Constructor and Description
AsyncReversedScannerCallable(AsyncRpcClient client, org.apache.hadoop.hbase.TableName tableName, org.apache.hadoop.hbase.client.Scan scan, org.apache.hadoop.hbase.client.metrics.ScanMetrics scanMetrics, byte[] locateStartRow, AsyncPayloadCarryingRpcController controller)

Method Summary

Methods

Modifier and Type	Method and Description
void	prepare(boolean reload) Prepare for connection to the server hosting region with row from tablename.

Methods inherited from class org.apache.hadoop.hbase.client.AsyncScannerCallable

call, checkIfRegionServerIsRemote, getHRegionInfo, getMaxResults, getScan, openScanner, setClose, setMaxResults

Methods inherited from class org.apache.hadoop.hbase.client.AsyncRegionServerCallable

getExceptionMessageAdditionalDetail, getLocation, getRow, getStub, getTableName, setLocation, sleep, throwable

Methods inherited from class java.lang.Object

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

Field Detail

locateStartRow

protected final byte[] locateStartRow

The start row for locating regions. In reversed scanner, may locate the regions for a range of keys when doing ReversedClientScanner.nextScanner(int, boolean)

Constructor Detail

AsyncReversedScannerCallable

public AsyncReversedScannerCallable(AsyncRpcClient client,
                            org.apache.hadoop.hbase.TableName tableName,
                            org.apache.hadoop.hbase.client.Scan scan,
                            org.apache.hadoop.hbase.client.metrics.ScanMetrics scanMetrics,
                            byte[] locateStartRow,
                            AsyncPayloadCarryingRpcController controller)

Parameters:

client - to connect with

tableName - table callable is on

scan - the scan to execute

scanMetrics - the ScanMetrics to used, if it is null, ScannerCallable won't collect metrics

locateStartRow - start row to locate

controller - to use when writing the rpc

Method Detail

prepare

public void prepare(boolean reload)
             throws java.io.IOException

Description copied from class: AsyncRegionServerCallable

Prepare for connection to the server hosting region with row from tablename. Does lookup to find region location and hosting server.

Specified by:

prepare in interface AsyncRetryingCallable<org.apache.hadoop.hbase.client.Result[]>

Overrides:

prepare in class AsyncScannerCallable

Parameters:

reload - force reload of server location

Throws:

java.io.IOException