org.apache.cassandra.db.compaction
Class LazilyCompactedRow

java.lang.Object
  org.apache.cassandra.db.compaction.AbstractCompactedRow
      org.apache.cassandra.db.compaction.LazilyCompactedRow

All Implemented Interfaces:

java.lang.Iterable<IColumn>, IIterableColumns

public class LazilyCompactedRow
extends AbstractCompactedRow
implements IIterableColumns

LazilyCompactedRow only computes the row bloom filter and column index in memory (at construction time); it does this by reading one column at a time from each of the rows being compacted, and merging them as it does so. So the most we have in memory at a time is the bloom filter, the index, and one column from each pre-compaction row. When write() or update() is called, a second pass is made over the pre-compaction rows to write the merged columns or update the hash, again with at most one column from each row deserialized at a time.

Field Summary

Fields inherited from class org.apache.cassandra.db.compaction.AbstractCompactedRow

key

Constructor Summary

LazilyCompactedRow(CompactionController controller, java.util.List<SSTableIdentityIterator> rows)

Method Summary

int	columnCount()
AbstractType	getComparator()
int	getEstimatedColumnCount()
boolean	isEmpty()
java.util.Iterator<IColumn>	iterator()
void	update(java.security.MessageDigest digest) update @param digest with the data bytes of the row (not including row key or row size)
void	write(java.io.DataOutput out) write the row (size + column index + filter + column data, but NOT row key) to @param out

Methods inherited from class java.lang.Object

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

Constructor Detail

LazilyCompactedRow

public LazilyCompactedRow(CompactionController controller,
                          java.util.List<SSTableIdentityIterator> rows)

Method Detail

write

public void write(java.io.DataOutput out)
           throws java.io.IOException

Description copied from class: AbstractCompactedRow

write the row (size + column index + filter + column data, but NOT row key) to @param out

Specified by:

write in class AbstractCompactedRow

Throws:

java.io.IOException

update

public void update(java.security.MessageDigest digest)

Description copied from class: AbstractCompactedRow

update @param digest with the data bytes of the row (not including row key or row size)

Specified by:

update in class AbstractCompactedRow

isEmpty

public boolean isEmpty()

Specified by:

isEmpty in class AbstractCompactedRow

Returns:

true if there are no columns in the row AND there are no row-level tombstones to be preserved

getEstimatedColumnCount

public int getEstimatedColumnCount()

Specified by:

getEstimatedColumnCount in interface IIterableColumns

getComparator

public AbstractType getComparator()

Specified by:

getComparator in interface IIterableColumns

iterator

public java.util.Iterator<IColumn> iterator()

Specified by:

iterator in interface java.lang.Iterable<IColumn>

columnCount

public int columnCount()

Specified by:

columnCount in class AbstractCompactedRow

Returns:

the number of columns in the row