org.apache.accumulo.core.client
Class IteratorSetting

java.lang.Object
  org.apache.accumulo.core.client.IteratorSetting

All Implemented Interfaces:

org.apache.hadoop.io.Writable

public class IteratorSetting
extends Object
implements org.apache.hadoop.io.Writable

Configure an iterator for minc, majc, and/or scan. By default, IteratorSetting will be configured for scan. Every iterator has a priority, a name, a class, a set of scopes, and configuration parameters. A typical use case configured for scan:

 IteratorSetting cfg = new IteratorSetting(priority, "myIter", MyIterator.class);
 MyIterator.addOption(cfg, 42);
 scanner.addScanIterator(cfg);
 

Nested Class Summary

static class

IteratorSetting.Column A convenience class for passing column family and column qualifiers to iterator configuration methods.

Constructor Summary

IteratorSetting(DataInput din)

IteratorSetting(int priority, Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass)
Constructs an iterator setting using the given class's SimpleName for the iterator name.

IteratorSetting(int priority, Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass, Map<String,String> properties)
Constructs an iterator setting using the given class's SimpleName for the iterator name and configured for the specified scopes with the specified parameters.

IteratorSetting(int priority, String name, Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass)
Constructs an iterator setting configured for the scan scope with no parameters.

IteratorSetting(int priority, String name, String iteratorClass)
Constructs an iterator setting configured for the scan scope with no parameters.

IteratorSetting(int priority, String name, String iteratorClass, Map<String,String> properties)
Constructs an iterator setting configured for the specified scopes with the specified parameters.

Method Summary

void	addOption(String option, String value) Add another option to the iterator.
void	addOptions(Map<String,String> properties) Add many options to the iterator.
void	addOptions(Set<Map.Entry<String,String>> propertyEntries) Add many options to the iterator.
void	clearOptions() Remove all options from the iterator.
String	getIteratorClass() Get the name of the class that implements the iterator.
String	getName() Get the iterator's name.
Map<String,String>	getOptions() Get the configuration parameters for this iterator.
int	getPriority() Get layer at which this iterator applies.
void	readFields(DataInput din)
String	removeOption(String option) Remove an option from the iterator.
void	setIteratorClass(String iteratorClass) Set the name of the class that implements the iterator.
void	setName(String name) Set the iterator's name.
void	setPriority(int priority) Set layer at which this iterator applies.
String	toString()
void	write(DataOutput dout)

Methods inherited from class java.lang.Object

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

Constructor Detail

IteratorSetting

public IteratorSetting(int priority,
                       String name,
                       String iteratorClass)

Constructs an iterator setting configured for the scan scope with no parameters. (Parameters can be added later.)

Parameters:

priority - the priority for the iterator (see setPriority(int))

name - the distinguishing name for the iterator

iteratorClass - the fully qualified class name for the iterator

IteratorSetting

public IteratorSetting(int priority,
                       String name,
                       String iteratorClass,
                       Map<String,String> properties)

Constructs an iterator setting configured for the specified scopes with the specified parameters.

Parameters:

priority - the priority for the iterator (see setPriority(int))

name - the distinguishing name for the iterator

iteratorClass - the fully qualified class name for the iterator

properties - any properties for the iterator

IteratorSetting

public IteratorSetting(int priority,
                       Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass)

Constructs an iterator setting using the given class's SimpleName for the iterator name. The iterator setting will be configured for the scan scope with no parameters.

Parameters:

priority - the priority for the iterator (see setPriority(int))

iteratorClass - the class for the iterator

IteratorSetting

public IteratorSetting(int priority,
                       Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass,
                       Map<String,String> properties)

Constructs an iterator setting using the given class's SimpleName for the iterator name and configured for the specified scopes with the specified parameters.

Parameters:

priority - the priority for the iterator (see setPriority(int))

iteratorClass - the class for the iterator

properties - any properties for the iterator

IteratorSetting

public IteratorSetting(int priority,
                       String name,
                       Class<? extends SortedKeyValueIterator<Key,Value>> iteratorClass)

Constructs an iterator setting configured for the scan scope with no parameters.

Parameters:

priority - the priority for the iterator (see setPriority(int))

name - the distinguishing name for the iterator

iteratorClass - the class for the iterator

IteratorSetting

public IteratorSetting(DataInput din)
                throws IOException

Throws:

IOException

Since:

1.5.0

Method Detail

getPriority

public int getPriority()

Get layer at which this iterator applies. See setPriority(int) for how the priority is used.

Returns:

the priority of this Iterator

setPriority

public void setPriority(int priority)

Set layer at which this iterator applies.

Parameters:

priority - determines the order in which iterators are applied (system iterators are always applied first, then user-configured iterators, lowest priority first)

getName

public String getName()

Get the iterator's name.

Returns:

the name of the iterator

setName

public void setName(String name)

Set the iterator's name. Must be a simple alphanumeric identifier.

Parameters:

name -

getIteratorClass

public String getIteratorClass()

Get the name of the class that implements the iterator.

Returns:

the iterator's class name

setIteratorClass

public void setIteratorClass(String iteratorClass)

Set the name of the class that implements the iterator. The class does not have to be present on the client, but it must be available to all tablet servers.

Parameters:

iteratorClass -

addOption

public void addOption(String option,
                      String value)

Add another option to the iterator.

Parameters:

option - the name of the option

value - the value of the option

removeOption

public String removeOption(String option)

Remove an option from the iterator.

Parameters:

option - the name of the option

Returns:

the value previously associated with the option, or null if no such option existed

addOptions

public void addOptions(Set<Map.Entry<String,String>> propertyEntries)

Add many options to the iterator.

Parameters:

propertyEntries - a set of entries to add to the options

addOptions

public void addOptions(Map<String,String> properties)

Add many options to the iterator.

Parameters:

properties - a map of entries to add to the options

getOptions

public Map<String,String> getOptions()

Get the configuration parameters for this iterator.

Returns:

the properties

clearOptions

public void clearOptions()

Remove all options from the iterator.

toString

public String toString()

Overrides:

toString in class Object

See Also:

Object.toString()

readFields

public void readFields(DataInput din)
                throws IOException

Specified by:

readFields in interface org.apache.hadoop.io.Writable

Throws:

IOException

Since:

1.5.0

write

public void write(DataOutput dout)
           throws IOException

Specified by:

write in interface org.apache.hadoop.io.Writable

Throws:

IOException

Since:

1.5.0