Package org.apache.accumulo.core.client.impl

Class BaseIteratorEnvironment

java.lang.Object

org.apache.accumulo.core.client.impl.BaseIteratorEnvironment

All Implemented Interfaces:

IteratorEnvironment

public class BaseIteratorEnvironment
extends Object
implements IteratorEnvironment

An implementation of IteratorEnvironment that throws UnsupportedOperationException for each operation. This is useful for situations that need to extend IteratorEnvironment and implement a subset of the methods.

Constructor Summary

Constructors

Constructor	Description
BaseIteratorEnvironment()

Method Summary

Modifier and Type	Method	Description
IteratorEnvironment	cloneWithSamplingEnabled()	Returns a new iterator environment object that can be used to create deep copies over sample data.
Authorizations	getAuthorizations()
AccumuloConfiguration	getConfig()
IteratorUtil.IteratorScope	getIteratorScope()
SamplerConfiguration	getSamplerConfiguration()
boolean	isFullMajorCompaction()
boolean	isSamplingEnabled()	There are at least two conditions under which sampling will be enabled for an environment.
void	registerSideChannel(SortedKeyValueIterator<Key,Value> iter)
SortedKeyValueIterator<Key,Value>	reserveMapFileReader(String mapFileName)

Methods inherited from class java.lang.Object

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

Constructor Detail

BaseIteratorEnvironment

public BaseIteratorEnvironment()

Method Detail

reserveMapFileReader

public SortedKeyValueIterator<Key,Value> reserveMapFileReader(String mapFileName)
                                                             throws IOException

Specified by:

reserveMapFileReader in interface IteratorEnvironment

Throws:

IOException

getConfig

public AccumuloConfiguration getConfig()

Specified by:

getConfig in interface IteratorEnvironment

getIteratorScope

public IteratorUtil.IteratorScope getIteratorScope()

Specified by:

getIteratorScope in interface IteratorEnvironment

isFullMajorCompaction

public boolean isFullMajorCompaction()

Specified by:

isFullMajorCompaction in interface IteratorEnvironment

registerSideChannel

public void registerSideChannel(SortedKeyValueIterator<Key,Value> iter)

Specified by:

registerSideChannel in interface IteratorEnvironment

getAuthorizations

public Authorizations getAuthorizations()

Specified by:

getAuthorizations in interface IteratorEnvironment

isSamplingEnabled

public boolean isSamplingEnabled()

Description copied from interface: IteratorEnvironment

There are at least two conditions under which sampling will be enabled for an environment. One condition is when sampling is enabled for the scan that starts everything. Another possibility is for a deep copy created with an environment created by calling IteratorEnvironment.cloneWithSamplingEnabled()

Specified by:

isSamplingEnabled in interface IteratorEnvironment

Returns:

true if sampling is enabled for this environment.

getSamplerConfiguration

public SamplerConfiguration getSamplerConfiguration()

Specified by:

getSamplerConfiguration in interface IteratorEnvironment

Returns:

sampling configuration is sampling is enabled for environment, otherwise returns null.

cloneWithSamplingEnabled

public IteratorEnvironment cloneWithSamplingEnabled()

Description copied from interface: IteratorEnvironment

Returns a new iterator environment object that can be used to create deep copies over sample data. The new object created will use the current sampling configuration for the table. The existing iterator environment object will not be modified.

Since sample data could be created in many different ways, a good practice for an iterator is to verify the sampling configuration is as expected.

 
   class MyIter implements SortedKeyValueIterator<Key,Value> {
     SortedKeyValueIterator<Key,Value> source;
     SortedKeyValueIterator<Key,Value> sampleIter;
     @Override
     void init(SortedKeyValueIterator<Key,Value> source, Map<String,String> options,
       IteratorEnvironment env) {
       IteratorEnvironment sampleEnv = env.cloneWithSamplingEnabled();
       //do some sanity checks on sampling config
       validateSamplingConfiguration(sampleEnv.getSamplerConfiguration());
       sampleIter = source.deepCopy(sampleEnv);
       this.source = source;
     }
   }
 
 

Specified by:

cloneWithSamplingEnabled in interface IteratorEnvironment