org.apache.accumulo.core.iterators.system
Class SourceSwitchingIterator

java.lang.Object
  extended by org.apache.accumulo.core.iterators.system.SourceSwitchingIterator
All Implemented Interfaces:
SortedKeyValueIterator<Key,Value>, InterruptibleIterator

public class SourceSwitchingIterator
extends Object
implements SortedKeyValueIterator<Key,Value>, InterruptibleIterator


Nested Class Summary
static interface SourceSwitchingIterator.DataSource
           
 
Constructor Summary
SourceSwitchingIterator(SourceSwitchingIterator.DataSource source)
           
SourceSwitchingIterator(SourceSwitchingIterator.DataSource source, boolean onlySwitchAfterRow)
           
 
Method Summary
 SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment env)
          Creates a deep copy of this iterator as though seek had not yet been called.
 Key getTopKey()
          Returns top key.
 Value getTopValue()
          Returns top value.
 boolean hasTop()
          Returns true if the iterator has more elements.
 void init(SortedKeyValueIterator<Key,Value> source, Map<String,String> options, IteratorEnvironment env)
          Initializes the iterator.
 void next()
          Advances to the next K,V pair.
 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)
           
 void switchNow()
           
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

SourceSwitchingIterator

public SourceSwitchingIterator(SourceSwitchingIterator.DataSource source,
                               boolean onlySwitchAfterRow)

SourceSwitchingIterator

public SourceSwitchingIterator(SourceSwitchingIterator.DataSource source)
Method Detail

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

getTopKey

public Key getTopKey()
Description copied from interface: SortedKeyValueIterator
Returns top key. Can be called 0 or more times without affecting behavior of next() or hasTop(). Note that in minor compaction scope and in non-full major compaction scopes the iterator may see deletion entries. These entries should be preserved by all iterators except ones that are strictly scan-time iterators that will never be configured for the minc or majc scopes. Deletion entries are only removed during full major compactions.

Specified by:
getTopKey in interface SortedKeyValueIterator<Key,Value>
Returns:
K

getTopValue

public Value getTopValue()
Description copied from interface: SortedKeyValueIterator
Returns top value. Can be called 0 or more times without affecting behavior of next() or hasTop().

Specified by:
getTopValue in interface SortedKeyValueIterator<Key,Value>
Returns:
V

hasTop

public boolean hasTop()
Description copied from interface: SortedKeyValueIterator
Returns true if the iterator has more elements.

Specified by:
hasTop in interface SortedKeyValueIterator<Key,Value>
Returns:
true if the iterator has more elements.

init

public void init(SortedKeyValueIterator<Key,Value> source,
                 Map<String,String> options,
                 IteratorEnvironment env)
          throws 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>
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:
IOException - unused.

next

public void next()
          throws IOException
Description copied from interface: SortedKeyValueIterator
Advances to the next K,V pair. Note that in minor compaction scope and in non-full major compaction scopes the iterator may see deletion entries. These entries should be preserved by all iterators except ones that are strictly scan-time iterators that will never be configured for the minc or majc scopes. Deletion entries are only removed during full major compactions.

Specified by:
next in interface SortedKeyValueIterator<Key,Value>
Throws:
IOException - if an I/O error occurs.

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.

Specified by:
seek in interface SortedKeyValueIterator<Key,Value>
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.

switchNow

public void switchNow()
               throws IOException
Throws:
IOException

setInterruptFlag

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


Copyright © 2012 The Apache Software Foundation. All Rights Reserved.