org.apache.accumulo.core.iterators.system

Class ColumnFamilySkippingIterator

java.lang.Object

org.apache.accumulo.core.iterators.WrappingIterator

org.apache.accumulo.core.iterators.SkippingIterator

org.apache.accumulo.core.iterators.system.ColumnFamilySkippingIterator

All Implemented Interfaces:

SortedKeyValueIterator<Key,Value>, InterruptibleIterator

public class ColumnFamilySkippingIterator
extends SkippingIterator
implements InterruptibleIterator

Field Summary

Fields

Modifier and Type	Field and Description
protected Set<ByteSequence>	colFamSet
protected boolean	inclusive
protected Range	range
protected TreeSet<ByteSequence>	sortedColFams

Constructor Summary

Constructors

Modifier	Constructor and Description
	ColumnFamilySkippingIterator(SortedKeyValueIterator<Key,Value> source)
protected	ColumnFamilySkippingIterator(SortedKeyValueIterator<Key,Value> source, Set<ByteSequence> colFamSet, boolean inclusive)

Method Summary

Methods

Modifier and Type	Method and Description
protected void	consume()
SortedKeyValueIterator<Key,Value>	deepCopy(IteratorEnvironment env) Creates a deep copy of this iterator as though seek had not yet been called.
void	seek(Range range, Collection<ByteSequence> columnFamilies, boolean inclusive) Seeks to the first key in the Range, restricting the resulting K,V pairs to those with the specified columns.
void	setInterruptFlag(AtomicBoolean flag)

Methods inherited from class org.apache.accumulo.core.iterators.SkippingIterator

next

Methods inherited from class org.apache.accumulo.core.iterators.WrappingIterator

getSource, getTopKey, getTopValue, hasTop, init, setSource

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

getTopKey, getTopValue, hasTop, init, next

Field Detail

colFamSet

protected Set<ByteSequence> colFamSet

sortedColFams

protected TreeSet<ByteSequence> sortedColFams

inclusive

protected boolean inclusive

range

protected Range range

Constructor Detail

ColumnFamilySkippingIterator

public ColumnFamilySkippingIterator(SortedKeyValueIterator<Key,Value> source)

ColumnFamilySkippingIterator

protected ColumnFamilySkippingIterator(SortedKeyValueIterator<Key,Value> source,
                            Set<ByteSequence> colFamSet,
                            boolean inclusive)

Method Detail

consume

protected void consume()
                throws IOException

Specified by:

consume in class SkippingIterator

Throws:

IOException

deepCopy

public SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment env)

Description copied from interface: SortedKeyValueIterator

Creates a deep copy of this iterator as though seek had not yet been called. init should be called on an iterator before deepCopy is called. init should not need to be called on the copy that is returned by deepCopy; that is, when necessary init should be called in the deepCopy method on the iterator it returns. The behavior is unspecified if init is called after deepCopy either on the original or the copy.

Specified by:

deepCopy in interface SortedKeyValueIterator<Key,Value>

Overrides:

deepCopy in class WrappingIterator

Parameters:

env - IteratorEnvironment environment in which iterator is being run.

Returns:

SortedKeyValueIterator a copy of this iterator (with the same source and settings).

seek

public void seek(Range range,
        Collection<ByteSequence> columnFamilies,
        boolean inclusive)
          throws IOException

Description copied from interface: SortedKeyValueIterator

Seeks to the first key in the Range, restricting the resulting K,V pairs to those with the specified columns. An iterator does not have to stop at the end of the range. The whole range is provided so that iterators can make optimizations. Seek may be called multiple times with different parameters after SortedKeyValueIterator.init(org.apache.accumulo.core.iterators.SortedKeyValueIterator, java.util.Map, org.apache.accumulo.core.iterators.IteratorEnvironment) is called. Iterators that examine groups of adjacent key/value pairs (e.g. rows) to determine their top key and value should be sure that they properly handle a seek to a key in the middle of such a group (e.g. the middle of a row). Even if the client always seeks to a range containing an entire group (a,c), the tablet server could send back a batch of entries corresponding to (a,b], then reseek the iterator to range (b,c) when the scan is continued. columnFamilies is used, at the lowest level, to determine which data blocks inside of an RFile need to be opened for this iterator. This set of data blocks is also the set of locality groups defined for the given table. If no columnFamilies are provided, the data blocks for all locality groups inside of the correct RFile will be opened and seeked in an attempt to find the correct start key, regardless of the startKey in the range. In an Accumulo instance in which multiple locality groups exist for a table, it is important to ensure that columnFamilies is properly set to the minimum required column families to ensure that data from separate locality groups is not inadvertently read.

Specified by:

seek in interface SortedKeyValueIterator<Key,Value>

Overrides:

seek in class SkippingIterator

Parameters:

range - Range of keys to iterate over.

columnFamilies - Collection of column families to include or exclude.

inclusive - boolean that indicates whether to include (true) or exclude (false) column families.

Throws:

IOException - if an I/O error occurs.

setInterruptFlag

public void setInterruptFlag(AtomicBoolean flag)

Specified by:

setInterruptFlag in interface InterruptibleIterator