org.janusgraph.diskstorage.util

Class MetricInstrumentedIterator

java.lang.Object

org.janusgraph.diskstorage.util.MetricInstrumentedIterator

All Implemented Interfaces:

Closeable, AutoCloseable, Iterator<StaticBuffer>, KeyIterator, RecordIterator<StaticBuffer>

public class MetricInstrumentedIterator
extends Object
implements KeyIterator

This class is used by MetricInstrumentedStore to measure wall clock time, method invocation counts, and exceptions thrown by the methods on RecordIterator instances returned from MetricInstrumentedStore.getSlice(org.janusgraph.diskstorage.keycolumnvalue.KeySliceQuery, org.janusgraph.diskstorage.keycolumnvalue.StoreTransaction).

Author:

Dan LaRocque ([email protected])

Method Summary

Modifier and Type	Method and Description
void	close()
RecordIterator<Entry>	getEntries() Returns an iterator over all entries associated with the current key that match the column range specified in the query.
boolean	hasNext()
StaticBuffer	next()
static MetricInstrumentedIterator	of(KeyIterator keyIterator, String... prefix) If the iterator argument is non-null, then return a new MetricInstrumentedIterator wrapping it.
void	remove()

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Iterator

forEachRemaining

Method Detail

of

public static MetricInstrumentedIterator of(KeyIterator keyIterator,
                                            String... prefix)

If the iterator argument is non-null, then return a new MetricInstrumentedIterator wrapping it. Metrics for method calls on the wrapped instance will be prefixed with the string prefix which must be non-null. If the iterator argument is null, then return null.

Parameters:

keyIterator - the iterator to wrap with Metrics measurements

prefix - the Metrics name prefix string

Returns:

a wrapper around keyIterator or null if keyIterator is null

hasNext

public boolean hasNext()

Specified by:

hasNext in interface Iterator<StaticBuffer>

next

public StaticBuffer next()

Specified by:

next in interface Iterator<StaticBuffer>

close

public void close()
           throws IOException

Specified by:

close in interface Closeable

Specified by:

close in interface AutoCloseable

Throws:

IOException

getEntries

public RecordIterator<Entry> getEntries()

Description copied from interface: KeyIterator

Returns an iterator over all entries associated with the current key that match the column range specified in the query.

Closing the returned sub-iterator has no effect on this iterator. Calling Iterator.next() might close previously returned RecordIterators depending on the implementation, hence it is important to iterate over (and close) the RecordIterator before calling Iterator.next() or Iterator.hasNext().

Specified by:

getEntries in interface KeyIterator

Returns:

remove

public void remove()

Specified by:

remove in interface Iterator<StaticBuffer>