org.apache.accumulo.examples.wikisearch.iterator
Class FieldIndexIterator

java.lang.Object
  extended by org.apache.accumulo.core.iterators.WrappingIterator
      extended by org.apache.accumulo.examples.wikisearch.iterator.FieldIndexIterator
All Implemented Interfaces:
SortedKeyValueIterator<Key,Value>

public class FieldIndexIterator
extends WrappingIterator

This iterator should only return keys from the fi\0{fieldName}:{fieldValue} part of the shard table. Expect topKey to be CF, {datatype}\0{UID}


Field Summary
protected static org.apache.log4j.Logger log
           
 
Constructor Summary
FieldIndexIterator()
           
FieldIndexIterator(FieldIndexIterator other, IteratorEnvironment env)
           
FieldIndexIterator(int type, org.apache.hadoop.io.Text rowId, org.apache.hadoop.io.Text fieldName, org.apache.hadoop.io.Text fieldValue, boolean neg, String operator)
           
FieldIndexIterator(int type, org.apache.hadoop.io.Text rowId, org.apache.hadoop.io.Text fieldName, org.apache.hadoop.io.Text fieldValue, String operator)
           
 
Method Summary
 SortedKeyValueIterator<Key,Value> deepCopy(IteratorEnvironment env)
          Creates a deep copy of this iterator as though seek had not yet been called.
 org.apache.hadoop.io.Text getCurrentRow()
           
 org.apache.hadoop.io.Text getfName()
           
 org.apache.hadoop.io.Text getfValue()
           
 Key getTopKey()
          Returns top key.
 Value getTopValue()
          Returns top value.
 boolean hasTop()
          Returns true if the iterator has more elements.
 boolean isNegated()
           
 boolean jump(Key jumpKey)
           
 void next()
          Advances to the next K,V pair.
 void seek(Range r, 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.
static void setLogLevel(org.apache.log4j.Level l)
           
 
Methods inherited from class org.apache.accumulo.core.iterators.WrappingIterator
getSource, init, setSource
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

log

protected static final org.apache.log4j.Logger log
Constructor Detail

FieldIndexIterator

public FieldIndexIterator()

FieldIndexIterator

public FieldIndexIterator(int type,
                          org.apache.hadoop.io.Text rowId,
                          org.apache.hadoop.io.Text fieldName,
                          org.apache.hadoop.io.Text fieldValue,
                          String operator)

FieldIndexIterator

public FieldIndexIterator(int type,
                          org.apache.hadoop.io.Text rowId,
                          org.apache.hadoop.io.Text fieldName,
                          org.apache.hadoop.io.Text fieldValue,
                          boolean neg,
                          String operator)

FieldIndexIterator

public FieldIndexIterator(FieldIndexIterator other,
                          IteratorEnvironment env)
Method Detail

setLogLevel

public static void setLogLevel(org.apache.log4j.Level l)

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>
Overrides:
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).

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>
Overrides:
getTopKey in class WrappingIterator
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>
Overrides:
getTopValue in class WrappingIterator
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>
Overrides:
hasTop in class WrappingIterator
Returns:
true if the iterator has more elements.

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>
Overrides:
next in class WrappingIterator
Throws:
IOException - if an I/O error occurs.

seek

public void seek(Range r,
                 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.

Specified by:
seek in interface SortedKeyValueIterator<Key,Value>
Overrides:
seek in class WrappingIterator
Parameters:
r - 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.

isNegated

public boolean isNegated()

getCurrentRow

public org.apache.hadoop.io.Text getCurrentRow()

getfName

public org.apache.hadoop.io.Text getfName()

getfValue

public org.apache.hadoop.io.Text getfValue()

jump

public boolean jump(Key jumpKey)
             throws IOException
Throws:
IOException


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