ScannerCallable (Apache HBase - Client 1.0.2 API)

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

所有已实现的接口:

RetryingCallable<Result[]>

直接已知子类:

ReversedScannerCallable
```
@InterfaceAudience.Private
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.

字段概要

字段
限定符和类型	字段和说明
`protected ClusterConnection`	`cConnection`
`protected boolean`	`closed`
`protected RpcControllerFactory`	`controllerFactory`
`protected int`	`id`
`protected boolean`	`instantiated`
`protected boolean`	`isRegionServerRemote`
`static org.apache.commons.logging.Log`	`LOG`
`static String`	`LOG_SCANNER_ACTIVITY`
`static String`	`LOG_SCANNER_LATENCY_CUTOFF`
`protected ScanMetrics`	`scanMetrics`
`protected long`	`scannerId`
`protected boolean`	`serverHasMoreResults`
`protected boolean`	`serverHasMoreResultsContext`

从类继承的字段 org.apache.hadoop.hbase.client.RegionServerCallable
connection, location, MIN_WAIT_DEAD_SERVER, row, tableName

构造器概要

构造器
构造器和说明
`ScannerCallable(ClusterConnection connection, org.apache.hadoop.hbase.TableName tableName, Scan scan, ScanMetrics scanMetrics, RpcControllerFactory rpcControllerFactory)`
`ScannerCallable(ClusterConnection connection, org.apache.hadoop.hbase.TableName tableName, Scan scan, ScanMetrics scanMetrics, RpcControllerFactory rpcControllerFactory, int id)`

方法概要

方法
限定符和类型	方法和说明
`Result[]`	`call(int callTimeout)` Computes a result, or throws an exception if unable to do so.
`protected void`	`checkIfRegionServerIsRemote()` compare the local machine hostname with region server's hostname to decide if hbase client connects to a remote region server
`int`	`getCaching()` Get the number of rows that will be fetched on next
`ClusterConnection`	`getConnection()`
`HRegionInfo`	`getHRegionInfo()`
`protected Scan`	`getScan()`
`ScannerCallable`	`getScannerCallableForReplica(int id)`
`protected boolean`	`getServerHasMoreResults()` Should the client attempt to fetch more results from this region
`protected boolean`	`hasMoreResultsContext()` Did the server respond with information about whether more results might exist.
`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
`protected void`	`setHasMoreResultsContext(boolean serverHasMoreResultsContext)`
`protected void`	`setServerHasMoreResults(boolean serverHasMoreResults)`
`protected void`	`updateResultsMetrics(Result[] rrs)`

从类继承的方法 org.apache.hadoop.hbase.client.RegionServerCallable
getExceptionMessageAdditionalDetail, getLocation, getRow, getStub, getTableName, setLocation, sleep, throwable

从类继承的方法 java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- 字段详细资料
  - LOG_SCANNER_LATENCY_CUTOFF
```
public static final String LOG_SCANNER_LATENCY_CUTOFF
```
    另请参阅:
    常量字段值
  - LOG_SCANNER_ACTIVITY
```
public static final String LOG_SCANNER_ACTIVITY
```
    另请参阅:
    常量字段值
  - LOG
```
public static final org.apache.commons.logging.Log LOG
```
  - scannerId
```
protected long scannerId
```
  - instantiated
```
protected boolean instantiated
```
  - closed
```
protected boolean closed
```
  - cConnection
```
protected final ClusterConnection cConnection
```
  - scanMetrics
```
protected ScanMetrics scanMetrics
```
  - id
```
protected final int id
```
  - serverHasMoreResultsContext
```
protected boolean serverHasMoreResultsContext
```
  - serverHasMoreResults
```
protected boolean serverHasMoreResults
```
  - isRegionServerRemote
```
protected boolean isRegionServerRemote
```
  - controllerFactory
```
protected RpcControllerFactory controllerFactory
```
- 构造器详细资料
  - ScannerCallable
```
public ScannerCallable(ClusterConnection connection,
               org.apache.hadoop.hbase.TableName tableName,
               Scan scan,
               ScanMetrics scanMetrics,
               RpcControllerFactory rpcControllerFactory)
```
    参数:
    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
    rpcControllerFactory - factory to use when creating RpcController
  - ScannerCallable
```
public ScannerCallable(ClusterConnection connection,
               org.apache.hadoop.hbase.TableName tableName,
               Scan scan,
               ScanMetrics scanMetrics,
               RpcControllerFactory rpcControllerFactory,
               int id)
```
    参数:
    connection -
    tableName -
    scan -
    scanMetrics -
    id - the replicaId
- 方法详细资料
  - prepare
```
public void prepare(boolean reload)
             throws IOException
```
    从类复制的说明: RegionServerCallable
    
    Prepare for connection to the server hosting region with row from tablename. Does lookup to find region location and hosting server.
    
    指定者:
    
    prepare 在接口中 RetryingCallable<Result[]>
    
    覆盖:
    
    prepare 在类中 RegionServerCallable<Result[]>
    
    参数:
    reload - force reload of server location
    
    抛出:
    
    IOException
  - 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 Result[] call(int callTimeout)
              throws IOException
```
    从接口复制的说明: RetryingCallable
    
    Computes a result, or throws an exception if unable to do so.
    
    参数:
    callTimeout - - the time available for this call. 0 for infinite.
    
    返回:
    computed result
    
    抛出:
    
    IOException
  - updateResultsMetrics
```
protected void updateResultsMetrics(Result[] rrs)
```
  - openScanner
```
protected long openScanner()
                    throws IOException
```
    抛出:
    
    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()
```
    覆盖:
    
    getHRegionInfo 在类中 RegionServerCallable<Result[]>
    
    返回:
    the HRegionInfo for the current region
  - getCaching
```
public int getCaching()
```
    Get the number of rows that will be fetched on next
    
    返回:
    the number of rows for caching
  - getConnection
```
public ClusterConnection getConnection()
```
    返回:
    HConnection instance used by this Callable.
  - setCaching
```
public void setCaching(int caching)
```
    Set the number of rows that will be fetched on next
    
    参数:
    caching - the number of rows for caching
  - getScannerCallableForReplica
```
public ScannerCallable getScannerCallableForReplica(int id)
```
  - getServerHasMoreResults
```
protected boolean getServerHasMoreResults()
```
    Should the client attempt to fetch more results from this region
    
    返回:
    True if the client should attempt to fetch more results, false otherwise.
  - setServerHasMoreResults
```
protected void setServerHasMoreResults(boolean serverHasMoreResults)
```
  - hasMoreResultsContext
```
protected boolean hasMoreResultsContext()
```
    Did the server respond with information about whether more results might exist. Not guaranteed to respond with older server versions
    
    返回:
    True if the server responded with information about more results.
  - setHasMoreResultsContext
```
protected void setHasMoreResultsContext(boolean serverHasMoreResultsContext)
```

类 ScannerCallable

字段概要

从类继承的字段 org.apache.hadoop.hbase.client.RegionServerCallable

构造器概要

方法概要

从类继承的方法 org.apache.hadoop.hbase.client.RegionServerCallable

从类继承的方法 java.lang.Object

字段详细资料

LOG_SCANNER_LATENCY_CUTOFF

LOG_SCANNER_ACTIVITY

LOG

scannerId

instantiated

closed

cConnection

scanMetrics

id

serverHasMoreResultsContext

serverHasMoreResults

isRegionServerRemote

controllerFactory

构造器详细资料

ScannerCallable

ScannerCallable

方法详细资料

prepare

checkIfRegionServerIsRemote

call

updateResultsMetrics

openScanner

getScan

setClose

getHRegionInfo

getCaching

getConnection

setCaching

getScannerCallableForReplica

getServerHasMoreResults

setServerHasMoreResults

hasMoreResultsContext

setHasMoreResultsContext