org.calrissian.accumulorecipes.commons.iterators

Class AbstractEvaluatingIterator

java.lang.Object

org.calrissian.accumulorecipes.commons.iterators.AbstractEvaluatingIterator

All Implemented Interfaces:

org.apache.accumulo.core.iterators.OptionDescriber, org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>

Direct Known Subclasses:

EvaluatingIterator

public abstract class AbstractEvaluatingIterator
extends Object
implements org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>, org.apache.accumulo.core.iterators.OptionDescriber

This iterator aggregates rows together using the specified key comparator. Subclasses will provide their own implementation of fillMap which will fill the supplied EventFields object with field names (key) and field values (value). After all fields have been put into the aggregated object (by aggregating all columns with the same key), the EventFields object will be compared against the supplied expression. If the expression returns true, then the return key and return value can be retrieved via getTopKey() and getTopValue().

Optionally, the caller can set an expression (field operator value) that should not be evaluated against the event. For example, if the criteria is "A == 'foo' and B == 'bar'", but for some reason B may not be in the data, then setting the UNEVALUATED_EXPRESSIONS option to "B == 'bar'" will allow the events to be evaluated against the remainder of the expression and still return as true.

By default this iterator will return all Events in the shard. If the START_DATE and END_DATE are specified, then this iterator will evaluate the timestamp of the key against the start and end dates. If the event date is not within the range of start to end, then it is skipped.

This iterator will return up the stack an EventFields object serialized using Kryo in the cell Value.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.accumulo.core.iterators.OptionDescriber

org.apache.accumulo.core.iterators.OptionDescriber.IteratorOptions

Field Summary

Fields

Modifier and Type	Field and Description
protected static byte[]	EMPTY_BYTE
protected org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>	iterator
static String	QUERY_OPTION
static String	UNEVALUTED_EXPRESSIONS

Constructor Summary

Constructors

Modifier	Constructor and Description
	AbstractEvaluatingIterator()
protected	AbstractEvaluatingIterator(AbstractEvaluatingIterator other, org.apache.accumulo.core.iterators.IteratorEnvironment env)

Method Summary

Methods

Modifier and Type	Method and Description
org.apache.accumulo.core.iterators.OptionDescriber.IteratorOptions	describeOptions()
abstract void	fillMap(EventFields event, org.apache.accumulo.core.data.Key key, org.apache.accumulo.core.data.Value value) Implementations will need to fill the map with field visibilities, names, and values.
abstract org.apache.accumulo.core.data.PartialKey	getKeyComparator() Implementations will return the PartialKey value to use for comparing keys for aggregating events
String	getQueryExpression()
abstract org.apache.accumulo.core.data.Key	getReturnKey(org.apache.accumulo.core.data.Key k) When the criteria expression evaluates to true against the event, the event fields will be serialized into the Value and returned up the iterator stack.
org.apache.accumulo.core.data.Key	getTopKey()
org.apache.accumulo.core.data.Value	getTopValue()
boolean	hasTop()
void	init(org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value> source, Map<String,String> options, org.apache.accumulo.core.iterators.IteratorEnvironment env)
abstract boolean	isKeyAccepted(org.apache.accumulo.core.data.Key key) Provides the ability to skip this key and all of the following ones that match using the comparator.
void	next()
void	reset() Reset state.
void	seek(org.apache.accumulo.core.data.Range range, Collection<org.apache.accumulo.core.data.ByteSequence> columnFamilies, boolean inclusive)
boolean	validateOptions(Map<String,String> options)

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.accumulo.core.iterators.SortedKeyValueIterator

deepCopy

Field Detail

QUERY_OPTION

public static final String QUERY_OPTION

See Also:

Constant Field Values

UNEVALUTED_EXPRESSIONS

public static final String UNEVALUTED_EXPRESSIONS

See Also:

Constant Field Values

EMPTY_BYTE

protected static final byte[] EMPTY_BYTE

iterator

protected org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value> iterator

Constructor Detail

AbstractEvaluatingIterator

protected AbstractEvaluatingIterator(AbstractEvaluatingIterator other,
                          org.apache.accumulo.core.iterators.IteratorEnvironment env)

AbstractEvaluatingIterator

public AbstractEvaluatingIterator()

Method Detail

getKeyComparator

public abstract org.apache.accumulo.core.data.PartialKey getKeyComparator()

Implementations will return the PartialKey value to use for comparing keys for aggregating events

Returns:

the type of comparator to use

getReturnKey

public abstract org.apache.accumulo.core.data.Key getReturnKey(org.apache.accumulo.core.data.Key k)
                                                        throws Exception

When the criteria expression evaluates to true against the event, the event fields will be serialized into the Value and returned up the iterator stack. Implemenations will need to provide a key to be used with the event.

Parameters:

k -

Returns:

the key that should be returned with the map of values.

Throws:

Exception

fillMap

public abstract void fillMap(EventFields event,
           org.apache.accumulo.core.data.Key key,
           org.apache.accumulo.core.data.Value value)
                      throws Exception

Implementations will need to fill the map with field visibilities, names, and values. When all fields have been aggregated the event will be evaluated against the criteria expression.

Parameters:

event - Multimap of event names and fields.

key - current Key

value - current Value

Throws:

Exception

isKeyAccepted

public abstract boolean isKeyAccepted(org.apache.accumulo.core.data.Key key)
                               throws IOException

Provides the ability to skip this key and all of the following ones that match using the comparator.

Parameters:

key -

Returns:

true if the key should be acted upon, otherwise false.

Throws:

IOException

reset

public void reset()

Reset state.

getTopKey

public org.apache.accumulo.core.data.Key getTopKey()

Specified by:

getTopKey in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>

getTopValue

public org.apache.accumulo.core.data.Value getTopValue()

Specified by:

getTopValue in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>

hasTop

public boolean hasTop()

Specified by:

hasTop in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>

next

public void next()
          throws IOException

Specified by:

next in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>

Throws:

IOException

seek

public void seek(org.apache.accumulo.core.data.Range range,
        Collection<org.apache.accumulo.core.data.ByteSequence> columnFamilies,
        boolean inclusive)
          throws IOException

Specified by:

seek in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>

Throws:

IOException

init

public void init(org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value> source,
        Map<String,String> options,
        org.apache.accumulo.core.iterators.IteratorEnvironment env)
          throws IOException

Specified by:

init in interface org.apache.accumulo.core.iterators.SortedKeyValueIterator<org.apache.accumulo.core.data.Key,org.apache.accumulo.core.data.Value>

Throws:

IOException

describeOptions

public org.apache.accumulo.core.iterators.OptionDescriber.IteratorOptions describeOptions()

Specified by:

describeOptions in interface org.apache.accumulo.core.iterators.OptionDescriber

validateOptions

public boolean validateOptions(Map<String,String> options)

Specified by:

validateOptions in interface org.apache.accumulo.core.iterators.OptionDescriber

getQueryExpression

public String getQueryExpression()