org.apache.accumulo.core.iterators.system
Class HeapIterator

java.lang.Object
  org.apache.accumulo.core.iterators.system.HeapIterator

All Implemented Interfaces:

SortedKeyValueIterator<Key,Value>

Direct Known Subclasses:

LocalityGroupIterator, MultiIterator, RFile.Reader

public abstract class HeapIterator
extends Object
implements SortedKeyValueIterator<Key,Value>

Constructs a PriorityQueue of multiple SortedKeyValueIterators. Provides a simple way to interact with multiple SortedKeyValueIterators in sorted order.

Constructor Summary

protected	HeapIterator()
protected	HeapIterator(int maxSize)

Method Summary

protected void	addSource(SortedKeyValueIterator<Key,Value> source)
protected void	clear()
protected void	createHeap(int maxSize)
Key	getTopKey() Returns top key.
Value	getTopValue() Returns top value.
boolean	hasTop() Returns true if the iterator has more elements.
void	next() Advances to the next K,V pair.

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, init, seek

Constructor Detail

HeapIterator

protected HeapIterator()

HeapIterator

protected HeapIterator(int maxSize)

Method Detail

createHeap

protected void createHeap(int maxSize)

getTopKey

public final Key getTopKey()

Description copied from interface: SortedKeyValueIterator

Returns top key. Can be called 0 or more times without affecting behavior of next() or hasTop(). Note that in minor compaction scope and in non-full major compaction scopes the iterator may see deletion entries. These entries should be preserved by all iterators except ones that are strictly scan-time iterators that will never be configured for the minc or majc scopes. Deletion entries are only removed during full major compactions.

Specified by:

getTopKey in interface SortedKeyValueIterator<Key,Value>

Returns:

K

getTopValue

public final Value getTopValue()

Description copied from interface: SortedKeyValueIterator

Returns top value. Can be called 0 or more times without affecting behavior of next() or hasTop().

Specified by:

getTopValue in interface SortedKeyValueIterator<Key,Value>

Returns:

V

hasTop

public final boolean hasTop()

Description copied from interface: SortedKeyValueIterator

Returns true if the iterator has more elements.

Specified by:

hasTop in interface SortedKeyValueIterator<Key,Value>

Returns:

true if the iterator has more elements.

next

public final void next()
                throws IOException

Description copied from interface: SortedKeyValueIterator

Advances to the next K,V pair. Note that in minor compaction scope and in non-full major compaction scopes the iterator may see deletion entries. These entries should be preserved by all iterators except ones that are strictly scan-time iterators that will never be configured for the minc or majc scopes. Deletion entries are only removed during full major compactions.

Specified by:

next in interface SortedKeyValueIterator<Key,Value>

Throws:

IOException - if an I/O error occurs.

clear

protected final void clear()

addSource

protected final void addSource(SortedKeyValueIterator<Key,Value> source)