org.apache.accumulo.core.iterators
Class FirstEntryInRowIterator
java.lang.Object
org.apache.accumulo.core.iterators.WrappingIterator
org.apache.accumulo.core.iterators.SkippingIterator
org.apache.accumulo.core.iterators.FirstEntryInRowIterator
- All Implemented Interfaces:
- OptionDescriber, SortedKeyValueIterator<Key,Value>
public class FirstEntryInRowIterator
- extends SkippingIterator
- implements OptionDescriber
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. |
OptionDescriber.IteratorOptions |
describeOptions()
|
void |
init(SortedKeyValueIterator<Key,Value> source,
java.util.Map<java.lang.String,java.lang.String> options,
IteratorEnvironment env)
Initializes the iterator. |
void |
seek(Range range,
java.util.Collection<ByteSequence> columnFamilies,
boolean inclusive)
An iterator must seek to the first key in the range taking inclusiveness into account. |
static void |
setNumScansBeforeSeek(Scanner scanner,
java.lang.String iteratorName,
int num)
|
boolean |
validateOptions(java.util.Map<java.lang.String,java.lang.String> options)
|
Methods inherited from class java.lang.Object |
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait |
FirstEntryInRowIterator
public FirstEntryInRowIterator()
FirstEntryInRowIterator
public FirstEntryInRowIterator(FirstEntryInRowIterator other,
IteratorEnvironment env)
setNumScansBeforeSeek
public static void setNumScansBeforeSeek(Scanner scanner,
java.lang.String iteratorName,
int num)
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>
- Specified by:
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).
init
public void init(SortedKeyValueIterator<Key,Value> source,
java.util.Map<java.lang.String,java.lang.String> options,
IteratorEnvironment env)
throws java.io.IOException
- Description copied from interface:
SortedKeyValueIterator
- Initializes the iterator. Data should not be read from the source in this method.
- Specified by:
init
in interface SortedKeyValueIterator<Key,Value>
- Overrides:
init
in class WrappingIterator
- Parameters:
source
- SortedKeyValueIterator source to read data from.options
- Map map of string option names to option values.env
- IteratorEnvironment environment in which iterator is being run.
- Throws:
java.io.IOException
- unused.
consume
protected void consume()
throws java.io.IOException
- Specified by:
consume
in class SkippingIterator
- Throws:
java.io.IOException
seek
public void seek(Range range,
java.util.Collection<ByteSequence> columnFamilies,
boolean inclusive)
throws java.io.IOException
- Description copied from interface:
SortedKeyValueIterator
- An iterator must seek to the first key in the range taking inclusiveness into account. However, an iterator does not have to stop at the end of the range.
The whole range is provided so that iterators can make optimizations.
- 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:
java.io.IOException
- if an I/O error occurs.
describeOptions
public OptionDescriber.IteratorOptions describeOptions()
- Specified by:
describeOptions
in interface OptionDescriber
validateOptions
public boolean validateOptions(java.util.Map<java.lang.String,java.lang.String> options)
- Specified by:
validateOptions
in interface OptionDescriber
Copyright © 2012 The Apache Software Foundation. All Rights Reserved.