org.apache.hadoop.hbase.client

Class AsyncScannerCallable

java.lang.Object

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

org.apache.hadoop.hbase.client.AsyncScannerCallable

All Implemented Interfaces:

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

Direct Known Subclasses:

AsyncReversedScannerCallable

@InterfaceAudience.Private
public class AsyncScannerCallable
extends AsyncRegionServerCallable<org.apache.hadoop.hbase.client.Result[]>

Scanner operations such as create, next, etc. Used by ResultScanners made by HTable. Passed to a retrying caller such as AsyncRpcRetryingCaller so fails are retried.

Field Summary

Fields

Modifier and Type	Field and Description
protected AsyncPayloadCarryingRpcController	controller
protected boolean	instantiated
protected boolean	isRegionServerRemote
protected org.apache.hadoop.hbase.client.metrics.ScanMetrics	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
AsyncScannerCallable(AsyncRpcClient client, org.apache.hadoop.hbase.TableName tableName, org.apache.hadoop.hbase.client.Scan scan, org.apache.hadoop.hbase.client.metrics.ScanMetrics scanMetrics, AsyncPayloadCarryingRpcController controller)

Method Summary

Methods

Modifier and Type	Method and Description
void	call(ResponseHandler<org.apache.hadoop.hbase.client.Result[]> handler) Calls the scan request
protected void	checkIfRegionServerIsRemote() compare the local machine hostname with region server's hostname to decide if hbase client connects to a remote region server
org.apache.hadoop.hbase.HRegionInfo	getHRegionInfo()
int	getMaxResults() Get the number of rows that will be fetched on next
protected org.apache.hadoop.hbase.client.Scan	getScan() Get scan of the callable
protected void	openScanner(ResponseHandler<java.lang.Long> responseHandler) Open the scanner
void	prepare(boolean reload) Prepare for connection to the server hosting region with row from tablename.
void	setClose() Call this when the next invocation of call should close the scanner
void	setMaxResults(int maxResults) Set the number of rows that will be fetched on next

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

instantiated

protected boolean instantiated

scanMetrics

protected org.apache.hadoop.hbase.client.metrics.ScanMetrics scanMetrics

isRegionServerRemote

protected boolean isRegionServerRemote

controller

protected final AsyncPayloadCarryingRpcController controller

Constructor Detail

AsyncScannerCallable

public AsyncScannerCallable(AsyncRpcClient client,
                    org.apache.hadoop.hbase.TableName tableName,
                    org.apache.hadoop.hbase.client.Scan scan,
                    org.apache.hadoop.hbase.client.metrics.ScanMetrics scanMetrics,
                    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

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

Parameters:

reload - force reload of server location

Throws:

java.io.IOException - if preparation fails

checkIfRegionServerIsRemote

protected void checkIfRegionServerIsRemote()

compare the local machine hostname with region server's hostname to decide if hbase client connects to a remote region server

call

public void call(ResponseHandler<org.apache.hadoop.hbase.client.Result[]> handler)

Calls the scan request

Parameters:

handler - to handle results

openScanner

protected void openScanner(ResponseHandler<java.lang.Long> responseHandler)

Open the scanner

Parameters:

responseHandler - handles response

getScan

protected org.apache.hadoop.hbase.client.Scan getScan()

Get scan of the callable

Returns:

Scan

setClose

public void setClose()

Call this when the next invocation of call should close the scanner

getHRegionInfo

public org.apache.hadoop.hbase.HRegionInfo getHRegionInfo()

Overrides:

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

Returns:

the HRegionInfo for the current region

getMaxResults

public int getMaxResults()

Get the number of rows that will be fetched on next

Returns:

the number of rows for maxResults

setMaxResults

public void setMaxResults(int maxResults)

Set the number of rows that will be fetched on next

Parameters:

maxResults - the number of rows for maxResults