Package org.apache.accumulo.core.iterators.user

Class WholeRowIterator

java.lang.Object

org.apache.accumulo.core.iterators.user.RowEncodingIterator

org.apache.accumulo.core.iterators.user.WholeRowIterator

All Implemented Interfaces:

OptionDescriber, SortedKeyValueIterator<Key,Value>, YieldingKeyValueIterator<Key,Value>

public class WholeRowIterator
extends RowEncodingIterator

The WholeRowIterator is designed to provide row-isolation so that queries see mutations as atomic. It does so by encapsulating an entire row of key/value pairs into a single key/value pair, which is returned through the client as an atomic operation.

This iterator extends the RowEncodingIterator, providing implementations for rowEncoder and rowDecoder which serializes all column and value information from a given row into a single ByteStream in a value.

As with the RowEncodingIterator, when seeking in the WholeRowIterator using a range that starts at a non-inclusive first key in a row, this iterator will skip to the next row.

To regain the original key/value pairs of the row, call the decodeRow function on the key/value pair that this iterator returned.

See Also:

RowFilter

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.accumulo.core.iterators.OptionDescriber

OptionDescriber.IteratorOptions

Field Summary

Fields inherited from class org.apache.accumulo.core.iterators.user.RowEncodingIterator

MAX_BUFFER_SIZE_OPT, sourceIter

Constructor Summary

Constructors

Constructor	Description
WholeRowIterator()

Method Summary

Modifier and Type	Method	Description
static SortedMap<Key,Value>	decodeRow(Key rowKey, Value rowValue)
static Value	encodeRow(List<Key> keys, List<Value> values)
SortedMap<Key,Value>	rowDecoder(Key rowKey, Value rowValue)	Given a value generated by the rowEncoder implementation, recreate the original Key, Value pairs.
Value	rowEncoder(List<Key> keys, List<Value> values)	Take a stream of keys and values.

Methods inherited from class org.apache.accumulo.core.iterators.user.RowEncodingIterator

deepCopy, describeOptions, filter, getTopKey, getTopValue, hasTop, init, next, seek, validateOptions

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.YieldingKeyValueIterator

enableYielding

Constructor Detail

WholeRowIterator

public WholeRowIterator()

Method Detail

rowDecoder

public SortedMap<Key,Value> rowDecoder(Key rowKey,
                                             Value rowValue)
                                      throws IOException

Description copied from class: RowEncodingIterator

Given a value generated by the rowEncoder implementation, recreate the original Key, Value pairs.

Specified by:

rowDecoder in class RowEncodingIterator

Throws:

IOException

rowEncoder

public Value rowEncoder(List<Key> keys,
                        List<Value> values)
                 throws IOException

Description copied from class: RowEncodingIterator

Take a stream of keys and values. Return values in the same order encoded such that all portions of the key (except for the row value) and the original value are encoded in some way.

Specified by:

rowEncoder in class RowEncodingIterator

Throws:

IOException

decodeRow

public static final SortedMap<Key,Value> decodeRow(Key rowKey,
                                                         Value rowValue)
                                                  throws IOException

Throws:

IOException

encodeRow

public static final Value encodeRow(List<Key> keys,
                                    List<Value> values)
                             throws IOException

Throws:

IOException