Class ColumnFamilySkippingIterator

  extended by org.apache.accumulo.core.iterators.WrappingIterator
      extended by org.apache.accumulo.core.iterators.SkippingIterator
          extended by org.apache.accumulo.core.iterators.system.ColumnFamilySkippingIterator
All Implemented Interfaces:
SortedKeyValueIterator<Key,Value>, InterruptibleIterator

public class ColumnFamilySkippingIterator
extends SkippingIterator
implements InterruptibleIterator

Field Summary
protected  Set<ByteSequence> colFamSet
protected  boolean inclusive
protected  Range range
protected  TreeSet<ByteSequence> sortedColFams
Constructor Summary
  ColumnFamilySkippingIterator(SortedKeyValueIterator<Key,Value> source)
protected ColumnFamilySkippingIterator(SortedKeyValueIterator<Key,Value> source, Set<ByteSequence> colFamSet, boolean inclusive)
Method Summary
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
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


protected Set<ByteSequence> colFamSet


protected TreeSet<ByteSequence> sortedColFams


protected boolean inclusive


protected Range range
Constructor Detail


public ColumnFamilySkippingIterator(SortedKeyValueIterator<Key,Value> source)


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


protected void consume()
                throws IOException
Specified by:
consume in class SkippingIterator


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>
deepCopy in class WrappingIterator
env - IteratorEnvironment environment in which iterator is being run.
SortedKeyValueIterator a copy of this iterator (with the same source and settings).


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>
seek in class SkippingIterator
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.
IOException - if an I/O error occurs.


public void setInterruptFlag(AtomicBoolean flag)
Specified by:
setInterruptFlag in interface InterruptibleIterator

Copyright © 2013 Apache Accumulo Project. All Rights Reserved.