org.apache.hadoop.hbase.client
Class ScannerCallable

java.lang.Object
  org.apache.hadoop.hbase.client.RegionServerCallable<Result[]>
      org.apache.hadoop.hbase.client.ScannerCallable

All Implemented Interfaces:

Callable<Result[]>, RetryingCallable<Result[]>

@InterfaceAudience.Public
@InterfaceStability.Stable
public class ScannerCallable
extends RegionServerCallable<Result[]>

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

Field Summary

static org.apache.commons.logging.Log	LOG
static String	LOG_SCANNER_ACTIVITY
static String	LOG_SCANNER_LATENCY_CUTOFF

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

MIN_WAIT_DEAD_SERVER

Constructor Summary

ScannerCallable(HConnection connection, TableName tableName, Scan scan, ScanMetrics scanMetrics)

Method Summary

Result[]	call()
int	getCaching() Get the number of rows that will be fetched on next
HRegionInfo	getHRegionInfo()
protected Scan	getScan()
protected long	openScanner()
void	prepare(boolean reload) Prepare for connection to the server hosting region with row from tablename.
void	setCaching(int caching) Set the number of rows that will be fetched on next
void	setClose() Call this when the next invocation of call should close the scanner

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

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

LOG_SCANNER_LATENCY_CUTOFF

public static final String LOG_SCANNER_LATENCY_CUTOFF

See Also:

Constant Field Values

LOG_SCANNER_ACTIVITY

public static final String LOG_SCANNER_ACTIVITY

See Also:

Constant Field Values

LOG

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

Constructor Detail

ScannerCallable

public ScannerCallable(HConnection connection,
                       TableName tableName,
                       Scan scan,
                       ScanMetrics scanMetrics)

Parameters:

connection - which connection

tableName - table callable is on

scan - the scan to execute

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

Method Detail

prepare

public void prepare(boolean reload)
             throws IOException

Description copied from class: RegionServerCallable

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 RetryingCallable<Result[]>

Overrides:

prepare in class RegionServerCallable<Result[]>

Parameters:

reload - force reload of server location

Throws:

IOException

call

public Result[] call()
              throws IOException

Throws:

IOException

See Also:

Callable.call()

openScanner

protected long openScanner()
                    throws IOException

Throws:

IOException

getScan

protected Scan getScan()

setClose

public void setClose()

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

getHRegionInfo

public HRegionInfo getHRegionInfo()

Returns:

the HRegionInfo for the current region

getCaching

public int getCaching()

Get the number of rows that will be fetched on next

Returns:

the number of rows for caching

setCaching

public void setCaching(int caching)

Set the number of rows that will be fetched on next

Parameters:

caching - the number of rows for caching